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Background: The high prevalence of leptospirosis in humans is of great public health concern, particularly in tropical and subtropical regions., Objective: This study aimed to determine the seroprevalence of leptospiral antibodies and the distribution of serovars in livestock breeders and farmers in Golestan province., Methods: Seventy samples of serum collected from farmers and ranchers suspected of leptospirosis were examined using an ELISA method for surveying Immunoglobulin M (IgM) anti-leptospiria. Also from samples, DNA was extracted and PCR was performed using by primers for 16s rRNA. Demographic properties of positive patients were analysed., Results: Chi-square statistical test shows a statistically significant difference between the gender and prevalence leptospirosis (p-value = 0.004). Also, by examining the age, it was shown that 68.57% of patients are in the middleaged rang. According to the results obtained from the study and investigation of blood serum IgM-and Immunoglobulin G (IgG) in people suspected of leptospirosis, 3 cases of the patients had IgM higher than 11 and were known to be positive for leptospirosis. Also, by examining the IgG level of patients, 5 cases had intermediate results, and 2 cases were found to be positive for IgG. The PCR results showed that 41.42% of patients tested positive for the 16s rRNA., Conclusion: Leptospirosis is a common disease among farmers, and in Golestan province, considering traditional farming methods, it is considered an important infectious disease. Therefore, health and safety measures should be expanded to control and prevent this disease. Also, by employing mechanised agricultural methods, the prevalence of leptospirosis in this region can be significantly reduced., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Introduction: Toxoplasma gondii (T. gondii) infection in dogs is distributed globally. Given the potential impact of T. gondii on human reproductive health and its zoonotic potential, focusing on infected dogs with breeding disorders may provide valuable new insights into the role of toxoplasmosis on reproductive disorders. This study aimed to elucidate the potential role of T. gondii on reproductive disorders by conducting a serosurvey on a kennel with breeding disorders in Kerman, Iran., Materials and Methods: Purebred dogs with American Kennel Club-certified Pedigrees were randomly selected in both genders from a breeding kennel with a history of reproductive problems such as neonatal deaths, abortion stillbirths, and male infertility. Blood samples were collected from selected dogs, and serosurvey was done with a Toxo-Screen kit using the modified agglutination test (MAT)., Findings: From 46 selected breeding dogs, 20 (43.5 %) were positive in the Toxoplasma MAT test, consisting of 24 samples (52.17 %) with different reproductive disorders and 22 (47.83 %) healthy dogs. However, the presence of reproductive disorder had no significant relationship with seropositivity (p = 0.067). Seroprevalence of toxoplasmosis had no significant relationship with sex (p = 0.28) and age (p = 0.18) in the studied population., Conclusion: Screening with the standard MAT method reduces the risk of transmitting toxoplasmosis by preventing the entry of infected dogs into the kennel, identifying the infected cases to start specific treatments, optimizing the proper nutritional conditions, and ensuring the hygiene of the environment. Fresh/refrigerated raw meat, unpasteurized milk feeding, rodent infestation of grass-covered dog runs, and the main dry food storage facilities were the primary risk factors in kennels., Competing Interests: Declaration of competing interest All authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: Toxoplasma gondii (T. gondii) and Toxocara spp. are two types of parasites that can infect humans and various animals, including dogs. Police dogs and their trainers have a vital role in law enforcement, and their health and well-being are crucial for them to effectively carry out their duties. No study has yet been conducted on the prevalence of T. gondii and Toxocara spp. infections among police dogs and their trainers in Iran. The objective of this study was to determine the sero-molecular prevalence of T. gondii and Toxocara spp. infections in police dogs and their trainers in Tehran, the capital of Iran., Methods: In Tehran province, the anti-narcotics police have nearly 200 well-trained police dogs. Each dog is assigned a dedicated trainer and upon completing missions, is housed separately in a designated area. In the present study, a total of 150 samples were gathered. These included 50 blood samples from randomly selected police dogs, 50 fecal samples from the same dogs, and 50 blood samples from their trainers. The Modified Agglutination Test (MAT) was performed to detect T. gondii antibodies in dog blood samples and the ELISA system was utilized to identify anti-Toxoplasma and anti-Toxocara antibodies in the sera of the dog trainers. A specific segment of the SAG2 and ITS genes were amplified via nested-PCR in order to molecularly detect T. gondii in human blood samples and Toxocara spp. in dog fecal samples., Results: Regarding serological findings, the prevalence of T. gondii in dog and human blood samples was 4% (2/50) and 10% (5/50), respectively. According to reports, the seroprevalence of Toxocara spp. in human blood samples was 6% (3/50). No statistically significant association was found between the prevalence of the examined parasites and variables (age, sex, and breed) in dogs, as well as the age variable in military personnel. Molecular findings showed that out of the 50 dog fecal samples and 50 human blood samples, there was no presence of Toxocara spp. and T. gondii, respectively., Conclusion: Understanding the prevalence of parasitic infections helps public health officials assess the risk to human and animal populations. This information can guide the development of prevention and control measures to reduce the spread of these infections. Overall, the prevalence of parasitic infections, particularly T. gondii and Toxocara spp., in police dogs and their trainers remains uncertain and necessitates further in-depth research., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Widely regarded as one of the chief causes of diseases in cattle population, bovine herpesvirus-1 (BoHV-1) has the potential to infect sheep and goat, making them potential reservoirs or hosts for this virus. Thus, preventive measures against BoHV-1 in cattle should not overlook the ability of this virus to infect other animals., Aims: Therefore, the focal point of this study was to ascertain the seroprevalence of BoHV-1 in 300 healthy goats, the relationship between host and the environmental determinants of infection, and the contributing role of goats in the epidemiology of the BoHV-1., Materials & Methods: In order to pinpoint the existing antibodies to BoHV-1, the obtained sera were analyzed by Virus Neutralization test., Results: According to this test, the seroprevalence of BoHV-1 appeared to be 64.33% in southwestern Iran. What logistic regression disclosed was that the odds ratio between age and infection with BoHV-1 was 0.83 (p = 0.01), representing a decrease of 17% as goats grew one year older. In addition, females manifested a higher relative frequency of infection compared to males, with the odds of infection in female goats being registered at 1.88, compared to those in males (p = 0.2). Moreover, contrasted with goats lacking any history of abortion, those with a history of abortion featured 1.1 as the odds ratio (p = 0.87). The seroprevalence in Hendijan, Ahvaz, Shushtar and Dasht e Azadegan was detected to stand at 73.24, 71.30, 55.56 and 47.06 percent, respectively, with 6% of fluctuation in the infection rates being attributed to various geographical locations under the scrutiny of this study (p = 0.003)., Discussion and Conclusion: Having attested the marked seroprevalence of BoHV-1, the definitive role of goats in the epidemiology of this virus as a secondary host or reservoir was confirmed by the present study, necessitating the strict monitoring of BoHV-1 in goats by animal health authorities in areas where BoHV-1 abounds in cattle., (© 2024 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Toxoplasmosis ranks among the most prevalent parasitic diseases globally. It seems that chronic toxoplasmosis is associated with several neuropsychiatric and other harmful effects in infected people, therefore, there is a need to investigate the prevalence of toxoplasmosis across various world regions. In this study, we conducted a meticulous meta-analysis to estimate the seroprevalence of anti-Toxoplasma gondii IgG antibodies within the general population in Iran (GPI). International and national scientific databases for studies published between January 1, 2000, and September 30, 2023, were searched. Observational studies reporting anti-T. gondii IgG seroprevalence in the GPI was selected/included. The data were synthesized using a random-effects model to calculate with a 95% confidence interval (95% CI) the national and regional anti-T. gondii IgG seroprevalence rates in Iran. Additionally, subgroup analyses were conducted to investigate the frequency of exposition to T. gondii in different socio-demographic, climatic, and geographical scenarios. From 18661 identified studies, 327 were included in the present meta-analysis, encompassing 122,882 individuals across the 31 Iranian provinces. The pooled nationwide anti-T. gondii IgG seroprevalence among the GPI was determined to be 32.9% (95% CI: 30.9-35.1%). The highest anti-T. gondii IgG seroprevalence was observed in Mazandaran province (North of Iran) (61%), whereas the lowest was in Semnan province (12.5%).Anti-T. gondii IgG seroprevalence demonstrated a higher occurrence in provinces characterized by moderate temperatures of 16-21°C, high relative humidity, and annual precipitation. Additionally, a higher anti-T. gondii IgG seroprevalence was identified among individuals with a habit of consumption of undercooked meat, raw fruits or vegetables, and untreated water. Moreover, those reporting direct contact with cats, possessing a lower level of education, residing in rural areas, being engaged in farming occupations, or playing the role of housewives exhibited higher anti-T. gondii IgG seroprevalence figures.The anti-T. gondii IgG seroprevalence within GPI closely aligns with the estimated worldwide average exposition rates. This underscores the imperative for public health policymakers to prioritize educational efforts regarding toxoplasmosis transmission pathways and its link to harmful effects., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Hamidi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Toxoplasma gondii (T. gondii) is a ubiquitous protozoan parasite on our planet that causes toxoplasmosis. This study evaluated the seroprevalence and related risk factors for T. gondii infection in a population referred to healthcare centers in Meshkin-Shahr, Northwest Iran., Methods: A total of 400 blood samples were randomly collected from the general population and assessed using the anti-Toxoplasma antibodies, Immunoglobulin G and M (IgG and IgM) Enzyme-linked immunosorbent assay (ELISA) Kits in two steps before and during the coronavirus disease 2019 (COVID-19) pandemic, 2019-2020. The results were analyzed through logistic regression via SPSS 26 software., Results: Before the COVID-19 pandemic, anti-toxoplasma antibodies were detected in 39% of individuals (IgG: 38%, IgM: 0.5%, and IgG-IgM: 0.5%). Among the eleven risk factors evaluated, contact with soil and people awareness were significantly associated with T. gondii infection (p < 0.05). However, factors such as females, 20-39 age groups, junior high schools, housewives, rural areas, raw meat or vegetable consumption, vegetable or fruits washed by water, not detergent, and cat owners did not show a significant relationship with seropositivity (p > 0.05). After the outbreak of the COVID-19 pandemic, the overall seroprevalence for anti-T. gondii antibody increased to 49.7% (IgG: 47.7%, IgM: 0.5%, and IgG and IgM: 1.5%). Among these patients, 26% were positive for COVID-19. Additionally, before the COVID-19 pandemic, 40 samples were negative for anti-T. gondii antibodies but later became positive. The crude and adjusted models suggested that toxoplasmosis may be a possible risk factor for increased susceptibility to COVID-19, with an odds ratio (OR) of 1.28 (95% confidence interval (CI), 0.82-1.99; P < 0.05). Conversely, a non-significant protective effect against latent toxoplasmosis was observed in COVID-19-positive individuals (OR = 0.99; 95% CI, 0.51-1.92; P > 0.05), and COVID-19 positivity did not increase the levels of anti-T. gondii IgG antibodies., Conclusions: The general population in this region had a moderate seroprevalence of T. gondii. The increased number of COVID-19-positive patients with latent toxoplasmosis highlights the need to pay attention to the early diagnosis and proper treatment of toxoplasmosis in these patients and implement preventive programs in these areas for future possible viral infections., (© 2024. The Author(s).)

Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) based on the ELISA test. Also, antibodies against T. gondii were detected in 41 horses (8.42%) based on IFAT and in 63 of 487 horses (12.94%) based on the ELISA test. Also, in 6 of the horses (1.23%) based on IFAT and in 13 of the 487 horses (2.67%) based on the ELISA test, double positivity suggested co-infection with both parasites. Gender, age groups, and the presence of dogs for neosporosis, and age groups and the presence of cats for toxoplasmosis, could be considered factors having an influence on the seroprevalences (P < 0.05). The results proved the importance of the urgent implementation of stringent regulatory measures to prevent and control the spread of these parasites., (© 2024. The Author(s).)

Background and Purpose: The seroprevalence of antibodies against measles, mumps, and rubella (MMR) was evaluated 17 years following a mass vaccination campaign in individuals aged 2 to 22 years who had received routine immunization but were not eligible for an extended immunization program., Methods: Samples were acquired from Iran's National Measles Laboratory (NML), with individuals showing positive IgM results excluded. Out of the samples collected in 2020, a random selection of 290 serum samples was chosen, representing individuals between the ages of 2 and 22 years from diverse regions in the country. These samples were subjected to analysis using an enzyme-linked immunosorbent assay (ELISA) to quantify specific IgG antibodies against MMR., Results: The seroprevalence rates of antibodies for measles, mumps, and rubella were determined to be 76.2%, 89.3%, and 76.9%, respectively. Younger age groups exhibited higher seropositivity rates for measles and mumps, whereas the 7- to 11-year-old group demonstrated the highest seropositivity rate for rubella. A reduction in antibody status was observed from younger to older age groups, particularly those aged 17-22., Conclusion: The study unveiled suboptimal antibody levels for measles and rubella, highlighting the necessity for further investigation and potential adjustments to future vaccination strategies. Moreover, the decline in antibody status post-vaccination can accumulate in seronegative individuals over time, elevating the risk of outbreaks., (© 2024. The Author(s).)

Background: On a global scale, approximately 350 million are affected by hepatitis B, and 71 million by hepatitis C. People in custody face elevated risks for these infections. The prevalence and risk factors in Iranian prisons are insufficiently documented. The principal objective of this study was to ascertain the prevalence of hepatitis B and C, coupled with the identification of pertinent influencing factors, within the confines of Zahedan central prison, situated in the southeastern region of Iran., Methods: In 2019, we conducted an analytical cross-sectional study involving 407 people in custody, using stratified random sampling. To definitively diagnose hepatitis C virus (HCV) infection ( P <0.05), a checklist developed by the researchers, along with enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques, were employed., Results: This study comprised 406 participants (96.3% male) with a median age of 32 years (27-38). Approximately 62% were married, and a substantial proportion of the participants had low education levels (47%), unemployment (64%), and belonged to the Baloch ethnicity (64%). The overall prevalence of hepatitis C and B infections was 2.7% and 10.6%, respectively. Tattooing (adjusted odds ratio [AOR]: 2.07, 95% CI: 1.9-4.5) and marriage (AOR: 1.78, 95% CI: 1.05-3.04) were identified as risk factors for hepatitis B. Moreover, hepatitis C showed a statistically significant association with a family history of hepatitis B and C (AOR: 3.31, 95% CI: 3.93-24.64) and intravenous (IV) drug use (AOR: 7.01, 95% CI: 1.52-32.78) according to the multivariable logistic regression analysis., Conclusion: The prevalence of hepatitis B and C was higher among people in custody in Zahedan central prison. Consequently, targeted interventions are vital to address and reduce viral hepatitis burden in custodial settings., (© 2024 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.)

Toxoplasmosis is a frequent infection among the human population. The infection can cause devastating complications for the fetus during pregnancy. The present study aimed to determine the serological and molecular prevalence of the infection and molecular characterization of Toxoplasma gondii isolates among pregnant women referred to Kowsar Hospital, Urmia, Iran. In a cross-sectional study, 340 blood samples were collected from pregnant women referred to Kowsar Hospital, Urmia, Iran from May to July 2022. Anti-T. gondii IgG and IgM seropositivity were determined by enzyme-linked immunosorbent assay. PCR was carried out by targeting the GRA6 gene of the parasite on all patients' buffy coats. Anti-T. gondii IgG and IgM antibodies were positive in two (0.6%) women, and 101 (29.7%) women had anti-T. gondii IgG and 70.3% were seronegative. PCR was positive in two IgM-positive women, and both isolates belonged to T. gondii carrying the GRA6 allele of lineage I. The risk of infection was significantly higher in women who had constant contact with cats and soil, and who were residents of rural areas. The two IgM-positive women were asymptomatic regarding acute toxoplasmosis. According to the results of the present study, the prevalence of toxoplasmosis in pregnant women in Urmia is similar to its prevalence in other areas in northwestern Iran, and despite the low prevalence of acute infection, it should not be ignored., (© 2024. The Author(s).)

Toxocariasis is one of the most common zoonotic diseases distributed worldwide. This study aimed to estimate the seroprevalence of anti- Toxocara immunoglobulin G (IgG) antibodies and the associated risk factors among general populations living in urban and rural areas of Abadan and Khorramshahr cities in Khuzestan Province, Southwest Iran. This cross-sectional study was conducted between March and September 2022. There were 363 participants (190 females and 173 males) aged from <20 to ≥60 years old. Anti- Toxocara IgG antibodies in serum samples were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was employed to collect information regarding sociodemographic status and probable risk factors associated with toxocariasis. It was found that the seroprevalence rate in males (15.0%, 95% CI = 10.47-21.11) was higher than in females (10.5%, 95% CI = 6.92-15.70). Moreover, we observed that the seroprevalence was higher in participants at younger ages compared to other age ranges (COR = 2.55, 95% CI = 0.92-7.12, p  =0.073). The findings of the univariate analysis revealed that residency in rural areas ( p   < 0.001), using unpurified water ( p   < 0.001), contact with dog ( p  =0.002), contact with soil ( p   < 0.001), consumption of improperly washed vegetables ( p   < 0.001), and history of drinking untreated water ( p   < 0.001) were risk factors associated with toxocariasis. Further comprehensive studies with a focus on humans and animals should be designed in different areas of the Province. The data represented by the current study are useful to health policymakers to consider precise surveillance and effective prevention measures to control this zoonotic infection among general populations., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Masoud Foroutan et al.)

