Conference Papers
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This collection contains abstracts of conference papers, presented at local and international conferences by the staff of the Faculty of Medicine
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Item Clinical and histopathological characteristics of cutaneous leishmaniasis in a group of military personnel in Sri Lanka(American Society of Tropical Medicine and Hygiene, 2015) Manamperi, N.H.; Fernando, C.S.; Pathirana, A.; Abeyewickreme, W.; de Silva, V.C.; Karunaweera, N.D.Cutaneous leishmaniasis (CL) is a newly established vector-borne parasitic disease in Sri Lanka. Military personnel have an occupational risk for CL due to being stationed in endemic areas and exposure to vectors outdoors. This study describes the clinical and histopathological features of CL in a group of military personnel. Thirty five patients with smear positive for Leishmania amastigotes were included, their data analyzed for clinical features and skin biopsies processed routinely for histology, examined at a conference microscope and classified into 4 groups using modified Ridley criteria for Leishmaniasis as: I-parasitized macrophages with variable lymphocytes and plasma cells; II-parasitized macrophages with lymphocytes, plasma cells and ill formed histiocytic granulomata; III-a mixture of macrophages (with or without parasites), lymphocytes, plasma cells and epithelioid granulomata; IV-epithelioid granulomatous response with a few lymphocytes and plasma cells but no amastigotes. Lesions were categorized by duration, as acute (< 6 months) or chronic (> 6 months). Study group composed of all males with a mean age of 32.6 years (range 22-47) and lesion duration of 5.6 months (range 1-24). Number of lesions varied from 1 to 6 with majority (71.4%, n= 25) having a single lesion. Nodular (37.1%, n=13) and nodulo-ulcerative (25.7%, n=9) lesions in upper limbs (68.6%, n=24) was the commonest presentation. Twenty nine (82.9%) of the biopsies were positive also by histology. Twenty two (62.9%) were acute and 13 (37.1%) chronic. Group I, II, III and IV patterns were seen in 14 (40%), 12 (34.3%), 5 (14.3%) and 4 (11.4%) respectively and 9 (40.9%), 9 (40.9%), 2 (9.1%) and 2 (9.1%) of acute lesions and 5 (38.5%), 3 (23.1%), 3 (23.1%) and 2 (15.4%) of chronic lesions respectively. Necrosis was not seen in any of the lesions. Majority in this group of military personnel with CL had single lesions affecting the upper limbs and sought treatment within 2 years of appearance of lesions. The histological picture varied from diffuse infiltration of parasitized macrophages admixed with chronic inflammatory cells to ill-formed histiocytic granulomata.Item In situ immune response to cutaneous leishmaniasis in Sri Lanka(Sri Lanka Medical Association, 2017) Manamperi, N.H.; Oghumu, S.; Pathirana, N.; de Silva, M.V.C.; Abeyewickreme, W.; Satoskar, A.R.; Karunaweera, N.D.INTRODUCTION & OBJECTIVES: Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani-MON 37, known to cause visceral leishmaniasis elsewhere. Localized immune response may play a role in disease outcome with T helper (Th) 1 response favouring lesion healing and Th2 response leading to disease progression in animal models. This study describes the localized host immune response to CL in Sri Lanka. METHOD: Skin punch biopsies from 58 patients with parasitologically confirmed CL and 25 healthy controls were quantified for cytokine gene expression of Th1 cytokines interferon (IFN)-γ, interleukin (IL)-12A and tumour necrosis factor (TNF)-α and Th2 cytokines, IL-4 and IL-10 by real-time RT-PCR. Relative copy numbers were calculated using the 2-ΔΔCt method. Non-parametric Mann-Whitney U test and the Spearman’s correlation test were used for statistical analysis. RESULTS: Study group consisted of 37 (63.8%) males and 21 (36.2%) females with a mean age of 35.0 years (SD=12.1, range=18-66), mean lesion duration of 6.75 ±9.1 months (range: 1-48) and a mean size of 176.59±185.76 mm2 (range: 12.6–908.3 mm2). Significant up regulation of IFN-γ (p<0.001) and down regulation of IL-4 (p<0.001) were seen in patients compared to healthy controls. Time taken for lesions to heal correlated significantly with in situ expression of IL-4 (Spearman’s r=0.321, p=0.034). CONCLUSION: Immune response to L. donovani induced CL in Sri Lanka tends to follow the typical Th1/Th2 convention with a Th2 biased milieu favouring poor responsiveness to antimony and delayed lesion healing.Item Study on Phlebotomine sand flies in selected areas in Sri Lanka(Sri Lanka College of Microbiologists, 2006) Senanayake, S.A.S.C.; Karunaweera, N.D.; Abeyewickreme, W.Sandflies are the known