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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty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 Clinical and virological features of dengue in 2010(Sri Lanka College of Microbiologists, 2011) Hapugoda, M.D.; Manamperi, H.; Gunasena, S.; Athapaththu, A.M.M.H.; Premawansa, G.; Wellawaththage, C.; Jayarathna, T.D.S.S.; Abeyewickreme, W.INTRODUCTION: Dengue is an important viral infection in Sri Lanka. All 4 serotypes co-circulate in Sri Lanka. OBJECTIVE: To study the clinical and virological features of dengue in 2010. DESIGN, SETTING AND METHODS: A hospital-based study was carried out at North Colombo Teaching Hospital, Ragama in 2010. Patients clinically suspected of having dengue, with fever less than 5 days were recruited. Acute and convalescent blood samples were collected within 7 days after obtaining informed written consent. Demographic, clinical information and laboratory results were obtained. Acute serum samples were tested using molecular (RT-PCR and Semi-Nested PCR) and serological (ELlSAs and HAI) assays. Convalescent samples were tested by serological assays. RESULTS: Of 209 patients enrolled, 93 % (195/209) were laboratory confirmed as recent positive cases of dengue viral infection; of these, 5% (9/195) were classified as dengue fever; 85%(1G5/195) dengue haemorrhagic fever (DHF) and 0.5% (1/195) dengue shock syndrome. Mean platelet value and packed cell volume (PCV) in laboratory confirmed dengue patients were 56,107/mm3 (range 10,000-306,000) and 42%(range 34-61 %) respectively. Patients infected with DHF showed both primary (n=45) and secondary (n=102) infections. Interestingly, secondary infection was not significantly correlated with DHF (x2-0.3:p=0.6). DEN-1 was responsible for the majority of cases, with a minority due to other three serotypes; all serotypes contributed to severe disease. CONCLUSION: DEN-1 was responsible for the majority of cases in 2010 but it circulated at a low level during previous epidemics. Majority of patients had severe clinical symptoms. In this epidemic, the clinical presentation of dengue differed according to the geographic region and viral serotype. ACKNOWLEDGMENTS: Financial assistance and technical co-operation by International Center for Genetic Engineering and Biotechnology (ICGEB CRP SRL 08/02), National Science Foundation (NSF/RG/2009/BT/01) and International Atomic Energy Authority (lAEA/SRL/5/042) is acknowledged.Item Shifting of circulating serotypes in dengue outbreaks during 2009/2010 in Sri lanka(Faculty of Tropical Medicine, Mahidol University, 2010) Manamperi, N.H.; Athapaththu, A.M.M.H.; Premawansa, G.; Wellawaththage, C.; Jayarathna, T. D. S. S.; Abeyewickreme, W.; Hapugoda, M.D.OBJECTIVES: Sri Lanka has experienced explosive outbreaks of dengue infection in 2009 and 2010. It has been identified that DEN- 3 and DEN- 2 were the predominant serotypes with DEN-1 and DEN- 4 circulating at a lower level in previous dengue outbreaks during 2003-2006, Objective of this study was to identify the circulating serotype/s during 2009 - 2010 outbreaks. METHODOLOGY: A prospective study was carried out at North Colombo Teaching Hospital, Sri Lanka during December 2009-August 2010. Clinically suspected dengue patients, with fever less than 5 days were recruited. An interviewer administered questionnaire was filled for each patient, by a Medical Officer. Venous blood samples confirmed for the presence of dengue virus by RT-PCR were typed by Semi-Nested PCR. RESULTS: Out of the 209 patients recruited in the study 80 (38%) were positive for dengue virus by RT-PCR. Of the positives, 43 (54%) were typed and circulation of all 4 serotypes was observed- Of the 43 positives, presence of DEN-1, DEN-2, DEN-3 and DEN-4 serotypes was 34 (79%), 3 (7%), 2 (5%) and 3 (7%) respectively DEN-1 was the predominant serotype in the recent epidemics which was circulating at a low level in previous epidemics. In DEN-1 infected patients, the mean platelet value was 58,588/ rnm3 and the mean PCV value was 41.4%. Associated symptoms such as headache, retro-orbital pain, neck pain and limb pain were present in 94% (32/34), 59% (20/34), 24% (8/34J and 91% (31/34) patients respectively. Bleeding manifestation developed in 47 % (16/34) patients. The