Annual Research Symposium (ARS)

Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/154

Browse

Author: search.filters.author.Gunawardene, Y.I.N.S.Has files: Yes

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Lymphatic filariasis in selected endemic communities in Gampaha district, Sri Lanka
    (University of Kelaniya, 2009) Wijegunawardana, N.D.A.D.; Gunawardene, Y.I.N.S.; Manamperi, A.; Abeyewickreme, W.
    Background: Epidemiological surveys are important tools for monitoring progress of lymphatic filariasis (Lf) eradication programs. Objective: The objective of this study was to identify the current status of Lf in Gampaha district, following the completion of 5 year mass-treatment program (MDA), by using traditional night blood screening test. Study design: Study sites were selected within the Lf endemic area while following guidelines of Anti Filariasis Campaign and study population consist of all individual living within the 500 m radius randomly selected land area. Methodology: Night blood screening was carried out between May to August 2009 in 9 sites in 3 closely situated Medical Officer of Health (MOH) areas of Gampaha district. All participants were screened for Microfilariae (mf) after examination by a medical officer for clinical manifestations of Lf and the awareness and practices of participating individuals of >15 years with regard to MDA programme surveyed using an interviewer administrated structured questionnaire. Results: Of the 1073 participants (286 children, 787 adult) screened, 6 were positive in 2 sites for mf, giving mf positive rates of 0.5% and 3.4% respectively in Hekiththa and Peliyagoda sites. While giving mean mf density (mf/60 μl blood) of 2 and 7 respectively. Questionnaire analysis revealed that, of the 1073 participants, 78% were aware of MDA and from that 65% had received the drugs and from that nearly 50% had taken the drugs. Out of those 50%, only 34% had taken it continuously all five years. According to the clinical investigation of 1073 participants, 7%, 3% and nearly 1% had symptoms of headlice, Lyphoedema and Hydrocoela respectively. Discussion: mf rate of Lf in this study population is greater than the currently reported in the country (0.18%). Therefore, an intensive MDA programme is recommended to contain the spread of infection.
  • Thumbnail Image
    Item
    Aedes albopictus the “underrated” Asian Tiger
    (University of Kelaniya, 2010) Jayasooriya, D.H.S.W.; Gunawardene, Y.I.N.S.; Manamperi, A.; de Silva, H.J.; Abeyewickreme, W.
    Introduction The mosquito Aedes aegypti was thought to be the main vector responsible for virtually all dengue epidemics; while Aedes albopictus was considered a vector in which the virus is maintained but does not cause epidemics. Objective The study was conducted covering three endemic districts in Sri Lanka to determine the role of genus Aedes during dengue transmission. Methods and Material Mosquitoes were collected within a 350m radius from the location of the positive patients. Heads and abdomens of 63 pools were tested for DENV RNA with and RT-PCR-LH-(P32) assays Results Discussion Ae. albopictus was present in majority of the locations in all districts surveyed. Ae. albopictus was found in 13/17 (76.47%), 24/25 (96%)and 19/22 (86.36%) sites in Colombo, Gampaha and Kurunegala respectively. The RT-PCR-LH-(P32) assays indicated that 5/25 (20%) sites in Gampaha, 2/17 (11.76%) in Colombo and 6/22 (27.27%) in Kurunegala were positive for DENV. In Gampaha and Colombo there were 3 and 1 of DEN-2 positive pools respectively, while there were 2 and 1 of DEN-3 positive pools respectively. A higher number of positive pools (4/1or 21.05%) for DEN-1 and 1/1(5.26 %) for DEN-4 were found in Kurunegala. In Kurunegala one pool was positive for both DEN-2 and DEN-4 indicating the circulation of multiple serotypes within close proximity. Moreover one of the three DEN-2 positive pools in Gampaha consisting of only male Ae. albopictus mosquitoes is supportive of the belief of vertical transmission of DENV. In a DEN-4 positive location in Kurunegala HI was found to be10%, BI= 1and CI= 5.88 %while anotherDEN-2 positive site in Wattala showed HI of 5.55%and a BI of 5.55 suggesting active transmission. The abundance of Ae. albopictus in all districts and the findings indicating that100% of the positive pools were made of Ae. albopictus in this study highlights the importance of Ae. albopictus in the transmission dynamics dengue. The ability of Ae. albopictus to be infected with low viremia and the degree to which it permits replication within the mosquito itself could have an impact on the transmission and these verity of the disease. Co-circulation of two or more serotypes in a single pool or in different pools of mosquitoes within the same district is suggestive of hyper endemic transmission dengue in the three districts. The greater susceptibility of Ae. albopictus to infection by DENV is said to lead to greater virus adaptation. Sri Lanka as a whole would be at serious risks for multiple outbreaks in future. Our results indicate that Ae. albopictus is more efficient in dengue transmission than previously thought. The results shed light on the efficiency of Ae. albopictus as a vector in transmitting DENV in the absence or low abundance of Ae. aegypti in Sri Lanka. The present study suggests that Ae. albopictus sp is underrated in terms of transmission potential during peak transmission periods of dengue in Sri Lanka. Key words: RT-PCR-LH-(P32) RT-PCR-Liquid Hybridization with P32 radio isotope, HI-House hold Index, BI- Breteau Index, CI-Container Index,DENV-Dengue Virus Authors wish to acknowledge the financial assistance rendered by the NSF Sri Lanka (GrantNo:SIDA/2006/BT/02)and the IAEA (Grant NoTC SRL 6/028).