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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty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 Malaria control, elimination, and prevention as components of health security: A review(American Society of Tropical Medicine and Hygiene, 2022) Perera, R.; Wickremasinghe, R.; Newby, G.; Caldera, A.; Fernando, D.; Mendis, K.International travel, a major risk factor for imported malaria, has emerged as an important challenge in sustaining malaria elimination and prevention of its reestablishment. To make travel and trade safe, the WHO adopted the International Health Regulations (IHR) which provides a legal framework for the prevention, detection, and containment of public health risks at source. We conducted a systematic review to assess the relevance and the extent of implementation of IHR practices that can play a role in reducing malaria transmission. Selected studies addressed control, elimination, and prevention of reestablishment of malaria. Study themes focused on appraisal of surveillance and response, updating national policies to facilitate malaria control and elimination, travel as a risk factor for malaria and risk mitigation methods, vector control, transfusion malaria, competing interests, malaria in border areas, and other challenges posed by emerging communicable diseases on malaria control and elimination efforts. Review results indicate that malaria has not been prioritized as part of the IHR nor has the IHR focused on vector-borne diseases such as malaria. The IHR framework in its current format can be applied to malaria and other vector-borne diseases to strengthen surveillance and response, overcome challenges at borders, and improve data sharing-especially among countries moving toward elimination-but additional guidelines are required. Application of the IHR in countries in the malaria control phase may not be effective until the disease burden is brought down to elimination levels. Considering existing global elimination goals, the application of IHR for malaria should be urgently reviewed and included as part of the IHR.Item Susceptibility to malaria during the prevention of re-establishment phase in Sri Lanka(BioMed Central, 2022) Jeevatharan, H.; Wickremasinghe, R.BACKGROUND: Sri Lanka eliminated malaria in November 2012 and was certified malaria-free by the World Health Organization (WHO) in September 2016 but is facing a challenge to prevent re-establishment of malaria. Influx of travellers from malarious countries and the presence of malaria vectors in formerly endemic areas make the country both receptive and vulnerable. Susceptibility to malaria, the predisposition of populations to be infected by malaria parasites, is influenced by biologic and generic factors such as the age-sex composition, socio economic status, and the migration history of the population. The aim of this study was to assess susceptibility to malaria during the prevention of re-establishment phase in Sri Lanka. METHODS: A national survey was conducted among 3454 households. A multistage cluster sampling technique was used to select the households. Susceptibility was assessed based on pre-defined variables by interviewing heads of households using an interviewer-administered questionnaire. Basic socio-demographic information, travel history, history of fever and past malaria infections in the preceding three years were collected. Data were analysed using SPSS version 20 package. RESULTS: The percentage of the population who had been overseas within the last 3 years in the urban sector (4.5%, n = 99) was higher than that of the rural (2.8%, n = 288) and estate sectors (0.2%, n = 2) (p < 0.001); it also declined with the wealth index up to the 4th quintile with a slight rise in the 5th quintile (p < 0.001). The likelihood of travel overseas was 1.75 times (95% CI: 1.38-2.22) higher for urban residents as compared rural estate residents; it was 1.46 times (95% CI: 1.16-1.92) higher for persons from the upper wealth index quintile as compared to persons from the 1st and 2nd quintiles after controlling for sex, age and area of residence. 177 persons had fever within the past 2 weeks of the survey. There was no association between presence of fever within the last 2 weeks and sector or travel abroad. CONCLUSIONS: Urban residents, upper socioeconomic class persons and males are more likely to travel overseas and bring the parasite into the country. Social vulnerability and risk of re-establishment of malaria can be assessed by combining susceptibility with resilience and receptivity.Item Epidemiological profile of imported malaria cases in the prevention of reestablishment phase in Sri Lanka(Taylor & Francis, 2022) Dharmawardena, P.; Premaratne, R.; Wickremasinghe, R.; Mendis, K.; Fernando, D.ABSTRACT: Sri Lanka reported the last case of indigenous malaria in October 2012, and received malaria-free certification from WHO in September 2016. Malaria cases have