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Objectives: Canine dirofilariasis is a mosquito borne zoonotic filarial parasitic disease caused by Dirofilaria species. In Sri Lanka, human dirofilariasis is endemic and well documented. Even though canine dirofilariasis is an established infection among dog populations in Sri Lanka, the prevalence and risk factors were not documented in Kanthale divisional secretariat, Eastern Province of Sri Lanka. Therefore, the main objective of this study is to determine the prevalence of dirofilariasis and to identify the exposure-related risk factors in dogs using an interviewer administered questionnaire in Kanthale divisional secretariat., Results: Out of 162 blood samples collected from dogs, 47.5% (n = 77/162) were positive for the presence of microfilariae by direct smear. Of 162 samples 58.6% (n = 95/162) were molecularly identified as D. repens. Species-specific primer pair DIR3/DIR4 that amplified 5S rRNA was used. The current study observed a significant association between mongrels and canine dirofilariasis (p = 0.049), where 61.3% (n = 95) out of 155 mongrels showed PCR positivity. This study showed no significant association between the occurrence of dirofilariasis and the age, sex, rearing method, presence or absence of skin rash, and stray or domestic dogs. Dirofilaria immitis was not identified in direct smear test and PCR., (© 2022. The Author(s).)

Background: Cytokines play a vital role in the host immune response to infection by initiating the healing process and/or accelerating the progression of the disease in cutaneous leishmaniasis (CL). Very little evidence is available on cytokine profiles and their regulatory function in CL patients in Sri Lanka. The aim of this study was to determine the cytokine expression pattern of IFN-γ, IL-4, IL-11 and IL-12p40 in CL patients and in healthy volunteers. Patients with suspected CL lesions attending to the Dermatology Clinic at the Anuradhapura Teaching Hospital were included in the study. Reverse transcription real time polymerase chain reaction (real-time RT-PCR) was performed to determine the relative expression level of target cytokines. Expression levels were quantified by 2 - ∆∆CT equation., Results: The expression of cytokines IFN-γ, IL-4, IL-11 and IL-12p40 were significantly higher in CL patients compared to healthy volunteers (p <  0.05). There was a significant association between the expression of IFN-γ and the duration of the lesion (p = 0.021). Wet CL lesions showed significantly higher expression of IL-4, IL-11 and IL-12p40 (p = 0.039, 0.018 and 0.021 respectively) compared to dry lesions. Papulo-nodular lesions showed significantly high expression of IFN-γ (p = 0.023). However, cytokine expression was not significantly associated with the number, size and the locations of lesions., Conclusions: The expression levels of all cytokines tested in the present study were significantly (p <  0.05) high in CL patients. Th1 response (IFN-γ and IL-12p40) had higher expression levels compared to Th2 (IL-4) and IL-11 in CL patients.

Background: Leishmaniasis, a vector borne tropical/subtropical disease caused by the protozoan Leishmania is transmitted to humans by sandfly vectors Phlebotomus and Lutzomyia. The principal form found in Sri Lanka is cutaneous leishmaniasis (CL) and is caused by Leishmania donovani. A rising trend in disease prevalence has been observed recently in Sri Lanka and the island is in fact the newest endemic focus in South Asia. Determining the prevalence of smear positivity among clinically suspected CL patients, identifying risk factors and specific clinical presentations of CL in order to implement preventive and early treatment strategies were the objectives of this study., Methods: A sample of 509 clinically suspected cases of CL referred to the Department of Parasitology from all across Sri Lanka between 2005 and 2015 was selected consecutively. Diagnosis was confirmed by microscopic visualization of the Leishmania amastigote from the slit skin smear. A structured questionnaire was used to identify exposure related risk factors and a clinical examination was performed to identify lesion characteristics., Results: Out of 509 clinical cases, 41.5% (n = 211) were smear positive. The study population ranged from ages 1 to 80 years (mean age = 34.76) and the most affected age group was 40-49. Of the smear positives, 58.85% were males. Majority (47.86%) were from the North Western region (Kurunegala) of the country and were exposed to scrub jungles. Sand fly exposure (p = 0.04) and positive contact history (p = 0.005) were significant risk factors for smear positivity. Erythema (p = 0.02), lack of pruritus (p = 0.02) and scaly appearance (p = 0.003) were significant lesion characteristics in smear positivity. Lesions were commonly found in the exposed areas and the commonest morphological type was papulo-nodular., Conclusions: An increasing trend in the spread of cutaneous leishmaniasis from endemic to non-endemic areas has become evident. Positive contact history and sandfly exposure were significant risk factors for smear positivity which may indicate the possibility of human reservoir hosts in infection transmission. Lack of pruritus, scaly appearance and erythema were highly significant lesion characteristics associated with Leishmania positive smears which can be used for the clinical diagnosis of CL.

