Hepatitis A is primarily caused by eating food or drinking water contaminated with the feces of a person infected with the virus. A two- or three-dose vaccination before exposure to the virus prevents the disease for as long as 20 years. More...

Vaccination can prevent most cases, but about 1 in 20 Americans has been infected. Transmission can occur during sexual relations; through injection with drugs; by sharing a toothbrush or razor; or by other contact with blood or body fluids. Most adults recover fully. But 5 to 10 percent develop a chronic infection. More...

Hepatitis C, the most serious form of hepatitis, affects approximately 4 million Americans; the true incidence is unknown, but it is estimated that there are between 35,000 and 185,000 new cases each year. According to the Centers for Disease Control and Prevention, 21 percent of all acute viral hepatitis in the United States may be attributed to hepatitis C infection. More...

Lyme disease was first identified in 1975 after large numbers of children in Lyme, Conn., and two neighboring towns were found to have arthritis. The symptoms are caused by infection with spiral-shaped bacteria that are carried by deer ticks. More...

The pain of shingles can be intense and feel unrelenting. It may be itching, stabbing, or shooting. Three to four days before the telltale blisters develop, you may feel sluggish or have a fever, chills, a headache, an upset stomach, diarrhea, or difficulties with urination. More...

Since the introduction of effective antibiotics, tuberculosis management has changed dramatically. People with tuberculosis are now treated in general hospitals and clinics. However, misuse of drugs has led to the development of drug-resistant tuberculosis, which is harder to cure. More...