Browsing by Author "Gunasekera, H.A.K.M."

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    A comparison of serological diagnostic techniques in Dengue fever
    (Sri Lanka College of Microbiologists, 2005) Gunasekera, H.A.K.M.; Senanayake, C.P.; Sunil-Chandra, N.P.; Mendis, L.
    INTRODUCTION: The Dengue Duo IgM and IgG Rapid Strip test (PanBio Pvt. Ltd., Brisbane, Australia) is a commercially available immunochromatographic test. The Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok Thailand, has developed an in-house anti-dengue/anti-JE IgM and IgG reference enzyme-linked immunosorbent assay (ELISA). OBJECTIVE: To compare the usefulness of the AFRIMS ELISA and PanBio Dengue Duo IgM and IgG Rapid Strip test (PanBio Strip test) in the diagnosis of dengue infections. MATERIALS AND METHOD: 93 non-bacterial undifferentiated fever cases and 50 suspected dengue fever cases were screened for dengue and JE virus infections by the AFRIMS ELISA and also by the PanBio Strip test for dengue. All cases positive for dengue antibodies by either test were also tested by the Haemagglutination Inhibition test. RESULTS: Results were considered conclusive when at least 2 or all 3 of the above tests agreed. The AFRIMS ELISA had a sensitivity of 91.7% and specificity of 100% while the PanBio Strip test has a sensitivity of 93.8% and specificity of 96.8% in diagnosing dengue infections. 91.7% primary and 91.4% secondary infections were correctly classified by the AFRIMS ELISA. The PanBio Strip test identified 100% primary infections and 65.7% of secondary infections. CONCLUSIONS: The PanBio Strip test has a sensitivity and specificity comparable to the AFRIMS ELISA in diagnosing dengue infections although it tends to underestimate the number of secondary infections.
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    Hepatitis C seroprevalence: a community survey from the Gampaha district
    (Sri Lanka Medical Association, 2002) Gunasekera, H.A.K.M.; Sunil-Chandra, N.P.; de Silva, H.J.
    INTRODUCTION: Seroprevalence of Hepatitis C (HCV) infection is low among Sri Lankan blood donors and new entrant medical students, but high among renal transplant recipients and multiply transfused patients. Prevalence of infection in the general community is not known. METHODS: A community survey of HCV sero-prevalence was performed in the Gampaha district employing a multi-stage cluster sampling technique. A cluster was based in a Public Health Midwife area, and included individuals over one year of age. A pre-tested questionnaire was administered to assess risk of exposure to infection. After informed consent, 1-3 ml of blood was obtained from those recruited. Serum was separated and stored at -20°C. Sera were tested for IgG anti-HCV using a third generation ELISA. Samples giving positive or intermediate results were retested by the same ELISA, a confirmatory Reverse Immunoblot Assay, and also tested for HCV-RNA by RT-PCR. RESULTS: Of the 534 individuals included in the survey [M:F=1.1:1; median age 36yrs (inter-quartile Range 17-55)], 174 (32.6%) had at least one risk factor and 48 (9%) had more than one risk factor for exposure to HCV infection. However, only 3 (0.6%) sera were confirmed positive for anti-HCV. All samples tested were negative for HCV-RNA. CONCLUSIONS: Sero-prevalence of HCV infection was low in this community survey in the Gampaha district. This is despite a significant proportion of those surveyed having risk factors for exposure to the infection, and the previously known relatively high (2.5%) sero-prevalence of Hepatitis B infection (HBsAg) in this district.
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    Japanese encephalitis virus infection in an endemic area: hospital based study 1998 to 2000
    (Sri Lankan Society for Microbiology, 2012) Gunasekera, H.A.K.M.; Senanayake, C.P.; Mendis, L.; Sunil-Chandra, N.P.
    Gampaha Deputy Provincial Director of Health Services division reported a large number of Japanese encephalitis cases during 1996 to 1997. Notified cases included unconfirmed and confirmed cases. A study to determine the true disease burden was considered necessary. Proportion of undifferentiated fever cases due to Japanese encephalitis virus varies in different populations and the Sri Lankan situation is not known. The objectives were to determine the proportion of undifferentiated fever cases and encephalitis cases due to Japanese encephalitis virus; and the case fatality rate and frequency of neurological sequelae in Japanese encephalitis, in a tertiary care hospital in Gampaha. A cross-sectional descriptive study was carried out in the paediatric and medicine units of the North Colombo Teaching Hospital, Ragama during 1998 to 2000. Ninety three randomly selected patients with a diagnosis of undifferentiated fever from whom paired sera could be collected and 32 patients suspected of encephalitis, which were not overtly due to mumps, measles or chicken-pox were included. The Armed Forces Research Institute in Medical Sciences Enzyme linked immunosorbent assay for anti-Japanese encephalitis virus immunoglobulin M and G was used to confirm Japanese encephalitis virus infection. One of 93 (1.08%) undifferentiated fever cases was due to Japanese encephalitis virus infection. Eleven of 32 (34.38%) encephalitis cases had Japanese encephalitis virus infection and 3 (27.3%) had IgM antibodies to Japanese encephalitis virus in cerebrospinal fluid. Case fatality rate and sequelae at discharge were 11.1% each. Japanese encephalitis virus was an important cause of encephalitis in Gampaha during this period
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    Low community seroprevalence of hepatitis C virus infection in the Gampaha district
    (Sri Lanka Medical Association, 2002) Gunasekera, H.A.K.M.; Sunil-Chandra, N.P.; de Silva, H.J.
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