Flu.gov is a website sponsored by the U.S. Department of Health and Human Services that provides information about the flu, including seasonal flu, H1N1 (swine) flu, and avian (bird) flu. It offers answers to frequently asked questions, and it has special sections for seniors, caregivers, travelers, pregnant women, and health professionals. This website also offers guidance on vaccinations.

The Centers for Disease Control and Prevention (CDC) is an agency of the U.S. Department of Health and Human Services. The CDC works with state and local health officials and the public to achieve better health for all people. The CDC creates the expertise, information, and tools that people and communities need to protect their health—by promoting health, preventing disease, injury, and disability, and being prepared for new health threats.

This website is sponsored by the Nemours Foundation. It has a wide range of information about children's health, from allergies and diseases to normal growth and development (birth to adolescence). This website offers separate areas for kids, teens, and parents, each providing age-appropriate information that the child or parent can understand. You can sign up to get weekly emails about your area of interest.

The World Health Organization (WHO) is an agency of the United Nations. It has about 200 member states. WHO promotes technical cooperation among nations on health issues, carries out programs to control and eliminate disease, and strives to improve the quality of human life.

The Web site has information on many health topics, including health and disease related to travel.