Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Development of recombinant proteins as diagnostic intermediates for chikungunya infection(Sri Lanka Association for the Advancement of Science, 2010) Athapaththu, A.M.M.H.; Khanna, N.; Gunasena, S.; Abeyewickreme, W.; Hapugoda, M.D.Chikungunya is an important disease with explosive outbreaks occurring in many South East Asian countries. As the clinical symptoms associated with chikungunya viral infections are often indistinguishable from those of many other viral, bacterial and parasitic infections confirmation of chikungunya outbreaks is important for clinicians for proper management of patients and for vector control programmers. Laboratory diagnosis of chikungunya in Sri Lanka is hindered by the non-availability of reliable commercial diagnostic kits and inaccessibility to reagents. There is a need to develop an assay that can confirm chikungunya, produced at low cost and easily standardized for the use in field settings. Currently available laboratory diagnostic kits depend on ELISA based on whole viral antigens which cause biohazard risk, high production cost and cross reactivity with other organisms of the same genus/family. Therefore, a diagnostic intermediate using a single recombinant protein antigen to overcome problems associated with whole viral antigen/lysate is important. The objective of this study was to assist laboratory confirmation of outbreaks through developing competencies for a rapid laboratory diagnostic method using recombinant protein antigens for chikungunya infection. We have designed 2 novel recombinant protein antigens based on Envelope domain (E), a critical antigenic region of the major structural protein of chikungunya virus. They were expressed in Escherichia coli separately, and resultant proteins were affinity purified and obtained ~5mg and 10mg respectively and protein of >95% purity per liter of culture. These 2 proteins were evaluated as potential diagnostic intermediates in ELISA separately for the detection of anti-chikungunya Immunoglobulin M (IgM) antibody using a panel of well characterized serum samples. E1 and E2 showed 60% and 67% positivity respectively. Specificity proteins were tested using serum from healthy volunteers and infected with other viral diseases. Two proteins could detect only anti-chikungunya IgM antibodies. We demonstrated that these 2 novel recombinant protein antigens can function as diagnostic intermediates. Acknowledgements: Financial assistance from the International Centre for Genetic Engineering and Biotechnology (ICGEB CRP/ SRI08 02) and International Atomic Energy Agency (IAEA SRI TC 5-042) are gratefully acknowledgedItem Chikungunya outbreak in 2008 in Ratnapura district, Sri Lanka - clinical and socio-economic analysis(Sri Lanka Association for the Advancement of Science, 2008) Sumanadasa, S.D.M.; Hapuarachchi, C.; Bandara, K.B.A.T.; Wellawaththage, L.C.; Abeyewickreme, W.Since 2006, Sri Lanka has experienced several outbreaks of chikungunya fever (CHIK) affecting several thousands of people. Today, CHIK has become one of the most important vector-borne diseases in the country. The objective of this study was to analyse the clinical manifestations and socio-economic status among CHIK patients reported from Pallebedda and Godakawela areas in Ratnapura district during the outbreak in February and March 2008. After obtaining the informed written consent, venous blood samples were collected from 80 suspected patients. A medical officer carried out clinical examination of each patient. Clinical information along with socio economic data of the patients was recorded in an interviewer-administered questionnaire. Serum samples were tested for CHIK by a Reverse-Transcription Polymerase Chain Reaction (RT-PCR) assay. Of eighty patients tested, 51% (n=42) were positive for CHIK. All positive patients had fever for less than 5 days duration. Majority of them (95%, n=40) had severe arthralgia with arthritis of small joints of hands and feet (81%, n=34). Moreover, a generalized, Itchy maculopapular rash was present in 78% (n=33) of them. The appearance of skin rash only after 4-5 days of fever was characteristic in the majority of patients. The mean age of positive patients was 38 years and consisted of 48% (n=20) of males. Many (43%, n=18) of them were farmers having a mean monthly family income of Rs. 4867.00. Analysis of educational status revealed that 60% (n=26) of family members had educated up to G.C.E. O/L whereas only 26% (n=12) had completed G.C.E. A/Ls. Twenty eight (67%) positive patients had at least one or more CHIK infected family members in addition. Moreover, 95% (n=40) of them were surrounded by infected neighbours indicating active, intense transmission in the area. According to the results, the most predominant clinical features of CHIK were fever either with severe arthralgia or arthritis of small joints of hands and feet. Skin rash, though characteristic, appeared to develop 4-5 days after the infection. CHIK has mainly affected the most productive labour force in these areas with majority belonging to the middle class farming community with a low monthly income. Hence, the sources of income of the affected families were severely hampered by the CHIK outbreak. Therefore, non-fatal, CHIK may have a negative impact on the socio-economic status of the affected communities. "The staff of the Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, Dr Richard Perera and the staff of Godakawela Hospital and Dr. Susanth Kariyawasam and the staff of Pallebadda Hospital are acknowledged".Item Rapid differential diagnosis of dengue and chikungunya infections by multiplex RT-PCR and impact of chikungunya infection on liver biochemical tests(Sri Lanka Association for the Advancement of Science, 2008) Manamperi, A.; de Silva, P.; Ekanayaka, C.; Gunawardene, Y.I.N.S.; de Silva, J.; Weerasena, O.V.D.S.J.; Dassanayake, R.S.Item Factors affecting transmission of chikungunya using Geographical Information System (GIS)(Sri Lanka Association for the Advancement of Science, 2009) Hapugoda, M.D.; Gunawardena, N.K.; Kusumawathie, P.H.D.; Jayasooriya, G.A.J.S.K.; Abeyewickreme, W.Transmission of chikungunya has been observed in many parts of Sri Lanka during the past few years. The objective of this study was to identify possible factors affecting transmission of chikungunya in a high risk area and to intervene and monitor those using GIS. Entomological, environmental, socio-economic and other possible factors were examined with regard to a chikungunya hot-spot in Kandy municipality for 12 months starting from April 2008. Hundred house-holds from 33 clusters were recruited. The distant between each cluster was maintained at a minimum of 200 m. Micro level approaches for collection of position, population, environmental, socio-economic and other related information were performed at each house-hold through a pre-tested questionnaire. Monthly entomological and epidemiological surveillance were conducted for 12 months. Digital topographical maps and meteorological information were obtained. GIS was used to map the selected households and to highlight the spatial and temporal distribution of factors under study. Selected risk area was an urban area where homesteads were the major land use pattern. The weather pattern of the study area was typical that of the Wet Zone. Entomological surveillance conducted showed the presence of high density of Aedes albopictus mosquitoes in more than 90% of the key (artificial) breeding habitats. Socio-economic data revealed although all house-holds have a sound knowledge on transmission on dengue including preventive measures, they were less concerned about the key mosquito breeding sites. GIS maps generated during the study showed distribution of these identified factors in all clusters. House index and man hour density of Ae. albopictus showed a positive correlation with rainfall, with a lag period of 2 and 3 months. The generalized high density of Ae. Albopictus suggest that this species may play a major role in transmitting chikungunya in the study area. In conclusion, the presence of high density of Ae. albopictus and lack of concern about key mosquito breeding sites in all clusters may be important risk factors. GIS-based maps can be used as an important tool to find out spatial and temporal distribution of possible risk factors in a selected hotspot, which would enable health authorities to prioritize implementation of control activities in a cost effective manner