since, shifted from indigenous to imported, and the country remains receptive and vulnerable to malaria. A case-based epidemiological study was conducted on all imported malaria cases reported in the country in 2015 and 2016 with the aim of profiling imported malaria to improve the effectiveness of the surveillance and case management system for malaria. Data were obtained from case reports of the Anti Malaria Campaign, hospital records and laboratory registers. Over the 2 years, 77 imported malaria infections were diagnosed in 54 Sri Lankans and 23 foreign nationals. A majority of the infections were reported among males (93%) in the age group of 21-50 years (85.8%), and all were recent travelers overseas. Most patients were detected by passive case detection, but 10% of cases were detected by Active Case Detection. Only 25% of patients were diagnosed within 3 days of the onset of symptoms. In 32% of patients, the diagnosis was delayed by more than 10 days after the onset of symptoms. Plasmodium falciparum infections manifested significantly earlier after arrival in Sri Lanka than did P.vivax infections. The majority of patients (74%) were diagnosed in the Western Province, which was not endemic for malaria. A third of patients were diagnosed in the private sector. The shift in the epidemiology of malaria infection from before to after elimination has implications for preventing the reestablishment of malaria. KEYWORDS: Imported malaria; case surveillance; delayed diagnosis; epidemiology; prevention of reestablishment; receptivity; risk factors.Item Preventing the re-establishment of malaria in Sri Lanka amidst the COVID-19 pandemic(BioMed Central, 2020) Ranaweera, P.; Wickremasinghe, R.; Mendis, K.ABSTRACT: The COVID-19 pandemic has had a considerable impact on other health programmes in countries, including on malaria, and is currently under much discussion. As many countries are accelerating efforts to eliminate malaria or to prevent the re-establishment of malaria from recently eliminated countries, the COVID-19 pandemic has the potential to cause major interruptions to ongoing anti-malaria operations and risk jeopardizing the gains that have been made so far. Sri Lanka, having eliminated malaria in 2012, was certified by the World Health Organization as a malaria-free country in 2016 and now implements a rigorous programme to prevent its re-establishment owing to the high receptivity and vulnerability of the country to malaria. Sri Lanka has also dealt with the COVID-19 epidemic quite successfully limiting the cumulative number of infections and deaths through co-ordinated efforts between the health sector and other relevant sectors, namely the military, the Police Department, Departments of Airport and Aviation and Foreign Affairs, all of which have been deployed for the COVID-19 epidemic under the umbrella of a Presidential Task Force. The relevance of imported infections and the need for a multi-sectoral response are features common to both the control of the COVID-19 epidemic and the Prevention of Re-establishment (POR) programme for malaria. Sri Lanka's malaria POR programme has, therefore, creatively integrated its activities with those of the COVID-19 control programme. Through highly coordinated operations the return to the country of Sri Lankan nationals stranded overseas by the COVID-19 pandemic, many from malaria endemic countries, are being monitored for malaria as well as COVID-19 in an integrated case surveillance system under quarantine conditions, to the success of both programmes. Twenty-three imported malaria cases were detected from February to October through 2773 microscopic blood examinations performed for malaria in quarantine centres, this number being not much different to the incidence of imported malaria during the same period last year. This experience highlights the importance of integrated case surveillance and the need for a highly coordinated multi-sectoral approach in dealing with emerging new infections. It also suggests that synergies between the COVID-19 epidemic control programme and other health programmes may be found and developed to the advantage of both. KEYWORDS: Contact tracing; Malaria and COVID-19; Multi-sectoral health collaboration; Prevention of re-establishment of malaria; Quarantine.Item A Comprehensive analysis on abundance, distribution, and bionomics of potential malaria vectors in Mannar District of Sri Lanka(Hindawi Publishing Corporation, 2019) Gunathilaka, N.; Hapugoda, M.; Wickremasinghe, R.; Abeyewickreme, W.BACKGROUND:A detailed knowledge of the distribution of the malaria vectors in Mannar district of Sri Lanka has not been studied after 1927. Past records indicated the presence of only seven species of anophelines, namely, An. culicifacies, An. subpictus, An. barbirostris, An. peditaeniatus, An. nigerrimus, An. Jamesii, and An. maculatus. There have been many changes in terms of distribution of Anopheles in the district over time. METHODS: Entomological surveillance was conducted on a monthly basis, comprising indoor hand collection, window trap collection, cattle-baited net collection, cattle-baited hut collection, and larval survey from June 2010 to June 2012 in 12 study areas under three entomological sentinel sites. The relationship between seven abiotic variables of the breeding habitats was measured. Pearson's correlation coefficients were used to determine the associations between climatic variables and anopheline densities. RESULTS:A total of 74,181 mosquitoes belonging to 14 Anopheles species were recorded. An. subpictus was the most predominant species from all techniques representing 92% (n=68,268) of the total anopheline collection. However, Anopheles culicifacies was not recorded from any site during the study period. Larval surveys identified 12 breeding habitat categories including waste water collections, lagoon water collections, and drains which were not recorded as breeding habitats by previous studies. The mean dissolved oxygen level of waste water collections was 3.45±0.15 mg/l. The mean salinity and conductivity of lagoon water collections were 21105±1344 mg/l and 34734±1974 μs/cm, respectively.CONCLUSION: The present study provides the updated knowledge on anopheline distribution and vector bionomics. Therefore, documentation of the current knowledge would be useful for learners and health authorities to design appropriate vector control measures in the prevention of reintroduction of malaria.Item Use of a public-private partnership in malaria elimination efforts in Sri Lanka; a case study(BioMed Central, 2018) Fernando, D.; Wijeyaratne, P.; Wickremasinghe, R.; Abeyasinghe, R.R.; Galappaththy, G.N.L.; Wickremasinghe, R.; Hapugoda, M.; Abeyewickreme, W.; Rodrigo, C.BACKGROUND: In special circumstances, establishing public private partnerships for malaria elimination may achieve targets faster than the state sector acting by itself. Following the end of the separatist war in Sri Lanka in 2009, the Anti Malaria Campaign (AMC) of Sri Lanka intensified malaria surveillance jointly with a private sector partner, Tropical and Environmental Diseases and Health Associates Private Limited (TEDHA) with a view to achieving malaria elimination targets by 2014. METHODS: This is a case study on how public private partnerships can be effectively utilized to achieve malaria elimination goals. TEDHA established 50 Malaria Diagnostic Laboratories and 17 entomology surveillance sentinel sites in consultation with the AMC in areas difficult to access by government officials (five districts in two provinces affected by war). RESULTS: TEDHA screened 994,448 individuals for malaria, of which 243,867 were screened at mobile malaria clinics as compared to 1,102,054 screened by the AMC. Nine malaria positives were diagnosed by TEDHA, while the AMC diagnosed 103 malaria cases in the same districts in parallel. Over 13,000 entomological activity days were completed. Relevant information was shared with AMC and the data recorded in the health information system. CONCLUSIONS: A successful public-private partnership model for malaria elimination was initiated at a time when the health system was in disarray in war ravaged areas of Sri Lanka. This ensured a high annual blood examination rate and screening of vulnerable people in receptive areas. These were important for certification of malaria-free status which Sri Lanka eventually received in 2016.Item Prevalence of Anopheline species in Ampara district, Sri Lanka(University of Kelaniya, 2012) Fernando, M.A.S.T.; Gunathilaka, P.A.D.H.N.; Hapugoda, M.D.; de Silva, B.G.D.N.K.; Wijeyerathne, P.; Abeyewickreme, W.Introduction: Investigating the presence of primary and secondary vectors of malaria in the selected areas where no entomological surveillance was carried out for about 30 years due to ethnic conflict. Objective: To study prevalence of malaria vector in Ampara District and to assess the risk of malaria in the area. Method: Surveillance was preformed from January 2011 to June 2012 in 4 selected areas (i.e. Panama, Thirukkovil, Mahaoya and Dehiattakandiya) in Ampara District. From each area 4 localities (total 16 localities) were selected for the sample collection in order to ensure full coverage of the District. Cattle Baited Hut Collection (CBHC) and Cattle Baited Net Collection (CBNC) were performed as sample collecting methods on monthly basis throughout the surveillance period. Results: Mosquito densities for each collected Anopheles species were calculated as density per hut or net for CBHT and CBNT respectively. 14 Anopheles species were recorded from CBHC with high prevalence for An. subpictus (68.58%), An. nigerrimus (14.02%) and An. vagus (6.73%). 