vectors of disease leishmaniasis. Though there are three clinical entities (viceral, mucocutaneous and cutaneous),^.only cutaneous form of the disease is seen in Sri Lanka. Presence of sandflies belonging to six species has been reported from various parts of the country since 1910. But the first indigenous case of cutaneous leishmaniasis was recorded in 1922. The number of cases rapidly increased during past few years and it is now been considered as an established disease. The causative organism of the disease is the protozoan parasite Leishmania donovani MON37. The vector of the Sri Lankan cutaneous leishmaniasis is still unknown. This study was carried out in two selected areas in Kurunegala and Matara ditricts where considerable number of patients was reported to the Department of Parasitology, Faculty of Medicine, Colombo. The objectives of the study were to identify the prevalent sandfly species in selected areas and establish the potential vector(s). The adult sandflies were collectedTrom four different sites in selected areas. Three different methodologies were used (cattle-baited net traps, CDC light traps, manual collection and mechanical aspirators). Collections were done for 18 months from Sep2004. Collected sandflies were dissected under dissecting microscope and mounted on glass slides. The specimens were examined under both light and phase contrast microscopes. A subset of collected samples were sent to CDC, Atlanta for molecular based identification. Blood fed females were subjected to gut dissection to demonstrate the presence of leishmania parasites within the vector. Real time PCR analysis was carried out with a subset of samples using Leishmania donovani primers. Two species of sandfies were identified in both areas. They were Phlebotomus argentepes and Sergentomiya zeylanica, two species which had been reported previously. P. argentepes is the established vector of visceral leishmaniasis in India and latter is a non human disease transmitter. A total of 3587 sandfies were examined (1756 from Matara and 1731 from Kurunegala) Male to female ratio of the collection was 6:1(3075 males and 522 females). Only 88 ( 5.01%) P. argentepes were found in Matara and rest 1168 (94.99%) were S. zeylanica. How ever, Kurunegala collection resulted with 1549 (89.48%) P. argentepes and 192 S. zeylanica. None of the method use to demonstrate leishmania parasites in sandflies gave positive results. Financial assistants by National Science Foundation for research Grant 2005 /HS/07 is acknowledged.Item Histopathological spectrum in acute and chronic cutaneous leishmaniasis in Sri Lanka(Sri Lanka College of Microbiologists, 2015) Manamperi, N.H.; de Silva, M.V.C.; Fernando, C.; Pathirana, K.P.N.; Abeyewickreme, W.; Karunaweera, N.D.OBJECTIVES: To describe the histological spectrum of acute and chronic cutaneous leishmaniasis. METHOD: Patients from Sri Lanka army were recruited by active and passive case detection methods and punch biopsies were obtained. Skin biopsies of 35 patients with smear positive for Leishmania amastigotes were processed routinely for histopathology, examined at a conference microscope and classified into 4 groups using modified Ridley criteria for Leishmaniasis as: I - parasitized macrophages with variable lymphocytes and plasma cells; II - parasitized macrophages with lymphocytes, plasma cells and ill formed histiocytic granulomata; III -a mixture of macrophages (with or without parasites), lymphocytes, plasma cells and epithelioid granulomata; IV - epithelioid granulomatous response with a few lymphocytes and plasma cells but no amasigotes. Lesions were categorized as acute (<6 months) or chronic (> 6 months). RESULTS: Study group composed of males with a mean age of 32.6 years (range 22-47) and lesion duration of 5.6 months (range 1-24). Twenty nine (82.9%) were also positive by histopathology. Twenty two (62.9%) were acute and 13 (37.1%) chronic. Group I, II, III and IV patterns were seen in 14 (40%), 12 (34.3%), 5 (14.3%) and 4 (11.4%) respectively and 9 (40.9%), 9 (40.9%), 2 (9.1%) and 2 (9.1 %) of acute lesions and 5 (38.5%), 3 (23.1 %), 3 (23.1 %) and 2 (15.4%) of chronic lesions respectively. CONCLUSION: Histology of cutaneous leishmaniasis shows marked inflammatory cell infiltrate with or without granuloma formation. Majority of patients presenting with either acute or chronic cutaneous leishmaniasis belong to histological groups I or II. ACKNOWLEDGEMENTS: Financial assistance from the University Grants Commission, Sri Lanka (UGC/VC/DRIC/PG/2013/KLN/ 03) and University of Kelaniya (RP/03/04/06/01/2014) are acknowledged. An abstract based on similar work was presented at the 128"1 Anniversary