Diseases that commonly require immunization when traveling abroad

The following diseases are present in many regions of the world, particularly in hotter or less well-developed countries. Immunization against some or all of these diseases will provide adequate cover for most travelers.

Hepatitis A

Hepatitis A is an infection of the liver caused by the hepatitis A virus. It causes liver inflammation and jaundice. Hepatitis A is spread by contact with human feces, normally through contaminated food and water or person-to-person contact.

Hepatitis A is more common in countries outside Northern and Western Europe, North America, Australia and New Zealand. The highest risk areas for travelers are the Indian, African, central American, south American subcontinents,and the Far East, but the risk extends to Eastern Europe. Immunization is not considered necessary for people traveling to Northern or Western Europe (including Spain, Portugal and Italy), or North America, Australia or New Zealand.

Hepatitis A vaccination is recommended for:

• Anyone traveling to areas of moderate or high risk for prolonged periods, particularly if sanitation and food hygiene is likely to be poor.
• Anyone going to live in, or be posted for a long period to, a country where hepatitis A is a risk.
• Anyone with chronic liver disease - hepatitis A can be a more serious illness in this group.

Hepatitis A vaccine cannot be given to children under 1 year old. However, hepatitis A is a less serious disease in children under 1, normally causing only mild symptoms.

A single injection of vaccine protects against hepatitis A for about a year. A booster dose, given 6-12 months after the first, gives protection for up to twenty years. Hepatitis A vaccine should be given at least two weeks before traveling to allow your body to develop full immunity, but if necessary the vaccine can be given up to the day of departure.

There are also combined hepatitis A and B, and combined hepatitis A and typhoid vaccines available. These vaccines may be useful if you require protection against both diseases.

Meningococcal disease

Meningococcal disease is a bacterial infection caused by meningococcal bacteria. It can cause meningitis and septicemia (blood infection), and can be serious or even fatal if not treated quickly. Meningococcal disease is spread by droplet infection or through person-to-person contact with someone with the disease.

There are different groups (types or strains) of meningococcal bacteria, each group causing a different meningococcal infection. Groups B and C are the most common. Groups A, Y and W135 are rare in this country, but more common in other parts of the world, particularly parts of sub-Saharan Africa (particularly in the dry season), and areas of Saudi Arabia. Those particularly at risk are travelers who live or travel 'rough', such as backpackers, and those living or working with local people.

Large outbreaks of group A and group W135 meningococcal disease have occurred during Hajj pilgrimages to Saudi Arabia in the past. As a result, Saudi Arabia now requires proof of vaccination against group A, C, W and Y meningitis for visitors arriving for the Hajj and Umrah pilgrimages, or for seasonal working in the Hajj areas.

Vaccination against group C meningitis is now part of the childhood immunization program. However, this vaccination does not provide protection against meningitis groups A, W or Y.

Immunization against groups A, C, W and Y meningitis is recommended for:

• Anyone traveling to a high-risk area for group A meningococcal meningitis who is staying for one month or more. High-risk areas for Group A meningitis include parts of sub-Saharan Africa, Northern India, Nepal, Bhutan, Pakistan, and Saudi Arabia.
• Anyone traveling to a high-risk area for group A meningococcal meningitis and engaging in high-risk activities, such as backpacking or living or working in rural communities.
• Anyone attending the Hajj (Mecca) or Umrah pilgrimages in Saudi Arabia.

Anyone doing seasonal work in the Hajj area.

Meningitis vaccine may be given to infants aged 2 months.

One type of vaccine - known as the quadrivalent meningococcal meningitis vaccine - can protect against meningitis groups A, C, Y and W135. The quadrivalent vaccine should be given 2-3 weeks before travel to allow your body to develop full immunity.

For adults and children over 2 years old, a single dose of vaccine will give protection. For children over 3 months old but under 2 years old, the initial dose of vaccine must be followed by a second dose three months later.

For adults and children over 5 years old, the vaccine gives protection for about five years. For children under 5 years old when they were first vaccinated, the vaccine gives protection for 2-3 years.

Poliomyelitis

Poliomyelitis (commonly known as 'polio') is a serious infection caused by the polio virus. The virus is spread by contact with human feces, normally through contaminated food and water or person-to-person contact. Most people (about 95%) who become infected with polio develop no symptoms and are never aware that they've been infected. However, in a small number who become infected (less than 1%), polio can cause difficulty breathing and paralysis.

Polio is extremely rare in the developed world. However, it is still present in some other parts of the world, particularly sub-Saharan Africa and the Indian subcontinent.

Children are vaccinated against polio under the childhood immunization program. This means that many people will already be fully immunized against polio.

However, polio vaccination is recommended for:

• Anyone traveling to a country where polio is present and who has not been immunized, or has not been fully immunized (received five doses of polio vaccine).
• Anyone traveling to a country where polio is present and who had their last dose of polio vaccine 10 years ago or more.

Polio vaccine cannot be given to children under 2 months old.

Anyone who has never had a polio vaccination will need three doses of vaccine one month apart. This provides protection for at least three years. Anyone who has not been fully vaccinated (received five doses of vaccine), or who has not had a booster dose in the last ten years, will need to have a booster dose of polio vaccine.

