Journal/Magazine Articles
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/13
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
Browse
14 results
Search Results
Item Integrated school-based surveillance for soil-transmitted helminth infections and lymphatic filariasis in Gampaha district, Sri Lanka(American Society of Tropical Medicine and Hygiene, 2014) Gunawardena, S.; Gunawardena, N.K.; Kahathuduwa, G.; Karunaweera, ND.; de Silva, N.R.; Ranasinghe, U.B.; Samarasekara, S.D.; Nagodavithana, K.C.; Rao, R.U.; Rebollo, M.P.; Weil, G.J.We explored the practicality of integrating surveillance for soil-transmitted helminthiasis (STH, assessed by Kato-Katz) with transmission assessment surveys for lymphatic filariasis (LF) in two evaluation units (EUs) in Gampaha district, Sri Lanka (population 2.3 million). The surveys were performed 6 years after five annual rounds of mass drug administration with diethylcarbamazine and albendazole. Each transmission assessment survey tested children (N = 1,462 inland EU; 1,642 coastal EU) sampled from 30 primary schools. Low filarial antigenemia rates (0% and 0.1% for the inland and coastal EUs) suggest that LF transmission is very low in this district. The STH rates and stool sample participation rates were 0.8% and 61% (inland) and 2.8% and 58% (coastal). Most STH detected were low or moderate intensity Trichuris trichiura infections. The added cost of including STH testing was ∼$5,000 per EU. These results suggest that it is feasible to integrate school-based surveillance for STH and LFItem Prevalence of childhood atopic diseases in the Western Province of Sri Lanka(Sri Lanka Medical Association, 2010) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Weerasinghe, A.BACKGROUND: Atopic diseases in children are major public health problems around the world and the prevalence is increasing. Our objective was to assess the prevalence of atopic diseases in schoolchildren in the Western Province of Sri Lanka. METHODS: Children attending grade 5 in 17 schools in the Western Province of Sri Lanka were recruited to the study. Data were collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, which was filled by the parent/guardian of the selected children. RESULTS: A total of 640 schoolchildren were recruited. Their mean age was 10 years (SD +/- 0.5) and 55.9% of the study population was boys. Prevalence (95% CI) of asthma, rhinitis and eczema was 17% (13.7-20.3), 21.4% (17.8-25.1) and 5% (3.1-7.0) respectively, while 33.7% (29.6-37.9) had one or more diseases. Only the prevalence of allergic rhinitis showed a statistically significant difference between the two sexes, being more common in boys. Less than 30% of affected children's parents recognised that their child had either asthma or rhinitis, whereas a higher number of parents (54.2%) recognised that their child had eczema. Among children with asthma, 44.4% had rhinitis. CONCLUSIONS: The prevalence of atopic diseases in schoolchildren in grade 5 in the Western Province of Sri Lanka is as common as in other countries in the south Asian region. Parental recognition of these conditions was not satisfactoryItem Ultrasonographic visualisation of live Wuchereria bancrofti adult worms in situ(Sri Lanka Medical Association, 2011) Chandrasena, T.G.A.N.; Gunawardena, N.K.; Premaratna, R.; de Silva, N.R.No Abstract AvailableItem Effect of repeated mass chemotherapy for filariasis control on soil-transmitted helminth infections in Sri Lanka(Sri Lanka Medical Association, 2008) Gunawardena, N.K.; Amarasekera, N.D.D.M.; Pathmeswaran, A.; de Silva, N.R.BACKGROUND: In July 2006 Sri Lanka completed 5 rounds of annual mass drug administration (MDA) with diethylcarbamazine citrate (DEC) and albendazole as part of its national programme for elimination of lymphatic filariasis (LF). Albendazole is highly effective against soil-transmitted helminths (STH). This study was carried out to assess the effect of repeated annual MDA on STH infections in the Western Province of Sri Lanka, an area co-endemic for LF and STH. METHODS: Faecal samples were obtained (during August-September 2006), from grade 5 students in 17 schools in the Western Province that were included in a national survey of schoolchildren's health in 2003, and examined using the modified Kato-Katz technique. The prevalence and intensity of roundworm, whipworm and hookworm infections in 2003 and 2006 