Seychelles Health Overview

A yellow fever vaccination is required for entry by those arriving from an infected area within six days. Immunisation against hepatitis A and typhoid are highly recommended. Visitors are advised to bring their own medication to avert the risk of travellers' diarrhoea, as well as sun block and insect repellent, local supplies being erratic and costly. During the rainy season in particular, visitors are advised to take precautions against mosquito bites due to the risk of dengue fever and the Chikungunya virus spread by bites. There is a risk of leptospirosis, and walking barefoot should be avoided on roads and paths. Tap water meets World Health Organisation standards, but most visitors prefer to drink bottled water, which is widely available. Fruit and vegetables should be peeled and meat well cooked before being eaten. Medical facilities on the islands are limited, but there is a government hospital in Victoria and some private clinics. Medical insurance with full evacuation cover is necessary.

Typhoid fever

Cause: Salmonella typhi, the typhoid bacillus, which infects only humans. Similar paratyphoid and enteric fevers are caused by other species of Salmonella, which infect domestic animals as well as humans. Transmission: Infection with typhoid fever is transmitted by consumption of contaminated food or water. Occasionally direct faecal-oral transmission may occur. Shellfish taken from sewage-polluted beds are an important source of infection. Infection occurs through eating fruit and vegetables fertilized by night soil and eaten raw, and milk and milk products that have been contaminated by those in contact with them. Flies may transfer infection to foods, resulting in contamination that may be sufficient to cause human infection. Pollution of water sources may produce epidemics of typhoid fever, when large numbers of people use the same source of drinking water. Nature of the disease: Typhoid fever is a systemic disease of varying severity. Severe cases are characterized by gradual onset of fever, headache, malaise, anorexia and insomnia. Constipation is more common than diarrhoea in adults and older children. Without treatment, the disease progresses with sustained fever, bradycardia, hepatosplenomegaly, abdominal symptoms and, in some cases, pneumonia. In white-skinned patients, pink spots (papules), which fade on pressure, appear on the skin of the trunk in up to 50% of cases. In the third week, untreated cases develop additional gastrointestinal and other complications, which may prove fatal. Around 2-5% of those who contract typhoid fever become chronic carriers, as bacteria persist in the biliary tract after symptoms have resolved. Geographical distribution: Worldwide. The disease occurs most commonly in association with poor standards of hygiene in food preparation and handling and where sanitary disposal of sewage is lacking. Risk for travellers: Generally low risk for travellers, except in parts of north and west Africa, in south Asia and in Peru. Elsewhere, travellers are usually at risk only when exposed to low standards of hygiene with respect to food handling, control of drinking water quality, and sewage disposal. Prophylaxis (protective treatment): Vaccination. Precautions: Observe all precautions against exposure to foodborne and waterborne infections. Source: WHO.

Leptospirosis (including Weil disease)

Cause: Various spirochaetes of the genus Leptospira. Transmission: Infection occurs through contact between the skin (particularly skin abrasions) or mucous membranes and water, wet soil or vegetation contaminated by the urine of infected animals, notably rats. Occasionally infection may result from direct contact with urine or tissues of infected animals, or from consumption of food contaminated by the urine of infected rats. Nature of the disease: Leptospiral infections, including Weil disease, take many different clinical forms, usually with sudden onset of fever, headache, myalgia, chills, conjunctival suffusion and skin rash. The disease may progress to meningitis, haemolytic anaemia, jaundice, haemorrhagic manifestations and other complications, including hepatorenal failure. Geographical distribution: Worldwide. Most common in tropical countries. Risk for travellers: Low for most travellers. There is occupational risk for farmers in paddy rice and sugar cane production. Visitors to rural areas and in contact with water in canals, lakes and rivers may be exposed to infection. There is increased risk after recent floods. The risk may be greater for those who practise canoeing, kayaking or other activities in water. Prophylaxis (protective treatment): None. Vaccine against local strains is available for workers where the disease is an occupational hazard but is not commercially available in most countries. Precautions: Avoid swimming or wading in potentially contaminated waters including canals, ponds, rivers, streams and swamps. Avoid all direct or indirect contact with rodents. Source: WHO.

Hepatitis A

Cause: Hepatitis A virus, a member of the picornavirus family. Transmission: The virus is acquired directly from infected persons by the faecal-oral route or by close contact, or by consumption of contaminated food or drinking water. There is no insect vector or animal reservoir (although some non-human primates are sometimes infected). Nature of the disease: An acute viral hepatitis with abrupt onset of fever, malaise, nausea and abdominal discomfort, followed by the development of jaundice a few days later. Infection in very young children is usually mild or asymptomatic (e.g. causes no symptoms); older children are at risk of symptomatic disease. The disease is more severe in adults, with illness lasting several weeks and recovery taking several months; case-fatality is greater than 2% for those over 40 years of age and 4% for those over 60. Geographical distribution: Worldwide, but most common where sanitary conditions are poor and the safety of drinking water is not well controlled. Risk for travellers: Non-immune travellers to developing countries are at significant risk of infection. The risk is particularly high for travellers exposed to poor conditions of hygiene, sanitation and drinking water control. Prophylaxis (protective treatment): Vaccination. Precautions: Travellers who are non-immune to hepatitis A (i.e. have never had the disease and have not been vaccinated) should take particular care to avoid potentially contaminated food and water. Source: WHO.

Dengue Fever

Cause: The dengue virus - a flavivirus of which there are four serotypes. Transmission: Dengue fever is transmitted by the Aedes aegypti mosquito, which bites during daylight hours. There is no direct person-to-person transmission. Monkeys act as a reservoir host in south-east Asia and west Africa. Nature of the disease: Dengue occurs in three main clinical forms: Dengue fever is an acute febrile illness with sudden onset of fever, followed by development of generalized symptoms and sometimes a macular skin rash. It is known as "breakbone fever" because of severe muscular pains. The fever may be biphasic (i.e. two separate episodes or waves of fever). Most patients recover after a few days; Dengue haemorrhagic fever has an acute onset of fever followed by other symptoms resulting from thrombocytopenia, increased vascular permeability and haemorrhagic manifestations; Dengue shock syndrome supervenes in a small proportion of cases. Severe hypotension develops, requiring urgent medical treatment to correct hypovolaemia. Without appropriate treatment, 40-50% of cases are fatal; with timely therapy, the mortality rate is 1% or less. Geographical distribution: Dengue fever is widespread in tropical and subtropical regions of central and south America and south and south-east Asia and also occurs in Africa; in these regions, dengue is limited to altitudes below 600 metres (2,000 feet). Risk for travellers: There is a significant risk for travellers in areas where dengue fever is endemic and in areas affected by epidemics of dengue. Prophylaxis (protective treatment): None. Precautions: Travellers should take precautions to avoid mosquito bites both during the day and at night in areas where dengue occurs. Source: WHO.