16 Anopheles species were recorded from CBNC with high prevelance of An. nigerrimus (50.07%), An. peditaeniatus (16.12%), An. pseudojemesi (9.21%) and An. subpictus (7.68%). An. culicifacies (primary malaria vector in Sri Lanka) recorded with lesser densities but An. subpictus, the secondary vector for malaria in Sri Lanka was predominant thorough out this study. Conclusions: The presence of primary and secondary malaria vectors in the area may cause a malaria epidemic in these areas. Hence, it is essential to study the seasonal prevalence of Anopheles species in order to initiate timely controlling measures in Ampara District.Item The impact of repeated malaria attacks on the school performance of children(American Society of Tropical Medicine and Hygiene, 2003) Fernando, S.D.; Gunawardena, D.M.; Bandara, M.R.; de Silva, D.; Carter, R.; Mendis, K.N.; Wickremasinghe, A.R.The impact of repeated malarial infections on the school performance of children was investigated in 571 school children 6-14 years of age in a malaria-endemic area in southern Sri Lanka where both Plasmodium falciparum and P. vivax infections are prevalent. Malaria infections confirmed by microscopy were monitored over a six-year period. School performance was assessed by two specially designed, school grade-specific, test papers for Sinhala language and mathematics. The scores for Sinhala language and mathematics for each school term test for the year 1997 were obtained. Malarial infections were a major predictor of children's performance in language and mathematics after controlling for parent's education, monthly family income, and house type. The education of the father predicted language scores but not mathematics scores. A child who experienced more than five attacks of malaria scored approximately 15 percent less than a child who experienced less than three attacks of malaria. The data suggest that repeated attacks of malaria have an adverse impact on the school performance of children.Item Use of routinely collected past surveillance data in identifying and mapping high-risk areas in a malaria endemic area of Sri Lanka(SEAMEO Regional Tropical Medicine and Public Health Project, 2002) Wickremasinghe, A.R.; Gunawardena, D.M.; Mahawithanage, S.T.C.Stratification of malaria endemic areas on eco-epidemiological criteria is an important step in planning and implementing malaria control programs. The uses of stratification of malaria endemic areas lead to better targeting of control measures such as residual insecticide spraying in countries where unstable malaria transmission occur. In this study, two methods that can be used for stratification of malaria endemic areas in Sri Lanka usingroutinely collected surveillance data over a period of 9 years are described. In the first method, the median Annual Parasite Incidence (API) was used as the criterion to classify an area as at risk for malaria while in the second method, the API and the Falciparum Rate (FR) were used as the criteria. Risk maps were produced by plotting the results of the analyses on maps generated by EPIMAP. The potential uses of risk maps are discussedItem Malaria risk factors in an endemic region of Sri Lanka, and the impact and cost implications of risk factor-based interventions(American Society of Tropical Medicine and Hygiene, 1998) Gunawardena, D.M.; Wickremasinghe, A.R.; Muthuwatta, L.; Weerasingha, S.; Rajakaruna, J.; Senanayaka, T.; Kotta, P.K.; Attanayake, N.; Carter, R.; Mendis, K.N.In an 18-month study of malaria in a population of 1,875 residents in 423 houses in an endemic area in southern Sri Lanka, the risk of malaria was found to be 2.5-fold higher in residents of poorly constructed houses than in those living in houses of good construction type. In residents of poorly constructed houses but not in others, the risk was even greater when the house was located near a source of water that could act as a potential breeding place for malaria vector mosquitoes (P = 0.0001). Based on previous findings that confirmed that house construction type was itself a risk determinant, and not merely a marker of other behavioral factors, we have estimated the potential impact of two feasible interventions to reduce the risk of malaria: 1) the imposition of a buffer zone of 200 meters around bodies of water from which houses of poor construction were excluded, which was estimated to lead to a 21 percent reduction of the malaria incidence in the overall population and a 43 percent reduction in the relocated community; and 2) the conversion of houses of poor construction type located in the buffer zone to those of a good construction type, which was estimated to lead to a 36 percent reduction in the incidence rates in the whole population and a 76 percent reduction in the residents of houses whose construction type was improved. Taking into consideration the cost to the Government of malaria prevention, we estimated the worth of a Government's investment in improving house construction type. The investment in housing was estimated to be offset in 7.2 years by savings to the Government on malaria costs alone, and beyond this period, to bring a return on the Government's investment by way of savings to the malaria control program.