Journal/Magazine Articles
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This collection contains original research articles, review articles and case reports published in local and international peer reviewed journals by the staff members of the Faculty of Medicine
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Item The use of recombinant K39, KMP11, and crude antigen-based indirect ELISA as a serological diagnostic tool and a measure of exposure for cutaneous leishmaniasis in Sri Lanka(Springer International, 2024) Karunathilake, C.; Alles, N.; Dewasurendra, R.; Weerasinghe, I.; Chandrasiri, N.; Piyasiri, S.B.; Samaranayake, N.; Silva, H.; Manamperi, N.; Karunaweera, N.Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani, a parasite widely known to cause visceral leishmaniasis. Despite the fact that CL is not generally believed to elicit serological immune responses, recent studies show the presence of antibody responses against this atypical form of CL. This study assesses the potential of using recombinant K39 (rK39), KMP11, and crude parasite antigen-based indirect ELISAs as serological diagnostic tools and measures of exposure for CL in Sri Lanka. The study used serum samples from confirmed CL patients (n = 266) and apparently healthy individuals from endemic settings (n = 411). Serum samples from individuals residing in non-endemic areas were used as negative controls. In-house indirect ELISAs were optimized and validated for recombinant antigens. Previously validated crude parasite extract-based indirect ELISA was performed for comparison. The statistical analyses were performed using SPSS v26.0. The rK39 (sensitivity = 71.2%, specificity = 64%) and KMP11 (sensitivity = 79.2%, specificity = 71.4%) based indirect ELISA were shown to be less suitable for the diagnosis of CL, while crude parasite extract-based indirect ELISA (sensitivity = 82.4%, specificity = 85.7%) might be a better method of diagnosis. All 03 ELISAs seemed to be good methods as measures of exposure since correlations were observed between the seropositivity of all 03 ELISAs (rK39: p = 0.037, KMP11: p = 0.007, CrudeAg: p = 0.000) with provincial case incidences. The findings will be important in identifying the disease hotspots in order to design the control measures for CL induced by L. donovani in Sri Lanka.Item The establishment of a population-specific reference value for the ruler drop test for the clinical assessment of reaction time(Elsevier, 2023) Rajapaksha, S.; Kitulwatte, I.; Senarathne, U.; Edirisinghe, A.; Perera, P.BACKGROUND: Reaction time (RT) is the interval between a stimulus and an appropriate voluntary response in an individual. Alcohol is known to result in delayed RT. In Sri Lanka, an alleged drunken driver is legally subjected to a medico-legal examination to confirm or exclude impairment. The guideline for examining a drunk person in Sri Lanka includes the ruler drop test (RDT) as a test of RT. RDT is a simple test of visual reaction time in which the subject attempts to stop a falling ruler, and the height fallen is used to determine the time taken to react to the event. However, a formal study has yet to be carried out to establish population-specific reference values to interpret RDT results. METHODS: A cross-sectional descriptive study was conducted using 903 adults ≥18 years. A nonparametric approach was applied for deriving the reference values based on an inter-percentile interval. RESULTS: The study population consisted of 56.6% females, and the mean age of the participants was 41.6 years. Most (95%) of the study population could catch the ruler at or less than 40.0 cm of average height. The average height on RDT increased from younger to older age groups. However, subgrouping based on other variables, including sex, age, and alcohol consumption, did not show any statistically significant difference. CONCLUSIONS: The population-specific cut-off limit to identify alcohol intoxication by RDT in a Sri Lankan adult is 'average height' >40 cm.Item Double-trouble: A rare case of co-infection with melioidosis and leptospirosis from Sri Lanka(Sage, 2023) Gunasena, J.B.; de Silva, S.T.Melioidosis and leptospirosis are two emerging tropical infections that share somewhat similar clinical manifestations but require different methods of management. A 59-year-old farmer presented to a tertiary care hospital with an acute febrile illness associated with arthralgia, myalgia and jaundice, complicated by oliguric acute kidney injury and pulmonary haemorrhage. Treatment was initiated for complicated leptospirosis but with poor response. Blood culture was positive for Burkholderia pseudomallei and microscopic agglutination test (MAT) for leptospirosis was positive at the highest titres of 1:2560, confirming a co-infection of leptospirosis and melioidosis. The patient made a complete recovery with therapeutic plasma exchange (TPE), intermittent haemodialysis and intravenous (IV) antibiotics. Similar environmental conditions harbour melioidosis and leptospirosis, making co-infection a very real possibility. Co-infection should