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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty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 Role of Aedes albopictus in transmitting dengue virus in some endemic areas in Kurunegala District.(University of Kelaniya, 2003) Hapugoda, M.D.; de Silva, N.R.; Abeysundara, S.; Bandara, K.B.A.T.; Dayanath, M.Y.D.; Abeyewickreme, W.Abstract AvailableItem Recent chikungunya outbreak in Sri Lanka 2006-2007(Faculty of Tropical Medicine, Mahidol University, 2007) Abeyewickreme, W.; Bandara, K.B.A.T.; Dayanath, M.Y.D.; Sumanadasa, D.; Hapuarachchi, H.A.C.; Gunawardena, N.K.; Hapugoda, M.D.; Wijesiriwardena, B.; de Silva, S.; Perera, T.BACKGROUND: Chikungunya(CHIK) is a viral disease transmitted by Aedes mosquitoes. Cases with symptoms of CHIK had been reported from several parts of Sri Lanka in 2006-2007. Laboratory testing of samples is a prime requirement for confirmation of transmission. OBJECTIVES: To confirm CHIK infection in suspected patients by rapid Reverse Transcription Polymerase Chain Reaction Assay(RT-PCR), find out manifestations specific for CHIK infection and study the transmission of CHIK virus by vector mosquitoes. METHODOLOGY: Serura. samples and information on clinical manifestations were collected from 189 chikungunya-suspected patients from different geographical areas in Sri Lanka from September 2006 to September 2007. Samples were tested for Chikungunya RNA by RT-PCR. Amplified products were visualized by agarose gel electrophoresis. Adult mosquitoes were also collected from chikungunya case-reported stations. They were tested for Chikungunya RNA through RT-PCR-followed by agarose gel electrophoresis assay. RESULTS: Of the CHIK-suspected patients reported from all parts of the island 86/189 (45.5%) were positive for CHIK virus. Of the PCR positive 06, all had fever with either arthralgia or arthritis or both. Headache (95.3%) and backache (84.6%) were also common among above patients. Eight percent (4/50) of both species of Aedes mosquitoes were RT-PCR positive. DISCUSSION: RT- PCR is important in early diagnosis of the infection and differentiation from dengue fever. The most common clinical symptoms observed were fever with either arthralgia, arthritis or both. Both Aedes aegypti and Aedes. albopictus are important in transmitting the disease.Item Polymerase Chain Reaction and mosquito dissection as tools to monitor filarial Infection levels following mass treatment in Gampaha District, Sri Lanka(Elsevier, 2008) Wijegunawardana, N.D.A.D.; Gunawardene, Y.I.N.S.; Manamperi, A.; Bandara, K.B.A.T.; Liyanage, T.; Abeyewickreme, W.BACKGROUND: Mass Drug Administration (MDA)-based Global Lymphatic filariasis (Lf) eradication programmes are aimed at stopping transmission of Wuchereria bancrofti by its mosquito vector. The study was designed to compare one year post treatment (mass distribution of Diethylcarbamazine-Albendazole) infection rates of Wuchereria bancrofti in Culex quenquifaciatus, the main vector of Lf in Sri Lanka using Conventional dissection techniques and a Polymerase Chain Reaction (PCR) assay based on parasite specific Ssp1 repeat which amplifies a fragment of 188 bp. METHODS: Field study was conducted in 45 sites in all Medical Officer of Health (MOH) areas in the Gampaha district, Sri Lanka; identified by the Anti Filariasis Campaign (AFC) as having high-risk for bancroftian filariasis transmission. Indoor-resting mosquitoes were collected by aspiration from 20 houses per each site. Part of the mosquitos were used for dissection and the remainder was used for PCR to detect the filarial parasites in mosquito. RESULTS: Mosquito dissection data revealed 42.22% (19/45) of the sites were infested with mosquitoes positive for Wuchereria bancrofti, indicating 8 transmission active MOH areas (53.33%; 8/15). An infection rate of 5.26% was observed among the mosquitoes caught from households and the larval density was 8.7 per positive mosquito. PCR investigation revealed that 46.67% (21/45) of the sites were positive for W. bancrofti DNA, indicating 11 transmission active areas (73.33%; 11/15). The PCR was found to be more sensitive compared to microscopy in detecting the filarial parasite in field collected mosquito samples with respect to the MOH areas. CONCLUSION: The PCR technique employed offers scope for detection of the filarial parasites with higher sensitivity and specificity; is efficient and rapid. This technique applied for the first time in Sri Lanka, can be adopted as a diagnostic tool for the detection of filarial parasites in the vector population in surveillance to enable effective control of filariasis in the country. Acknowledgements: Authors acknowledge the WHO/SEARO/TDR (grant no. SN 1152) and University of Kelaniya (Research grant no. RP/03/04/06/01/2006) and to Ms. H.M.Renuka and Mr. H.P.Anura U. Pathirana, Mr. M.I.M.Peris and Mr. Y.L.Rassapana for their support during field study activities. © 2008 