Tetanus

Tetanus is a serious infection caused by tetanus bacteria (Clostridium tetani). It affects the body's nervous system, causing painful muscle spasms, and can be fatal. Tetanus bacteria are present in soil and manure and the disease develops when the bacteria enter the body, usually through a wound or cut that has become contaminated with dirt or soil.

Tetanus is found throughout the world. Immunization against tetanus is normally a precautionary measure for travelers, in case they have an injury that might expose them to tetanus bacteria and medical attention is not available.

Children are vaccinated against tetanus under the childhood immunization program. This means that many people will already be fully immunized against tetanus.

However, tetanus vaccination is normally recommended for:

• Anyone who has not been immunized against tetanus, or not been fully immunized (received five doses of vaccine).
• Anyone traveling to a country where medical attention may not be available and whose last dose of tetanus vaccine was more than ten years ago.
• Tetanus vaccine cannot be given to children under 2 months old.

Anyone who has never had a tetanus vaccination will need three doses of vaccine one month apart. This provides protection for a number of years. Anyone who has not been fully vaccinated (received five doses of vaccine), or who has not had a booster dose in the last ten years, will need to have a booster dose of tetanus vaccine.

Typhoid fever

Typhoid fever is a serious infection caused by the bacterium Salmonella typhi. Typhoid fever causes diarrhea, fever, and a serious illness that may last for some time, and can be fatal.

Typhoid fever is spread by contact with human feces, normally through contaminated food and water or person-to-person contact as a result of poor sanitation and personal hygiene.

Typhoid fever is more common in Asia, Africa, Central and South America. Travellers to areas where typhoid is a problem should be immunized, particularly in areas where hygiene and sanitation are poor.

Typhoid fever vaccination is recommended for:

• Anyone traveling to an area where typhoid is a risk (South Asia, parts of South-East Asia, the Middle East, Central and South America, and Africa), especially if they are staying with or visiting the local population.
• Anyone traveling to an area where typhoid is a risk and where sanitation and food hygiene are likely to be poor.

Typhoid fever vaccine cannot be given to children under 18 months old.

Typhoid fever vaccine is not 100% effective, so not everyone who receives the vaccine will be protected against the disease. This means that if you are traveling to an area where typhoid fever is a risk you should take great care to avoid contaminated food or water, and pay careful attention to personal, food and water hygiene.

A single injection of vaccine protects against typhoid fever for about three years. A booster dose is recommended after three years for those still at risk. Ideally, typhoid vaccine should be given at least one month before traveling to allow your body to develop full immunity, but if necessary the vaccine can be given closer to your travel date.

A combined typhoid and hepatitis A vaccine is also available. This vaccine may be useful if you require protection against both diseases.

Yellow fever

Yellow fever is a serious disease caused by a virus. It can cause headache, fever, vomiting, jaundice and bleeding, and can be fatal. Yellow fever is passed to humans by bites from infected mosquitoes.

Yellow fever is only found in sub-Saharan Africa and South America. There have been no cases in North America, Europe or Asia in recent times. Some countries require a certificate of immunization against yellow fever before they will let you into the country.

Yellow fever vaccination is recommended for:

• Anyone traveling to, or living in, an area or country where yellow fever is found.
• Anyone traveling to a country that requires an International Certificate of Vaccination against yellow fever for entry.

Children aged 6-9 nine months should only be immunized if the risk of yellow fever during travel is unavoidable. Yellow fever vaccine cannot be given to children under 6 months old.

Your doctor or nurse practitioner can advise whether you should be immunized against yellow fever for your travel destination, and whether you need a certificate of immunization.

A single injection of vaccine protects against yellow fever for about ten years. A booster dose can be given after ten years for those at continued risk. Yellow fever vaccine should be given at least ten days before traveling to allow your body to develop full immunity and for an International Certificate of Vaccination to become valid. An International Certificate of Vaccination only becomes valid ten days after vaccination, and remains valid for a period of ten years.

Other diseases that may require immunization when traveling abroad

The following diseases are present in some parts of the world, but do not usually pose a serious risk to travelers overseas. However, in some circumstances (for example backpacking in remote areas) there may be a specific risk of contracting one or more of these diseases, so your doctor may recommend immunization against them.

Cholera

Cholera is a disease caused by the bacterium Vibrio cholerae. Cholera can cause severe diarrhea and vomiting which can quickly lead to severe dehydration, and can be fatal. Cholera is spread through contaminated food (especially shellfish) and water, and so is more common during floods and rainy seasons.

The areas worst affected by cholera are the Indian subcontinent, the Far East, Africa and South America.

Cholera vaccination is recommended for:

• Anyone traveling to an area where there have been outbreaks of cholera.
• Anyone traveling abroad to work as a relief worker or disaster aid worker.
• Anyone traveling to remote areas in a country where cholera is a risk, and where there may be limited access to medical care.

Cholera vaccine cannot be given to children under 2 years of age.