Background: Toxoplasmosis is a serious or life-threatening disease in immunosuppressed patients and pregnant women. This study examined the likely association between Toxoplasma gondii infection and COVID-19 patients with moderate illness., Methods: Seventy blood samples were collected from patients at the Health Reference Laboratory of Tabriz, Northwest Iran from April 2021 to September 2021. In addition, 70 healthy subjects of the same age (37 ± 15 years) and sex distribution were ethnically matched. Sera samples were examined for the detection of anti-Toxoplasma antibodies using ELISA. Nested-PCR targets were amplified based on the B1 and GRA6 genes. GRA6 amplicons were subjected to sequencing and phylogenetic analysis., Results: The seroprevalence of toxoplasmosis based on IgG titer was 35.7% in the COVID‑19 patients and 27.1% in the control group, representing not to be associated with the Toxoplasma seropositivity in COVID‑19 patients (P = 0.18) compared to healthy subjects. Anti-T. gondii IgM was not found in any of the patients and healthy individuals. According to PCR amplification of the B1 and GRA6 genes, the frequency of T. gondii in COVID-19 patients was 14.2% (10/70). However, no T. gondii infection was detected in the healthy group. The CD4 + T cell count was relatively lower in toxoplasmosis-infected patients (430-450 cells/mm3) than in control group (500-1500 cells/mm3). High genetic diversity (Hd: 0.710) of the type I strain of T. gondii was characterized in the patients. Present results showed that consumption of raw vegetables and close contact with stray cats can increase the transmission of T. gondii to COVID-19 patients (P < 0.01)., Conclusions: The current study revealed that T. gondii type I infection is unequivocally circulating among the COVID-19 patients in Tabriz; However, no significant association was observed between the occurrence of Toxoplasma and the severity of COVID-19. To make more accurate health decisions, multicenter investigations with a larger sample size of different ethnic groups of the Iranian population are needed., (© 2024. The Author(s).)

Akabane disease is an arthropod-borne viral disease that affects ruminants. This teratogenic pathogen causes severe economic losses in ruminants worldwide and in Iran; however, it has not received enough attention in Fars province, Iran. Therefore, this study aimed to determine the influence of age, gender, climate, farming system, and history of abortions on the seroprevalence of the Akabane disease in sheep and goats in Fars province. In the present study, Fars province was divided into three climates, and three cities were randomly selected from each climatic region. In each city, two epidemiologic units were selected, and all sheep and goats in each unit were sampled. Overall, 540 serum samples (391 sheep and 149 goats) were collected and examined with the commercial ELISA kit. The results showed that 83 out of 540 (15.4%) samples were seropositive and had antibodies against the Akabane virus (AKAV). The effect of gender and age on the rate of the AKAV was not significant. Animals in warm climates were 4.218 times more likely to have antibodies against the AKAV than animals in cold climates. Females were 1.32 times more likely to exhibit seropositivity. The odds of AKAV infection were higher in animals with an abortion history than in healthy animals. The findings of the present study indicated that the prevalence of the AKAV was high in small ruminants in Fars province. Therefore, it is necessary to conduct more studies to control the risk factors involved in the spread of this virus., Competing Interests: The authors declare that they have no conflict of interest.

Neospora caninum is a significant cause of abortion and economic losses in cattle worldwide. The main aim of the present work was to detect the prevalence of N. caninum infection in bulls in Hamedan (Iran) using serology and molecular techniques. All blood samples (n = 792) were screened for detecting the antibodies to N. caninum using enzyme-linked immunosorbent assay (ELISA). Then seropositive animals were rechecked using the immunofluorescent antibody test (IFAT). Also, blood, epididymis, and spinal cord samples were collected from animals for molecular analysis using nested PCR. In serology, using ELISA, 3.91% of animals were seropositive for N. caninum. Additionally, true prevalence based on the sensitivity and specificity of the ELISA was calculated 1.25% (95% CI: 0.48-2.02%). Neospora-infection in animals, calculated as the number of bulls seropositive and/or one sample positive to nested PCR, was 3.40%; and 19 bulls tested positive by both serology and molecular diagnostic methods. The overlaps between ELISA and molecular results were observed in 74.19% of whole blood samples, 80.64% of the epididymis, and 87.09% of the spinal cord. Using ELISA, the seroprevalence of N. caninum was detected 1.8% in ≤2 and 5.45% in >2 years old group of animals (p = 0.009, PR = 3.1). In addition, the seropositivity in Holstein and native breed animals was calculated 6.57% and 2.93%, respectively (p = 0.019, PR = 2.3). Seven sequences with 94.9-99.3% similarity were detected in multiple alignments of positive PCR products. Our work was the first comprehensive evaluation of Neospora-infection/neosporosis in Iranian bulls. We detected a low prevalence of infection in animals compared to previous reports. The ELISA is a sensitive serological technique for detecting the highest number of positive bulls in the present investigation and, the nested PCR is a reliable technique to identify Neospora-DNA., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The COVID-19 disease emerged in Wuhan, China, in December 2019 and quickly became a global health threat. Around 6,947,192 people have been killed around the world so far, including 146,292 in Iran. In addition to the definitive diagnosis of the disease by RT-PCR, immunological and serological tests can check the anti-SARS-CoV-2 N protein antibody titer in people at different stages of infection with acceptable sensitivity and specificity. The serological examination is an effective and efficient method for determining the prevalence of the disease, especially when asymptomatic cases are present or the diagnosis of symptomatic cases is incomplete. The study examined the seroprevalence of COVID-19 at the Razi Vaccine and Serum Research Institute (RVSRI) and the Agricultural Research, Education, and Extension Organization (AREEO). A total of 493 blood samples were collected from volunteers in June 2020 in AREEO, and 380 samples were collected in June and July 2020 in RVSRI. The total number of volunteers from both organizations was 873. Standard ELISA kits were used to measure IgG and IgM antibodies against SARS-CoV-2. A statistical analysis of the obtained data was conducted using SPSS (version 22.0). Among the total 873 volunteers examined in RVSRI and AREEO, 10.5% had elevated serum titers either for IgM or IgG, 3.55% of whom were women and 6.95% were men. Generally, 8.8% of people tested positive for IgM, which showed a recent infection with COVID-19 in people at that time and partially indicated the start of a new wave of COVID-19. In RVSRI, 3.42% of people with positive IgM titers (positive or negative IgG titers) were women and 5.53% were men. In AREEO, 3.02% were women and 5.72% were men. The seroprevalence rate of COVID-19 in RVSRI was 11.6%, 4.2% of which were women and 7.35% were men, with no significant difference between women and men. The COVID-19 seroprevalence in AREEO was 9.7%, 3.22% of which were women and 6.5% were men, with no significant difference between women and men., Competing Interests: The authors declare that they have no conflicts of interest.

Toxoplasmosis is a worldwide disease of various animals and human and results from infection with the Toxoplasma gondii parasite. Abortion and congenital defects are important consequences of the T. gondii infection. The aim of this study was to determine the Toxoplasma-induced abortions among women with miscarriage and the presence of T. gondii in their aborted fetuses in Urmia, the northwest of Iran. This cross-sectional study was conducted with 215 women with abortion and their aborted fetuses, from 2020 to 2021. Seroprevalence of anti-Toxoplasma IgG and IgM were determined using the sera of the aforesaid women. Nested PCR was carried out using RE-529 gene sequences, and sequencing was performed using the T. gondii GRA6 gene on the remnant of pregnancy after abortion. The tissue positive samples were then subjected to another PCR on GRA6 gene and sequenced for genotyping. Among 215 serum samples of women with abortion, 70 (32.6%) were positive for anti-Toxoplasma IgG, and three (1.4%) were positive for IgM. The RE-529 sequence of T. gondii was positive in three (1.4%) of the aborted fetuses. The analysis of GRA6 gene indicated that all three positive samples carried a GRA6 allele (GRA6I) of T. gondii type I genotype. Our findings suggest that T. gondii is one of the causative agents of spontaneous abortion in West Azerbijan Province, the northwest of Iran., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Zeinali et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Toxoplasmosis, an important zoonotic disease, is caused by Toxoplasma gondii. Camels are one of several host species for T. gondii parasites and play an important role in the transmission of T. gondii to humans., Objectives: The present study aimed to describe the seroprevalence of T. gondii in dromedary camels (Camelus dromedarius) from three provinces (Fars, Bushehr and Hormozgan), southern Iran first for this host., Methods: A total of 180 serum samples were analysed for the presence of anti-Toxoplasma IgG antibodies using the enzyme-linked immune-sorbent assay., Results: Our results showed an overall seroprevalence of T. gondii in 15% of animals. Antibodies to T. gondii were found in sera of 27 of 180 dromedary camels from Fars, Bushehr and Hormozgan provinces, southern Iran. Age or the gender of the camel did not significantly affect the seroprevalence (p > 0.05). There was no significant association between herd-level seroprevalence of T. gondii infection and abortion history, province location residence, history of animal keeping and history of contact with other animals (p > 0.05)., Conclusions: The results of this study showed the presence of T. gondii antibodies among camels in Southern Iran, which could be a public health concern. According to the prevalence of T. gondii infection in camel, the implementation of control measures to reduce infection in both definitive and intermediate hosts is needed., (© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Background: Toxoplasma gondii, a ubiquitous parasitic protozoan, may be an important cause of neurological and psychiatric diseases. The present systematic review and meta-analysis, therefore, was conducted to investigate the scientific evidence regarding the potential association between T. gondii infection and psychiatric disorders in Iran., Methods: We systematically reviewed articles from world-wide databases, including PubMed, Scopus, Science Direct, Web of Science, Google Scholar, and Iranian national databases up to July 30th, 2021. The Newcastle Ottawa Scale (NOS) was used to assess the quality of included studies. The common odds ratio (OR) was estimated using inverse variance and a random-effects model. Heterogeneity was assessed using the χ2-based Cochrane test (Q) and the I2 index. Also, sensitivity analyses and publication bias were calculated. Moreover, subgroup analysis was performed based on the type of disorder and quality score of different eligible studies., Results: 16 studies were included in this meta-analysis. Our meta-analyses found that the OR of the risk of anti- T. gondii IgG and IgM in psychiatric patients compared to the control group was 1.56 (95% CI; 1.23-1.99) and 1.76 (95% CI: 1.19-2.61), respectively. Subgroup analysis based on the type of disorder showed that the OR of the risk of anti- T. gondii IgG in Iranian schizophrenia patients and other psychiatric disorders compared to the control group were 1.50 (95% CI; 1.09-2.07) and 2.03 (95% CI: 1.14-3.60), respectively, which are statistically significant. Also, the OR of the risk of anti- T. gondii IgM in Iranian schizophrenia and depression patients compared to the control group was 1.54 (95% CI; 0.9-2.64) and 1.03 (95% CI: 0.2-5.24), respectively, which are not statistically significant. Additionally, subgroup analysis based on quality scores showed no significant influence on the results according to the moderate quality studies. However, this association was significant according to the high quality studies. The obtained results of Egger's test were 1.5 (95% CI; -0.62-3.73, P = 0.15) and 0.47 (95% CI; -0.82-1.76, P = 0.45), respectively, indicating publication bias. The significant results of the heterogeneity analysis confirmed a high level of heterogeneity in the IgG test (P = 0.000, I2 = 66.6%). However, no significant results from the test of heterogeneity were detected in the IgM test (P = 0.15, I2 = 27.5%). The results of the sensitivity analysis showed that the impact of each study on the meta-analysis was not significant on overall estimates., Conclusions: Despite the limited number of studies, these outcomes supported a possible link between T. gondii infection and psychiatric disorders in Iran. However, more high-quality investigations are needed in the future., Competing Interests: The authors of this manuscript have no competing interests., (Copyright: © 2023 Montazeri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: People with mental defects are more likely to get the infection due to their low levels of health care and personal hygiene. The current study aimed to determine the seroprevalence of Toxoplasma infection among individuals with intellectual disabilities in Hormozgan province, southern Iran., Methods: The study population was 117 individuals with intellectual disabilities. Venous blood (3 mL) was taken from each subject. A commercial ELISA kit was used to determine anti-Toxoplasma IgG antibodies., Results: Of 117 recruited subjects, 55 (47.0%) were men and 62 (53.0%) were women. The mean age of participants was 27.6 (±12.31) years. Out of 117 studied subjects, 76 had severe and 41 had profound intellectual disabilities. Anti-Toxoplasma IgG antibodies were detected in the sera of 35 out of 117 (29.9%) individuals. Seropositivity to toxoplasmosis was significantly higher in severe than in individuals with profound intellectual disabilities (P < 0.05). There was no statistically significant association between Toxoplasma infection and age, sex and duration of residency in the rehabilitation centre., Conclusions: The findings of this study indicate that the prevalence of Toxoplasma in people with intellectual disabilities is not much different from other groups of the community., (© 2023 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.)

