Hepatitis C 
Hepatitis C is caused by the hepatitis C virus (HCV). Most persons who acquire acute HCV infection either have no symptoms or have a mild clinical illness. However, chronic HCV infection develops in 75%–85% of those acutely infected, with active liver disease developing in 60%–70% of chronically infected persons.
HCV is transmitted primarily through activities that result in the exchange of blood; it is less commonly transmitted by sexual activity. The most frequent mode of transmission in the United States is through sharing of drug-injecting equipment among injecting drug users. For international travelers, the principal activities that can result in blood exposure include receiving blood transfusions that have not been screened for HCV; having medical or dental procedures or engaging in activities (e.g., acupuncture, tattooing, or injecting drug use) in which equipment has not been adequately sterilized or disinfected or in which contaminated equipment is reused; and working in health-care fields (e.g., medical, dental, or laboratory) that entail direct exposure to human blood.
Approximately 3% (170 million) of the world's population has been infected with HCV. For most countries, the prevalence of HCV infection is <3%. Prevalence is higher (up to 15%) in some countries in Africa and Asia, and highest (>15%) in Egypt.
Risk for Travelers
Travelers' risk for contracting HCV infection is generally low. To assess risk, travelers should be advised to consider the extent of their direct contact with blood, particularly receipt of blood transfusions from unscreened donors, or exposure to contaminated equipment used in health care-related or cosmetic (e.g., tattooing) procedures.
Most persons (80%) with acute HCV infection have no symptoms. If symptoms occur, they might include loss of appetite, abdominal pain, fatigue, nausea, dark urine, and jaundice. Chronic infection occurs in 75%–85% of infected persons, leading to chronic liver disease in 60%–70%. The most common symptom of chronic hepatitis C is fatigue, although severe liver disease develops in 10%–20% of infected persons. Chronic hepatitis C is the leading cause for liver transplantation in the United States.
No vaccine is available. When seeking medical or dental care, travelers should be advised to be alert to the use of medical, surgical, and dental equipment that has not been adequately sterilized or disinfected, reuse of contaminated equipment, and unsafe injecting practices (e.g., reuse of disposable needles and syringes). HCV and other bloodborne pathogens can be transmitted if tools are not sterile or if the artist or piercer does not follow other proper infection-control procedures (e.g., washing hands, using latex gloves, and cleaning and disinfecting surfaces and instruments). Travelers should be advised to consider the health risks if they are thinking about getting a tattoo or body piercing in areas where adequate sterilization or disinfection procedures might not be available or practiced.
There is no specific treatment available for acute hepatitis C. Antiviral drugs are available for the treatment of chronic hepatitis C in persons >18 years of age.