1. Epidemic Intelligence Service, Scientific Education and Professional Development Office, Centers for Disease Control and Prevention, Atlanta, Georgia;
2. Clinton Health Access Initiative (CHAI), Machinga District Hospital, Liwonde, Malawi;
3. Malawi Ministry of Health, Machinga District Hospital, Liwonde, Malawi;
4. Division of Foodborne, Waterborne, and Environmental Diseases, Waterborne Diseases Prevention Branch, Centers for Disease Control and Prevention, Atlanta, Georgia;
5. Division of Global HIV/AIDS, Center for Global Health, Centers for Disease Control and Prevention, Lilongwe, Malawi;
6. Program for Appropriate Technology in Health (PATH), Seattle, Washington