Elsevier Inc.Item A Case report of dengue and chikungunya co-infection in Sri Lanka(The Parasitology and Tropical Medicine Association of Thailand, 2008) Abeyewickreme, W.; Hapuarachchi, H.A.C.; Bandara, K.B.A.T.; Hapugoda, M.D.; Williams, S.Dengue fever and chikungunya are arboviral diseases transmitted by Aedes mosquitoes. Though dengue has been an important communicable disease in Sri Lanka for many years, chikungunya has not been reported in Sri Lanka since late 1960s. However, in November 2006, an outbreak suggestive of chikungunya erupted in the country. We report here the first laboratory confirmed case of dengue and chikungunya co-infection in Sri Lanka. The objective is to confirm the co-infection of dengue and chikungunya in a clinical case reported in November 2006. Clinical history of high fever, severe headache, nausea, loss of appetite, severe arthralgia and mild oedema of knees, small joints of hands and feet for 3 days suggested the possibility of dengue and chikungunya in a 70 year old male. There was no skin rash or bleeding manifestations. Laboratory investigations performed included total white blood corpuscle count/differential count (WBC/DC), platelet count (PLT), serum, haemoglobin (Hb%) and packed cell volume levels (PCV). Reverse Transcription- Polyrnerase Chain Reaction (RT-PCR) technology was used to confirm the presence of either dengue or chikungunya. Viral RNA was extracted from serum samples collected during the first five days of infection using QiAmp Viral RNA Kits and amplified products were visualized by 2% agarose gel electrophoresis and ethidium bromide staining. WBC/DC analysis showed a leucopaenia (WBC count 3.04 x 103 per μl) with relative lymphocytosis (51.0%). The total PLT was 115 x 103 per μl. Hb% was 14.3 g/dl with a PCV of 43.8%. The presence of both infections was confirmed by RT-PCR which amplified 225 bp and 354 bp products for dengue and chikungunya respectively. This was the first laboratory confirmed case of dengue and chikungunya co-infection, which was also the first confirmed report of chikungunya since 1969 in Sri Lanka. As clinical and biochemical manifestations of this patient suggested the probability of a mixed infection of dengue and chikungunya, the confirmation was achieved by a RT-PCR assay. This report highlights the importance of using molecular assays to confirm mixed viral infections during their early stages, especially infections such as dengue which can result in fatal complications.Item Confirmation of 2006 chikungunya outbreak in Sri Lanka using RT-PCR(Malaysian Society of Parasitology and Tropical Medicine, 2007) Abeyewickreme, W.; Bandara, K.B.A.T.; Perera, H.; Dayanath, M.Y.D.; Hapuarachchi, C.Chikungunya, a mosquito-borne viral infection caused by a single-stranded RNA virus of the family Togaviridae, is considered as a rare, non-fatal disease. During February to October 2006, an epidemic of over 1.3 million suspected cases was reported in India and neighbouring countries causing a significant economic loss due to crippling manifestations of this infection. With the outbreak of many viral fevers including dengue and dengue haemorrhagic fever, in October–November 2006, patients with manifestations suggestive of chikungunya such as high fever, headache, arthralgia and arthiritis (particularly, in ankle, knee and small joints of hands) were reported in many parts of Sri Lanka. As no chikungunya cases had been officially reported in the island since 1969, laboratory investigations for the presence of chikungunya virus was a prime requirement for confirmation of the outbreak. A total of 60 venous blood samples collected from suspected patients from different geographical regions of Sri Lanka were analysed using a reverse transcriptase-polymerase chain reaction (RT-PCR) technique to confirm the presence of chikungunya virus. Viral RNA was extracted from samples collected within 1-4 days of fever by using a Qiagen RNA extraction kit. RT-PCR was performed using chikungunya specific oligonucleotides. Both positive and negative controls were included in each set of reactions. The amplified products (354 bp) were visualized by running in a 1.5% agarose gel followed by ethidium bromide staining. Of the 60 samples, 33 (55%) were positive for chikungunya. They were distributed among almost all the geographical regions, highlighting the presence of a wide-spread epidemic in the country.Item Genetic evidence of emerging sulfadoxine-pyrimethamine resistance of Plassmodium falciparum isolates in an operational area in the Northern Province of Sri Lanka(Sri Lanka Association for the Advancement of Science, 2004) Hapuarachchi, H.A.C.; Dayanath, M.Y.D.; Abeysundara, S.; Bandara, K.B.A.T.; Abeyewickreme, W.; de Silva, N.R.Item Population data for CSF1PO, TPOX, THO1, D16S539, D7S820, D13S317, FESFPS, vWA and F13B short tandem repeat (STR) polymorphisms in Sri Lanka(Sri Lanka Association for the Advancement of Science, 