Browsing by Author "Wellawaththage, L.C."

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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".
Evaluation of an IS 6110 - based PCR assay for laboratory detection of M. tuberculosis complex DNA in clinical samples
(Sri Lanka Association for the Advancement of Science, 2008) Palliyaguruge, R.H.; Gunawardene, Y.I.N.S.; Manamperi, A.; Wijekoon, C.N.; Wellawaththage, L.C.; Abeyewickreme, W.
Due to the slow growth rate of the causative agent, the diagnosis of Tuberculosis (TB) takes considerable time period leading to the complication and spread of the disease. Towards this end, use of Polymerase Chain Reaction (PCR) technology, has revolutionized diagnosis of TB by reducing the diagnostic time. The aim of the present study was to compare two primer pairs and DNA extraction methods for the PCR based detection of M. tuberculosis complex (MTB) DNA in clinical samples for the routine laboratory diagnosis of TB. Two DNA extraction methods (Modified Boom's method and Roche commercial kit) and two IS 6110-based primer pairs were compared with respect to the sensitivity, time and quality/quantity of DNA. Extra pulmonary and pulmonary specimens from 45 TB suspected patients referred to the Molecular Medicine Unit, University of Kelaniya from February 2007 to April 2008 were analyzed. Results indicated 50 % and 70 % of the samples extracted from modified Boom's method and commercial kit, respectively, had high quality DNA, while 17 % and 67 % of the specimens extracted by the Boom's method and commercial kit, respectively, had over 200 µg/ml DNA. Both primer pairs exhibited similar level of sensitivity (200 fg of MTB DNA). In comparison to the time consuming culture, which takes 4 to 6 weeks, the modified Boom's method and commercial kit combined with PCR takes only 48 and 24 hrs, respectively. Of the 19 positives (42.22%) 11 were males while 17 and 02 were extra-pulmonary and pulmonary TB, respectively. The commonest clinical indication for sending samples was suspected disseminated TB. Presence or absence of fever or presence or absence of very high ESR (>100 mm) did not have a significant positive or negative predictive value for PCR. Moderately high ESR (>50 mm) had a negative predictive value of 0.8 and Mantaux test had a positive predictive value of 0.8. According to the time required for completion, labour, quality/quantity of DNA (statically significant at p=0.05) and reproducibility the commercial kit proved to be an efficient DNA extraction procedure. Both sets of primers elicited similar discriminating power. There was not a single clinical indicator with satisfactory predictive values, which is useful in clinical decision making regarding the need for PCR diagnosis in individual patients. We report a simple, rapid and reproducible PCR assay for routine laboratory diagnosis of MTB DNA from both pulmonary and extra-pulmonary specimens.
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 cooperation
Silent transmission of the dengue fever in Gampaha District, Sri Lanka
(Malaysian Society of Parasitology and Tropical Medicine, 2007) Hapangama, H.A.D.C.; Gunawardene, Y.I.N.S.; Gunasena, S.; Hapugoda, M.D.; Premaratna, R.; Wellawaththage, L.C.; Abeyewickreme, W.
Dengue fever is a major infectious disease in Sri Lanka. Silent transmission of dengue virus has been suggested as a possible risk factor for the increasing incidence of dengue. The present study was carried out in the District of Gampaha using cluster investigation method. A cluster consisted of a minimum of 20 volunteers (family members and immediate neighbours) of a hospitalized serologically/molecular biologically confirmed dengue patient. Serum samples were collected from 148 volunteers in 7 clusters. Samples were tested for anti-dengue antibodies using Dengue Duo IgM and IgG Rapid Strip Test. Of these, positives were further tested for anti-dengue IgG antibody by Haemagglutination Inhibition (HAI) assay, the gold standard test for serological diagnosis of virus infection. Of the 148, 41 had evidence of exposure to dengue virus by Dengue Duo IgM and IgG Rapid Strip Test [positive for IgM: 28(68.4%), IgM & IgG: 7(17%) and IgG: 6(14.6%)]. Of that 41, paired sera were collected from 36 volunteers and tested by HAI assay which confirmed dengue virus infection in 4(11.1%) [confirmed secondary-4(100%)]. Additional 32(88.9%) were diagnosed as recent dengue infections [probable secondary-17(53.1%), probable dengue- 15(46.9%)]. Out of 36 volunteers, 12(33.3%) were symptomatic [confirmed secondary-1(8.3%), probable secondary-10(83.4%), probable dengue-1(8.3%)] and 24(66.7%) were asymptomatic [confirmed secondary-3(12.5%), probable secondary-7(29.2%), probable dengue-14(58.3%)]. Presence of dengue vectors, Aedes aegypti and/or Aedes albopictus were detected around all 7 clusters. The present study serologically confirms the persistence of silent transmission of dengue virus with a trend towards clustering around cases. Presence of vector species in the area further supports this phenomenon.