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Background Application of chemotherapeutics in cancer patients may provide an immunosuppressive milieu, favourable for parasitic infections. Giardia duodenalis is an important zoonotic intestinal parasite responsible for diarrhoea in humans worldwide. Methods The present systematic review and meta-analysis was conducted to estimate the prevalence of G. duodenalis and respective odds ratios (ORs) in cancer patients around the globe. Four online databases—PubMed, Scopus, Web of Science and Google Scholar—were carefully explored for relevant literature without time limitation until 28 November 2020. Meta-analysis was done based on a random effects model to pool the estimations and define 95% confidence intervals (CIs). Results The overall weighted prevalence of G. duodenalis infection in cancer patients was calculated to be 6.9% (95% CI 0.5 to 9.3) globally, based on data from 32 studies. Although not statistically significant, eight case–control studies revealed that cancer patients were 1.24 times (95% CI 0.66 to 2.31; p=0.501) more exposed to G. duodenalis infection than healthy controls. Moreover, the prevalence of infection was not significantly associated with quantitative variables, including publication year (regression coefficient −0.0135, p=0.578), sample size (regression coefficient −0.0007, p=0.074) and human development index (regression coefficient −1.6263, p=0.419). Also, subgroup analysis of the pooled G. duodenalis infection was performed for publication year, World Health Organization regions, countries, continents, cancer types and country income. Conclusions Altogether, the epidemiology of G. duodenalis infection and its associated risk factors in immunocompromised individuals, especially cancer patients, is still open to question and deserves comprehensive investigations. [ABSTRACT FROM AUTHOR]

Infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), is one of the most important respiratory diseases in poultry. The implementation of preventive measures, including vaccination and biosecurity, is necessary for controlling the disease. To maintain biosecurity, it is important to identify the entry route of new viruses into a region and characterizing markers such as unique mutations that make viruses traceable. During a genotyping study for IBV infected commercial chicken flocks in Khorasan Razavi province, 11 viruses from 11 broiler and layer chicken flocks were detected in different cities by PCR. Sequencing of the S1 partial gene followed by phylogenetic analysis showed that eight viruses can be classified in GI-23 lineage (Is-Variant2), two viruses are classified in GI-1 lineage (Mass), and one virus is classified in GI-12 lineage (793B). Although detected viruses of GI-23 lineage are originated from Iran, seven viruses have synonymous (T954C and G1056A) and non-synonymous (C797T) mutations that have not been previously reported. It was found that the new genetic changes in Iranian IBVs of GI-23 lineage occurred in two different regions in Khorasan Razavi. In conclusion, this study indicates that the high prevalence of GI-23 lineage viruses in Iran may enhance the chance of virus mutations and the emergence of new viral strains, so effective vaccination and biosecurity measures are required to control the virus spread. [ABSTRACT FROM AUTHOR]

The intestinal parasite Blastocystis sp. is a widely distributed protist among humans and various animal hosts, with significant prevalence in developing countries. Due to the zoonotic nature of its subtypes (STs), we aimed at global estimation of the prevalence, STs distribution, zoonotic potential, and associated risk factors of Blastocystis sp. infection in domestic pigs (Sus domesticus) and wild pigs/wild boars (Sus scrofa). The study was designed and conducted in 2021 via searching articles in PubMed, Scopus, Google Scholar, and Web of Science databases, based on the PRISMA checklist, and meta-analysis was done using a random-effects model to calculate the weighted estimates and 95% confidence intervals (95% CIs). Totally, 43 papers (47 datasets) reported data on 7977 examined pigs in 24 countries with a total prevalence of 50.9% (95% CI: 42.8–59%). In details, prevalence was higher among domestic pigs [52.4% (95% CI: 43.9–60.7%)] than wild boars [31.2% (95% CI: 11.2–62%)], but is poorly statistically supported as far as the CIs largely overlap. Out of 28 reported STs, nine (ST1-ST7, ST10, and ST15) were reported from domestic pigs, while six (ST1, ST3-ST5, ST8, and ST15) had been isolated from wild boars. Among nine zoonotic STs (ST1-ST8, and ST12), all were identified in examined swine populations, except for ST12. As well, ST1 and ST5 were probably the most frequently circulating STs among these animals. In addition, male and older pigs showed higher Blastocystis sp. infection. Altogether, Blastocystis epidemiology and the distribution of its related STs in pigs is still open to question and requires more extensive studies, especially in the neglected regions of the world. • The total prevalence of Blastocystis sp. infection in swine populations was 50.9% (95% CI: 42.8–59%). • The pooled frequency was higher among domestic pigs [52.4% (95% CI: 43.9–60.7%)] than wild boars [31.2% (95% CI: 11.2–62%)], but is poorly statistically supported as far as the CIs largely overlap. • Nine STs (ST1-ST7, ST10, and ST15) were reported from domestic pigs, while six STs (ST1, ST3-ST5, ST8, and ST15) had been isolated from wild boars. • Among nine zoonotic STs (ST1-ST8, and ST12), all were identified in examined swine populations, except for ST12. • Male and older pigs showed higher Blastocystis sp. infection. [ABSTRACT FROM AUTHOR]