Role of mass drug administration in elimination of Plasmodium falciparum malaria: a consensus modelling study.
- Brady OJ Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, and Malaria Modelling Consortium, London School of Hygiene & Tropical Medicine, London, UK.
- Slater HC MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College, London, UK.
- Pemberton-Ross P Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
- Wenger E Institute for Disease Modeling, Bellevue, WA, USA.
- Maude RJ Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK; Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA.
- Ghani AC MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College, London, UK.
- Penny MA Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
- Gerardin J Institute for Disease Modeling, Bellevue, WA, USA.
- White LJ Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
- Chitnis N Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
- Aguas R Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK.
- Hay SI Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK; Malaria Modelling Consortium, University of Washington, Seattle, WA, USA; Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
- Smith DL Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
- Stuckey EM Malaria Modelling Consortium, Bill & Melinda Gates Foundation, Seattle, WA, USA.
- Okiro EA Malaria Modelling Consortium, Bill & Melinda Gates Foundation, Seattle, WA, USA; Kemri Wellcome Trust Research Programme, Nairobi, Kenya.
- Smith TA Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
- Okell LC MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College, London, UK. Electronic address: l.okell@imperial.ac.uk.
- 2017-06-02
Published in:
- The Lancet. Global health. - 2017
Antimalarials
Artemisinins
Consensus
Humans
Malaria, Falciparum
Mass Drug Administration
Models, Theoretical
Plasmodium falciparum
Prevalence
English
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.
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.
- Language
-
- English
- Open access status
- gold
- Identifiers
-
- DOI 10.1016/S2214-109X(17)30220-6
- PMID 28566213
- Persistent URL
- https://sonar.ch/global/documents/150135
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