Featured Malaria Publication - Measuring the path toward malaria elimination

13 June 2014

Malaria modeller Dr Tom Churcher and colleagues have developed a new evaluation method to assess malaria elimination programmes to enable valuable initiatives to continue to receive support.

Measuring the path toward malaria elimination

Thomas S. Churcher, Justin M. Cohen, Joseph Novotny, Nyasatu Ntshalintshali, Simon Kunene, Simon Cauchemez

Researchers have developed a new way to evaluate malaria elimination programmes to enable valuable initiatives to continue to receive support.

The World Health Organisation (WHO) currently defines malaria elimination as the absence of locally acquired malaria cases over three years. Although an excellent target, many programmes cannot attain this goal because malaria can be ‘imported’ by infected people travelling into a region from abroad.

Although the long-term focus on elimination is commendable, evaluation of programs cannot rely on a dichotomous approach where “success” would correspond to no locally acquired malaria cases, and anything else would be seen as failure. Evaluation needs to take into account the local and regional epidemiological circumstances, because countries that manage to control local transmission to relatively low levels but receive large numbers of imported cases are likely to see locally acquired cases. Effective programs may therefore be wrongly perceived as unsuccessful, which would jeopardize their long-term viability. In addition to the long-term objective of elimination, we must develop intermediate milestones that better capture and acknowledge these scenarios.

Such a milestone should be the interruption of endemic transmission, meaning that the country would eventually see malaria go away if importation ceased. The country could then aim to reduce chains of transmission generated from imported cases down to zero. Although this sounds sensible, there are no operational measures and tools for evaluating local transmission as it approaches elimination, because incidence estimates require either surveillance data with perfect case detection or surveys with impractically large sample sizes. In addition, incidence does not measure local transmission in the context of importation.

Writing in Science a team of researchers from Imperial College London, Institut Pasteur Paris and other organisations have called for new methods to evaluate malaria programmes.

Read the full article in Science.