be suspected in patients from endemic areas with water and soil exposure. Using two antibiotics to cover both pathogens effectively is prudent. IV penicillin with IV ceftazidime is one such effective combination.Item Community perceptions on intimate partner violence: A qualitative study from Sri Lanka(SAGE Publications, 2023) Reyal, H.P.; Perera, M.N.; Guruge, D.Although plenty of research is conducted to explore the causes of intimate partner violence (IPV), findings are inadequate about the community members' perceptions on IPV. This qualitative study was conducted in a health administrative area of Sri Lanka to explore IPV as perceived by community members in terms of what is IPV, what causes IPV, and what are the responses to prevent IPV. Five focus group discussions and 11 in-depth interviews were conducted with 34 women and eight men. Data were thematically analyzed, and a model on community perception of IPV was developed. It incorporated the individual, relationship, community, and societal levels of the existing ecological framework on causes of interpersonal violence. Perceived apparent and underlying determinants were operating directly and indirectly with complex interactions for the occurrence and continuation of IPV. Pathways of preventing or responding to IPV were identified. Findings on determinants can be incorporated into IPV interventions.Item The epidemiological trend of cutaneous leishmaniasis in Kegalle district, Sri Lanka: A newly established disease focus and assessment of bioclimatic suitability for disease establishment using ecological niche modelling(Elsevier, 2023) Wijerathna, T.; Wickramasinghe, K.; Gunathilaka, N.; Perera, A.; Bandara, S.Cutaneous leishmaniasis is prevalent in Sri Lanka since 1992. It remains as a health issue with increasing numbers and spreading from endemic to non-endemic areas in the county. Kegalle district is a new disease focus, which notified the first case in 2016. However, there is no documented evidence of the vector distribution, abundance and potential risk factors in this district. Two Medical Officer of Health (MOH) areas (Rambukkana and Warakapola) that had reported the highest numbers of cases in the Kagalle district was selected and recorded cases (2016-2020) were obtained. The patients were visited and socio-economic, demographic, environmental and awareness-related information was collected using an interviewer-administered questionnaire. Entomological surveys were conducted from July 2019- July 2020 using three standard entomological techniques. Bioclimatic suitability for the disease transmission was evaluated using ecological niche modelling. A total of 107 patients were reported from both MOH areas and 88 were recruited for the study. The study showed that leishmaniasis in the Kegalle district progressed to an outbreak level within 3 years after reporting the first case. School students (n = 22, 25%, P < 0.05) and individuals between 11 and 20 years of age (n = 33, 37.5%, P<0.05) were identified as the main risk groups, while the presence of composting sites (n = 65, 73.9%, P < 0.05), abandoned lands (n = 63, 71.6%, P < 0.05) in the surrounding and suboptimal (dark or normal) lighting conditions (n = 87, 98.8%, P < 0.05) in the house were identified as main risk factors. Areas closer to the adjacent district (Kurunegala), which is a known endemic district for leishmaniasis indicated a high probability (0.3-0.5) for disease transmission. Sergentomyia zeylanica (n = 164, 56.94%), was identified as the predominant sand fly species followed by Phlebotomus argentipes (n = 121, 42.01%), Sergentomyia babu insularis (n = 2, 0.69%) and Sergentomyia punjabensis (n = 1, 0.35%). Phlebotomus argentipes was captured mostly for outdoor resting sites and S. zeylanica was recoded from both indoor and outdoor. The presence of vectors that can transmit leishmaniasis in these areas along with the potential risk factors could increase the transmission risk and disease establishment in new areas that are ecologically favourable for disease transmission. Therefore, vector control entities should undertake immediate measures to stop spreading the disease into new areas.Item Alpha thalassaemia and extended alpha globin genes in Sri Lanka(Elsevier-Academic Press, 2013) Suresh, S.; Fisher, C.; Ayyub, H.; Premawardhena, A.; Allen, A.; Perera, A.; Bandara, D.; Olivieri, N.; Weatherall, D.The α-globin genes were studied in nine families with unexplained hypochromic anaemia and in 167 patients with HbE β thalassaemia in Sri Lanka. As well as the common deletion forms of α(+) thalassaemia three families from an ethnic minority were found to carry a novel form of α(0) thalassaemia, one family carried a previously reported form of α(0) thalassaemia, --(THAI), and five families had different forms of non-deletional thalassaemia. The patients with HbE β thalassaemia who had co-inherited α thalassaemia all showed an extremely mild phenotype and reduced levels of HbF and there was a highly significant paucity of α(+) thalassaemia in these patients compared with the normal population. Extended