About the Authors

John Bradley

john.bradley@Ishtm.ac.uk

Affiliation Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom

Andrea M. Rehman

Affiliation Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom

Christopher Schwabe

Affiliation Medical Care Development International, Silver Spring, Maryland, United States of America

Daniel Vargas

Affiliation Medical Care Development International, Malabo, Equatorial Guinea

Feliciano Monti

Affiliation Medical Care Development International, Malabo, Equatorial Guinea

Camilo Ela

Affiliation Ministry of Health and Social Welfare, Malabo, Equatorial Guinea

Matilde Riloha

Affiliation Ministry of Health and Social Welfare, Malabo, Equatorial Guinea

Immo Kleinschmidt

Affiliation Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom

Competing Interests

This study was partly funded by the Marathon Oil Corporation. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: CS IK. Performed the experiments: DV. Analyzed the data: JB AR IK. Wrote the manuscript: JB AR CS DV EM CE MR IK.