Travel health guides

Altitude illness includes a number of conditions that may occur in individuals travelling to high altitude, usually above 2,500 metres (8,200 feet). Most trips to altitude can be enjoyed safely if sensible precautions are taken. High altitude is defined as an elevation above 1,50

Avian influenza, also called bird flu, is an infection in birds caused by several strains of influenza A virus. Avian influenza is found in bird populations worldwide and some of these strains have spread from wild birds to domestic poultry. Some specific viruses (e.g. H5, H7 and

Chikungunya is a viral infection caused by the chikungunya virus (CHIKV), an alphavirus which is spread through mosquito bites. The mosquitoes that transmit chikungunya bite during the day, from sunrise to sunset, especially at dawn and dusk. They breed in natural and man-made co

Cholera is a disease, characterised by profuse, watery diarrhoea, caused by certain toxin-producing forms of the bacteria called  Vibrio cholerae . Cholera is transmitted by ingesting (eating and drinking) contaminated water or food. It is common in many low-income coun

COVID-19 is a disease caused by a virus called SARS-CoV-2 and is mainly spread between humans by breathing in droplets from the nose or mouth of an infected person or by touching infected droplets on surfaces, then touching the eyes, nose or mouth. COVID-19 cases have been report

Crimean-Congo haemorrhagic fever (CCHF) is an infectious disease caused by the Crimean-Congo haemorrhagic fever virus (CCHFV). The virus cycles between a wide range of domestic and wild animals, with humans infected via tick bites (Hyalomma species), crushing ticks or through con

Cryptosporidium is a parasite that occurs in most countries worldwide and is found in water, food, soil or on any surface contaminated with animal or human faeces. Cryptosporidium can also contaminate lakes, rivers, streams and swimming pools. Contaminated food, especially raw mi

Dengue is an infection caused by the dengue virus of which there are four different types (serogroups) DENV-1, DENV-2, DENV-3 and DENV-4. The disease is spread through the bite of an infected mosquito. The mosquitoes that spread dengue usually breed in urban areas close to human

Diphtheria is a highly infectious bacterial infection that can affect the nose and throat (respiratory diphtheria), and sometimes the skin (cutaneous diphtheria). Respiratory diphtheria is spread typically by coughing and sneezing and close contact with infected people. There is

Ebola is an infectious disease caused by a virus (filovirus). It was first recognised in 1976 when two outbreaks were reported in the Democratic Republic of the Congo, near the Ebola River, and in South Sudan. Since then, sporadic outbreaks have been reported Central and West Afr

Haemolytic uraemic syndrome (HUS) is a rare but serious, potentially life-threatening condition, which can cause anaemia, kidney failure and can affect the brain, guts, heart, liver and pancreas. HUS can develop as a complication of a stomach bug caused by a harmful type of E. co

Hand, foot and mouth disease (HFMD) is a common infectious disease caused by several different viruses and found worldwide. It is not related to foot and mouth disease, which is found in cattle, pigs and sheep. It is spread person to person through direct contact with infected bo

Hantaviruses are a group of viruses carried by rodents, such as mice, rats or voles, that can infect humans through contact with their urine, faeces, or saliva. Hantavirus infections are relatively uncommon worldwide. Those present in North, Central and South America are known to

Hepatitis A is a highly infectious virus that can cause inflammation of the liver. The virus is usually transmitted through food or water contaminated by human faeces or by direct contact with an infectious person. Hepatitis A is rare in the UK with most cases occurring in travel

Hepatitis B is a viral infection of the liver spread through contact with blood or body fluids contaminated with hepatitis B virus (HBV). It occurs worldwide with highest rates of infection reported in the Western Pacific and African regions. Risk for most travellers is usually l

Japanese encephalitis (JE) is a viral infection of the brain transmitted to humans by mosquitoes in parts of Asia and the Western Pacific. The mosquitoes that transmit JE feed mostly at night, between dusk and dawn and are prolific in rural areas, where rice cultivation and pig f

Lassa fever is an infectious disease caused by Lassa virus, a member of the arenavirus family. The disease was first recognised in the 1950s and the virus was later identified in the town of Lassa, Nigeria in 1969. Lassa fever is endemic in parts of West Africa, particularly Guin

Leishmaniasis is an infection caused by the Leishmania parasites. The infection is transmitted by the bite of infected phlebotomine sandfly. There are over 20 types of Leishmania parasites which cause infection in people and 30 different types of sand flies to spread infection. L

Leptospirosis is a bacterial infection which can infect humans and animals (most commonly rodents, cattle, pigs and dogs). The bacteria are spread to people through direct contact with tissue or body fluids from an infected animal or through contact with freshwater (or wet soil)

Malaria is a serious parasitic infection spread through the bite of an infected mosquito. Five species of the Plasmodium parasite can cause malaria in people. Malaria occurs in many tropical parts of the world including parts of Africa, Asia, Central and South America, the Caribb

Marburg virus (MARV) belongs to the Filovirus family, along with Ebola virus. It can cause a severe and often fatal haemorrhagic fever called Marburg disease (MARD). The case fatality rate in previous outbreaks ranges from 25% to 88% (average of 50%). The disease was first recogn

Measles is a highly infectious viral illness, with potentially serious, life-threatening complications. Travel remains an important risk factor for the international spread of measles. Measles is spread by airborne or droplet (coughing, sneezing, drops from mouth/nose) transmissi

