Diphtheria
Found – rare in developed countries due to vaccination, but is still endemic in developing countries and the former states of the USSR.
Vaccine is recommended for those who will be in close contact with infected people in endemic areas.
Cause – a disease of close contact, a bacterial illness transmitted through droplets in the air.
Symptoms – sore throat and fever. Can be life-threatening.
Prevention – by updating your diphtheria vaccine.
Tetanus
Found – rare in developed countries due to vaccination.
Prevention – by the tetanus vaccine. A booster is recommended every ten years, perhaps even every five years for developing world travel. Sometimes can be fatal.
Polio
Found – virtually eliminated in the developed world, but is still a threat to non-vaccinated travellers in developing countries.
Cause – by a virus.
Treatment – there is no effective treatment for polio.
Prevention – with either the oral or injectable vaccine.
Cholera
Found – mostly in the developing world. However, risk to travellers is slight.
Cause – infection is by ingesting food or water infected with the bacteria, but especially from shellfish.
Symptoms – severe water loss due to watery diarrhea and vomiting. Death can result in a few hours from rapid fluid loss.
Treatment – immediate rehydration therapy to prevent dehydration and death. ninety-nine percent of victims recover given adequate rehydration.
Prevention – drink only bottled or boiled water. Be careful with food as possible. There is a vaccine but this is not usually recommended due to its ineffectiveness, expense, and the rarity of cholera in travellers.
Dysentery
Found – bacillary and amebic. Both are prevalent in many developing countries, but rare in travellers.
Prevention – (for both types) eating only cooked vegetables and peeled fruits, and by only drinking boiled or purified water.
- Bacillary dysentery
Cause – from infected food handlers not washing hands and from unclean flies landing on food.
Symptoms – sudden watery diarrhea, abdominal pain, vomiting, nausea, and fever, then passing blood and mucus after a few days.
Treatment – rehydration therapy, with no solid food for the first day or two. Antibiotics can help. Most people start to recover after about a week. Death can be caused by dehydration in vulnerable people.
- Amebic dysentery
Cause – swallowing the histolytica cysts from infected water or food (lettuce, uncooked vegetables, and unpeeled fruit).
Symptoms – range from a few loose stools with rumbling pains in the stomach, to a severe case with high fever and bloody, watery diarrhea. Shaking chills, fever, weight loss, and painful enlargement of the liver.
Treatment – rehydration therapy and drugs (e.g. metronidazole). Doesn’t go away on its own, unlike bacillary dysentery.
Hepatitis type A
Found – worldwide. Most common serious disease among travellers in the developing world where food preparation standards are poor.
Cause – transmitted by a virus through contamination of food or drinks prepared by an infected person with poorly washed hands.
Symptoms – either nonexistent or begin abruptly two to six weeks after exposure. Similar to flu, fever, aches, loss of appetite, nausea, abdominal discomfort, and liver pain, darkened urine, light yellow stools. Four to seven days later the symptoms may become more severe, with diarrhea, vomiting, itching, and jaundice (yellow skin and whites of the eyes).
Treatment – there is no treatment for hepatitis A. Most people recover within six weeks. Hepatitis type A does not lead to chronic hepatitis. Rest and abstaining from alcohol until recovered are recommended.
Prevention – take care of what and where you eat. Vaccination with the full, two-dose series of hepatitis A vaccine is the best way to prevent hepatitis A virus infection. Immune globulin is available for short-term protection (approximately 3 months) and must be administered within 2 weeks after exposure for maximum protection. Good hygiene, including handwashing or use of hand sanitizer after using the bathroom and before preparing or eating food is essential.
Hepatitis type B
Found – in body fluids of infected persons. Type B is found worldwide, but is much more prevalent in Asia and Africa.
Symptoms – are the same as for hepatitis A, except sometimes more severe. Many people have no symptoms. About 10% of hepatitis type B cases lead to chronic hepatitis, a severe inflammation and destruction of cells within the liver, leading to cirrhosis.
Prevention – the hepatitis B vaccine, although this is usually only recommended for health care workers, people who have many unprotected sex partners, and drug addicts.
AIDS
Found – worldwide. The hardest hit area is sub-Saharan Africa. Also spreading rapidly in Asia.
