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A yellow fever vaccination certificate is required from travellers coming from countries with risk of yellow fever transmission.Visitors to Réunion should take precautions against mosquito bites due to illnesses such as dengue fever and the Chikungunya virus. A yellow fever certificate is required from travellers arriving from an infected area. Réunion's medical and sanitary facilities are very good. Most towns have doctors and clinics, while the principal hospital is in Saint-Denis. Tap water is usually safe for drinking. Public water sources are unsafe if labelled 'Eau non potable'. There is a reciprocal health agreement with the UK and most EU countries, whose citizens are entitled to low-cost emergency medical treatment on presentation of a European Health Insurance Card (EHIC).
Yellow fever
Cause: The yellow fever virus, an arbovirus of the Flavivirus genus. Transmission: Yellow fever in urban and some rural areas is transmitted by the bite of infective Aedes aegypti mosquitoes and by other mosquitoes in the forests of south America. The mosquitoes bite during daylight hours. Transmission occurs at altitudes up to 2,500 metres. Yellow fever virus infects humans and monkeys. In jungle and forest areas, monkeys are the main reservoir of infection, with transmission from monkey to monkey carried out by mosquitoes. The infective mosquitoes may bite humans who enter the forest area, usually causing sporadic cases or small outbreaks. In urban areas, monkeys are not involved and infection is transmitted among humans by mosquitoes. Introduction of infection into densely populated urban areas can lead to large epidemics of yellow fever. In Africa, an intermediate pattern of transmission is common in humid savannah regions. Mosquitoes infect both monkeys and humans, causing localized outbreaks. Nature of the disease: Although some infections are asymptomatic, most lead to an acute illness characterized by two phases. Initially, there is fever, muscular pain, headache, chills, anorexia, nausea and/or vomiting, often with bradycardia. About 15% of patients progress to a second phase after a few days, with resurgence of fever, development of jaundice, abdominal pain, vomiting and haemorrhagic manifestations; half of these patients die 10-14 days after onset of illness. Geographical distribution: The yellow fever virus is endemic in some tropical areas of Africa and central and south America. The number of epidemics has increased since the early 1980s. Other countries are considered to be at risk of introduction of yellow fever due to the presence of the vector and suitable primate hosts (including Asia, where yellow fever has never been reported). Risk for travellers: Travellers are at risk in all areas where yellow fever is endemic. The risk is greatest for visitors who enter forest and jungle areas. Prophylaxis (protective treatment): Vaccination. In some countries, yellow fever vaccination is mandatory for visitors. Precautions: Avoid mosquito bites during the day as well as at night. Endemic Countries: The World Health Organization considers the following countries to be endemic for yellow fever: Angola, Benin, Bolivia, Brazil, Burkino Faso, Burundi, Cameroon, Central African Republic, Chad, Colombia, Congo, Congo, Côte d'Ivoire, Democratic Republic of the Congo, Ecuador, Equatorial Guinea, Ethiopia, French Guyana, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Guyana, Kenya, Liberia, Mali, Niger, Nigeria, Panama, Peru, Rwanda, Sao Tome and Principe, Senegal, Sierra Leone, Somalia, Sudan, Suriname, Togo, Trinidad and Tobago, Uganda, United Republic of Tanzania and Venezuela. Source: WHO.
Back to TopTyphoid 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.
Back to TopHepatitis B
Cause: Hepatitis B virus (HBV), belonging to the Hepadnaviridae. Transmission: Hepatitis B is transmitted from person to person by contact with infected body fluids. Sexual contact is an important mode of transmission, but infection is also transmitted by transfusion of contaminated blood or blood products, or by use of contaminated needles or syringes for injections. There is also a potential risk of Hepatitis B transmission through other skin-penetrating procedures including acupuncture, piercing and tattooing. Perinatal transmission may occur from mother to baby. There is no insect vector or animal reservoir. Nature of the disease: Many HBV infections are asymptomatic (e.g. causes no symptoms) or cause mild symptoms, which are often unrecognised in adults. When clinical hepatitis results from infection, it has a gradual onset, with anorexia, abdominal discomfort, nausea, vomiting, arthralgia and rash, followed by the development of jaundice in some cases. In adults, about 1% of cases are fatal. Chronic HBV infection persists in a proportion of adults, some of whom later develop cirrhosis and/or liver cancer. Geographical distribution: Worldwide, but with differing levels of endemicity. In north America, Australia, northern and western Europe and New Zealand, prevalence of chronic HBV infection is relatively low (less than 2% of the general population). Risk for travellers: Negligible for those vaccinated against hepatitis B. Unvaccinated travellers are at risk if they have unprotected sex or use contaminated needles or syringes for injection, acupuncture, piercing or tattooing. An accident or medical emergency requiring blood transfusion may result in infection if the blood has not been screened for HBV. Travellers engaged in humanitarian relief activities may be exposed to infected blood or other body fluids in health care settings. Prophylaxis (protective treatment): Vaccination. Precautions: Adopt safe sexual practices and avoid the use of any potentially contaminated instruments for injection or other skin-piercing activity. Source: WHO.
Back to TopHepatitis 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.
Back to TopDiphtheria
Disease: Diphtheria is a bacterial disease caused by Corynebacterium diphtheriae. The infection commonly affects the throat and may lead to obstruction of the airways, and death. Transmission is from person to person, through close physical contact, and is increased in overcrowded and poor socioeconomic conditions. Exotoxin-induced damage occurs to organs such as the heart. Nasal diphtheria may be mild, and chronic carriage of the organism frequently occurs; asymptomatic infections are common. A cutaneous form of diphtheria is common in tropical countries and may be important in transmission of the infection. Occurrence: Diphtheria is found worldwide, although it is not common in industrialized countries because of long-standing routine use of DTP vaccine. Recently, large epidemics have occurred in several east European countries. Risk for travellers: Potentially life-threatening illness and severe, lifelong complications are possible in incompletely immunized individuals. Vaccine: All travellers should be up to date with the vaccine, which is usually given as "triple vaccine"-DTP (diphtheria/tetanus/pertussis). After the initial course of three doses, additional doses may be given as DT until 7 years of age, after which a vaccine with reduced diphtheria content (Td) is given. Since both tetanus toxoid and diphtheria toxoid can reasonably be given on a booster basis about every 10 years, there is little reason to use monovalent diphtheria vaccine. Precautions and contraindications: Avoid diphtheria-containing vaccines if a severe or life-threatening reaction has occurred to a previous dose. Use a vaccine with reduced diphtheria content (Td) from age 7 years onwards. Source: WHO.
Back to TopDengue 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.
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