NOTE: Many CDC publications are available to download, view online, or order at no cost.
CDC does not see patients, diagnose illness, provide treatment, prescribe medication, or refer to specialists. For emergencies, see your healthcare provider or go to an emergency room. If you are a healthcare provider, contact your state epidemiologist or local health department.
- Page last reviewed: February 23, 2016
- Page last updated: February 23, 2016
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