Abstract
Background Mass drug administration for elimination of Plasmodium falciparum malaria is recommended by WHO in some settings. We used consensus modelling to understand how to optimise the effects of mass drug administration in areas with low malaria transmission. Methods We collaborated with researchers doing field trials to establish a standard intervention scenario and standard transmission setting, and we input these parameters into four previously published models. We then varied the number of rounds of mass drug administration, coverage, duration, timing, importation of infection, and pre-administration transmission levels. The outcome of interest was the percentage reduction in annual mean prevalence of P falciparum parasite rate as measured by PCR in the third year after the final round of mass drug administration. Findings The models predicted differing magnitude of the effects of mass drug administration, but consensus answers were reached for several factors. Mass drug administration was predicted to reduce transmission over a longer timescale than accounted for by the prophylactic effect alone. Percentage reduction in transmission was predicted to be higher and last longer at lower baseline transmission levels. Reduction in transmission resulting from mass drug administration was predicted to be temporary, and in the absence of scale-up of other interventions, such as vector control, transmission would return to pre-administration levels. The proportion of the population treated in a year was a key determinant of simulated effectiveness, irrespective of whether people are treated through high coverage in a single round or new individuals are reached by implementation of several rounds. Mass drug administration was predicted to be more effective if continued over 2 years rather than 1 year, and if done at the time of year when transmission is lowest. Interpretation Mass drug administration has the potential to reduce transmission for a limited time, but is not an effective replacement for existing vector control. Unless elimination is achieved, mass drug administration has to be repeated regularly for sustained effect. Funding Bill & Melinda Gates Foundation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | e680-e687 |
| Journal | The Lancet Global Health |
| Volume | 5 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2017 |
Funding
OJB, SIH, EMS, and EAO are members of the Malaria Modelling Consortium Secretariat and Advisors. We thank Steven Kern at the Malaria Modelling Consortium secretariat of the Bill & Melinda Gates Foundation for valuable advice on the Article. OJB is supported by the Bill & Melinda Gates Foundation (OPP1119467). HCS acknowledges support from an Imperial College London Junior Research Fellowship and the Bill & Melinda Gates Foundation. PP-R, MAP, NC, and TAS were supported by the Bill & Melinda Gates Foundation (OPP1032350), with calculations done at the sciCORE scientific computing core facility at the University of Basel (Basel, Switzerland). EW and JG are supported by the Bill & Melinda Gates Foundation through the Global Good Fund. RJM, LJW, and RA are supported by the Bill & Melinda Gates Foundation (OPP1110500) and the Wellcome Trust (106698/Z/14/Z). RJM also acknowledges additional funding from the Bill & Melinda Gates Foundation (OPP1129596 and CPT000390), the Asian Development Bank (TA-8656), and the Australian Department of Foreign Affairs and Trade (71215). ACG acknowledges funding from the Bill & Melinda Gates Foundation, the MRC under the MRC–Department for International Development Concordat agreement, and the MRC Centre for Outbreak Analysis and Modelling. SIH is funded by a Senior Research Fellowship from the Wellcome Trust (#095066) and grants from the Bill & Melinda Gates Foundation (OPP1119467, OPP1093011, OPP1106023 and OPP1132415). EAO is funded by an Intermediate Research Fellowship from the Wellcome Trust (201866/Z/16/Z). LCO acknowledges funding from a UK Royal Society Dorothy Hodgkin Fellowship, Medicines for Malaria Venture, the Bill & Melinda Gates Foundation, and a Population Health Scientist Fellowship jointly funded under the MRC–Department for International Development Concordat agreement.
ASJC Scopus subject areas
- General Medicine
