Browsing by Author "Hapugoda, G.P.G.M.D."

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Breeding of aedes Aegypti and Aedes albopictus in some dengue endemic areas.
(Sri Lanka College of Microbiologists, 2000) Hapugoda, G.P.G.M.D.; de Silva, N.R.; Abeyewickreme, W.
Dengue fever (DF)/Dengue haemorrnagic fever (DHF) is now- the most important and rapidly spreading vector borne disease in the world. Since 1956, over 350 000 patients have been hospitalized and nearly 12 000 deaths have been reported. In Sri Lanka the incidence of DF/DHF has increased cyclically since the first outbreak in Sri Lanka during which 26 deaths were reported. Aedes aegypti is classified as the predominant vector of dengue in Sri Lanka. Ae, albopictus is considered as an important vector in the absence of Ae. aegypti. In this study, larval surveillance was carried out in fixed monitoring stations / hot-spots and random monitoring stations. Fixed monitoring stations were selected based on high incidence of DF/DHF recorded since 1996 in Kurunegala district. Ten premises within one fixed monitoring station were checked for mosquito breeding weekly using ovitraps and the average monthly ovitrap index (%) was calculated. During outbreaks larval surveillance was conducted in fifteen random monitoring stations including 66 houses which were selected based on serologically confirmed DPI DHF cases in and around Kurunegala and Ragama. Observations on average monthly ovitrap index (%) in the fixed monitoring stations showed that the highest ovitrap index was in Kurunegala town area, Ovitrap index of Ae. albopictus was higher than of Ae. aegypti all localities in and around Kurunegala throughout the study period. Data obtained from random monitoring-stations in and around Kurunegala and Ragama revealed that only Ae. albopictus larvae were present in seven stations. There were no stations in which only Ae.aegypti larvae were present. House index of Ae. albopictus was 28% whereas it was 10.6% for both species in random monitoring stations. Results suggest that Ae.albopictus may play a major role in transmitting dengue in some localities in Sri Lanka. This investigation received financial support from University of Kelaniya (Research Grant no-97/1-23) and from the IAEA (Technical Corporation Grant no-SRL/06/024).
Density of Aedes aegypti and Aedes Albopictus in some dengue endemic areas
(University of Kelaniya, 2000) Hapugoda, G.P.G.M.D.; de Silva, N.R.; Abeyewickreme, W.; Rajamanthri, R.
A Simplified non radioactive DNA probe technique for the field detection of sibling species A of the Anopheles culicifacies (Diptera: Culicidae) complex
(University of Sri Jayewardenepura, 2010) de Silva, B.G.D.N.K.; Hapugoda, G.P.G.M.D.; Karunanayake, E.H.
Three cloned highly repetitive DNA sequences Rp36, Rp217 and Rp234 isolated from An. culicifacies Giles, sensu lato were developed as non radioactive DNA probes by using a biotinylated labeling and colorimetric detection system. These non radioactive DNA probes distinguish sibling species A from species B and C of the An. culicifacies complex in a dot blot hybridization assay using single mosquito DNA extracts diluted 50 fold. The biotinylated Rp217 probe was further assayed in a more simple procedure which involves the hybridization of blots prepared from squashed mosquito heads. This technique avoids the separate extraction of mosquito DNA and facilitates a number of samples to be processed rapidly while also allowing several field analyses to be carried out on one mosquito specimen.