Background: Ascaris lumbricoides infections are one of the commonnest intestinal nematode infections in the world, with a profound negative effect on nutritional status among underprivileged populations. In Sri Lanka, Ascaris infections and low nutritional status still persist in the plantation sector. However, research regarding the association between Ascaris infections and nutritional status is scarce. The main purpose of this study was to determine the association between Ascaris infections and physical growth among children in a plantation sector in Sri Lanka., Methods: A cross sectional study was conducted among 489 children aged between 1 and 12 years ina plantation sector, Sri Lanka, from January to April 2013. Anthropometric measurements were collected to assess height-for-age (HAZ), weight-for-age (WAZ) and weight-for-height (WHZ) to determine stunting, underweight and wasting respectively. Data on socio-demographic and antihelminthic treatment were ascertained using an interviewer administrated structured questionnaire. Stool samples were subjected to wet mount preparation followed byformaldehyde-ether sedimentation technique to diagnose Ascaris infection and a Kato Katz technique was performed to determine the eggs intensity. AnthroPlus, EpiInfo and SPSS software was used to analyze data., Results: Of the study sample, 38.4% showed Ascaris lumbricoides infections. Light intensity infections (51%) were common in the infected children, followed by moderate (30%) and heavy (19%) infections. Prevalence of Ascaris infections was significantly associated with de-worming more than six months prior to the study. Prevalence of undernutrition among children was 61.7%. Forty-five per cent were underweight, while 24.1% and 21.5% of children were stunted and wasted respectively. However, no significant association was found between Ascaris infections status and undernutrition. Meanwhile, heavy intensity infections were associated with decreased values of WHZ (p = 0.020)., Conclusions: Ascaris infections and undernutrition are still highly prevalent and a major public health problem in the plantation sector in Sri Lanka. Health and nutrition intervention programs should be implemented to increase the nutritional status of children.

Background: Leishmaniasis is listed as one of the eight neglected tropical diseases by the World Health Organization and the number of cases in endemic areas has seen a sharp rise in the past decade. More alarmingly, reports have shown that leishmaniasis is spreading to non-endemic areas of the world due to co-infection with HIV. In Sri Lanka, leishmaniasis is considered as a notifiable disease from 2008 and has seen a rising trend of incidence since then. This is the first study describing the burden, seasonal variation and spatial distribution of leishmaniasis in Sri Lanka since the disease has been included as a notifiable disease., Methods: Data on health statistics from 2009 to 2016 were obtained from published databases maintained by the Epidemiology Unit of the Ministry of Health in Sri Lanka. Climatic data for Sri Lanka were obtained from the Department of Meteorology and the populations in administrative districts were obtained from the Department of Census and Statistics, Sri Lanka. Descriptive spatiotemporal analysis, correlation between leishmaniasis incidence and climatic variables were analyzed using SPSS statistical software., Results: The total number of people reported with leishmaniasis during the study period was 8487. Cutaneous leishmaniasis is the prominent form in Sri Lanka while few visceral and muco-cutaneous cases were reported. Although leishmaniasis patients were identified from all 25 districts in the island, almost 90% of the total caseload was reported from Anuradhapura, Hambantota, Polonnaruwa, Kurunegala and Matara districts. The highest number of patients was reported from the Anuradhapura district and the highest incidence per 100,000 persons was reported from the Hambantota district. The disease has a seasonal trend, a peak of leishmaniasis occur in July to September in the north-central region and in October to December in the southern region. Maximum temperature, humidity and wind speed are significantly associated climatic variables with leishmaniasis in endemic regions., Conclusions: Leishmaniasis is an emerging public health problem in north-central and southern Sri Lanka. Public awareness programs for the prevention and control of the disease in endemic regions are essential to reduce the incidence of leishmaniasis.

Background: Clinically diagnosed amoebic liver abscess (ALA) caused by Entamoeba histolytica has been an important public health problem in Jaffna district, northern Sri Lanka for last three decades. In order to draw up a control strategy for elimination of this condition, knowledge of its epidemiology and factors associated with this condition in the local context is vital., Methods: All clinically diagnosed ALA patients admitted to the Teaching Hospital, Jaffna during the study period were included in the study and the data were collected using an interviewer administered questionnaire. One hundred blood samples from randomly selected toddy (a local alcoholic drink consisting of the fermented sap of the Palmyrah palm) consumers and 200 toddy samples were collected. Toddy samples were cultured in Robinson's medium to establish the presence of Entamoeba histolytica in the sample. Climatic data and the total toddy sales in the district were obtained from the Meteorological and Excise Departments respectively. A sub group of randomly selected 100 patients were compared with 100 toddy consumers who were negative for E. histolytica antibody to explore the potential risk factors., Results: Between July 2012 and July 2015, 346 of 367 ALA patients were enrolled in this study. Almost all patients (98.6%) were males with a history of heavy consumption of alcohol (100%). Almost all (94.2%) were within the age group 31-50 years. None of the cultured toddy samples grew E. histolytica. The monthly incidence of disease peaked in the dry season, matching the total toddy sales in the district. Age, type of alcohol and frequency of drinking were identified as potential risk factors whereas frequency of alcohol consumption and type of alcohol (consuming toddy and arrack) were identified as the independent risk factors. Moreover, the knowledge, attitude and practices towards ALA were poor among participants and the control group., Conclusions: Though the number of cases has declined in recent years, ALA still remains as an important public health problem in Jaffna district. The transmission route of E. histolytica leading to ALA has to be further explored. Moreover, greater awareness among the public who are at risk would be beneficial in order to eliminate the disease.