Background: Some evidence reveled that chronic infection with Toxoplasma gondii (T. gondii) has recently been associated with infertility in human and experimental model. This baseline study aimed to investigate serological evidence of Toxoplasma infection among infertile women who admitted to the in vitro fertilization (IVF) clinic at Imam Khomeini Hospital, Mazandaran province, Sari, northern Iran., Subjects and Methods: In this retrospective (descriptive-analytical) study, all infertile women referred to the IVF clinic during 2010-2019 (10 years), constitute the study population. All data including demographic and some related characteristics were collected into a questionnaire and registered at the Iranian National Registry Center for Toxoplasmosis (INRCT) at the Mazandaran University of Medical Sciences, northern Iran. The existence of anti-Toxoplasma antibodies (IgG and IgM) was explored using a commercially available enzyme-linked immune sorbent assay (ELISA) kit (PishtazTeb, Iran), based on the manufacturer's protocol., Results: Of 520 infertile women, anti-T. gondii IgG, IgM and both IgG and IgM antibodies were detected among 342/520 (65.77%), 1/520 (0.19) and 4/520 (0.77) infertile women, respectively. Primary and secondary infertility was detected in 74.56% and 25.44% of IgG seropositive infertile women, respectively. Also, most of the IgG seropositive subjects had no history of abortion, polycystic ovary syndrome (PCO), fibroma, contraceptive use and varicocele in spouse as primary cause of infertility. Furthermore, serum levels of prolactin and antimullerian (AMH) hormones were normal in 81.29 and 80.12% of infertile women with anti- T. gondii IgG, respectively. There was also a statistically significant difference between the seroprevalence of Toxoplasma infection and these variables associated to primary infertility (P < 0.05)., Conclusion: According to the high prevalence (about two thirds) of chronic T. gondii infection among infertile women, particularly those with a history of abortion and primary infertility, it can be concluded that latent Toxoplasma infection pose a risk to infertile woman in the study area. Therefore, we advise that screening and treatment of Toxoplasma infection among infertile women must be favorably considered., (© 2023. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Background: Toxocara infection is one of the most common neglected infections of poverty and a helminthiasis of global importance. Traditional diagnostic methods such as antibodies detection in serum samples are limited due to cross-reactivity and poor sensitivity. The use of molecular base methods for diagnosis of Toxocara infection in Iran has not been fully explored. The purpose of the current study was to estimate the prevalence of Toxocara infection from serum samples of people living with HIV in Alborz province, Iran using serological and molecular methods., Methods: Blood samples were collected from 105 people living with HIV. Epidemiological data of participant were obtained through a structured questionnaire to investigate the risk factors. Patients CD4 + T cell count were recorded. Anti-Toxocara IgG antibodies were detected by ELISA, with a cut-off point of 11. PCR was performed to detect genetic material of Toxocara species in the serum samples., Results: The mean CD4 + count in HIV-infected individuals with positive toxocariasis serology was 255.1 ± 21.6 cells/µL. Seropositivity for Toxocara species was observed in 12/105 (11.4%) people living with HIV. Three samples gave positive results on PCR analysis. Based on the data, a statistically significant relationship was found between anti-Toxocara IgG antibodies seropositivity and underlying conditions (p = 0.017). No significant statistical association was observed between seropositivity for Toxocara and gender, age, exposure to domestic animals or pet keeping, education levels, and occupation (p > 0.05). The findings of PCR confirmed Toxocara DNA in 3/12 (25.0%) serum samples., Conclusion: These findings demonstrated for the first time that people living with HIV from Alborz province, are being exposed to this zoonosis and a relatively high seroprevalence of Toxocara in HIV/AIDS people needs comprehensive health education regarding personal hygiene and how to avoid exposure to this parasite infection, especially in people with an impaired immune system., (© 2023. The Author(s).)

Objective: Q fever is a main occupational zoonotic disease. Slaughterhouse is one of the most remarkable ways of transmitting the infection from livestock to humans. This study aimed to survey the prevalence of Q fever in slaughterhouse workers in Fars province, Iran, for the first time., Methods: Ninety serum samples were collected from slaughterhouse workers and tested to detect Immunoglobulin G (IgG) against Coxiella burnetii using ELISA and indirect immunofluorescence assay (IFA). PCR was also applied to identify C. burnetii DNA in the blood samples., Results: Q fever seroprevalence was found at 26.7% in ELISA, showing recent infection. This result indicates that Q fever seroprevalence is relatively high in the Fars region. IFA showed a high seroprevalence of total IgG antibodies at 1:64 titer (73.3%) and relatively high IgG at 1:256 titer (40%) against C. burnetii. 2.2% of the workers were recognized as having probable acute Q fever. The IgG II prevalence at 1:64 and 1:256 titers was, respectively, 63.3% and 24.4% positive. The IgG I prevalence at 1:64 and 1:256 titers was also found 33.3% and 22.2% positive, respectively. Molecular prevalence of Q fever was also 8.9%. A significant relationship was found between IgG I seropositivity and longer work experience and employing other livestock-related jobs (animal husbandry and butchery) (P < 0.05)., Conclusions: As such, the high seroprevalence of Q fever among abattoir workers highlights the importance of further comprehensive epidemiological studies, occupational screening programs, and preventive measures for Q fever in high-risk groups. This also warns animal health care organizations about the risk of Q fever infection in livestock in this region., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study was performed to determine the prevalence, genotype distribution and risk factors of hepatitis B virus (HBV) infection among β-thalassemia patients. ELISA was used to detect HBsAg and HBcAb. Molecular evaluation of HBV infection was performed by nested PCR, targeting S, X and pre-C regions of the genome, and sequencing. Of 126 thalassemia patients, 4 cases (3.17%) were positive for HBsAg, 23 cases (18.25%) were positive for HBcAb, and 6 cases (4.76%) had HBV viremia with genotype D, sub-genotype D3 and subtype ayw2. HBV prevalence among thalassemia patients was not statistically associated with gender distribution, place of residency, marital status and frequency of blood transfusion. HBsAg seroprevalence was significantly higher in Afghan immigrants and patients with ALT levels of 41-80 IU/L. The prevalence of HBV viremia was significantly higher among thalassemia patients aged >20 years compared to the patients aged <20 years. Moreover, 1.59% of thalassemia patients had seropositive occult HBV infection, which was positive for HBV-DNA and HBcAb but negative for HBsAg. Considering the relatively high prevalence of occult HBV infection among thalassemia patients, there is a possibility of their contamination through donated blood. Therefore, screening of donated blood based on detection of HBsAg cannot abolish HBV transmission through blood transfusion.

