Conference Papers
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/6561
This collection contains abstracts of conference papers, presented at local and international conferences by the staff of the Faculty of Medicine
Browse
64 results
Search Results
Item A Statistical Approach to Define Thresholds for Dengue Epidemic Management in Akurana Medical Officer of Health Area, Kandy District of Sri Lanka(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Udayanga, N.W.B.A.L.; Gunathilaka, P.A.D.H.N.; Iqbal, M.C.M.; Fernando, M.A.S.T.; Abeyewickreme, W.Stegomyia indices, namely; Premise Index (PI), Breteau Index (BI) and Container Index (CI) are used forvector management approaches in Sri Lanka. Properly defined threshold values for larval indices are of higher importance to provide forecasts on dengue epidemics and also for effective larval management of dengue vectors. However, such critical thresholds are poorly defined for Sri Lanka. The present study aimed to define threshold values forabove larval indices for dengue epidemic management in the Akurana Medical Officer of Health (MOH) in the Kandy District. Larval surveys were conducted on a monthly basis from January, 2016 to June, 2018. Four larval indices, namely BI for Aedesaegypti (BIA) and Aedesalbopictus (BIB), PI and CI were calculated. Further, monthly larval indices of AkuranaMOH area from January, 2012 to December, 2015, were obtained from the MOH office, along with monthly reported dengue cases for the entire study period. Receiver Operating Characteristic (ROC) curves in SPSS (version 23) were used to assess the discriminative power of the larval indices in determiningdengue epidemics and thresholds based on larval indices. As indicated by the area of ROC curve (AUC), the BIA (0.661) and PI (0.637) were having a notable discriminative power to forecast dengue epidemics at a two-month lag period. Both BIB (0.397) and CI (0.526) were non-informative influencers at one and two-month lag periods. The BIA and PI were better predictors of dengue incidence than BIB and CI. Based on the ROC curve, three risk thresholds were defined for BIA as Low Risk (BIA≤2.1), Moderate Risk (3.9≤BIA<4.85), and High Risk (BIA≥4.85), with respect to Ae. aegypti. According to the PI, thresholds were defined as Low Risk (PI≤6.2), Moderate Risk (7.7≤ PI<9.9), and High Risk (PI≥ 9.9). Threshold values defined for BI of Ae. aegypti and PI, could be recommended to be considered in implementing vector control efforts in the above study area for effective dengue epidemic management, through pre planned entomological management of dengue vectors.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 Clearance of microfilaraemia and red blood cell glutathione peroxidase(GPX) levels in asymptomatic microfilaraemics after single dose and 14 days’ treatment with diethyl carbamazine citrate(DEC) (Sri Lanka Medical Association, 2001) Premaratna, R.; Chandrasena, T.G.A.N.; Abeyewickreme, W.; de Silva, N.R.; Chandrasena, L.G.; de Silva, H.J.Abstract AvailableItem Clearance of microfilaraemia and red blood cell glutathione peroxidase(GPX) levels in asymptomatic microfilaraemics after single dose and 14 days’ treatment with diethyl carbamazine citrate(DEC)(Wiley, 2001) Premaratna, R.; Chandrasena, T.G.A.N.; Abeyewickreme, W.; de Silva, N.R.; Chandrasena, L.G.; de Silva, H.J.Abstract AvailableItem Red blood cell antioxidant levels after treatment with diethyl carbamazine(Wiley, 2001) Premaratna, R.; Chandrasena, T.G.A.N.; Abeyewickreme, W.; de Silva, N.R.; Chandrasena, L.G.; de Silva, H.J.Abstract AvailableItem Red blood cell antioxidant levels after treatment with diethyl carbamazine citrate in persons with asymptomatic microfilaraemia(Sri Lanka Medical Association, 2001) Premaratna, R.; Chandrasena, T.G.A.N.; Abeyewickreme, W.; de Silva, N.R.; Chandrasena, L.G.; de Silva, H.J.Abstract AvailableItem Paediatric rotavirus diarrhoea in Sri Lanka: a preliminary report(Sri Lanka College of Paediatricians, 2007) Chandrasena, T.G.A.N.; Rajindrajith, S.; Ahmed, K.; Pathmeswaran, A.; Abeyewickreme, W.; Nakagomi, O.BACKGROUND: Group A rotavirus is the leading cause of acute gastroenteritis in children. Serotypes Gl, G2, G3 and G4 are mainly responsible for human infections. Strain characterization and serotype distribution of rotavirus in a country is an importaa determinant of future vaccine strategy. Information in this regard is scarce in Sri Lanka. OBJECTIVES: To determine the prevalence, severity and molecular epidemiology of rotavirus diarrhoea among children hospitalized with diarrhoea in Sri Lanka. DESIGN, SETTING AND METHOD: A prospective hospital-based study was conducted in the paediatric units of the North Colombo Teaching Hospital from April 2005-February 2006. Stool samples of children admitted with diarrhoea were analyzed for Group A rotavirus antigen by enzyme linked immunosorbent assay (EL1SA) (Rotaclone). Samples positive for rotavirus were characterized