Malaria surveillance in low-transmission areas of Zambia using reactive case detection

Abstract

Background: Repeat national household surveys suggest highly variable malaria transmission and increasing coverage of high-impact malaria interventions throughout Zambia. Many areas of very low malaria transmission, especially across southern and central regions, are driving efforts towards sub-national elimination.

Case description: Reactive case detection (RCD) is conducted in Southern Province and urban areas of Lusaka in connection with confirmed incident malaria cases presenting to a community health worker (CHW) or clinic and suspected of being the result of local transmission. CHWs travel to the household of the incident malaria case and screen individuals living in adjacent houses in urban Lusaka and within 140 m in Southern Province for malaria infection using a rapid diagnostic test, treating those testing positive with artemether-lumefantrine.

Discussion: Reactive case detection improves access to health care and increases the capacity for the health system to identify malaria infections. The system is useful for targeting malaria interventions, and was instrumental for guiding focal indoor residual spraying in Lusaka during the 2014/2015 spray season. Variations to maximize impact of the current RCD protocol are being considered, including the use of anti-malarials with a longer lasting, post-treatment prophylaxis.

Conclusion: The RCD system in Zambia is one example of a malaria elimination surveillance system which has increased access to health care within rural communities while leveraging community members to build malaria surveillance capacity.

Fig. 1

Map of areas of Zambia conducting reactive case detection

Fig. 2

Schematic of RCD system in rural areas. A system of passive and reactive case detection includes the follow-up of confirmed malaria cases detected at clinics and health posts. Community health workers then test and treat in the house and neighbouring houses of the index case

Fig. 3

Community health workers involved in the surveillance system travel long distances to follow-up malaria incident cases within the community, or to collect commodities to test and treat for malaria. To accomplish their duties CHWs receive ‘Test for Life’ bicycles, which also serve as an incentive for their work

Fig. 4

Example of mapping capacity of the RCD system. Size of the circles represent the number of people tested by CHWs for malaria during RCD in Gwembe District, Southern Province from July–December 2014. Suspected malaria cases tested over this time period ranged from 21 to 1703. This map taken directly out of the DHIS2 interface illustrating the usability of the system