The protozoan parasite Neospora caninum infects carnivores as definitive and a wide range of mammals as intermediate hosts. This parasite is regarded as an important cause of abortion in cattle worldwide, causing significant economic losses. Although there is serological evidence of infection in Old World camelids, the significance of N. caninum in these animal species is still poorly understood. The aim of this study was to use molecular and histological methods to detect N. caninum in the blood and tissues of 100 slaughtered one-humped camels (Camelus dromedarius) in Iran. For this, genomic DNA was extracted from blood, brain, portal lymph node and liver of the camels, and nested-PCR assay followed by sequencing were performed. Besides, paraffin-embedded tissue sections were stained with hematoxylin and eosin (H&E) and studied microscopically. In addition, immunohistochemical staining for N. caninum was attempted on brain samples with positive PCR results. All animals were tested for antibodies against N. caninum and Toxoplasma gondii by whole tachyzoite-agglutination tests. N. caninum DNA was detected in blood, brain, and portal lymph node, but not in the liver of two (2%) camels. Histopathological examination revealed cysts resembling N. caninum in brain samples of one of these camels; however, immunohistochemical staining for N. caninum and T. gondii did not allow a morphological identification. IgG antibodies to N. caninum and T. gondii were detected in 36% and 35% of the camels, respectively. This study provides the first insight into direct detection of N. caninum in C. dromedarius in Iran. Further molecular studies on aborted fetuses, stillborn animals and cases of perinatal mortality are needed to understand the possible involvement of N. caninum in cases of reproductive failure. As the definitive hosts of N. caninum are domestic and wild canids, producers should be advised to monitor and limit exposure of their camelids to these species and their feces., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Reliable estimation of prevalence is important for monitoring and evaluation of COVID-19 prevention programmes among at-risk populations., Aims: We compared the capture-recapture method with a seroprevalence survey for accurate estimation of the prevalence of COVID-19 during a 1-year period in Guilan Province, northern Islamic Republic of Iran., Methods: We used the capture-recapture method to estimate the prevalence of COVID-19. Records from the primary care registry system and the Medical Care Monitoring Center were compared, using 4 matching approaches based on combinations of the following variables: name, age, gender, date of death, positive or negative cases, and alive or dead cases., Results: The estimated prevalence of COVID-19 in the study population from the beginning of the pandemic in February 2020 until the end of January 2021 was 16.2-19.8%, depending on the matching approach used, which was lower than in previous studies., Conclusion: The capture-recapture method may provide better accuracy than seroprevalence surveys in measuring the prevalence of COVID-19. This method may also reduce the bias in the estimation of prevalence and correct the misconception of policymakers about seroprevalence survey results., (Copyright © Authors 2023; Licensee: World Health Organization. EMHJ is an open access journal. This paper is available under the Creative Commons Attribution Non-Commercial ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo).)

Pigeons are common birds around the world and may act as intermediate hosts of the tissue cyst-forming apicomplexan parasites Toxoplasma gondii, Neospora caninum and Sacrocystis spp. This study aimed to provide an overview on the prevalence of and exposure to these parasites in Iranian domestic rock pigeon (Columba livia domestica) through molecular, serological and histopathological examination. Blood and tissue samples (i.e., brain, heart, gizzard, neck, thigh, and pectoral muscles) were taken from 100 pigeons. Sera were screened by agglutination tests for detection of anti- T. gondii and N. caninum antibodies, genomic DNA from tissue samples were assessed by respective species-specific PCRs, and histopathological examination of tissues was carried out. A seroprevalence of 45 % to anti-T. gondii and 35 % to anti-N. caninum IgG was recorded. PCR detected T. gondii DNA in 28 pigeons. Sacrocystis spp. was detected in one animal, but sequencing of the 28 S rRNA gene product did not reveal the identity of the species. Histopathology revealed myocarditis, myositis, and gliosis in the heart, skeletal muscles, and brain, respectively. No Sarcocystis tissue-cysts were detected, but T. gondii tissue cyst-like structures in the brain (i.e., 4 %) and heart (i.e., 3 %) were found by histology. Data reported herein demonstrate that pigeons from Iran are infected with tissue cyst-forming apicomplexans, particularly T. gondii. Since domestic pigeons are in close contact with human populations, and consumption of their meat and egg is popular in different societies, control strategies for minimizing the risk of infection in both pigeons and humans are suggested., Competing Interests: Conflict of interest The authors declare that they have no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Brucellosis is one of the most prevalent zoonotic diseases. Using serological tests are valid and rapid methods that could be used in the detection of the history of getting brucellosis. Considering that Iran is an endemic country for brucellosis, we aimed to investigate the rate of seroprevalence of brucellosis among livestock and human in Kurdistan province., Material and Method: Serum sampling was performed from 51 slaughterhouse workers, veterinarians, and husbandry workers, along with 260 livestock (80 cattle, 120 sheep, and 60 goats). Rose Bengal plate test (RBPT), and Enzyme-linked immunosorbent assay (ELISA) were used for livestock and the anti-Brucella IgG antibody was evaluated in human participants., Results: The seroprevalence (based on ELISA assay) in sheep, goats, and cows was 5.8%, 5%, and 1.2%, respectively. Also, the rate of anti-Brucella IgG was 3.9% among human participants., Discussion: the current study, provided some valuable information on the seroprevalence of brucellosis in animal and human participants from the west of Iran. Considering the effects of brucellosis on causing reproductive disorders, including abortion, placental retention, andendometritis controlling the infection could have a significant impact on terms of economy., Competing Interests: Competing interests The authors declare no conflict of interest., (Copyright © 2023. Published by Elsevier Ltd.)

Objectives: Iran is one of the countries that have been confronted with the SARS-CoV-2 epidemic since February 2020. This study aimed to determine the levels of specific IgG antibodies against SARS-CoV-2 among healthy blood donors to estimate the burden of the epidemic., Material and Methods: A serial cross-sectional study was conducted on blood donors who referred to 31 main blood donation centers in different provinces during the third weeks of September, October, and November 2020. A questionnaire was filled out to collect socio-demographic characteristics, history of contact with COVID-19 patients, and history of COVID-19. A blood sample was collected from each participant to assess the antibodies against SARS-CoV-2 using the ELISA method. The crude prevalence of anti-SARS-CoV-2 IgG was calculated. Then it was weighted based on the gender and age groups of the general population in each province and adjusted for test sensitivity and specificity., Results: During three time points of the study, 3840, 3697, and 3152 participants enrolled. The seroprevalence of SARS-CoV-2 IgG antibodies was 19.59% (17.18-22.00), 22.67% (20.70-24.65), and 32.63% (29.93-35.33) over the three rounds of the study. We found an association between the seropositivity and the highest educational level; AOR 0.76 (0.63-0.93), history of close contact with COVID-19 patients; AOR 1.69 (1.35-2.11), and history of confirmed SARS-CoV-2 infection; AOR 8.86 (5.38-14.60)., Conclusion: This study showed that about one-third of the population had been infected with COVID-19. Furthermore, a significant upward trend in seroprevalence was observed. The predisposing factors indicate the importance of public health., (Copyright © 2022 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

It is estimated that nearly one-third of the world's human population is infected with Toxoplasma gondii (Nicolle et Manceaux, 1908). Human infection is commonly asymptomatic, multifaceted, and can manifest in severe pathological forms in congenital toxoplasmosis and immunocompromised individuals. This study attempted to recognise the seroprevalence of T. gondii infection in Iranian residents referred to medical laboratories for toxoplasmosis tests throughout the country. This retrospective cross-sectional study was conducted from 2015 to 2019 on individuals referred to diagnostic laboratories in 26 provinces, and these laboratories sent their samples to the referral centres. Accordingly, data associated with serodiagnosis of toxoplasmosis, age, sex, anti-T. gondii IgG, and IgM status in Iranian residents were collected from two referral diagnostic laboratories. All individuals were evaluated using the antibody immunocapture-chemiluminescence assay (CLIA) method with the Immulite ® 2000s XPi system. In this study, the first large-scale assay of T. gondii infection in Iran, an overall seroprevalence of 30.4% was among 35,047 patients examined. The highest IgM seropositivity rate was in the 10-20 years old patients. In addition, this study showed a very different prevalence of T. gondii across the country, highest in the humid areas, such as the Caspian Sea basin in the North, and the North West with seroprevalence of 48.6%.