electropherotyping (PAGE) and serotyping (reverse transcription-poiymerase chain reaction (RT-PCR)) respectively. Severity of diarrhoea was assessed by the Vesikari severity score. RESULTS: A total of 341 children [204 males mean age 25.7 months (range 1-144)] were studied. Sixty seven (19.6%) had rotavirus diarrhoea. RT-PCR and PAGE were done on 58 rotavirus positive samples. Thirty one were PAGE positive with 6 different electropherotypes. RT-PCR revealed the presence of serotypes Gl, G2, G3, G4 and G9 in 7 (12.1%), 16 (27.6%),2 (3.4%), 2 (3.4%), and 11 (19.0%) samples respectively. Twenty (34.5%) were untypable. Severity score, assessed in 326 patients, revealed a mean score of 13.3 and 11.4 in rotavirus positive and negative patients respectively (p=0.05). Presence frequency and duration of vomiting and duration of diarrhoea were significantly higher in rotavirus diarrhoea (p<0.05). CONCLUSIONS: Rotavirus is an important agent of severe paediatric diarrhoea in Sri Lanka. Molecular analysis indicates genetic diversity among group A rotavirus in Sri Lanka. This study reports for the first time of G9 type rotavirus infection in Sri Lanka.Item Optimization of the cell culture media to obtain the most effective nutrient concentrations in the medium for the growth and maintenance of the Myeloma cells(University of Peradeniya, 2015) Munasinghe, M.M.E,; Athapaththu, A.M.M.H.; Gunathilaka, H.N.; Abeyewickreme, W.Cell culture can be described as the removal of cells, tissues or organs from an animal or a plant and their subsequent placement into an artificial environment. Basically, proper temperature, substrate for cell attachment, appropriate growth medium and correct pH and osmolality in the medium should be properly maintained in order to achieve a better growth in the cells. Typically, a culture medium is composed of a complement of amino acids, vitamins, inorganic salts, glucose, and serum as a source of growth factors, hormones, and attachment factors. The objective of this study is to optimize culture media in order to obtain the most effective nutrient concentrations in the medium for the growth/maintenance of NSO Myeloma cell. Myeloma cells for the monoclonal antibody production were prepared using Dulbecco's Modified Eagle Medium (DMEM) as the growth media for the NSO cell culture. In this study, the culture media was optimized in order to obtain the most effective concentrations in the media. Primarily, in order to culture the cells soon after thawing, 10% growth media was used and then the grown cells were transferred in to a nutrition rich media- Hypoxanthine Thymidine (HT) medium. The growth of the Primary cell culture, soon after thawing, was observed within 2 days of culturing. A 60% of the bottom of the culture flask was covered with the healthy NSO myeloma cells. The transferred cells were also grown to a rate of 60% within 2 days of transferring. The 10% growth media comprises with 422 mL of DMEM with added 4500 mg/L glucose without L-glutamine and sodium pyruvate, 50 mL of Fetal Clone Serum, IZ5 mL of 1M HEPES buffer (4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid), 5 m of 200 mM Glutamin, 5 mL of 100X Non-essential amino acids, 5 mL of 100 mM Sodium pyruvate and 0.5 mL of 55mM jj-mercaptoethanol. The HT medium comprises with 366.5 422 mL of DMEM with added 4500 mg/L glucose without L- glutamine and sodium pyruvate, 100 of mL FetalClone serum, 12.5 mL of 1M HEPES buffer, 5 mL 100X HT supplement, 5 mL of 200 mM Glutamin, 5 mL of 100X Non-essential amino acids, 5 mL of 100 mM Sodium pyruvate, 0.5 mL of 50 mg/mL Genatamicin, 0.5 mL of 55 mM p-mercaptoethanol and 25 uL of Interlukin-6. Since both the culture media showed optimum growth of the Myeloma cells, the above protocol with the provided concentrations of the nutrients could be used to maintain/ grow NSO myeloma cell line in the laboratory.Item Evaluation of the spatial and temporal trends of dengue outbreaks in Gampola, Central Province, Sri Lanka(University of Peradeniya, 2015) Udayanaga, N.W.B.A.L.; Gunathilaka, H.N.; Iqbal, M.C.M.; Abeyewickreme, W.Dengue is the world's fastest growing vector borne disease, and it has become one of the major health concerns in many countries including Sri Lanka. Despite immense efforts and control strategies it claims 30,000 - 35,000 deaths per year, making dengue a priority heath issue in Sri Lanka. Investigation of the recent trends of dengue outbreaks on both a spatial and temporal scale is of high importance in drafting and implementing effective management/action plans to ensure successful management and control of dengue epidemics on a regional scale. Hence, a statistic and geo informatics based analysis of the recent trends in dengue distribution was carried out to identify spatial and temporal trends in distribution patterns of dengue in the Gampola Medical Officer of Health (MOH) division. Monthly records of reported dengue cases from 2009 to 2013 of the Gampola MOH