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.
Wood E, Tyndall MW, Li K, Lloyd-Smith E, Small W, Montaner JS, Kerr T.Wood E, et al.Am J Prev Med. 2005 Aug;29(2):126-30. doi: 10.1016/j.amepre.2005.04.011.Am J Prev Med. 2005.PMID: 16005809