Cholera. An infection of the small intestine by a certain bacteria. These germs produce a toxin that prompts the small intestine to secrete large amounts of fluid, salts, and minerals, leading to watery diarrhea. The disease may be mild, but in serious cases can cause severe dehydration and death.
Flukes. Not common in the United States but are a serious problem in many Asian, tropical, and subtropical countries. The Chinese liver fluke enters the body in raw or insufficiently cooked fish and may cause enlargement of the liver, jaundice, anemia, and weakness. Blood flukes penetrate the skin, make their way to the blood and travel to various parts of the body (this condition is known as schistosomiasis--see below).
Giardiasis. An intestinal infection with a parasite commonly known as Giardia. The parasite infects the upper intestine and causes diarrhea and increased intestinal gas. The disease is not as common as many people think, and accounts for only a tiny percentage of diarrhea in short-term travelers (less than two weeks), and only a small percentage of diarrhea in long-term travelers and expatriates. Untreated infections can last for weeks to months, but the organism is easily eradicated with one of several antibiotics.
Hepatitis A. A liver infection caused by a virus that is transmitted in human feces. In developing countries, the disease spreads mainly among children. In some nations, virtually 100% of children have had hepatitis A by age ten. When children have hepatitis A, they shed the virus in their stool, which can then contaminate food and water and place tourists at risk. In children, the disease is usually very mild, even unnoticeable. In adults, the illness is incapacitating.
Schistosomiasis or Bilharzia. A disease caused by three certain species of flatworms. People are exposed to these worms when their skin comes in contact with bodies of freshwater in regions where this disease exists. Once the worms enter the skin, they migrate to the liver, intestines, or urinary bladder, where they cause inflammation and tissue damage. Light infections may cause no symptoms, but heavy infections can lead to medical problems.
Tapeworm. This parasite enters human bodies in contaminated and insufficiently cooked pork, beef, or fish. The larvae, embedded in cysts in the meat or fish, develop to maturity in the human intestine and attach themselves to the intestinal wall; from there they release eggs. In mild or even moderate infections, tapeworms cause few or no symptoms. In heavy infections there may be diarrhea, abdominal cramps (resembling hunger pains), flatulence, distention, and nausea. In most cases, before these symptoms develop, the infected person discovers the tapeworm segments in clothes or bedding. Many new drugs, usually specific for the particular type of tapeworm, are being used for control.
Travelers Diarrhea (TD). The illness associated with a number of organisms that cause diarrhea when a traveler journeys to an area of poor hygiene. Initially believed to be due to a change of diet, a change of climate, or a change in time zone, it has become clear that TD is due to infection with a variety of bacteria, viruses, and protozoa that are accidentally ingested by eating or drinking contaminated food or water.
Typhoid. Disease caused by certain bacteria. Typhoid, or enteric, fever consists of prolonged fever, headache, loss of appetite, nausea, and extreme fatigue. Untreated, the illness can last for three to four weeks and can, albeit rarely, be fatal. Because fatal complications happen only in the latter stages of the disease, travelers very rarely die from enteric fever. Once diagnosed, the infection can be cured with antibiotics, often on an outpatient basis.
Typhus. Not to be confused with typhoid, this disease describes illness caused small bacteria that live within the cells of their victims: epidemic typhus, endemic typhus (murine typhus), and scrub typhus. All three diseases are associated with fever and headache and (usually) a characteristic rash.
Undulant Fever or Brucellosis. A bacterial infection that humans can acquire from domestic farm animals; therefore it tends to occur primarily in rural settings. There is little risk to travelers unless they work with animals or ingest unpasteurized dairy products. The common name by which the disease is often known, Undulant Fever, describes its wave-like symptoms of intermittent fever, which occur mainly at night, with sweats and chills occurring in two- to four-week cycles. The illness may last many months but it is rarely fatal.