Congenital toxoplasmosis can cause severe consequences in the fetus, such as spontaneous abortion which is affected by parasite strain. Also, recent studies revealed the high genetic diversity of Toxoplasma gondii. This study aims to investigate the serological status of T. gondii in pregnant women, multilocus genotyping in aborted fetuses' tissue, and archived formalin-fixed paraffin-embedded placenta. This study was performed on 100 pregnant women with spontaneous abortion and their aborted fetuses, and 250 of the archived placentae in Iran. The blood and tissue were examined for seroprevalence and genotype determination of T. gondii using ELISA and multilocus nested-PCR-RFLP, respectively. Anti-T. gondii IgG and IgM were detected in 68 samples (68%) and 1 (1%) out of 100 serums. Toxoplasma DNA was identified in 1 (1%) aborted fetuses' tissue and 32 (12.8%) placenta samples. Overall, ten positive DNA samples were successfully genotyped, and five genotypes were recognized (ToxoDB#1, #2, #10, #27, and #48). The obtained results indicated congenital toxoplasmosis is a severe risk in this region. As type I is highly pathogen and can lead to severe complications, the prevention of the infection should be considered in seronegative pregnant women., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Toxoplasma gondii is an obligate intracellular protozoan that can infect almost all warm-blooded animals, including humans. Patients with co-infection with toxoplasmosis and HIV have a 30-40% risk of developing toxoplasmosis encephalitis. This study aimed to describe the epidemiology and burden of Toxoplasma gondii in HIV-infected individuals in Iran., Methods: We searched the five English databases (Science Direct, PubMed, Scopus, Ovid, Embase, and Cochrane) and four Persian databases (Scientific Information Database (SID), Iran Medex, Iran Doc, and Magiran) with the terms of (Toxoplasma gondii OR "toxoplasmosis") AND (HIV OR "AIDS" OR immunodeficiency OR acquired immune deficiency syndrome) AND (Seroprevalence) AND (Seroepidemiologic Studies) AND (Elisa OR IgG) AND (PCR) AND (Iran) by two authors up to Feb 2021. Studies were included if they investigated people with HIV infection and presented data that allowed us to establish the prevalence of Toxoplasma gondii infection in Iran., Results: According to the inclusion/exclusion criteria, 15 studies were selected. A total number of 2275 HIV-infected individuals were tested and evaluated for toxoplasmosis from 2005 up to 2018 in different regions of Iran. The weighted overall prevalence of toxoplasmosis in HIV-infected individuals with Elisa was obtained using a random-effects model, which was estimated at 47% (95% CI = 31% - 62%). Also, the Weighted overall prevalence of toxoplasmosis in HIV-infected individuals with PCR was obtained using a random-effects model, which was estimated at 7% (95% CI = 3% - 12%)., Conclusion: According to the results of this study, it can be clearly understood that a large population of HIV patients living in Iran have toxoplasmosis. Therefore, due to the high susceptibility of these groups to toxoplasmosis, healthcare professionals must consider measures such as training in the ways of transmission and prevention of the infection to this high-risk group in order to reduce the risk of infection., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Neospora caninum plays an important role in abortion and economic losses in dairy industry worldwide. The main target of this work was to detect the infection rate of N. caninum in various hosts in dairy farms for identifying the risk factors and applying appropriate control programs to reduce the number of abortions. The study was conducted in dairy farms with high incidence of abortion in Hamedan province, West of Iran. After the primary assessment, we conducted a controlling program for reducing the Neospora‑infection rate and associated abortions. Before implementing the control program, the seropositivity was 24.8% in cows (N=476 distributed in 10 farms) and 8.6% (N=185) in dogs. Abortion occurred in 3.57% of pregnant cows. 94.1% of aborted cows were positive for Neospora‑infection. Based on molecular technique, the infection rate was detected in 7.3% of cats (N=41), in 25% of pigeons (N=19)and in 11.8% of rodents (N=51). After the implementation of neosporosis control programs in the farms, the seropositivity of N. caninum decreased to 8.2% in cows and 2.9% in dogs. After the one‑year follow‑up, no cases of abortions were reported in the farms. This was the first parallel evaluation of Neospora‑infection and controlling programs in Iranian dairy farms. Regular control of rodents, retesting of seronegative animals and farm biosecurity measures are recommended for reducing the abortion incidence. The access of dogs to the herd and to aborted materials should be restricted.

Toxoplasmosis, a zoonotic infection that is significant for public health (immunocompromised patients, pregnant women) and veterinary medicine (economic losses in the herd), is caused by an intracellular protozoan parasite belonging to the phylum Apicomplexa called Toxoplasma gondii. Consumption of unpasteurized milk and contaminated undercooked meat is a significant source for humans. The present study aimed to determine Toxoplasma gondii DNA in sheep, goats and donkeys Milk kept in East Azerbaijan province using the PCR method based on the B1 gene. For this purpose, 100 milk samples, including 45 sheep, 45 goats and 10 donkeys, were collected from different regions of northwestern Iran using direct milking and then transferred to the Food and Aquatic Health Laboratory under refrigerated conditions. The results showed that out of 100 milk samples examined, 16 samples (16%) were contaminated, and Toxoplasma gondii DNA was detected in 5 (11.11%) sheep, 9 (20%) goats and 2 (20%) donkeys milk specimen, respectively. These findings indicated that Toxoplasma gondii contaminated the raw milk, a human infection source., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest relevant to this study., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Hepatitis C virus (HCV) infection is a significant health concern in patients with end-stage renal disease under dialysis. Epidemiological studies have reported a prevalence rate of 5.5-55.9% for this condition in Iran. Objectives: We evaluated the risk factors for HCV infection and seroconversion in hemodialysis patients. Patients and Methods: A retrospective analysis was performed on 455 hemodialysis patients from each of the five dialysis units in Tabriz, northwest Iran. Possible risk factors for HCV infection and seroconversion were evaluated. Results: A total of 37 patients were HCV positive (8.1% of the study population) and seroconversion occurred in 18 of them during the dialysis treatment (3.95% of the study population). History of renal transplantation (44.4%, P < 0.0001), surgical intervention (except for renal transplantation and AV fistula placement) (94.4%, P = 0.03), and mean duration of dialysis (106.06 ± 55.519, P < 0.0001) had strong statistically significant associations with the seroconversion. Conclusions: The current study indicates increased risk for HCV infection in patients under dialysis and its relation with the mean duration of hemodialysis, history of renal transplantation and surgical intervention. Considering the immune deficiency in these patients, intense education to both patients and medical staff will be beneficial. [ABSTRACT FROM AUTHOR]

Bovine viral diarrhea virus (BVDV) and bovine herpes virus-1 (BHV-1) have been known as the major pathogens with significant economic consequences on the cattle industry worldwide, including in Iran. In this cross-sectional study, the seroprevalences of BVDV and BHV-1 and their associated risk factors were investigated in dairy cattle farms of Fars province, Iran, where with 0.4 million head of cattle, mainly crossbred, is ranked the first in cow population in southern Iran. A total number of 420 cattle in 18 herds were randomly selected from three geographical regions (140 samples from each of the north, central, and south regions) and their serum samples were analyzed to detect antibodies to these viruses using a commercially available enzyme-linked immunosorbent assay kit. Chi-square test and logistic regression analyses were employed to investigate associations between risk factors and the seroprevalence of viruses. The overall seroprevalence rates for BVDV and BHV-1 were estimated at 91.67% and 77.87% at the herd level and 55.48% and 39.76% at the animal level, respectively. The only significant factor associated with the seroprevalence of both viruses at the herd level was found to be the literacy level of farmers ( P <0.05). The significant risk factors for both viruses in cattle were identified as geographical region, age, and breeding method by the univariate analysis ( P <0.05), while gender and farming system were determined as risk factors only for BHV-1 ( P <0.001). A significant relationship of concurrent infection with BVDV and BHV-1 (φ=0.268, P <0.001) was recorded, and 28.6% of sera had antibodies to both viruses. The results of the present study demonstrated that BVDV and BHV-1 had a wide distribution in dairy cattle herds in southern Iran and highlighted the need for intensive surveillance and control strategies to reduce the risk of the spread of these viruses., Competing Interests: The authors declare that they have no conflict of interest.

Background: The current study aimed to determine the seroprevalence of Toxoplasma gondii infection among HIV-positive patients and healthy subjects., Methods: This study was carried out on HIV-positive patients and healthy individuals in Southwest Iran. Five millilitres of venous blood samples were collected aseptically from each individual. Sera and buffy coats were isolated from each sample and evaluated for anti-Toxoplasma antibodies and T. gondii DNA using ELISA kit and real-time PCR, respectively. Statistical analysis was performed using SPSS 18 software., Results: Of 64 AIDS/HIV-positive patients, six (9.3%, 95% CI 7.2 to 11.3%) were seropositive for only IgG and five (7.8%, 95% CI 6.0 to 9.5%) were seropositive for both IgG and IgM. Moreover, among 64 healthy controls, 10 (15.6%, 95% CI 12.1 to 19.0%) were seropositive for only IgG and 2 (3.1%, 95% CI 2.4 to 3.7%) were seropositive for both IgG and IgM. Toxoplasma gondii DNA was detected in six samples (9.3%, 95% CI 7.2 to 11.3%) in the AIDS/HIV-positive patients group and eight samples (5.95%, 95% CI 4.6 to 7.2%) in the control group using real-time PCR. Consumption of undercooked meat was documented as an associated risk factor for T. gondii seropositivity in AIDS patients (OR 4.06, 95% CI 0.966 to 17.09; p=0.045)., Conclusions: Our findings showed a lower prevalence of Toxoplasma infection in AIDS/HIV-positive patients vs healthy controls; however, a considerable number of AIDS/HIV-positive patients were also seen to be at risk of toxoplasmosis. Based on the findings, screening and prophylaxis for toxoplasmosis should be implemented for all AIDS/HIV-positive patients in Southwest Iran., (© The Author(s) 2022. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)

Cystic echinococcosis (CE) is a common zoonotic infection in all provinces of Iran, especially in areas where people live on agriculture and animal husbandry. The current cross-sectional population-based study is aimed at determining the seroprevalence of CE in Kavar County, Fars province, southern Iran. Blood samples were collected from 1500 individuals (749 males and 751 females). Anti-hydatid cyst antibodies were detected, using a recombinant B8/1 antigen of Echinococcus graunlosus in an ELISA system. Multivariate logistic regression analysis was used to find out the independent risk factor for CE seropositivity. Anti-hydatid cyst antibodies were detected in the sera of 131 out of 1500 participants, corresponding to a seroprevalence rate of 8.73%. With a statistically significant difference ( p < 0.05), the seroprevalence of hydatid cyst in males and females was 5% and 7%, respectively. Differences in the seropositivity of hydatid cysts were also statistically significant by occupation ( p < 0.05). The seroprevalence of hydatid cyst was significantly higher in the age group of 35-45 years than in other age groups ( p < 0.05). Multivariate logistic regression showed that only age was associated with seropositivity to CE (OR = 2.23, 95% CI: 1.33-3.72). Moreover, there was a statistically significant association between seropositivity to hydatid cysts and underlying diseases such as hypertension ( p = 0.049) and fatty liver ( p = 0.048). The findings of this study indicate that the seroprevalence rate of CE is relatively high in the Fars province, southern Iran, and this high rate of infection is mainly linked to people's jobs and lifestyles., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2022 Ali Reza Safarpour et al.)

