Hepatitis A is a viral infection transmitted through contaminated food and water or by direct contact with an infectious person. Symptoms are often mild or absent in young children, but the disease can be more serious with advancing age. Recovery can vary from weeks to months. Following hepatitis A infection immunity is lifelong.

Prevention

All travellers should take care with personal, food and water hygiene.

Hepatitis A vaccination

As hepatitis A vaccine is well tolerated and affords long-lasting protection, it is recommended for all previously unvaccinated travellers.

Hepatitis A in brief

Tetanus is caused by a toxin released from Clostridium tetani bacteria and occurs worldwide. Tetanus bacteria are present in soil and manure and may be introduced through open wounds such as a puncture wound, burn or scratch.

Prevention

Travellers should thoroughly clean all wounds and seek medical attention for injuries such as animal bites/scratches, burns or wounds contaminated with soil.

Tetanus vaccination

• Travellers should have completed a tetanus vaccination course according to the UK schedule.
• If travelling to a country or area where medical facilities may be limited, a booster dose of a tetanus-containing vaccine is recommended if the last dose was more than ten years ago even if five doses of vaccine have been given previously.

Country-specific information on medical facilities may be found in the 'health' section of the FCDO foreign travel advice pages.

Tetanus in brief

Typhoid is a bacterial infection transmitted through contaminated food and water. Previous typhoid illness may only partially protect against re-infection.

Vaccination is recommended for most travellers, particularly travellers visiting friends and relatives, those in contact with an infected person, young children, frequent or long-stay travellers visiting areas where sanitation and food hygiene are likely to be poor, and laboratory personnel who may handle the bacteria for their work.

Prevention

All travellers should take care with personal, food and water hygiene.

Typhoid vaccination

• Oral and injectable typhoid vaccinations are available.

Typhoid in brief

Cholera is a bacterial infection transmitted by contaminated food and water. Cholera can cause severe watery diarrhoea although mild infections are common. Most travellers are at low risk.

Prevention

All travellers should take care with personal, food and water hygiene.

Cholera vaccination

This oral vaccine is recommended for those whose activities or medical history put them at increased risk. This includes:

• aid workers.
• those going to areas of cholera outbreaks who have limited access to safe water and medical care.
• those for whom vaccination is considered potentially beneficial.

Cholera in brief

Hepatitis B is a viral infection spread through blood, semen and vaginal fluids. This mostly occurs during sexual contact or as a result of blood-to-blood contact (for example from contaminated equipment during medical and dental procedures, tattooing or body piercing procedures, and sharing of intravenous needles). Mothers with the virus can also pass on the infection to their baby during childbirth.

Hepatitis B in Comoros

This country is considered to have an intermediate or high prevalence of hepatitis B.

Prevention

Travellers should avoid contact with blood or body fluids. This includes:

• Avoiding unprotected sexual intercourse.
• Avoiding tattooing, piercing, public shaving, and acupuncture (unless sterile equipment is used).
• Not sharing needles or other injection equipment.
• Following universal precautions if working in a healthcare or other higher risk setting.

A sterile medical equipment kit may be helpful when travelling to resource poor areas.

Hepatitis B vaccination

Vaccination could be considered for all travellers and is recommended for those whose activities or medical history put them at increased risk. This includes:

• Those who may have unprotected sex.
• Those who may be exposed to contaminated needles through injecting drug use.
• Those who may be exposed to blood or body fluids through their work (e.g. health and aid workers).
• Those at high risk of requiring medical or dental procedures or hospitalisation e.g. those with pre-existing medical conditions, those who may require travelling for medical care abroad, or those travelling to visit families or relatives.
• Long-stay travellers.
• Those who are participating in contact sports.
• Families adopting children from this country.

Hepatitis B in brief

Rabies is a viral infection which is usually transmitted following contact with the saliva of an infected animal most often via a bite, scratch or lick to an open wound or mucous membrane (such as on the eye, nose or mouth). Although many different animals can transmit the virus, most cases follow a bite or scratch from an infected dog. In some parts of the world, bats are an important source of infection.

Rabies symptoms can take some time to develop, but when they do, the condition is almost always fatal.

The risk of exposure is increased by certain activities and length of stay (see below). Children are at increased risk as they are less likely to avoid contact with animals and to report a bite, scratch or lick.

Rabies in Comoros

Rabies is considered to be a risk in this country. Bats may also carry rabies-like viruses.

Prevention

• Travellers should avoid contact with all animals. Rabies is preventable with prompt post-exposure treatment.
• Following a possible exposure, wounds should be thoroughly cleansed and an urgent local medical assessment sought, even if the wound appears trivial.
• Post-exposure treatment and advice should be in accordance with national guidelines.

Rabies vaccination

A full course of pre-exposure vaccines simplifies and shortens the course of post-exposure treatment and removes the need for rabies immunoglobulin which is in short supply world-wide. Pre-exposure vaccinations are recommended for travellers whose activities put them at increased risk including:

• those at risk due to their work (e.g. laboratory staff working with the virus, those working with animals or health workers who may be caring for infected patients).
• those travelling to areas where access to post-exposure treatment and medical care is limited.
• those planning higher risk activities such as running or cycling.
• long-stay travellers (more than one month).

