Importance of active case detection in a malaria elimination programme

Abstract

INTRODUCTION AND OBJECTIVES: Malaria surveillance methods routinely used in Sri Lanka are passive and active case detection (PCD, ACD) and activated passive case detection (APCD). Active case detection is carried out by mobile malaria clinics. Tropical and Environmental Diseases and Health Associates (TEDHA) an implementation partner of the Anti Malaria Campaign (AMC) carries out APCD and ACD in four districts in Sri Lanka namely Trincomalee, Batticaloa, Ampara and Mannar, complementing the parasitological surveillance activities carried out by the AMC. DESIGN, SETTING AND METHODS: The ACD programme of TEDHA involves screening of populations irrespective of the presence of fever or any other signs or symptoms of malaria to detect infections and residual parasite carriers. TEDHA screens a) high risk populations using ACD through mobile malaria clinics including armed forces personnel and b) pregnant females who visit antenatal clinics for asymptomatic malaria infections during their first trimester. Populations are selected in consultation with the Regional Malaria Officer of the AMC thus avoiding any overlap with the population screened by the government. RESULTS: TEDHA screened 387.309 individuals between January 2010 and December 2012, for malaria by ACD including high risk groups and pregnant women and diagnosed eight malaria positive cases (7 Ptasmodium vivax infections and one mixed infection with P. vivax and Plasmodium falciparum}. All these cases were from the Mannar district amongst resettled populations and army personnel. During this period 125 cases were detected in the Mannar district by the Anti Malaria Campaign by passive case detection. No cases of malaria were detected by ACD by the AMC. CONCLUSIONS: The progress made by Sri Lanka in the malaria elimination drive is largely due to increased surveillance and judicious use of control methods. The country now needs to focus on enhanced surveillance to be malaria free and to prevent re-introduction of malaria into the country. As highlighted here, ACD played a major role in interrupting malaria transmission in the country. ACKNOWLEDGEMENTS: Financial assistance by the Global Fund (Grant, No. PR2 SRL809G11-M) is gratefully acknowledged. The authors would like to acknowledge the support given by the staff of TED HA.