were compared. RESULTS: Faecal samples from 255 children were examined in 2003; 448 were examined in 2006. Roundworm prevalence was marginally lower in 2006 (4.0%) than in 2003 (4.7%), as was hookworm (0.2% vs 0.4%), whereas whipworm prevalence was higher (13.8% vs 9.4%). These differences as well as that between the geometric mean egg counts were not statistically significant. Compliance with MDA in 2006, as reported by the schoolchildren examined, was only 59%. CONCLUSIONS: Four annual rounds of MDA with DEC and albendazole had virtually no effect on STH infections in the study area.Item A Case of imported malaria: the first report of Plasmodium malariae infection in Sri Lanka after 37 years(Sri Lanka Medical Association, 2008) Hapuarachchi, H.A.C.; Gunawardena, N.K.; Senevirathne, M.P.; Abeyewickreme, W.; de Silva, N.R.We report a case of Plasmodium falciparum and P. malariae mixed infection in a patient who had been living in Malawi. This is the first case of P. malariae reported in Sri Lanka in 4 decades. The presence of both parasites was confirmed by microscopy and polymerase chain reaction (PCR). The history strongly indicated that the infection had been acquired from Malawi. The patient had liver dysfunction and a transient glomerulonephritis, both of which subsided with antimalarial treatment.Item Social mobilization, drug coverage and compliance and adverse reactions in a Mass Drug Administration (MDA) Programme for the elimination of Lymphatic Filariasis in Sri Lanka(BioMed Central, 2007) Weerasooriya, M.V.; Yahathugoda, T.C.; Wickremasinghe, D.; Gunawardena, N.K.; Dharmadasa, R.A.; Vidanapathirana, K.K.; Weerasekara, S.H.; Samarawickrema, W.A.BACKGROUND: In Sri Lanka filariasis is endemic in Southern, Western and North Western provinces covering eight districts designated as implementation units in the Programme for the Elimination of Lymphatic Filariasis (PELF). Despite control activities over sixty years including multidose diethylcarbamazine, 6 mg/kg treatment microfilaria rates had persisted at low levels. Following systematic social mobilisation the first MDA with DEC albendazole combination was conducted in 2002. METHODS: We investigated the extent social mobilisation had reached the people, their drug compliance and adverse reactions. Three localities were selected from each district to pick target population samples for pre-tested questionnaire. Three teams each with six people visited one district each day. One team worked from three starting points in one locality. A member applied eight part questionnaire to one family member totalling 150-160 people from one locality. Questions included social mobilisation, drug compliance and adverse reactions. RESULTS: Information was disseminated by television, radio, banners and leaflets, to a lesser extent by people. Information reached more people in the periphery than in Colombo. 35.2% from Colombo municipality were unaware of the MDA. Drug coverage was 79.6%, home delivery 71.7% and delivery centres 7.9%. 35.6% in Colombo district and 53.4% from Colombo municipality did not receive drugs. Drugs were consumed by 71.4%. 28.6% who did not comply included 20.4% who did not receive them. 91.4% showed no adverse reactions, 7.5% were mild, 1.1% recovered with home remedies. CONCLUSION: Drug compliance showed significant positive correlation with awareness of the MDA. Door to door delivery was more successful than delivery from centres. More delivery centres conveniently located would have rectified this disparity. Poor awareness and compliance in Colombo and urban areas could be rectified with separate strategy for urban areas. More time for MDA and trained adequate manpower would ensure coverage to achieve elimination.Item Differential effects of diethylcarbamazine, tetracycline and the combination on Brugia pahangi adult females in vitro(Elsevier, 2005) Gunawardena, N.K.; Fujimaki, Y.; Aoki, Y.; Mishima, N.; Ezaki, T.; Uni, S.; Kimura, E.Anti-filarial effects of diethylcarbamazine (DEC), tetracycline (TC) and the combination on Brugia pahangi adult females were studied in 7-day cell-free culture, in terms of microfilaria release, parasite motility, MTT assay for parasite viability and embryogram. TC 50 microg/ml (TC50) effectively reduced microfilaria release from day 1 of culture. Combined with DEC 100 microg/ml (DEC100) or DEC 500 microg/ml (DEC500), microfilaria