At the beginning of 2000, heavy rains triggered a sharp increase in insect-borne diseases in Ecuador, particularly malaria and dengue fever in the coastal provinces. By far the best way of avoiding such diseases is not to get bitten in the first place. The malaria mosquito is usually active from dawn till dusk: straightforward precautions include using insect repellent (those with at least 35 percent DEET in them are most effective, though this is strong stuff and care should be taken in application) and covering up as much skin as possible (light-coloured, loose-fitting and with tight cuffs is best, with the insides of the ends of shirt and trouser cuffs dabbed with DEET). Sleeping in screened rooms with a mosquito net (preferably treated with Permethrin insecticide) tucked under your mattress and spraying your room with insecticide and yourself with insect repellent are also good ideas.

 

The risk of malaria should never be taken lightly: tens of thousands of people contract the disease every year in Ecuador, about a quarter of them with the very serious falciparum variety. The worst-affected areas are below 1500m, especially in or around population centres and when there's plenty of stagnant water for the mosquitoes to breed in. Above 1500m the risk falls substantially, and above 2500m the malaria mosquito cannot survive. Quito and the Galápagos Islands are free of malaria. You'll need to consult your doctor if travelling in malarial areas, and follow a course of medication. This usually consists of chloroquine (Avloclor or Nivaquine) and proguanil (Paludrine); mefloquine (Lariam) is an alternative, though some nasty side effectshave been reported - it's a good idea to start taking it two weeks before you leave to see whether it adversely affects you. It should be stressed that these drugs do not completely wipe out the risk of the disease, and you should always take care to avoid being bitten. Malaria symptoms include fever, diarrhoea, joint pain, shivering and flu-like symptoms; if you suspect you've caught the disease, see a doctor immediately and have a blood test. Remember that symptoms can appear several months after leaving a malarial area.

Dengue fever is a painful and debilitating disease spread by the Aedes mosquito, which bites during the day. There's no vaccine against dengue fever and there's not a lot you can do should you contract it except from resting, and taking pain killers (avoid aspirin) and plenty of fluids. Symptoms include headaches, severe joint pain (its other name, "breakbone fever", is indicative) and high fever, though it's usually only fatal if caught repeatedly.

Avoiding insect bites will also provide you protection against a number of rarer diseases, such as the parasitic disease, leishmaniasis , spread by the bite of infected sand flies, which produces skin sores or fever, anaemia and enlargement of the spleen and liver, usually months after infection. The flies are about one-third the size of mosquitoes, so a fine-mesh (18 holes per inch is recommended) mosquito net, preferably treated with insecticide, is advisable for rural tropical and subtropical areas. In parts of Esmeraldas province, river blindness (onchocerciasis) is spread by the bite of black flies found around fast-moving water. It can lead to unpleasant inflammation around the eyes, with blindness resulting in a small proportion of cases. Chagas disease (also called American trypanosomiasis) is carried by reduviid bugs found in rural mud, thatch and adobe buildings, and transmitted when the bug's faeces are unwittingly rubbed into its bite wound. The disease can take up to twenty years to show, but can lead to severe heart problems. You're very unlikely to come in contact with the disease - if you have to sleep in these conditions, use a mosquito net.