Rabies in brief

Atovaquone 250mg/Proguanil 100mg combination preparation:

• start one to two days before arrival in the malaria risk area
• for adults, one tablet is taken every day, ideally at the same time of day for the duration of the time in a malaria risk area and daily for seven days after leaving the malaria risk area
• take with a fatty meal if possible
• for children paediatric tablets are available and the dose is based on body weight (see table below)

Doxycycline 100mg:

• start one to two days before arrival in the malaria risk area
• adults and children over 12 years of age take 100mg daily, ideally at the same time of day for the duration of the time in a malaria risk area and daily for four weeks after leaving the malaria risk area
• take with food if possible; avoid taking this drug just before lying down
• not suitable for children under 12 years of age

Mefloquine 250mg:

• this drug is taken weekly, adults take one 250mg tablet each week
• start two to three weeks before arrival in the malaria risk area and continue weekly until four weeks after leaving the malaria risk area
• for children the dose is based on the body weight (see table below)

Insect or tick bites can cause irritation and infections of the skin at the site of a bite. They can also spread certain diseases.

Diseases in East Africa

There is a risk of insect or tick-borne diseases in some areas of East Africa.

This includes diseases such as African Trypanosomiasis (sleeping sickness), African tick bite fever, chikungunya, Crimean-Congo haemorrhagic fever, leishmaniasis, Rift Valley fever and West Nile virus.

Prevention

• All travellers should avoid insect and tick bites day and night.
• There are no vaccinations (or medications) to prevent these diseases.

Further information about specific insect or tick-borne diseases for this country can be found, if appropriate on this page, in other sections of the country information pages and the insect and tick bite avoidance factsheet.

Dengue is a viral infection spread by mosquitoes which mainly feed during daytime hours. It causes a flu-like illness, which can occasionally develop into a more serious life-threatening illness. Severe dengue is rare in travellers.

The mosquitoes that spread dengue are more common in towns, cities and surrounding areas.

Dengue in Comoros

There is a risk of dengue in this country.

Prevention

• Travellers should avoid mosquito bites particularly during daytime hours.
• A dengue vaccine is licensed in the UK for the prevention of dengue disease in individuals from 4 years of age. The Joint Committee on Vaccination and Immunisation (JCVI) and World Health Organization are in the process of reviewing the product information. Recommendations on the use of this vaccine will be published in due course.

Dengue in brief

Seasonal influenza is a viral infection of the respiratory tract and spreads easily from person to person via respiratory droplets when coughing and sneezing. Symptoms appear rapidly and include fever, muscle aches, headache, malaise (feeling unwell), cough, sore throat and a runny nose. In healthy individuals, symptoms improve without treatment within two to seven days. Severe illness is more common in those aged 65 years or over, those under 2 years of age, or those who have underlying medical conditions that increase their risk for complications of influenza.

Seasonal influenza in Comoros

Seasonal influenza occurs throughout the world. In the northern hemisphere (including the UK), most influenza occurs from as early as October through to March. In the southern hemisphere, influenza mostly occurs between April and September. In the tropics, influenza can occur throughout the year.

Prevention

All travellers should:

• Avoid close contact with symptomatic individuals
• Avoid crowded conditions where possible
• Wash their hands frequently
• Practise ‘cough hygiene’: sneezing or coughing into a tissue and promptly discarding it safely, and washing their hands
• Avoid travel if unwell with influenza-like symptoms
• A vaccine is available in certain circumstances (see below)*

*In the UK, seasonal influenza vaccine is offered routinely each year to those at higher risk of developing of severe disease following influenza infection, and certain additional groups such as healthcare workers and children as part of the UK national schedule (see information on vaccination). For those who do not fall into these groups, vaccination may be available privately.

If individuals at higher risk of severe disease following influenza infection are travelling to a country when influenza is likely to be circulating they should ensure they received a flu vaccination in the previous 12 months.

The vaccine used in the UK protects against the strains predicted to occur during the winter months of the northern hemisphere. It is not possible to obtain vaccine for the southern hemisphere in the UK, but the vaccine used during the UK influenza season should still provide important protection against strains likely to occur during the southern hemisphere influenza season, and in the tropics.

Avian influenza

Avian influenza viruses can rarely infect and cause disease in humans. Such cases are usually associated with close exposure to infected bird or animal populations. Where appropriate, information on these will be available in the outbreaks and news sections of the relevant country pages. Seasonal influenza vaccines will not provide protection against avian influenza.

Avian influenza in brief

Poor air quality is a significant public health problem in many parts of the world. Exposure to high levels of air pollution over short time periods (e.g. minutes/hours/days) and longer time periods (e.g. years) is linked to many different acute and chronic health problems. These effects are mainly on the respiratory (lungs and airways) and cardiovascular (heart function and blood circulation) systems.

Current information on world air quality is available from the world air quality index project.

Prevention

Travellers with health problems that might make them more vulnerable to the effects of air pollution who are travelling to areas of high pollution should:

• discuss their travel plans with their doctor, and carry adequate supplies of their regular medication.
• take sensible precautions to minimise their exposure to high levels of air pollution.
• check local air quality data and amend their activities accordingly.
• take notice of any health advisories published by the local Ministry of Health and Department for Environment, and follow the guidance provided.

It is unclear if face masks are beneficial at reducing exposure and may make breathing more difficult for those with pre-existing lung conditions. Those who choose to use one should make sure that the mask fits well and know how to wear it properly.

Outdoor air quality in brief