An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Spencer HC, Watkins WW, Sixsmith DG, Koech DK.Spencer HC, et al. Among authors: sixsmith dg.Trans R Soc Trop Med Hyg. 1986;80(2):201-3. doi: 10.1016/0035-9203(86)90009-x.Trans R Soc Trop Med Hyg. 1986.PMID: 3538522
Spencer HC, Watkins WM, Sixsmith DG, Koech DK, Chulay JD.Spencer HC, et al. Among authors: sixsmith dg.Bull World Health Organ. 1984;62(4):615-21.Bull World Health Organ. 1984.PMID: 6386209Free PMC article.