Cause – spread primarily through heterosexual sex, blood transfusions. Nearly 20,000 people are infected every day.
Prevention – travellers in Africa should bring their own hypodermic needles for emergencies. Many countries now require HIV testing for long-term visitors of greater than six months, or applicants for work or residency. In most cases HIV testing is not required for visitors of a few months or less. Most HIV carriers don’t know they’re infected, and HIV is thought most infectious the first year after infection.
Typhoid
Found – developing parts of Asia, Africa, and Latin America.
Cause – is caused by the bacteria salmonella typhi. Feces, urine, and contaminated food and water are the principal sources of infection. Again often through a food handler with poor hygiene. Sewage-contaminated shellfish is also a source.
Symptoms – limited to a fever of one week, but can include headache, anorexia, general malaise, and constipation, giving way to diarrhea, a non-productive cough, nosebleed, and raised pink spots on the upper abdomen. Complications may result, and the death rate for serious cases is ten percent for those untreated, one percent for those treated.
Treatment – with antibiotics.
Prevention – by cautious eating and drinking, and by an oral or injectable vaccine, both of which are about sixty-five percent effective for five years. The oral vaccine is four pills taken every other day; the injectable requires two shots one month apart. The oral vaccine has fewer side effects. Antibiotics are not recommended as a preventive since they disrupt normal intestinal bacteria and can facilitate infection with salmonella typhi.
Malaria
Found – Africa and Asia. Poses the greatest health risk to travellers in warm climates, and is in fact the greatest health threat to humanity with up to 300 million cases occurring worldwide each year, with about one million deaths. The tragedy is currently increasing as mosquitoes become insecticide-resistant and forms of malaria become drug-resistant.
Symptoms – for the first three types may include the classic malarial fever in three stages. First is a cold stage characterized by severe shivering, followed by a high fever stage of up to 105F (40C). Finally there is intense sweating which brings the fever down. The victim may also vomit and have a bad headache. The patient is left weak and tired, and sleeps.
These stages may occur cyclically, either every other day or every third day, but only after the disease is well-established. Malaria can be very difficult to diagnose in early stages.
Falciparum is a more severe type of malaria as all red blood cells are attacked. Death may result a few hours after symptoms begin. The brain may be affected, and liver and kidney failure are common.
Treatment – usually with a big dose of chloroquine. Falciparum malaria is resistant to chloroquine, however, so other drugs must be used. Discuss treatment with your travel clinic before you go, and immediately with local medical professionals if you acquire malaria-possible symptoms.
Prevention – is complicated, so only trust a high quality travel clinic to prescribe the proper medications for your specific destinations and physiology.
Yellow fever
Found – Yellow fever is found east of the Panama canal, in parts of South America, and in much of Africa.
Cause – a virus hemorrhagic (bleeding) disease transmitted in urban areas from person to person by Aedes aegypti mosquitoes, which feed during the day. In jungle areas it is transmitted from monkey to man by various mosquitoes.
Symptoms – begin three to six days after infection, are relatively mild in eighty percent of cases, and include fever, headache, and weakness, which last up to four days. The other twenty percent are more serious, including high fever, chills, nausea, vomiting, bleeding from the gums and nose, and severe pain in the neck, back, and legs. These may last a few days, followed by a remission, and then followed by a more severe illness, including increased fever, vomiting of blood, and jaundice due to liver damage, hence the name yellow fever. Approximately five percent of all victims die within days of the onset of symptoms.
Treatment – maintaining blood volume and fluids. No drug works against this virus.
Prevention – by the yellow fever vaccine, which lasts ten years. A yellow fever vaccination certificate (yellow card) is required for entry into and from countries where the disease is prevalent.
Dengue fever
Found – in tropical and subtropical regions worldwide.
Cause – a viral, hemorrhagic disease transmitted by day-feeding Aedes aegypti mosquitoes.
Symptoms – appear five to eight days after a bite from an infected mosquito, and include high fever, severe muscle and joint pain, and rash. They subside and recur about every three days. Recovery takes several weeks, with victims rarely dying.
Treatment – pain killers to relieve symptoms. There is no specific treatment.
Prevention – avoiding mosquito bites. There is no vaccine.