This study was conducted to determine the exposure rate of Hepatitis A and Hepatitis E viruses in urban solid waste collectors/sweepers in the south of Iran. The 385 samples (serums) were collected from Shiraz Municipality waste sweepers.. A questionnaire was used to gather data on their demographic and occupational characteristics, as well as their awareness of viral hepatitis disease. The viral seroprevalence was determined by commercial IgG ELISA kit. All participants were male, mean age of 41 ± 8 years. ELISA assay showed that all of them were positive for anti-HAV IgG. Also, 62 out of 385 individuals were positive for anti-HEV IgG. The statistical analysis showed that the frequency of HEV IgG antibody among age groups 20-30, 31-40, 41-50 and >50 years old had an increasing trend, 4.5%, 10.1%, 17.4%, and 36.7%, respectively, indicating age factor significance (p = .001). Based on some investigated factors including the duration of work experience, current and previous jobs, habitation, personal hygiene status, and knowledge on viral hepatitis diseasees/their transmission, there was no statistically significant difference between anti-HEV IgG positive versus negative sweepers. The results indicated a slighty higher frequency of anti-HAV and anti-HEV IgG among sweepers compared to other pre-investigated population. It doesn't seem that garbage collecting/sweeping could be a significant risk factor for HAV and HEV infection.

Background: Toxocariasis is a serious zoonotic helminthic disease caused by the nematodes; Toxocara species., Aim: A cross-sectional study was conducted to determine the seroprevalence of toxocariasis and related risk factors in eosinophilic children referred to the pediatrics hospital of Qazvin province northwest Iran during 2019-2020., Methods: A total of 200 blood samples were collected from eosinophilic children referred to the Qods Pediatrics Hospital. Demographic data, clinical symptoms, and dogs- and soil-contact history were collected. The presence of anti- Toxocara IgG antibody was evaluated by T. canis IgG ELISA kit., Results: Anti- Toxocara IgG antibodies were detected in 14 (7%) of the total eosinophilic children. The seropositive rate of toxocariasis in hyper-eosinophilic children (>1000/mm3) was 15.1%, while the seropositivity was 4.1% in children with eosinophilia status (500-999/mm3). There was a significant association between the eosinophilia rate and seropositivity (P<0.05). Also, seroprevalence in asymptomatic eosinophilic children was 4.4%, while in children with clinical symptoms it was 17.1%. Accordingly, a statistically significant difference was found between clinical symptoms and Toxocara infection (P<0.05)., Conclusion: The prevalence of toxocariasis in eosinophilic children is a serious health problem in the study area. Therefore, serologic evaluation for the diagnosis of Toxocara infection is recommended for eosinophilic children., (© 2022 Pourgholaminejad A et al.)

Purpose: This study aimed to determine the possible association between Toxoplasma gondii infection and COVID-19 outcomes among 133 patients with an RT-PCR-positive test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hospitalized at Imam Khomeini Hospital, Sari, Mazandaran Province, northern Iran, during August to November 2020., Methods: A questionnaire was used to collect baseline data from the patients who were registered to the Iranian National Registry Center for Toxoplasmosis (INRCT). Also, blood samples were taken from each patient for detecting anti-T. gondii antibodies and T. gondii DNA using enzyme-linked immunosorbent assay (ELISA) and conventional-PCR methods, respectively. Variables related to the COVID-19 severity and outcomes were indicated based on multiple multinomial logistic regression models., Results: Of 133 patients enrolled in the INRCT with COVID-19 through RT-PCR, 50 (37.59%), 52 (39.1%), and 31 (23%) suffered from mild, moderate, and severe COVID-19, respectively. 57.1% of the patients who died had severe COVID-19, while among those with other outcomes, only 18.60% had severe COVID-19 (P < 0.05). Anti-T. gondii IgG was detected in 109/133 (81.95%) patients, which was not statistically significant (P > 0.05). Among those with negative and positive anti-T. gondii IgG, 2 (8.30%) and 29 (26.60%) had severe COVID-19, respectively (P > 0.05). T. gondii DNA and anti-T. gondii IgM were not found in any of the patients. Moreover, all deaths occurred in those with moderate or severe COVID-19 and a positive anti-T. gondii IgG., Conclusion: To our knowledge, this is the first registry-based study concerning T. gondii infection among patients with COVID-19. Our data show the high rate of latent T. gondii infection among COVID-19 with different severity. However, there is no significant relationship between latent T. gondii infection and COVID-19 severity and outcomes. Thus, conducting multicenter studies in different geographic regions of the world could offer a better understanding of this relationship., (© 2022. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Rickettsia conorii is the causative agent of Mediterranean spotted fever (MSF) and reports of its geographical distribution are spreading every day. Recently, some cases of the MSF have been reported from Iran. However, little information is available about the MSF epidemiology in Iran. The aim of the current study was to investigate anti-R. conorii IgG seroprevalence among farmers living in the rural regions of Kerman province (in southeastern Iran). In this study, 281 blood samples were collected from farmers in Zarand and Jiroft counties and tested for detection of anti-R. conorii IgG antibodies using the ELISA method. Among the 281 samples, 14 farmers (4.98%, CI 95%; 2.45-7.55%) had anti-R. conorii IgG antibodies. Seroprevalence of MSF in Zarand and Jiroft counties were 4.58% and 5.33%, respectively. The serological evidence of this study indicates the seroprevalence of R. conorii in rural areas of the Kerman province of Iran. So, it is recommended that the Iranian health care system pay attention to the MSF., Competing Interests: Conflict of interest The authors declare that there is no conflict of interest., (Copyright © 2022. Published by Elsevier Ltd.)

Background: Leptospirosis is an important, neglected zoonotic disease that affects people and animals in humid (sub)tropical regions. Wild canines carry the pathogen and may contaminate natural resources which may then act as a source of human infection., Objectives: The study was designed to understand the seroprevalence of leptospirosis among domestic and wild canines in Bojnurd County, Northeast Iran., Methods: A total of 77 serum samples, comprising 29 sera from asymptomatic wild canines [foxes (n = 25) and jackals (n = 4)] and 48 sera from asymptomatic stray dogs, was investigated. Serovars were identified and antibody titres were measured by standard microscopic agglutination test (MAT) using serial serum dilutions., Results: Among all serum samples, 44.1% reacted positively to a Leptospira interrogans serovars. The average percentage of positive reactions was higher in stray dogs than in wild canines although this did not reach statistical significance (55.2% and 37.5%, p = 0.159). Positive reactions with L. i. Pomona, L. i. Australis and L. i. Tarasovi was detected only among jackals and foxes. Among the stray dogs, the highest number of positive sera were for L. i. Grippotyphosa (61.1%) and L. i. Canicola (50%). The highest titre detected was for L. i. canicola (1:1600) in two stray dogs and against L. i. Icterohaemorrhagiae and L. i. Pomona (1:800) in a single jackal., Conclusions: The study revealed that leptospirosis is endemic among various canine species in the North Khorasan Province of Iran. Detailed monitoring of canines is necessary for better understanding the epidemiology of infection in our and other Iranian regions., (© 2022 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

BACKGROUND Hepatitis A is often asymptomatic in children, however it can become a serious disease in adults. For countries that do not have a universal vaccination strategy targeted vaccination for high risk groups is recommended. Health workers could be at a higher risk of infection with hepatitis A virus (HAV) compared to the general population. The aim of this study is to investigate the seroprevalence of hepatitis A among enrolled students in Tehran University of Medical Sciences in 2011. METHODS This study included all students enrolled in Tehran University of Medical Sciences during 2011. We checked serum samples for anti-HAV antibody and participants completed a simple questionnaire. RESULTS From 1864 health sciences students enrolled in Tehran University of Medical Sciences, 1813 samples were analyzed for anti-HAV IgG antibody. The results showed that 970 (53.5%) were seronegative, 722 (39.8%) were seropositive, and 121 (6.7%) were equivocal. There were significantly higher seropositive results for males (54%) compared to females (37%; RR = 1.46; 95% CI: 1.31-1.62). CONCLUSION The seroprevalence of HAV among enrolled medical science students is considerably lower than previous reports from Iran. Targeted vaccination for health sciences students prior to exposure should be seriously considered. [ABSTRACT FROM AUTHOR]

This study was performed to determine the prevalence and risk factors of hepatitis E virus (HEV) infection among thalassemia patients. All β-thalassemia major patients on regular blood transfusion attending the blood transfusion centers located in southern Iran were invited to participate in this study. ELISA was used to detect anti-HEV IgM and anti-HEV IgG antibodies. The molecular detection of HEV infection was performed by nested RT-PCR assay, targeting the ORF2 region of HEV genome, and sequencing. In this study, 16.67% of thalassemia patients were positive for anti-HEV IgG compared to 12.1% of the controls. Thalassemia patients were negative for anti-HEV IgM and HEV viremia. Patients with blood transfusion every two weeks had significantly higher anti-HEV IgG seroprevalence compared to the patients with blood transfusions at longer intervals (OR: 12.50; 95% CI: 1.76-88.74; P = .012). Anti-HEV IgG seroprevalence was not statistically associated with age, gender distribution, ethnicity, place of residency, education level, and serum levels of liver enzymes. This study reports a high seroprevalence of HEV among thalassemia patients, while frequency of blood transfusion was significantly associated with anti-HEV IgG seropositivity. This suggests that frequent blood transfusion may be a risk factor for exposure to HEV infection among thalassemia patients.

