Browsing by Author "Amarasinghe, S."

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    The first case of introduced malaria in Sri Lanka after elimination: Approach by the Anti Malaria Campaign to prevent re-establishment of malaria
    (Sri Lanka Medical Association., 2019) Karunasena, V.M.; Marasinghe, M.M.M.B.; Amarasinghe, S.; Senaratne, P.A.S.; Hasantha, M.B.R.; Hevawitharana, M.
    INTRODUCTION & OBJECTIVES: Apart from imported malaria infections Sri Lanka has been free of malaria cases for the past six years after elimination until December 26th 2018, when the first introduced case was reported. This manuscript describes the probable index case and the introduced case of malaria, and actions taken to curtail the spread of transmission. METHODS: Detailed case investigations of the probable index and introduced cases were carried out and appropriate responses were mounted by the Anti Malaria Campaign (AMC). Genome sequencing was performed on parasites obtained from the two cases to determine relatedness of the two parasite isolates. RESULTS: An Indian employed at a construction site in Moneragala district, developed a Plasmodium vivax infection 23 days after arriving in Sri Lanka. Thirteen days later a Sri Lankan with no travel history to a malaria endemic country was diagnosed with P.vivax malaria following his visit to the same site. Multi-locus genome sequencing show that P. vivax strains obtained from these cases share 100% genetic identity at five loci of three polymorphic genes (CSP, MSPI and MSP3a genes), suggesting that both patients were infected with the same P.vivax strain. AMC mounted a rapid response including parasitological and entomological surveillance, active case detection, appropriate vector control measures and raising public and clinician awareness at relevant sites. CONCLUSION: An outbreak and the re-introduction of malaria to Sri Lanka from an index and introduced cases were prevented by prompt interventions which illustrate a very effective surveillance and response system.
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    The first introduced malaria case reported from Sri Lanka after elimination: implications for preventing the re-introduction of malaria in recently eliminated countries
    (BioMed Central, 2019) Karunasena, V. M.; Marasinghe, M.; Koo, C.; Amarasinghe, S.; Senaratne, A.S.; Hasantha, R.; Hewavitharana, M.; Hapuarachchi, H.C.; Herath, H.D.B.; Wickremasinghe, R.; Mendis, K.N.; Fernando, D.; Ranaweera, D.
    BACKGROUND:There has been no local transmission of malaria in Sri Lanka for 6 years following elimination of the disease in 2012. Malaria vectors are prevalent in parts of the country, and imported malaria cases continue to be reported. The country is therefore at risk of malaria being re-established. The first case of introduced vivax malaria in the country is reported here, and the surveillance and response system that contained the further spread of this infection is described.METHODS:Diagnosis of malaria was based on microscopy and rapid diagnostic tests. Entomological surveillance for anophelines used standard techniques for larval and adult surveys. Genotyping of parasite isolates was done using a multi-locus direct sequencing approach, combined with cloning and restriction fragment length polymorphism analyses. Treatment of vivax malaria infections was according to the national malaria treatment guidelines.RESULTS:An imported vivax malaria case was detected in a foreign migrant followed by a Plasmodium vivax infection in a Sri Lankan national who visited the residence of the former. The link between the two cases was established by tracing the occurrence of events and by demonstrating genetic identity between the parasite isolates. Effective surveillance was conducted, and a prompt response was mounted by the Anti Malaria Campaign. No further transmission occurred as a result.CONCLUSIONS:Evidence points to the case of malaria in the Sri Lankan national being an introduced malaria case transmitted locally from an infection in the foreign migrant labourer, which was the index case. Case detection, treatment and investigation, followed by prompt action prevented further transmission of these infections. Entomological surveillance and vector control at the site of transmission were critically important to prevent further transmission. The case is a reminder that the risk of re-establishment of the disease in the country is high, and that the surveillance and response system needs to be sustained in this form at least until the Southeast Asian region is free of malaria. Several countries that are on track to eliminate malaria in the coming years are in a similar situation of receptivity and vulnerability. Regional elimination of malaria must therefore be considered a priority if the gains of global malaria elimination are to be sustained.