International Medical Congress of the Sri Lanka Medical Association, 5th to 8th July 2015.Item Histopathological spectrum in acute and chronic Cutaneous Leishmaniasis in Sri Lanka(Sri lanka Medical Association, 2015) Manamperi, N.H.; Fernando, C.; Pathirana, K.P.N.; Karunaweera, N.D.; Abeyewickreme, W.; de Silva, M.V.C.INTRODUCTION AND OBJECTIVES: Histological spectrum in cutaneous leishmaniasis (CL) is wide and varied. The objective of this study is to describe the histological spectrum of acute and chronic CL. METHOD: Skin biopsies of 35 patients with smear positive for Leishmania amastigotes were processed routinely for histopathology, examined at a conference microscope and classified into 4 groups using modified Ridley criteria for Leishmaniasis as: I- parasitized macrophages with variable lymphocytes and plasma ceils; 1! - parasitized macrophages with lymphocytes, plasma cells and ill formed histiocytic granulomata; 111 - a mixture of macrophages (with or without parasites), lymphocytes, plasma cells and epithelioid granulomata; IV - epithelioid granulomatous response with a few lymphocytes and plasma cells but no amastigotes. Lesions were categorized as acute (< 6 months) or chronic (> 6 months). RESULTS: Study group composed of all males with a mean age of 32.6 years (range 22 - 47) and lesion duration of 5.6 months (range 1-24). Twenty nine (82.9%) were also positive by histopathology. Twenty two (62.9%) were acute and 13 (37.1%) chronic. Group I, II, Ml and IV patterns were seen in 14 (40%), 12 (34.3%), 5 (14.3%) and 4 (11.4%) respectively and 9 (40.9%), 9 (40.9%), 2 (9.1%) and 2 (9.1%) of acute lesions and 5 (38.5%), 3 (23.1%), 3 (23.1%) and 2 (15.4%) of chronic lesions respectively. CONCLUSION: Histology of CL shows marked inflammatory cell infiltrate with or without granuloma formation. Majority of patients presenting with either acute or chronic CL belong to histological groups I or II.Item Clinical outcome of infection with L.donovani in Sri Lankan patients(Sri Lanka Medical Association, 2008) Siriwardana, H.V.Y.D.; Sirimanna, G.; Udagedara, C.; Chandrawansa, P.H.; Wickremasinghe, A.R.; Karunaweera, N.D.OBJECTIVE: To describe the clinical profile of leishmaniasis in Sri Lanka. DESIGN, SETTING AND METHODS: This prospective descriptive study was conducted on incident cases of suspected cutaneous leishmaniasis (CL) referred to the Department of Parasitology, Faculty of Medicine, Colombo over 4 years. An interviewer administered questionnaire was administered to obtain clinical information. Diagnosis was confirmed with microscopy and/or PCR. RESULTS: Four hundred and one (401) patients with 549 lesions were studied. Over 70% lesions were parasitologically confirmed and further analyzed. The majority were soldiers (57.4%). The male to female ratio was 4:1. The majority were single lesions (73.9%) on exposed areas (forearms/hands- 44.1%), face/head/neck/pinna region-30.1%). Lesion included: papules (23.4%), nodules (25.4%), ulcerating nodules (19.6%), ulcers (23.7%), plaques (6.4%) and other types (1.7%). Non ulcerative lesions (NUL) were the commonest type observed up to 6 months. After 6-9 months, the proportion of ulcerative lesions was almost twice as that of NUL (60.8% vs 31.4%), Parasite positivity was highest in nodules (n=100, 75.5%), and in lesions of 5-9 months duration, and lowest in ulcers (n=92, 65.8%). After 12 months, the majority of leishmanial skin lesions either showed complete ulceration (44.1%) or remained non ulcerative (47.1%). Lesions in their 3rd year were mainly papules (42.9%) or ulcers (35.7%). Chronic lesions (>lyear) were mainly single. Sporo-trichoid spread (n=44, 11.9%), satellite lesions (n=35, 8.9%) and lymphatic spread (n=109, 27.7%) were observed. CONCLUSIONS: CL affects many provinces of the country, with most patients referred to this department from northern and southern provinces. Males comprised the majority of cases probably due to their higher risk due to exposure to outdoor biting habits of Phlebotomus sp. sand flies as an occupational hazard. The clinical spectrum of CL in Sri Lanka is wide. Parasitological confirmation of the diagnosis is important and investigations performed between 5-9 months of duration of a lesion may have higher chances of detecting parasites/parasite DNA.Item Integrated school-based surveillance for soil-transmitted helminth infections and for lymphatic filariasis in Gampaha district, Sri Lanka(American Society of Tropical Medicine and Hygiene, 2013) Gunawardena, N.K.; Gunawardena, S.; Kahathuduwa, G.; Karunaweera, N.D.; de Silva, N.R.; Ranasinghe, U.S.; Rao, R. U.; Rebollo, M.; Weil, G. J.The Sri Lankan Anti-Filariasis Campaign (AFC) conducted 5 rounds