Browsing by Author "Gunasekera, W.M.K.T.A.W."

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    A Comparative analysis of the outcome of malaria case surveillance strategies in Sri Lanka in the prevention of re-establishment phase
    (BioMed Central, 2021) Gunasekera, W.M.K.T.A.W.; Premaratne, R.; Fernando, D.; Munaz, M.; Piyasena, M.G.Y.; Perera, D.; Wickremasinghe, R.; Ranaweera, K.D.N.P.; Mendis, K.
    BACKGROUND: Sri Lanka sustained its malaria-free status by implementing, among other interventions, three core case detection strategies namely Passive Case Detection (PCD), Reactive Case Detection (RACD) and Proactive Case Detection (PACD). The outcomes of these strategies were analysed in terms of their effectiveness in detecting malaria infections for the period from 2017 to 2019. METHODS: Comparisons were made between the surveillance methods and between years, based on data obtained from the national malaria database and individual case reports of malaria patients. The number of blood smears examined microscopically was used as the measure of the volume of tests conducted. The yield from each case detection method was calculated as the proportion of blood smears which were positive for malaria. Within RACD and PACD, the yield of sub categories of travel cohorts and spatial cohorts was ascertained for 2019. RESULTS: A total of 158 malaria cases were reported in 2017-2019. During this period between 666,325 and 725,149 blood smears were examined annually. PCD detected 95.6 %, with a yield of 16.1 cases per 100,000 blood smears examined. RACD and PACD produced a yield of 11.2 and 0.3, respectively. The yield of screening the sub category of travel cohorts was very high for RACD and PACD being 806.5 and 44.9 malaria cases per 100,000 smears, respectively. Despite over half of the blood smears examined being obtained by screening spatial cohorts within RACD and PACD, the yield of both was zero over all three years. CONCLUSIONS: The PCD arm of case surveillance is the most effective and, therefore, has to continue and be further strengthened as the mainstay of malaria surveillance. Focus on travel cohorts within RACD and PACD should be even greater. Screening of spatial cohorts, on a routine basis and solely because people are resident in previously malarious areas, may be wasteful, except in situations where the risk of local transmission is very high, or is imminent. These findings may apply more broadly to most countries in the post-elimination phase. KEYWORDS: Active case detection; Malaria case surveillance; Malaria in Sri Lanka; Passive case detection; Prevention of re-establishment of malaria; Proactive case detection; Reactive case detection; Spatial cohorts; Travel cohorts; Yield.
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    Technical and operational underpinnings of malaria elimination from Sri Lanka
    (BioMed Central, 2019) Premaratne, R.; Wickremasinghe, R.; Ranaweera, D.; Gunasekera, W.M.K.T.A.W.; Hevawitharana, M.; Pieris, L.; Fernando, D.; Mendis, K.
    Malaria was eliminated from Sri Lanka in 2012, and the country received WHO-certification in 2016. The objective of this paper is to describe the epidemiology of malaria elimination in Sri Lanka, and the key technical and operational features of the elimination effort, which may have been central to achieving the goal, even prior to schedule, and despite an ongoing war in parts of the country. Analysis of information and data from the Anti Malaria Campaign (AMC) of Sri Lanka during and before the elimination phase, and the experiences of the author(s) who directed and/or implemented the elimination programme or supported it form the basis of this paper. The key epidemiological features of malaria on the path to elimination included a steady reduction of case incidence from 1999 onwards, and the simultaneous elimination of both Plasmodium falciparum and Plasmodium vivax. Against the backdrop of a good health infrastructure the AMC, a specialized programme within the Ministry of Health operated through a decentralized provincial health system to implement accepted strategies for the elimination of malaria. Careful planning combined with expertise on malaria control at the Central level with dedicated staff at all levels at the Centre and on the ground in all districts, for several years, was the foundation of this success. The stringent implementation of anti-relapse treatment for P. vivax through a strong collaboration with the military in whose cadres most of the malaria cases were clustered in the last few years of transmission would have supported the relatively rapid elimination of P. vivax. A robust case and entomological surveillance and investigation system described here enabled a highly focused approach to delivering interventions leading to the interruption of transmission.