mortality rate ranged from 0.7%- 1.0% during the recent outbreaks. Acknowledgement: Financial and technical assistance from the International Centre for Genetic Engineering and Biotechnology (ICGEB CRP/ SRI08-02) and the International Atomic Energy Agency (IAEA SRI 5/042) is gratefully acknowledged.Item Screening of hepatitis C (HCV) antibody reactive donors by RT-PCR in a sample population of blood bank donors in Sri Lanka(Malaysian Society of Parasitology and Tropical Medicine, 2007) Manamperi, A.; Gunawardena, N.K.; Nugawela, P.; Bandara, A.; Wellawaththage, C.; Bindusara, R.M.; de Silva, H.J.; Abeyewickreme, W.The practice of screening donors for HCV antibodies has substantially lowered the risk of acquiring HCV infection from a transfusion. However, detection of molecular markers in blood is the most reliable means of diagnosing active viral infection. Molecular studies on HCV antibody reactive donors have not been previously performed in Sri Lanka. The present study was carried out to investigate the RNA positive rates in a sample population of anti-HCV antibody reactive blood donors in Sri Lanka, with a view of determining whether RT-PCR testing for HCV RNA should be carried out at the initial donor screening level. Eighty nine (89) HCV antibody reactive donors were tested for the presence of HCV RNA by RT-PCR (sensitivity 200 copies/ml) during the period October 2005 to May 2006. The 89 serology positive donors were initially detected by a third generation ELISA by routine screening of an initial pool of 26,176 blood donors. Of the 89 Anti-HCV antibody positive donors (0.34% of the total donor pool), 6 (0.023% of the total donor pool, and 6.74 % of antibody positive individuals) were positive for HCV RNA. The prevalence of HCVRNA positivity was low in this cohort of Sri Lankan blood donors. This is in keeping with the low prevalence of HCV infection in the community. Routine individual HCV-RNA screening of donors does not seem cost-effective in our setting. The RNA negative, antibody positive profiles reflect either false positive serology results or donors who have been exposed to HCV previously and subsequently resolved their infections.Item Comparison of different RNA extraction methods for Dengue Reverse Transcription -Polymerase Chain Reaction (RT-PCR)(Sri Lanka Association for the Advancement of Science, 2011) Adihetty, D.D.; Wellawaththage, C.; Abeyewickreme, W.; Abeywickrema, K.; Hapugoda, M.D.Item Correlation of clinical presentation and laboratory confirmation of dengue patients(Sri Lanka Association for the Advancement of Science, 2010) Manamperi, N.H.; Athapaththu, A.M.M.H.; Premawansa, V.; Wellawaththage, C.; Jayarathna, T.D.S.S.; Abeyewickreme, W.; Hapugoda, M.D.Dengue is one of the most important arthropod-borne diseases in the world and it has become a very important disease in Sri Lanka, today. In Sri Lanka, diagnosis of dengue depends mainly on clinical signs and symptoms. Only a few suspected patients are confirmed by laboratory assays based on aetiological agents. The objective of this study was to determine the correlation between clinical presentation and laboratory confirmation of dengue patients. Acute serum samples (n=100) collected from patients clinically suspected of having dengue fever ("'ª-"ý¦> 5 days) warded at the North Colombo Teaching Hospital, Ragama were used for the present study. Serum samples were collected after obtaining informed written consent frompatients and samples were tested by RT-PCR which has high sensitivity (10 FFU/reaction) and specificity. Final diagnosis as dengue or non-dengue was assigned based on the results of RT-PCR assay. Differences in clinical and laboratory data were analyzed in dengue and non dengue patients. Chi-square test was used for comparison of data. The proportion of laboratory confirmed dengue patients were 56% (56/100). Mean platelet count and PCV in laboratory confirmed dengue patients were 60 269/mm 3 (range 3000-306000) and 41% (range 27-61%) and in non dengue patients were 106 318/mm 3 (range 5000-290000) and 41.6% (range 29-53%). Based on WHO criteria for diagnosis of dengue, heada (48/56 vs 41/44, ÝÖ 2 =0.7, p=0.38), retro-orbital pain (30/56 vs 14/44, ÝÖ 2 =3.8, p=0.04), limb pain (51/56 vs 30/44, ÝÖ 2 =7, p=0.00) and external bleeding (29/56 vs 4/44, ÝÖ 2 =18, p=0.00) showed significant association with dengue. Neck pain (10/56 vs 09/44, ÝÖ 2 =0.01, p=0.94), and lymphadenopathy (3/56 vs 02/44, ÝÖ 2 =0.08, p=0.78) did not show significant association with dengue. The infection was confirmed as dengue fever in 11% (6/56) and dengue hemorrhagic fever in 89% (50/56) based on WHO criteria. Surveillance based on clinical diagnosis may result in over estimation of the disease as clinical diagnosis is not specific enough. Laboratory confirmation of dengue suspected patients is important to measure the real incidence of the disease which leads implementation of control measures. Further, thisis important for efficient management of patients.Acknowledgements: Financial and technical assistance from the International Centre for Genetic Engineering and Biotechnology (ICGEB CRP/ SRI08-02) and International Atomic Energy Agency (IAEA SRI 5/042)Item A Comparative field study of novel commercial Antigen Detection Enzyme-Linked Immunosorbent Assay (ELISA) with Reverse Transcription Polymerase Chain Reaction (RT- PCR) assay for early definitive laboratory diagnosis of dengue viral infection in Sri Lanka(Sri Lanka Association for the Advancement of Science, 2007) Hapugoda, M.D.; Jayasooriya, D.H.S.W.; Gunawardene, Y.I.N.S.; Wellawaththage, C.; Premaratna, R.; Abeyewickreme, W.Dengue is an important mosquito borne viral infection in South East Asia. Early definitive laboratory diagnosis of infection would help in management of patients and reducing the case fatality rate. The objective of this study was to determine the accuracy of novel commercial Antigen Detection Enzyme-Linked Immunosorbent Assay (ELISA) using Non Structural protein 1 (NS1) (Bio Rad) for early definitive laboratory diagnosis of dengue infection under field conditions in Sri Lanka. A panel of acute serum samples collected from 99 patients clinically suspected of having dengue fever (<5 days) warded at the North Colombo Teaching Hospital, Ragama, Sri Lanka were used for the present study. Serum samples were tested using Antigen Detection ELISA according to the method described by the manufacturer. Results of this novel assay were compared with RT-PCR assay using Chi-squared test. Two variables were analyzed at a 95% confidence interval and P value <0.05 was considered as significant. Twenty two and 65 patients were positive and negative, respectively, for dengue infection by both assays. Nine patients were confirmed as dengue by the Antigen Detection ELISA only. Three patients were confirmed as dengue by RT-PCR assay only. Antigen detection ELISA showed 88% of agreement with the RT-PCR assay. According to the Chi-squared test, there was no significant difference between the two assays for early diagnosis of dengue infection (?2=46, P=0.0000). Novel commercial Antigen Detection ELISA kit (Bio-Rad 72830) can be used for early definitive laboratory diagnosis of dengue infection in Sri Lanka under field conditions. Acknowledgement: the International Atomic Energy Agency (SRL 06/28) for technical co-operation and APCOT Marketing LTD, Sri Lanka for supplying Antigen detection ELISA kits.Item Application of nucleic acid technology (NAT) in the diagnosis of active viral replication in HBV and HCV infections and evidence for HBV surface antigen mutants(Sri Lanka Association for the Advancement of Science, 2008) Manamperi, A.; Gunawardene, Y.I.N.S.; Hapuarachchi, C.; Bandara, A.; Wellawaththage, C.; Abeyewickreme, W.; de Silva, J.Introduction: The community prevalence of Hepatitis B (HBV) and hepatitis C (HCV) infections, although considered low (< 1%) in Sri Lanka based on serological markers, pose a significant health threat to patients in high risk groups. The early diagnosis of active viral infection is crucial in such situations to prevent further transmission and to enable the clinicians to initiate successful therapeutic interventions. Objective: This study was carried out to investigate the usefulness of polymerase chain reaction (PCR) in the diagnosis of active viral replication in HBV and HCV infections. Methodology: All specimens from patients with serological evidence of hepatitis B (HBV surface antigen and/or antibodies for HBV core protein) or hepatitis C (antibodies for hepatitis C core protein-Anti-HCV) and