of annual mass drug administration (MDA) with albendazole and DEC in 2002-2006 in 8 districts that were endemic for lymphatic filariasis (LF) (target population approximately 10 million). AFC conducted transmission assessment surveys (TAS) in 2012, about 6 years after the last round of MDA. This study explored the practicality of integrating surveillance for soil transmitted helminth (STH) infections with TAS for LF in Gampaha district (population 2.3 million). The district was divided into two Evaluation Units (EUs), coastal and inland. Each TAS tested 1st and 2nd grade school children drawn from 30 randomly selected schools (N=1,462 inland, 1,642 coastal). Tests included the ICT card test for filarial antigenemia (performed by AFC personnel) and the Kato-Katz test for detection of STH ova (performed by university personnel). ICT rates were 0% and 0.1% (0.01-0.3% CI) in the inland and coastal EUs, respectively. These results suggest that LF transmission rates are very low in Gampaha District. The STH survey was conducted at the same time as the TAS in the inland EU (955 stools from 1,211 children) and several weeks after the TAS in the coastal EU (927 stools from 1,586 children). STH infection rates and stool sample participation rates were 0.8% and 79% in the inland EU and 2.8% and 58% in the coastal EU. Most of the STH infections detected were lowintensityTrichuris (present in 73% of positive stools). The low STH rates are probably due to the country’s national school deworming program (mebendazole in grades 1, 4, and 7) and relatively good sanitation in Gampaha district. The cost for STH testing was approximately $5,000 per EU. These results suggest that it is feasible for national NTD programs to integrate school based surveillance for STH and LF. Further work is needed to streamline procedures and to determine optimal sampling strategies for STH surveys, because these may not require as many samples or sampling sites as TAS.Item Clinical features of cutaneous leishmaniasis in Sri Lanka and molecular identification of L. donovani as the cause(Elsevier, 2008) Siriwardana, H.V.Y.D.; Noyes, H.A.; Beeching, N.J.; Wickremasinghe, A.R.; Chance, M.L.; Bates, P.A.; Karunaweera, N.D.BACKGROUND: Cutaneous leishmaniasis (CL) is a newly established disease in Sri Lanka with over 1500 locally acquired cases reported since year 2001. OBJECTIVES: To study the clinical profile, associated risk factors and genetic analysis of the causative parasite of CL in Sri Lanka. METHODOLOGY: Clinical evaluation was carried out on patients who visited the Department of Parasitology, Faculty of Medicine, Colombo for diagnosis using a pre-tested questionnaire. Light microscopy and/or PCR were performed on lesion material to confirm diagnosis. Formol gel test (FGT) was done on all patients. The causative species was identified by sequencing of the partial 6PGDH gene, followed by microsatellite analysis to study the phylogenetic relationships. RESULTS: There were 401 patients (78.9% males, out of which 57.4% were soldiers) with at least 549 lesions. Most infections were acquired in Northern (55.7%) or Southern (39.3%) Sri Lanka. Several lesion types were noted: papules 23.4%, nodules 25.4%, ulcerating nodules 19.6%, ulcers 23.7%, plaques 6.4% and other 1.7%. Nodules with 5–9 months duration had the highest parasite positivity (n = 100, 75.5%). Sporotrichoid spread (n = 44, 11.9%), satellite lesions (n = 35, 8.9%) and lymphatic spread (n = 109, 27.7%) were commonly observed. No patients had visceral features and the FGT was negative in all subjects. Male sex, 20–40 years of age and over 5 hours/day spent outdoors were identified as risk factors, but not household clustering. The causative species was identified as L. donovani, belonging to a distinct genetic group within that complex. CONCLUSIONS: A dermotrophic variant of L. donovani causes cutaneous leishmaniasis in Sri Lanka. The ability of the local Leishmania parasite to visceralize, self heal or develop drug resistance is yet to be determined. In spite of the generally accepted anthroponotic nature of L donovani, in this study favours zoonotic transmission of the local species. Acknowledgements: Mr. RL Ihalamulla, Mr. S Jayasinghe for technical assistance. Financial support for this study was from Sri Lanka National Science Foundation and the Commonwealth Scholarship Association. © 2008 Elsevier Inc.Item Cost analysis of application of Poecilia reticulata (guppy) and temephos in anopheline mosquito control in river bed pools below the major dams in Sri Lanka(Sri Lanka Association for the Advancement of Science, 2004) Kusumawathie, P.H.D.; Wickremasinghe, A.R.; Karunaweera, N.D.; Wijeyaratne, M.J.S.