α gene arrangements, including ααα, αααα and ααααα, occurred at a low frequency and were commoner in the more severe phenotypes of HbE β thalassaemia. As well as emphasising the ameliorating effect of α thalassaemia on HbE β thalassaemia the finding of a novel form of α(0) thalassaemia in an ethnic minority, together with an unexpected diversity of forms of non-deletion α thalassaemia in Sri Lanka, further emphasises the critical importance of micro-mapping populations for determining the frequency of clinically important forms of the disease.Item Rotavirus-associated diarrhoea in buffalo calves in Sri Lanka(British Veterinary Association, Elseveir, 1994) Sunil-Chandra, N.P.; Mahalingam, S.Faecal samples from 150 buffalo calves, one to 150 days old, located in various districts of Sri Lanka, were examined for group A rotavirus antigen by a screening enzyme linked immunosorbent assay (ELISA). Positive samples were confirmed by the blocking ELISA. In the calves studied 27.3 per cent were diarrhoeic, and the rest were non-diarrhoeic but were in contact with the animals showing diarrhoea. Antigen was detected in 36.6 per cent of the diarrhoeic animals and in 11.9 per cent of the non-diarrhoeic animals. There was a strong association between the presence of antigen in faeces and diarrhoea in these animals (chi 2 = 46.98; P < 0.001). Of the 146 serum samples examined for antirotaviral antibodies, by the blocking ELISA at a single serum dilution (1:20) against a constant dose of antigen (8 units), 68.5 per cent were positive indicating a widespread infection with the virus in the population studied. This is the first record of the detection of rotavirus and its association with diarrhoea in buffalo calves in Sri Lanka.Item Study of natural rotavirus infection in buffalo calves in Sri Lanka(Springer, 1995) Sunil-Chandra, N.P.; Mahalingam, S.No Abstract AvailableItem Concomitant leptospirosis-hantavirus co-infection in acute patients hospitalized in Sri Lanka: implications for a potentially worldwide underestimated problem(Cambridge University Press, 2015) Sunil-Chandra, N.P.; Clement, J.; Maes, P.; de Silva, H.J.; Van Esbroeck, M.; Van Ranst, M.Two global (re-)emerging zoonoses, leptospirosis and hantavirus infections, are clinically indistinguishable. Thirty-one patients, hospitalized in Sri Lanka for acute severe leptospirosis, were after exclusion of other potentially involved pathogens, prospectively screened with IgM ELISA for both pathogens. Of these, nine (29·0%) were positive for leptospirosis only, one (3·2%) for hantavirus only, seven (22·5%) for both pathogens concomitantly, whereas 13 (41·9%) remained negative for both. Moreover, in a retrospective study of 23 former patients, serologically confirmed for past leptospirosis, six (26·0%) were also positive in two different IgG ELISA hantavirus formats. Surprisingly, European Puumala hantavirus (PUUV) results were constantly higher, although statistically not significantly different, than Asian Hantaan virus (HTNV), suggesting an unexplained cross-reaction, since PUUV is considered absent throughout Asia. Moreover, RT-PCR on all hantavirus IgM ELISA positives was negative. Concomitant leptospirosis-hantavirus infections are probably heavily underestimated worldwide, compromising epidemiological data, therapeutical decisions, and clinical outcome.Item Influence of non-alcoholic fatty liver disease on the development of diabetes mellitus(Wiley-Blackwell, 2013) Kasturiratne, A.; Weerasinghe, S.; Dassanayake, A.S.; Rajindrajith, S.; de Silva, A.P.; Kato, N.; Wickremasinghe, A.R.; de Silva, H.J.BACKGROUND AND AIM: Non-alcoholic fatty liver disease (NAFLD) is linked to metabolic syndrome, and is known to be associated with impaired fasting glycemia and diabetes mellitus. This prospective community-based study was conducted to determine the association between NAFLD and incidence of diabetes mellitus in an urban adult population in Sri Lanka. METHODS: Participants of the Ragama Health Study cohort were assessed for NAFLD using established ultrasound criteria in 2007. Those who were free of diabetes at baseline were followed up for 3 years. Incidence rates of diabetes mellitus were compared between subjects with and without NAFLD at baseline. RESULTS: Out of 2984 subjects, 926 had NAFLD and 676 had diabetes in 2007. Of the 2276 subjects who were free of diabetes in 2007, 1914 were re-assessed in 2010. After 3 years, 104 out of 528 subjects with NAFLD and 138 out of 1314 subjects without NAFLD had developed diabetes mellitus de novo. Incidence rates of diabetes were respectively 64.2 and 34 per 1000 person-years of follow up for those with and without NAFLD. NAFLD was an independent predictor of developing diabetes mellitus. Other independent predictors were impaired fasting glycemia and dyslipidemia. CONCLUSIONS: Subjects with ultrasonically diagnosed NAFLD have an increased risk of developing diabetes mellitus. Intervention for NAFLD through lifestyle modification may prevent progression of the current diabetes epidemic. © 2012 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.