The World Health Organization is the health authority of the United Nations and the most comprehensive source for information pertaining to pandemic and epidemic threats worldwide.
The US Department of Health and Human Services encompasses both the Center for Disease Control and the Food and Drug Administration. Though neither are regulatory agencies, both offer recommendations for local and state regulatory bodies on issues of health and food safety.
The US Department of Homeland Security monitors all potential terrorist threats and oversees the inspection of incoming freight into the country.
The US Department of Agriculture provides information and recommendations pertaining to the country's food and agriculture.