referred to the Molecular Medicine Unit from May 2005 to May 2008 were analyzed by PCR and reverse-transcription PCR (RT-PCR) for HBV DNA (n=130) and HCV RNA (n=95) respectively. Results: Of the 130 patients tested, 57 (44%) were positive for HBV DNA. The positive group of patients included 10 renal transplant patients, 4 multiply transfused patients, 4 paediatric patients with lymphoma, and 1 patient with cirrhosis. Six HBV DNA positive patients had negative HBsAg serology profiles indicating the possibility of surface antigen mutant strains. The HBV DNA negative patients with positive serology profiles indicate sero-converted/ patients with resolved infections or false positive serology results. Of the 95 patients tested, 14 (15%) were positive for HCV RNA and included 3 paediatric patients with thalassaemia. HCV RNA negative, anti-HCV positive profiles reflect either false positive serology results (due to less specific antibody assays) or donors who have been exposed to HCV previously and subsequently resolved their infections. Conclusions: A major proportion of patients with serological markers for HBV have active viral infection whereas only relatively a minor proportion of patients with serological markers for HCV have active viral replication. We have also found the first possible evidence of hepatitis B surface antigen mutant strains. This underlines the importance of the nucleic acid based technology in the diagnosis and assessment of infection with or suspected to have hepatitis B or C infections. We also emphasize the importance of introducing NAT for screening donors for HBV DNA and HCV RNA to substantially lower the risk of acquiring HBV/HCV infection from a transfusion.Item Molecular Diagnosis for confirmation of Infectious Diseases in Sri Lanka in 2009(Sri Lanka Association for the Advancement of Science, 2009) Hapugoda, M.D.; Bandara, K.B.A.T.; Dayanath, M.Y.D.; Wellawaththage, C.; Hapuarachchi, H.A.C.; Abeyewickreme, W.Confirmation of infectious disease outbreaks in Sri Lanka is an important national requirement. Many clinicians as well as general practitioners find it difficult to confirm diagnosis of some infectious diseases only on clinical grounds. Molecular assays can rapidly confirm diagnosis at the early phase of diseases when aetiological agents are present and before antibody titers are at detectable levels. PCR-based assays are more sensitive and more specific than all conventional methods. Overall objective of this study was early, rapid and definitive laboratory confirmation of the aetiology of chikungunya, dengue, Japanese Encephalitis (JE), leishmaniasis, leptospirosis, malaria and West Nile Virus (WNV) through molecular assays. A rapid mobile investigation team equipped with the case definition, questionnaires, sample collection methods and diagnostic methods for each disease was established. This group visited outbreak areas and collected clinical and laboratory information and clinical samples from suspected patients at the early stage of symptoms: 1-5 days. Clinical samples were laboratory tested by disease specific molecular assays (PCR/RT-PCR). Clinical parameters of each disease were analyzed. Only chikungunya, dengue and leptospirosis outbreaks out of the above mentioned diseases were reported during the preceding six months in 2009. The team collected blood samples from clinically suspected cases of chikungunya (n=430), dengue (n=116) and leptospirosis (n=23) from different parts of the island. Molecular assays confirmed infections only in 81% (350/430) for chikungunya, 7% (8/116) for dengue and 9% (2/23) for leptospirosis in selected suspected patients. Reports of the confirmation of the disease outbreak by molecular assay were sent to the relevant health authority within two days to highlight the magnitude of the infection. These results showed importance of aetiological confirmation of infectious diseases by molecular assays. In conclusion, molecular diagnosis using a single clinical sample is important for rapid, definitive and early confirmation of aetiology of a particular infectious disease outbreak when serological methods are of little value at the early stage of infection. This is important for cost effective and efficient control of the outbreaks through proper clinical management.