Meningococcal disease is a rare, but potentially devastating infection. It is caused by the bacteria Neisseria meningitidis of which there are 6 disease-causing strains called serogroups (A, B, C, W, Y and X). Approximately 10 percent of the general population of the UK are thoug

Methanol is a clear, colourless liquid. It is used in industrial products, like antifreeze and some cleaning products. Drinking methanol, even in very small amounts, is extremely dangerous. This is because your body turns it into harmful chemicals like formic acid that are poison

Middle East respiratory syndrome coronavirus (MERS-CoV) is a virus that has spread to humans from animals. It is a type of coronavirus (a family of viruses that can cause respiratory infections, including the common cold). MERS-CoV was first recognised in Saudi Arabia in 2012, an

Mpox is an infectious disease caused by the monkeypox virus (MPXV). Other diseases in the same family include variola virus (which causes smallpox), vaccinia virus and cowpox virus. The first human case of mpox was recorded in 1970 in the Democratic Republic of the Congo (DRC) an

Nipah virus disease is caused by the Nipah virus (NiV). The virus is carried by fruit bats, also known as flying foxes. The virus can be spread directly from bats to people through consuming fruits or fruit products (such as raw date palm juice) contaminated with urine or saliva

Oropouche virus disease is an infection caused by the Oropouche virus (OROV). This virus is mainly spread by a bite from an infected midge ( Culicoides paraensis ) that usually bite from dawn to dusk. These midges are common in the Americas and the Caribbean but are not a type of

In many parts of the world, poor air quality is a significant public health problem. The health effects of air pollution are complex; studies have shown exposure to high levels of air pollution over short time periods (e.g. minutes/hours/days) and longer time periods (e.g. years)

Soil-transmitted helminths are parasitic worms that infect humans who come into contact (either by eating contaminated food or by walking barefoot in infected areas) with worm eggs or larva in soil. These worms live in the intestines (guts) and their eggs pass into soil from faec

Pertussis, also known as whooping cough, is a highly infectious disease, caused by the bacterium Bordetella pertussis. It is typically spread by the respiratory route when, for example, an infected person coughs or sneezes. Pertussis starts with non-specific catarrhal ('common co

Plague is an infectious disease caused by bacteria ( Yersinia pestis ) that spreads to humans from animals, usually by rat (rodent) flea bites. People can also catch it from bites or scratches from other infected animals such as cats, by working with plague bacteria or infected a

Poliomyelitis (polio) is a potentially paralysing, vaccine preventable, viral infection. The virus is transmitted through food or water contaminated by infected human faeces or by direct contact with an infectious person. Polio is extremely rare in UK travellers with the last imp

Rabies is a virus carried in animal saliva that usually spreads to humans from a bite, scratch, lick to an open wound from an infected animal (typically a dog). It can also be a risk if an animal spits and saliva gets into the eyes, mouth or nose. The virus attacks the central ne

Schistosomiasis (also known as Bilharzia) is a parasitic infection, caused by Schistosoma worms. Infection occurs through direct contact with contaminated fresh water where certain snails may harbour the infection. Larval forms of the worm are released from these snails into fres

Tetanus is a vaccine-preventable disease caused by a toxin produced by bacteria called Clostridium tetani . Tetanus spores are found in soil throughout the world. The disease is acquired when material containing these spores, such as soil, contaminates a wound. The toxin released

Tick-borne encephalitis (TBE) is a viral infection usually transmitted through the bite of an infected tick. The disease occurs in parts of central, northern and Eastern Europe, Siberia and parts of Asia. Ticks are found on forest fringes within adjacent grassland, forest glades,

Trypanosomiasis is an infection caused by the Trypanosoma parasites. Trypanosomiasis can be found in Africa, commonly known as sleeping sickness, and in Central and South America where it is known as Chagas disease.

Tuberculosis (TB) is a bacterial infection most commonly spread from person to person through the air by coughing and sneezing. Globally the disease is extremely common with millions of new infections and many deaths occurring yearly. The rate of disease varies widely from countr

Typhoid and paratyphoid are infections acquired by the ingestion of food or water contaminated by the bacteria Salmonella Typhi or Salmonella Paratyphi. They cause very similar diseases collectively known as enteric fever and mainly affect low-income areas of the world where sani

Chickenpox, also known as varicella, is a common infection caused by the varicella zoster virus (VZV). Currently, most people in the UK catch chickenpox in childhood, but this is expected to change once chickenpox vaccine becomes routine. The age at which infection occurs varies

West Nile virus (WNV) is a type of flavivirus (like dengue or Zika) that can cause a potentially serious infection in humans. WNV is found in birds and spreads to animals and humans via a bite from an infected mosquito. Most people infected with WNV do not any have symptoms or ex

Yellow fever (YF) is a vaccine preventable viral infection spread predominantly by certain species of day biting mosquitoes. Most people who get YF either have no symptoms or a mild illness and then fully recover. A small proportion of patients develop a severe illness with fever

Zika virus infection is spread by day-biting mosquitoes. A small number of Zika virus cases have also been reported as spread by sexual contact. Zika virus is a flavivirus (similar to dengue) and was first discovered in a monkey in the Zika forest, Uganda in 1947. It is found in