Remark: Until an area is nearing elimination or is post-elimination, it is unlikely that reactive case detection and treatment (RACDT) will have any effect on malaria transmission. However, RACDT becomes an essential component of surveillance when countries are nearing interruption of transmission to monitor progress towards elimination. When countries are postelimination and working towards certification, RACDT can strengthen a country’s claim that it has reached and maintained zero indigenous cases. RACDT is an essential part of surveillance and response to prevent re-establishment of malaria.

Practical info RACDT should be implemented when areas are nearing interruption of transmission and malaria cases are rare. When used, RACDT should be one of several components of a programme to eliminate or prevent re-establishment of malaria, including intensive surveillance as described in the Framework for malaria elimination [9]. RACDT depends on a strong passive surveillance system that detects suspected cases, tests all suspected cases for malaria with a parasitological test and investigates all cases at their place of residence. RACDT complements this surveillance system through active case finding around index cases. It is essential to determine the likely location of infection through a case investigation that identifies the location of the person during the likely period of infection in order to understand where or in what group of people an RACDT intervention should take place. RACDT should be administered to other residents of the same house if the person is determined to have been infected locally. Programmes may consider extending the radius of RACDT to neighbours depending on the local epidemiology and ecology of malaria. If a person was not likely to have been infected at the residence, programmes should administer RACDT to all people identified as having the same risk of acquiring infection as the index case. People with the same risk of infection are likely to be those who travelled, worked or engaged in leisure activities with the index case. Countries that are at very low or low transmission but not yet close to achieving zero indigenous cases should prioritize implementation of RDA and reactive IRS over RACDT. However, RACDT may be added on top of RDA when countries are closer to elimination to strengthen the sensitivity of the surveillance system to monitor progress towards elimination and, post-elimination, to provide additional evidence of a malaria-free status. When RACDT and RDA are jointly implemented, chemoprevention is provided to everyone, irrespective of the results of the parasitological test. However, testing results are used to monitor progress towards elimination or demonstrate that the country has reached zero indigenous cases. RACDT should be implemented according to SOPs. A household listing of all people residing within the limits of RDA as specified by the SOPs should be developed and verified, along with a list of all individuals who may have been coexposed. The RACDT programme should seek to test everyone listed, using different approaches as needed to reach everyone at risk. Malaria cases detected during RACDT should be treated with antimalarial medicine according to the national treatment protocol if not already provided chemoprevention through RDA.