release reduced further and synergistically. TC50 also reduced motility, but DEC100 and DEC500 did not. Thecombination of TC50 and DEC500 reduced motility synergistically. The MTT assay supported the results of motility study in general. The embryogram showed that only DEC500 reduced the total number of intrauterine embryos, especially ova, indicating that DEC500 inhibited early embryogenesis. TC50 did not affect the total number of embryos, but resulted in apparent accumulation of microfilariae in the uterus, suggesting that the drug inhibited release of microfilariae in this in vitro system. These results clarified different anti-female mechanisms between DEC and TC. A PCR-based study showed that endosymbiont bacteria, Wolbachia, in B. pahangi females decreased significantly after TC treatment. However, this study could not determine whether the effects of TC were direct or Wolbachia-mediated.Item Human infection with Wuchereria bancrofti in Matara, Sri Lanka: the use, in parallel, of an ELISA to detect filaria-specific IgG4 in urine and of ICT card tests to detect filarial antigen in whole blood(Academic Press, 2003) Weerasooriya, M.V.; Itoh, M.; Mudalige, M.P.; Qiu, X.G.; Kimura, E.; Gunawardena, N.K.; Fujimaki, Y.The ICT card test to detect circulating filarial antigen and an ELISA that detects filaria-specific urinary IgG(4) were each used to screen 473 subjects from a community in Sri Lanka where Wuchereria bancrofti is endemic. When the ICT test was used as the gold standard, the ELISA was found to have a sensitivity of 91.2%. However, far more of the subjects were found ELISA-positive than ICT-positive (76.5% v. 31.1%). The youngest children studied (aged 1-10 years) were similar to the adult subjects in terms of the prevalence of antigenaemia (33.8%) and the prevalence (72.1%) and concentration of filaria-specific IgG(4) in their urine. Therefore, especially as urine samples are easier, less painful and safer to collect than blood samples, the ELISA may be particularly useful to screen very young and school-age children, to estimate current levels of transmission in a particular area.Item Chemotactic response of Brugia pahangi infective larvae to jird serum in vitro(Springer International, 2003) Gunawardena, N.K.; Fujimaki, Y.; Aoki, Y.The Brugia pahangi infective larval response to jird serum was studied using an agar plate assay. Larvae placed onto the agar remained at the same place for 60 min. Once the larvae were stimulated by serum, more than 95% oriented towards the serum and reached it within few minutes. This larval response was inhibited by an activator of phosphodiesterase (imidazole), adenylate cyclase inhibitors (SQ22536 and MDL-12330A) and protein kinase A inhibitor. An inhibitor of phosphodiesterase (IBMX), an activator of adenylate cyclase (forskolin) and an membrane permeant analogue of cAMP (8-bromo-cAMP), caused a number of larvae to move out from the inoculation area towards the other zones. To our knowledge, this is the first report of a chemotactic response by B. pahangi larvae to host serum. We conclude that B. pahangi larvae show a chemotaxic response to host serum, and that cAMP and cAMP dependent protein kinase are involved in the signal transduction.Item Prevalence and intensity of Wuchereria bancrofti antigenaemia in Sri Lanka by Og4C3 ELISA using filter paper-absorbed whole blood(Oxford University Press, 2002) Weerasooriya, M.V.; Gunawardena, N.K.; Itoh, M.; Qiu, X.G.; Kimura, E.In Sri Lanka 2741 people from Matara, an endemic area for Wuchereria bancrofti, were examined in 1996/97 for microfilariae by 60-microL blood smear and for circulating filarial antigens by Og4C3 ELISA using filter paper-absorbed whole blood. The overall prevalence of microfilaraemia was 3.4%, and that of antigenaemia 14.4%. The prevalence of antigen-positive and microfilaria-negative people was 11.3%. Analysed by age-group,antigenaemia prevalence was similar in all groups, and the average number of antigen units was already very high in the age-group < 10 years, indicating that the infection started in early childhood. Among those who were antigen positive, the microfilaria prevalence was lower in females than in males. Diethylcarbamazine treatment eliminated microfilariae in 78% of the positives. However, 17 months after the treatment, antigenaemia was still positive in 76% of those who were parasitologically cured.