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 Randomized placebo-controlled trial of the efficacy of mebendazole polymorphs in the treatment of hookworm infections(Sri Lanka College of Microbiologists, 2013) Gunawardena, N.K.; Kumarendran, B.; Manamperi, N.H.; Senarathna, B.P.; Silva, M.; Pathmeswaran, A.; de Silva, N.R.INTRODUCTION: Mebendazole has three polymorphic forms, identified as A, B and C. Animal studies and one previous study in humans have suggested that unlike polymorph C, polymorph A is ineffective in the treatment of hookworm and whipworm infections. OBJECTIVES: A randomized double-blind, placebo-controlled trial was carried out to compare the efficacy of single dose 500 mg tablets of pure mebendazole polymorph C with those containing a 1:1 mixture of polymorphs Aand C, for the treatment of hookworm infections. . DESIGN, SETTING AND METHODS: All eligible individuals living in 219 households in 8 estate divisions in Ratnapura District known to have a high prevalence of hookworm, were recruited after obtaining written, informed consent. A single faecal sample was obtained and examined the same day, using the Kato-Katz technique for quantification of intestinal nematode infections. Those who were found infected with hook¬worms were randomized to one of three treatment arms and requested to provide a second faecal sample 10-14 days after treatment. This was examined in the same manner as the first. RESULTS: A total of 892 individuals were recruited; 601 provided faecal samples; 214 were found positive for hookworm infection; 70, 74 and 70 individuals were randomized to treatment arms A (mixture of polymorphs A and C), B (pure polymorph C) and C (placebo) respectively. Follow-up faeca! samples were provided by 53,48 and 49 persons respectively in each treatment arm. The cure rates in the three treatment arms were 28.3%, 18.8% and 16.3% respectively; they were not significantly different from one another. Comparison of faecal egg count reductions (FECR) in the 3 treatment arms (86.1%, 84.5% and -6.6% in arms A, B and C respectively) showed that both mebendazole formulations performed significantly better than placebo, but there was no statistically significant difference between FECR with the two drug formulations. CONCLUSIONS: A single SOOmg dose of mebendazole, either as Polymorph C alone, or as a mixture of Polymorphs A and C, has little efficacy in curing hookworm infections. However, both formulations are significantly better than placebo in reducing the intensity of infection, with no statistically significant difference between the two formulations.Item Comparison of laboratory techniques for diagnosis of hookworm infections(Sri Lanka College of Microbiologists, 2011) Manamperi, N.H.; Anjalee, K.G.C.; Gunawardena, N.K.; Sudusinghe, H.; Nilaweera, T.H.W.T.; de Silva, N.R.INTRODUCTION: Hookworm infection may be diagnosed by detection of eggs or culturing of larvae from stools. OBJECTIVE: To compare the efficacy of modified Kato-Katz (K-K) technique, saline smears, Harada-Mori (H-M) and nutrient agar culture plate (NACP) methods in diagnosis of hookworm infections. METHODOLOGY: A total of 324 stool samples, from the plantation sector families in Ratnapura district were examined by modified Kato-Katz technique and saline smears, and cultured by Harada-Mori and on NACP according to standard protocols, at the Faculty of Medicine, Ragama. Harada-Mori and NACP were maintained for 7-10 days and larvae or larval tracts observed by a stereomicroscope. Positivity in any two of the four techniques was considered the gold standard positive. Statistical analysis was done using SPSS version 16. RESULTS: A total of 172 (53.1%) samples were positive by at least one method. The positivity rates with K-K, H-M, NACP and saline smears were 42.3% (137/324), 37.7% (122/324), 23.5% (76/324) and 22.2% (72/324) respectively. The highest sensitivity (89.8%) and lowest specificity (88.3%) was seen in modified K-K, the lowest sensitivity (50.4%) in saline smears and the highest specificity in NACP (98.5%). Detection rates with saline smears, H-M and NACP rose with increasing intensity of infection as determined by K-K technique. Harada-Mori had the highest detection rate (70.7%) in light infections. It also detected 11.8% of K-K negative samples. CONCLUSIONS: The modified K-K technique is a reasonably good diagnostic method for detection of hookworm infections. A combination of methods will increase the diagnostic accuracy in hookworm infections.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 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 Randomized placebo-controlled trial of the efficacy of mebendazole polymorphs in the treatment of hookworm infections(American Society of Tropical Medicine and Hygiene, 2013) Gunawardena, N.K.; Kumarendran, B.; Manamperi, N.H.; Senarathna, B.P.; Silva, M.; Pathmeswaran, A.; de Silva, N.R.Mebendazole has three polymorphic forms, identified as A, B and C. It has been suggested that unlike polymorph C, A is ineffective in the treatment of hookworm and whipworm infections. A randomized doubleblind, placebo-controlled trial was carried out to compare the efficacy of single dose 500 mg tablets of pure mebendazole Polymorph C with those containing a 1:1 mixture of Polymorphs A and C, for the treatment of hookworm infections. All eligible individuals living in 219 households were recruited after obtaining written, informed consent. A single fecal sample was obtained and examined the same day, using the Kato-Katz technique for intestinal nematode infections. Those who were found infected with hookworms were randomized to one of three treatment arms and requested to provide a second faecal sample 10 - 14 days after treatment. This was examined in the same manner as the first. A total of 892 individuals were recruited; 601 provided fecal samples; 214 were found positive for hookworm; 70, 74 and 70 individuals were randomized to treatment arms A (mixture of polymorphs A and C), B (pure polymorph C) and C (placebo) respectively. Follow-up samples were provided by 53, 48 and 49 persons respectively in each treatment arm. The cure rates in the three treatment arms were 28.3%, 18.8% and 16.3% respectively; they were not significantly different from one another. Comparison of fecal egg count reductions (FECR) in the 3 treatment arms (86.1%, 84.5% and -6.6% in Arms A, B and C respectively) showed that both mebendazole formulations performed significantly better than placebo, but there was no statistically significant difference between FECR with the two drug formulations. It is concluded that a single 500mg dose of mebendazole, either as Polymorph C alone, or as a mixture of Polymorphs A and C, has little efficacy in curing hookworm infections. However, both formulations were significantly better than placebo in reducing the intensity of infection, with no statistically significant difference between the two formulations.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)