Human toxocariasis (HT) is one of the most prevalent zoonotic diseases with a worldwide distribution. There is no epidemiological study showing the seroprevalence of toxocariasis among children in southwest Iran, Khuzestan Province. Accordingly, this study was designed to estimate the seroprevalence of Toxocara canis (T. canis) IgG antibodies in children (2-15 years old) and assess the main risk factors associated to human infection. In this cross-sectional study, a total of 259 children were invited to participate from the southwest Iran (Abadan and Khorramshahr cities, Khuzestan Province) between April to August 2021. Serum anti-T. canis IgG antibodies were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was also employed to collect some socio-demographic information and probable risk factors associated to T. canis infection. The overall seroprevalence rate of T. canis in children was 7.3% (95% CI = 4.75 - 11.17%). The univariate analysis demonstrated that living in rural communities (P < 0.001), drinking unpurified water (P < 0.001), contact with cat (P = 0.033), consumption of improperly washed vegetables (P = 0.002), and history of drinking water from unsafe sources (P = 0.003) were risk factors associated with T. canis seroprevalence in children. However, after adjusting for confounders, multivariable logistic regression analysis verified that only drinking unpurified water (P = 0.016) remained a significant risk factor. In addition, both univariate (P = 0.032) and multivariate logistic regression analysis (P = 0.037) revealed that seropositivity of T. canis infection was significantly associated with asthma. The current report provides beneficial baseline epidemiological findings regarding the seroprevalence of T. canis in children as a vulnerable group for this infection. This data can be used by health policy makers to plan effective prevention programs and control this neglected infection among high risk subjects., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

We carried out a study to determine the seroprevalence of HBV and HCV infections in HIV positive patients at a main referral center for HIV/AIDS in Iran. Serum samples from 201 HIV positive patients referring to a referral center for HIV/AIDS were analyzed for the presence of some hepatitis B (HBsAg, anti-HBc, anti-HBs) and Hepatitis C (anti-HCV) markers, during 2004- 2005. HBsAg was positive in 27 patients (13.4%), anti-HBc was positive in 60 patients (29.8%) and anti-HBs in 23 patients (11.4%). Anti-HCV Ab was positive in 135 of 201 (67.2%). HBV and HCV coinfection was observed in 73 of 201 (36.3%). The maximum prevalence of HBV-HIV and HCV-HIV coinfections were seen in intravenous drug users; 61.2% and 85.1%, respectively (P<0.0001). The minimum prevalence of HBV-HIV and HCV-HIV were seen in HIV patients' wife (HIV+ patients who were infected by monogamous sexual contact with their HIV positive husband) both of them were 8% (P<0.0001). This study showed that HBV-HIV and HCV-HIV coinfections are significant in patients with HIV/AIDS in Iran. A greater relevance was observed in the association between HCV and HIV. This study suggests that it is necessary to investigate risk factors and risk groups for these infections in Iran. [ABSTRACT FROM AUTHOR]

Background: Brucellosis is a major zoonosis worldwide. Many people for their professions are at higher risk of contracting the disease. Objective: To determine the seroprevalence of brucellosis and its risk factors in a group of high risk professions. Methods: In a cross-sectional study, all personnel or students of veterinary schools, slaughters and butchers working in the city were invited to participate (n=141). A comparison group (n=44) randomly selected from patients who were selected at random from people attended our healthcare center for reasons other than the infectious diseases. Results: 4 veterinarians, 15 veterinary assistants, 42 veterinarian students, 52 butchers, 17 slaughters, 8 slaughterhouse workers and 3 chefs made the first group and 14 storekeepers, 5 students of engineering, 11 clerks, 13 freelance workers, and 1 high school student made the comparison group. While the rate of consumption of most of the studied dairy products was almost similar in both groups, comparison group patients consumed more often milk (p<0.001) and cream (p<0.001) than the high risk group. 11 (7.8%; 95% CI: 3.4%-12.2%) cases from high risk group and none of the comparison group were found seropositive for Brucella. Conclusion: Profession is the main factor in seropositivity. Consumption of dairy products and raw milk is not associated with a higher risk of seropositivity. [ABSTRACT FROM AUTHOR]

Background: In older studies, the seroprevalence of hepatitis A virus infection has been reported to be over 95% in Iranians. Most of these studies were performed on volunteer blood donors. Studies on the general population are sparse. The purpose of this study was to determine the current seroprevalence of hepatitis A virus infection in the general population of Iran. Methods: During 2006, 1869 subjects between 18 and 65 years of age were randomly selected from the general population of three Iranian provinces (Tehran, Golestan, and Hormozgan). Subjects were interviewed and a plasma sample was obtained for serologic testing for antihepatitis A virus. Univariate and multivariate analysis was performed to identify risk factors. Results: The seroprevalence of hepatitis A virus in Tehran, Golestan and Hormozgan was 85%, 99%, and 96%, respectively. The overall seroprevalence of hepatitis A virus in the general population of the three provinces studied was 86% and did not differ between the two genders. The prevalence in younger subjects and in urban populations was under 70%. In multivariate analysis, older age, being married, and level of the father's education was associated with hepatitis A virus seropositivity. Conclusion: The seroprevalence of hepatitis A virus still appears to be too elevated for recommending routine vaccination in the general population. However, the trend towards a lower prevalence in younger age groups and people from urban areas points towards the possible benefit of vaccination in these subgroups. [ABSTRACT FROM AUTHOR]

The transmission dynamics and burden of SARS-CoV-2 in many regions of the world is still largely unknown due to the scarcity of epidemiological analyses and lack of testing to assess the prevalence of disease. In this work, we develop a quantitative framework based on excess mortality data to reconstruct SARS-CoV-2 transmission dynamics and assess the level of underreporting in infections and deaths. Using weekly all-cause mortality data from Iran, we are able to show a strong agreement between our attack rate estimates and seroprevalence measurements in each province and find significant heterogeneity in the level of exposure across the country with 11 provinces reaching near 100% attack rates. Despite having a young population, our analysis reveals that incorporating limited access to medical services in our model, coupled with undercounting of COVID-19-related deaths, leads to estimates of infection fatality rate in most provinces of Iran that are comparable to high-income countries., (© 2022. The Author(s).)

Background: The first large serosurvey in Iran found a SARS-CoV-2 antibody seroprevalence of 17.1% among the general population in the first wave of the epidemic by April, 2020. The purpose of the current study was to assess the seroprevalence of COVID-19 infection among Iranian general population after the third wave of the disease., Methods: This population-based cross-sectional study was conducted on 7411 individuals aged ≥10 years old in 16 cities across 15 provinces in Iran between January and March, 2021. We randomly sampled individuals registered in the Iranian electronic health record system based on their national identification numbers and invited them by telephone to a healthcare center for data collection. Presence of SARS-CoV-2-specific IgG and IgM antibodies was assessed using the SARS-CoV-2 ELISA kits. The participants were also asked about their recent COVID-19-related symptoms, including cough, fever, chills, sore throat, headache, dyspnea, diarrhea, anosmia, conjunctivitis, weakness, myalgia, arthralgia, altered level of consciousness, and chest pain. The seroprevalence was estimated after adjustment for population weighting and test performance., Results: The overall population-weighted seroprevalence adjusted for test performance was 34.2% (95% CI 31.0-37.3), with an estimated 7,667,874 (95% CI 6,950,412-8,362,915) infected individuals from the 16 cities. The seroprevalence varied between the cities, from the highest estimate in Tabriz (39.2% [95% CI 33.0-45.5]) to the lowest estimate in Kerman (16.0% [95% CI 10.7-21.4]). In the 16 cities studied, 50.9% of the seropositive individuals did not report a history of symptoms suggestive of COVID-19, implying an estimation of 3,902,948 (95% CI 3,537,760-4,256,724) asymptomatic infected individuals., Conclusions: Nearly one in three individuals were exposed to SARS-CoV-2 in the studied cities by March 2021. The seroprevalence increased about two-fold between April, 2020, and March, 2021., (© 2022. The Author(s).)