Plague
Found – While a few cases of plague occur every year in the American Southwest, it is mostly a disease of South America, Africa, Southeast Asia, and India.
Cause – transmitted to humans by the bites of rodent fleas. The risk of plague to travellers is almost zero, especially if you make a habit of not handling rats, dead or alive.
Rabies
Found – worldwide.
Cause – a viral disease of the nervous system. Transmitted by animal bites, scratches, or even licks on an open cut.
Skunks, raccoons, and bats are the major carriers in North America. In Central and South America dogs and vampire bats are the primary vectors. Jackals are the primary carriers of rabies in Africa. In Southeast Asia and India dogs are the leading vectors to humans. Note, however, that any mammal bite may transmit rabies. Ireland, Britain, Norway, Sweden, Japan, Australia, and New Zealand do not have the disease, and require an extensive quarantine for pets entering the country.
Symptoms – begin from nine days to many months after exposure. These include fever, hyperactivity, seizures, and often an intense thirst that cannot be quenched since liquids produce violent and painful spasms in the throat. The victim will die within three to twenty days from onset of symptoms.
Prevention and Treatment – passive immunization before symptoms appear, and ideally within two days of exposure. Competent medical advice should be immediately sought after a bite in a rabies endemic country. Clean the wound thoroughly with soap and clean water for at least five minutes, but don’t stitch it closed. The sooner vaccination is begun, the better the prognosis. Today’s vaccines are not so painful, and are no longer given through the stomach.
There are about 30,000 deaths every year from rabies, nearly all in developing countries. Almost invariably fatal if left untreated.
Chagas’ disease
Found – rural Central and South America, but especially Brazil. Also called American sleeping sickness. Can be fatal.
Cause – transmitted by the bite of the assassin bug, which makes its home in thatched roof and adobe huts in This bug prefers to bite on the face and defecate. Single-celled parasites called trypanosomes enter the body, grow to huge numbers, then attack many organs, including the heart.
Symptoms – a hard, purple swelling which appears on the bite site about a week later.
Treatment – effective only if caught early.
Prevention – not sleeping in mud huts, by using mosquito netting, or by at least sleeping in the middle of the room away from walls. This disease is extremely rare in travellers.
Brucellosis
Found – rare in the US but not in Latin America and Mediterranean countries.
Cause – bacteria from unpasteurised dairy products.
Symptoms – high fever, shaking, sweating, and severe depression.
Treatment – antibiotics and rest.
Schistosomiasis (bilharziasis)
Found – is common in tropical regions worldwide, affecting about 200 million people.
Cause – several species of flukes (flattened worms) called shistosomes. They live in fresh water lakes and rivers, where they live part of their life cycle in snails.
Symptoms – vary from none to serious. The first is usually an itchy rash where the parasite has burrowed through the skin. Weeks later flu-like symptoms may begin, including high fever, chills, muscle aches, and diarrhea. The symptoms may go away and recur a month or two later. Long-term damage includes cirrhosis and kidney failure.
Treatment – a single dose of an anthelminthic (antiparasitic) drug, which kills the flukes.
Prevention – avoiding freshwater rivers and lakes in the tropics, but especially the Nile Valley, where schistosomiasis is rife.
Leishmaniasis
Found – the Middle East, South America.
Cause – a single-celled parasite transmitted via sandfly bites.
Symptoms – Some varieties affect mostly the skin, producing large ulcers at the bite area. In the Middle East this is known as the Baghdad boil. South American forms of the disease may cause more severe tissue damage, especially to the face. Another variety, called kala azar, causes internal organ damage.
Treatment – sodium stibogluconate.
Prevention – avoid sand fly bites by wearing shoes, socks, pants, long-sleeves, and by using DEET.
Filariasis
Found – in the tropics.
Cause – larvae or worms, and transmitted to man by insects.
Onchocerciasis (river blindness)
Found – in Central and South America, and Africa.
Cause – a worm infestation. The parasite is transmitted from person to person by the black simulium fly, which is found only near fast-moving rivers and streams.
Treatment – with diethylcarbamazine, which must be administered under close medical supervision since severe reactions to the dead and dying worms may occur.
Prevention – avoid black fly bites.