Background: Toxoplasma gondii is an intracellular protozoan infecting humans and animals. Infection in adults usually causes mild disease but greater importance lies in preventing transplacental transmission which can cause major foetal anomalies and is vital to identify infection in pregnancy. Research on this regard in Sri Lanka is scarce and would be beneficial in developing antenatal care strategies for improved foetal outcome., Methods: A random sample of 536 pregnant women attending antenatal care in Teaching Hospital Peradeniya from 2010 to 2013 was recruited for this study. Blood samples were tested for Toxoplasma gondii IgG and IgM antibodies from the participants by using a commercial ELISA kit with a cut-off OD value of >1 and a structured questionnaire was used to identify the exposure to risk. Bivariate analysis using the Chi Square test was used to calculate associations between documented risk factors and seropositivity and a p value of <0.05 was taken as significant., Results: Among the participants 160 (29.9%) were positive for T. gondii IgG antibodies and 2 (0.37%) were IgM positive. The seroprevalence in the first, second and third trimesters were 30.4%, 30.6% and 26.1% respectively. Of the risk factors studied, preparation and selling raw meat (p = 0.05) and household gardening (p = 0.01) were significant whereas the presence of domesticated cats and dogs, eating locally produced meat or dairy products did not show significant associations., Conclusions: Seroprevalence of T. gondii present among pregnant women attending antenatal care in Peradeniya was 29.9% indicating high level of transmission among the study population. However 70.1% of the study population were seronegative and were susceptible to primary acute infection during pregnancy and possible foetal anomalies. Therefore implementing health education especially on the aforementioned risk factors is recommended.

Background: Child malnutrition is a major public health concern worldwide, leading to higher morbidity and mortality. It is mostly preventable through public health and economic development. The aim of the present study was to determine socio-economic factors associated with nutritional status among children in plantation communities, Sri Lanka., Methods: A cross-sectional study was performed among preschool and school going children in three rural communities of Sri Lanka from January to August 2014. Demographic and household characteristics were documented and anthropometric measurements were collected to calculate weight-for-age (WAZ), height-for-age (HAZ) and BMI-for-age (BAZ). Anthroplus, epiinfo and SPSS versions were used for the analysis of data., Results: A total of 547 children (aged 1-15 years, mean 7.0 ± 3.6 years, 53% female) participated in the study. 35.6%, 26.9% and 32.9% of children were underweight, stunting and wasting respectively. Undernutrition was more common in primary school children. Maternal employment, high number of siblings, high birth orders and female children were significantly associated with undernutrition among preschool children. Living in small houses, large number of family members, low monthly income and maternal employment were significantly associated with undernutrition among school children., Conclusions: Child undernutrition is a major public health concern in the plantation sector, Sri Lanka. Health education programs among the study population could be effective for solving the problem.

Background: Human toxocariasis, caused by Toxocara canis, T. cati, and T. vitulorum of dogs, cats and ruminants respectively, is recognized as an important zoonotic infection worldwide. The typical clinical syndromes of toxocariasis in humans are ocular larva migrans (OLM) and visceral larva migrans (VLM). The most commonly affected sites of OLM are the peripheral retina and/or vitreous humor. In Sri Lanka, there is a dearth of information on prevalence of ocular infection in our population. Therefore, the present study was carried out to determine the prevalence of Toxocara antibodies in suspected OLM patients and to describe demographic factors and clinical manifestations of seropositive patients. A total of 250 clinically suspected ocular toxocariasis cases referred by consultant eye surgeons to the Department of Parasitology, University of Peradeniya were studied between the years 1995 to April 2015., Methods: Data (age, sex, fundoscopic findings) were gathered from the referral letters. Each serum sample was subjected to Toxocara excretory - secretory antigen ELISA (TES - ELISA)., Results: Out of the 250 cases, 155 (62%) were seropositive. The age range of the seropositive cases was 1 to 78 years with the mean age of 27 years. The highest seropositivity (25/155) was observed within the age group of 10 to 14 years. The most frequent clinical presentation of seropositive OLM cases were unilateral reduced vision and red eye. The other symptoms include tearing, photophobia and leukokoria. A high proportion of seropositive OLM cases had uveitis (34.19%) followed by reduced vision (21.94%), vitritis (12.9%) and choroiditis (7.74%). However none of these clinical manifestations were significantly associated with TES-ELISA seropositivity except vitreits (X 2  = 8.557, p = 0.003)., Conclusion: In conclusion, the results of this study showed high seroprevalence of toxocariasis among clinically suspected OLM cases confirming the toxoplasmic etiology. This high rate of Toxocara seropositivity in ocular patients should alert ophthalmologists in Sri Lanka to include toxocariasis in the differential diagnosis of ocular diseases presented with the symptoms and signs stated above.