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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 possibility of the fever. There is no specific treatment. Aspirin should be avoided, as it increases the risk of haemorrhaging. There is no vaccine against dengue fever.
To prevent diarrhoea, avoid tap water unless it has been boiled, filtered, or chemically disinfected (e.g. with iodine tablets); only eat fresh fruits and vegetables if cooked or peeled; be wary of dairy products that might contain unpasteurised milk, and be highly selective when eating food from street vendors.
If you develop diarrhoea, be sure to drink plenty of fluids, preferably an oral re-hydration solution containing lots of salt and sugar. A few loose stools don't require treatment but, if you start experiencing more than four or five stools a day, you should start taking an antibiotic (usually a quinolone drug) and an antidiarrhoeal agent (such as loperamide).
If diarrhoea is bloody, or persists for more than 72 hours, or is accompanied by fever, shaking chills or severe abdominal pain you should seek medical attention.
These parasites are most common in rural, tropical areas. The different worms have different ways of infecting people. Some may be ingested on food such as undercooked meat (eg, tapeworms) and some enter through your skin (eg, hookworms). Infestations may not show up for some time, and although they are generally not serious, if left untreated some can cause severe health problems later. Ascaris worm is common in East Africa. Consider having a stool test when you return home to check for worm infestation and determine the appropriate treatment.