Giardiasis
Found – in the United States and worldwide, especially in the tropics and the public water systems of the former Soviet Union.
Cause – an intestinal infection caused by a single-celled parasite. Giardia cysts (eggs) are spread from the feces of infected animals.
Symptoms – the cysts hatch two or three weeks after ingestion, causing abdominal symptoms such as violent diarrhea, foul-smelling gas, and cramps. Sixty percent of those infected, however, show no symptoms.
Treatment – giardiasis clears up on its own after two or three weeks, although metronidazole speeds recovery.
Prevention – drink only pure or treated water.
Jiggers
Found – a type of sandfly found in tropical areas of the Americas and Africa.
Symptoms – burrow between toes and under toenails, where eggs are deposited under the skin causing a painful and itchy pea-sized swelling.
Treatment – removing the jigger with a sterile needle, and thoroughly cleaning with antiseptic.
Prevention – wear shoes or at least sandals, and by keeping nails well-trimmed.
Chiggers
Found – worldwide on grass and weeds.
Symptoms – red mites attach themselves to bare legs and ankles and feed on blood. May cause a painful, itchy swelling about a half inch in diameter.
Prevention – wear socks and pants, and by applying DEET to exposed skin, socks, and pant cuffs.
Bedbugs
Found – worldwide. Small, flat, usually brown bugs found in beds and furniture during the day, and come out at night.
Symptoms – a straight line of red bites across the skin. They rarely spread disease, but the bites should be cleaned with antiseptic to prevent infection.
Prevention – check bedding carefully, look for tiny red splotches on sheets and blankets. If found, take another room or use a hammock.
Sandflies
Found – tiny, nearly-invisible long-legged flies common to tropical areas.
Symptoms – walking at at dawn and dusk stirs up flies and results in bites. Can transmit several diseases to humans.
Prevention – remain indoors or in a hammock during dawn and dusk. Cover exposed skin, especially legs, ankles, and arms, and use DEET. Wear socks.
Lice
Found – tiny, flat, wingless bugs found wordlwide.
Treatment – body lice are killed by washing clothes in very hot water, or by using a hot dryer. Other lice can be killed with lotions and shampoos containing benzene hexachloride.
Scabies
Found – are tiny mites found worldwide that burrow into the skin and lay eggs.
Symptoms – intense itching, especially at night.
Treatment – with an insecticide lotion.
Hookworms
Found – half-inch long worms that live in the small intestines of 700 million people around the world, especially in the tropics.
Cause – burrowing into the feet, or by ingestion.
Symptoms – a red and very itchy rash on the feet that lasts for several days. A cough and pneumonia are also possible when a heavy infestation passes through the lungs.
Prevention – wear shoes or sandals.
Treatment – an anti-worm drug.
Guinea worm
Found – numerous African and Asian countries.
Cause – drinking water containing the cyclops crustacean water flea.
Symptoms – begin a year later when the worm is fully grown and ready to reproduce. It comes to the surface of the skin where a blister forms. Hives, diarrhea, and vomiting often occur at this time. When the blister bursts the end of the worm is exposed, and debilitating pain begins.
Treatment – wrap the exposed worm around a stick, and then gently wind it out over several days. This is dangerous (although impressive) as if the worm breaks an infection can develop.
Beefworm (botfly larvae)
Found – Central America. It is common in the jungles of Belize.
Symptoms – like a mosquito bite that doesn’t go away. After several weeks it resembles a boil, except for a tiny hole in the center. If you look closely with a magnifying glass you will see something pushing to the surface every so often to breathe and expel waste. As it feeds it occasionally delivers a sharp pain like a hot needle stabbing into flesh, which lasts only a few but very long seconds.
Treatment – the traditional Mayan method is to pour tobacco juice into the hole which kills the beefworm in about an hour. You then easily squeeze it out. Another method is to suffocate it overnight by covering the hole with multiple layers of glue and plastic wrap. It becomes poppable if you manage to cut off 100% of its air.
Tumbu fly
Found – in Africa.
Cause – fly lays eggs on clothing left out to dry, which later hatch with skin contact.
Treatment – similar to the botfly.
Prevention – ironing clothes to kill the eggs.
