Malaria - malaaria
This serious and potentially fatal disease is spread by mosquito bites. If you are traveling in endemic areas it is extremely important to avoid mosquito bites and to take tablets to prevent this disease. Symptoms range from fever, chills and sweating, headache, diarrhea and abdominal pains to a vague feeling of ill-health. Seek medical help immediately if malaria is suspected. Without treatment malaria can rapidly become more serious and can be fatal.
If medical care is not available, malaria tablets can be used for treatment. You should seek medical advice, before you travel, on the right medication and dosage for you.
If you do contract malaria, be sure to be re-tested for malaria once you return home as you can harbor malaria parasites in your body even if you are symptom free.
Travelers are advised to prevent mosquito bites at all times. The main messages are: wear light-colored clothing; wear long trousers and long-sleeved shirts; use mosquito repellents containing the compound DEET on exposed areas (prolonged overuse of DEET may be harmful, especially to children, but its use is considered preferable to being bitten by disease-transmitting mosquitoes); avoid perfumes and aftershave. Use a mosquito net impregnated with mosquito repellent (permethrin) - it may be worth taking your own.
Hepatitis - hepatiidid
Several different viruses cause hepatitis; they differ in the way that they are transmitted. The symptoms in all forms of the illness include fever, chills, headache, fatigue, feelings of weakness and aches and pains, followed by loss of appetite, nausea, vomiting, abdominal pain, dark urine, light-colored feces, jaundiced (yellow) skin and yellowing of the whites of the eyes.
There are 6 known types of viral hepatitis: A, B, C, D, E and G. G is not dangerous. A and E are passed on by the fecal-oral route of transmission; there is a vaccine. Seek medical advice, but there is not much you can do apart from resting, drinking lots of fluids, eating lightly and avoiding fatty foods. A and E cause an acute illness, but you will recover fully from it.
B and D are passed on via blood, saliva, semen and vaginal fluids. They can be passed on by close contact, sexual contact, and blood-to-blood contact. The symptoms of hepatitis B may be more severe than type A and the disease can lead to long-term problems such as chronic liver damage, liver cancer or a long-term carrier state. There is a vaccine.
Hepatitis C is only passed on from blood-to-blood contact. There is no vaccine.
Dengue fever
Unlike the malaria mosquito, the Aedes aegypti mosquito, which transmits the dengue virus, is most active during the day, and is found mainly in urban areas, in and around human dwellings.
Signs and symptoms of dengue fever include a sudden onset of high fever, headache, joint and muscle pains, nausea and vomiting. A rash of small red spots sometimes appears three to four days after the onset of fever. Severe complications do sometimes occur.
You should seek medical attention as soon as possible if you think you may be infected. A blood test can indicate the presence of the fever. There is no specific treatment. Aspirin should be avoided, as it increases the risk of hemorrhaging. There is no vaccine against dengue fever.
Cholera - koolera
This diarrheal disease can cause rapid dehydration and death. Cholera is caused by a bacteria, Vibrio cholerae . It's transmitted from person to person by direct contact (often via healthy carriers of the disease) or via contaminated food and water. It can be spread by seafood, including crustaceans and shellfish, which get infected via sewage.
Cholera exists where standards of environmental and personal hygiene are low. Every so often there are massive epidemics, usually due to contaminated water in conditions where there is a breakdown of the normal infrastructure.
The time between becoming infected and symptoms appearing is usually short, between one and five days. The diarrhea starts suddenly, and pours out of you. It's characteristically described as 'rice water' diarrhea because it is watery and flecked with white mucus. Vomiting and muscle cramps are usual, but fever is rare. In its most serious form, it causes a massive outpouring of fluid (up to 20L a day). This is the worst case scenario - only about one in 10 sufferers get this severe form.
It's a self-limiting illness, meaning that if you don't succumb to dehydration, it will end in about a week without any treatment.
You should seek medical help urgently; in the meantime, start re-hydration therapy with oral re-hydration salts. You may need antibiotic treatment with tetracycline, but fluid replacement is the single most important treatment strategy in cholera.
Prevention is by taking basic food and water precautions, avoiding seafood and having scrupulous personal hygiene. The currently available vaccine is not thought worthwhile as it provides only limited protection for a short time.
Yellow fever - kollapalavik
Yellow fever is transmitted through the bite of an infected mosquito. There is an effective vaccine against yellow fever, so if you have been immunized, you can basically rule this disease out. Symptoms of yellow fever range from a mild fever which resolves over a few days to more serious forms with fever, headache, muscle pains, abdominal pain and vomiting. This can progress to bleeding, shock, and liver and kidney failure. The liver failure causes jaundice, or yellowing of your skin and the whites of your eyes - hence the name. There's no specific treatment but you should seek medical help urgently if you think you have yellow fever.
Salto Ángel 