division were collected. A scatter plot analysis in MINITAB (version 14.12.0) was devised to identify the temporal patterns in the reported dengue cases. Arc GIS (version 10.1) was devised to develop spatial maps (at the GND level) of the recorded dengue case distribution for each month and for the whole study period, for Gampola. Furthermore, spatial (at GND level) and temporal (annual) variations in dengue outbreak distribution within the Gampola MOH were analyzed to recognize the recent trends in dengue distribution. Gampola East, Gampola West, Illawathura, Keerapane, Kahatapitiya, Egodakalugamuwa and Pussellawa localities emerged as high-risk areas, while Polkumbura, Kurukude, Galgediyawa, Amuhena and Hunukotugama emerged as low risk areas for dengue outbreaks. Further localities, namely Godagama, Kalugalhinna, Kekulanda, Millagaspitiya, Sinhapitiya North, Sinhapitiya South, Pussellawagama, Ranawala and Wanahapuwa remained unchallenged by dengue throughout 2009 - 2013. The paired-Chi square test revealed significant spatial and temporal variations in the emergence of dengue outbreaks within the Gampola MOH throughout the study period \>x2 w. 0.95} = 65.156]. Regionalized evaluation of recent trends in temporal and spatial distribution of dengue outbreaks are recommended in the design and implementation of management plans to control the rise of dengue, and also in the evaluation of the effectiveness of already implemented practices taken to reduce and control dengue outbreaks, by the government sector and other relevant entities.Item Establishment and maintenance of laboratory colonies of Aedes albopictus mosquitoes(University of Peradeniya, 2015) Wijegunawardana, A.D.; Gunathilaka, H.N.; Dassanayake, R.; Gunawardene, Y.I.N.S.; Abeyewickreme, W.With a mission of "providing authenticated, high-quality Aedes albopictus mosquito rearing information to the research community" maintenance of a Ae. albopictus mosquito colony was started. All environmental facilities inside the insectary were carefully maintained to better suit the Ae. albopictus mosquito colonization. The mean temperature of 27°C (± 0.5°C) was constantly maintained inside the insectary. Wet towels on adult mosquito cage racks were used for proper maintenance of humidity. Lighting was using fluorescent light and regulated with 16:8 hour continuous dark and light period. Pest insect was controlled to ensure essential absence of ants and cockroaches. This was achieved without any harm to the mosquito colonies either directly or by contamination with toxicants transported by pests. An adult mosquito trap placed inside the insectary was used to monitor released mosquitoes. Consistent effort was also made to improve the level of cleanliness inside the insectary. Written guidelines were given to each person responsible for a task. Insectary operations included egg counting, preparation of hatching bottles with boiled distilled water following cooling to room temperature, egg hatching, larvae rearing with International Atomic Energy Agency (IAEA) recommended diet of tuna meal, bovine liver powder, brewery yeast and vitamin complex in a ratio of 37.5:27:10.5:2 g in 1L up to one week, pupae counting and putting into adult emergency cages, adult male feeding with 10% sugar solution with Vitamin complex, adult female blood feeding from 4th day onwards with bovine blood, placing egg laying cups and collecting egg laying cups, drying egg papers and starting next generation from the dried eggs. Adult mosquito cages were blood fed every 4th day after emergence from pupa and for quality control reasons each adult cage was blood fed only 3 times and there after only 10% sugar solution with vitamin syrup was supplemented until all adult mosquitoes died. Documentation for maintenance and data record was maintained and updated daily. Records included larvae feeding records, larvae tray maintenance and cleaning charts, adult feeding records with both sugar solution and blood, insectary cleaning records with time and dates. Number of eggs and percentage of egg hatching, larvae death, pupation, adult emergence, egg laying and adult mosquito death with respect of the sex and time difference were recorded. For bio-safety reasons all discarded material from larvae trays, egg laying cups and adult cages were boiled thoroughly to facilitate total destruction of the contaminated mosquito eggs. All other infectious material were incinerated. Finally, all above conditions facilitated achievement of 100% egg hatching rate within maximum of 24 hours, 100% survival of larvae to pupa (~ 7 days), 100% survival of pupated larvae to adult emergence (~ 2 days) and 95.5% adult survival up to 12 days. No difference was observed on adult longevity between males and females within first 12 days of adult emergence. However, approximate life span for males (-17 days) was lower than the females (~ 25 days) and the mortality was regular through all generations (Fl to F21).