2004) Manamperi, A.; Gunawardene, Y.I.N.S.; Bandara, K.B.A.T.; Dayanath, M.Y.D.; Hapuarachchi, H.A.C.; Abeyewickreme, W.Item Re-emergence of chikungunya in Sri Lanka: First confirmation of the 2006 outbreak by molecular diagnosis(Sri Lanka Association for the Advancement of Science, 2007) Perera, E.D.T.; Wijesiriwardena, B.; Hapugoda, M.D.; Bandara, K.B.A.T.; Dayanath, M.Y.D.; Wellawaththage, L.C.; Gunawardena, N.K.; Hapuarachchi, C.; Abeyewickreme, W.Chikungunya virus infection is clinically similar to many other acute febrile illnesses, such as dengue infection, malaria, west nile fever and leptospirosis. Rapid confirmation of the outbreak by laboratory diagnosis is important to ensure public health safety by appropriate patient management and controlling the disease. Molecular diagnosis by Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) assists rapid diagnosis. The objective of the present study was to determine the clinical manifestations of chikungunya confirmed patients in Sri Lanka. Venous blood samples and clinical information were collected from 66 chikungunya suspected patients having fever of less than 4 days from different geographical areas in Sri Lanka during the period September 2006 to February 2007. Serum samples were tested for chikungunya RNA by RT-PCR. Amplified products were visualized by agarose gel electrophoresis. Among 66 suspected patients, 51% (34/66) were positive for chikungunya by RT-PCR assay and 55.9% (19/34) were females. All age groups were affected similarly with the mean age of 41 years (range = 4 months to 80 years). Of the PCR positive 34, all had fever with either arthralgia or arthritis or both. Most of them had only pain in the joints without swelling (arthralgia only); 67.6% (23/34) in knee, 55.9% (19/34) in ankle, 50% (17/34) in wrist, 44.1% (15/34) in elbow and 52.9% (18/34) in small joints. Arthritis of ankle joint 35.2% (12/34) was more frequent compared with arthritis of the knee joint17.6% (6/34). PCR positive patients manifested more symptoms compared with PCR negative patients; 85.3% (29/34) headache, 79.4% (27/34) backache, 58.8% (20/34) nausea and 61.8% (21/34) vomiting. Compared with dengue, most of the chikungunya patients did not have dermatological manifestations. This is the first confirmation of the 2006 chikungunya outbreak in Sri Lanka. Some of the patients who had symptoms suggestive of chikungunya, tested by PCR were negative. These patients were probably suffering from other illnesses such as dengue. Acknowledgements: The International Atomic Energy Agency (TC SRL 6/028) for technical cooperationItem Potential use of blood-fed mosquitoes as evidence in forensic casework(Sri Lanka Association for the Advancement of Science, 2007) Marasinghe, M.P.L.R.; Sirisena, D.M.; Bandara, K.B.A.T.; Hapuarachchi, H.A.C.; Abeyewickreme, W.Medico - criminal entomology has been an important source of evidence in forensic investigations for many years. However, it has not been widely used to provide direct evidence for personal identification in forensic casework so far. In this study, we made an attempt to determine the usefulness of human DNA extracted from blood-fed mosquitoes as evidence in forensic casework. Approximately 1500 adult female mosquitoes of same age from four different species, i.e. Culex quinquefasciatus, Armigerus sabalbatus, Aedes aegypti and Anopheles tessellatus were fed with the same volume of human blood and maintained under the same environmental conditions. Three batches (N=1, 5 and 10) of randomly selected blood-fed mosquitoes were crushed and blotted onto filter paper strips separately at two hour intervals subsequent to blood meals up to 48 hours to determine the longitudinal variation in the extraction of polymerase chain reaction (PCR) amplifiable human DNA from mosquitoes. Human DNA was extracted from filter papers using a chelex-100 extraction protocol and amplified by PCR technique using human primers. Amplified products were run in 1.5% agarose gels. PCR amplifiable human DNA could be extracted from mosquitoes of Cx. quinquefasciatus and An. tessellatus up to 48 hours subsequent to blood meals. However, this duration was up to 46 and 42 hours in Ae. aegypti and Ar. Sabalbatus, respectively. The amount of amplifiable DNA was inversely proportionate to the post-feeding duration, but increased with number of mosquitoes at each time interval. Amplifiable human DNA could be extracted even from a single mosquito of four different species even after 48 hours from a blood meal with slight variation among species. However, as the amount of DNA decreases with time interval, more mosquitoes will have to be used for extraction in late sample collections. Similarly, it may be required to use a highly sensitive PCR protocol when analyzing such samples. Blood-fed mosquitoes collected even after 2 days from a crime scene may be used as a source of direct evidence for personal identification in forensic casework.Item 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".