1 African Population and Health Research Center, Nairobi, Kenya; Department of Global Health, Academic Medical Centre, Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam, Netherlands. Electronic address: svijver@aphrc.org.
2 African Population and Health Research Center, Nairobi, Kenya; Department of Global Health, Academic Medical Centre, Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam, Netherlands.
3 African Population and Health Research Center, Nairobi, Kenya.
4 Department of Global Health, Academic Medical Centre, Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam, Netherlands.
5 Department of Public Health, Academic Medical Centre, University of Amsterdam, Netherlands.