Cholera vaccination is not recommended for the majority of travelers, as normal food and water hygiene precautions will be enough to prevent infection for most. Immunization against cholera is not recommended as a means of preventing non-cholera diarrhea (often referred to as travelers' diarrhea).

For adults and children over 6 years old, two doses of vaccine are needed for protection. For children aged 2-6 years, three doses of vaccine are needed. The doses must be given at least one week apart, but no more than six weeks apart.

For all age groups, the vaccinations should be completed at least one week before traveling to allow the body to develop full immunity.

For adults and children over 6 years old, a booster dose is needed two years after vaccination for continued protection. For children aged 2-6, a booster dose is needed six months after vaccination.

Hepatitis B

Hepatitis B is an infection of the liver caused by the hepatitis B virus. Hepatitis B can cause flu-like symptoms, jaundice, and in some cases liver failure, and can be fatal. Hepatitis B is spread through contact with infected blood or body fluids during vaginal or anal intercourse, blood -to- blood contact (for example by infected blood entering a wound, or by injecting drug users sharing contaminated needles or other equipment), by an infected mother passing it to her baby, or, very rarely, by a human bite from an infected person.

Areas where hepatitis B is considered a high risk include sub-Saharan Africa, most of Asia and the Pacific islands. Areas where hepatitis B is considered a medium risk include the Amazon, southern parts of Eastern and Central Europe, the Middle East, and the Indian sub-continent. Areas where hepatitis B is considered a low risk include most of Western Europe and North America.

The risk of hepatitis B for tourists is normally considered to be low. However, this risk increases with certain activities, for example unprotected sexual intercourse, receiving blood transfusions in countries that do not screen donated blood for the virus, and sharing needles by injecting drug users. Working in a medical setting, doing relief work, or receiving body piercings may also increase the risk.

Hepatitis B vaccine is recommended for:

• Anyone traveling to an area of high or medium risk and who is likely to be doing an activity that places them at increased risk, such as sexual activity, injecting drugs, doing relief work, or participating in contact sports.
• Anyone traveling to an area of high or medium risk who is planning to remain there for a long period.
• Anyone who may require medical care or hospitalization while traveling to an area of high or medium risk, or who is traveling for the purpose of medical care.

Hepatitis B vaccine can be given from birth.

There are several different vaccines available for hepatitis B. Most require a course of three doses for protection. The second dose is normally given one month after the first dose, and the third dose given five months after the second dose.

Once you have completed the vaccination course, and the blood test has confirmed that you are immune, you will be protected against hepatitis B for life. However if you are a health care workers are advised to receive a booster dose, five years after the primary course..

A combined hepatitis A and B vaccine is also available. This vaccine may be useful if you require protection against both diseases.

Japanese encephalitis

Japanese encephalitis is an illness caused by a virus known as a flavivirus. It is usually a mild illness, often causing no symptoms. However, in some cases it can cause inflammation of the brain (encephalitis), leading to permanent brain damage and even death. Japanese encephalitis is passed to humans by bites from infected mosquitoes.

Japanese encephalitis is only found in South-East Asia, the Far East, and tropical North East Australia. It is particularly common in rural agricultural areas, and is associated with the rainy season in some countries.

Japanese encephalitis vaccination is recommended for:

• Anyone traveling to South-East Asia, the Far East or tropical North East Australia who is staying for a month or longer in an area where the disease is found.
• Anyone traveling to South-East Asia or the Far East and considered to be at higher risk, for example because they are spending time in rice fields or close to pig farming.
• Anyone traveling to South-East Asia or the Far East and traveling through areas of rice fields or marshland, or doing activities considered to be high-risk, such as camping, backpacking or cycling.
• Anyone traveling to live in an area where Japanese encephalitis is found.

Japanese encephalitis vaccine cannot be given to children under 1 year of age.

Japanese encephalitis vaccination should always be completed at least ten days before traveling to allow any delayed allergic reaction to the vaccine to be dealt with. Ideally, vaccination should be completed at least one month before traveling to allow your body to develop full immunity.

Vaccination against Japanese encephalitis normally requires a course of three doses for protection. The second dose is normally given seven days after the first, with the third dose given 28 or 30 days after the first, depending on the vaccine.

If there is not enough time before you travel to complete a normal course of vaccination, you may be able to have an accelerated course of two doses given one week apart, with a booster dose given three months later. This course gives a lower level of protection that lasts for a shorter time.

Rabies

Rabies is a serious disease caused by a virus. Rabies causes spasms, extreme thirst, fear of water (hydrophobia), madness, and paralysis, and is almost always fatal. Rabies is usually spread through saliva from the bite of an animal carrying the virus, most commonly a dog.

Rabies is found in most countries, and all regions of the world are affected, with the exception of the British Isles, Scandinavia, Japan, Australia and New Zealand, and Antarctica.

Although rabies is nearly always fatal once it develops, if you are bitten by an animal outside the country you should seek medical attention immediately, as treatment can reduce to a minimum the risk of the disease developing as a result of the bite. Immunization against rabies is normally a precautionary measure for travelers, in case they receive a bite that might expose them to rabies and medical attention is not available.

Rabies vaccine is recommended for:

• Anyone traveling for more than one month to an area where rabies is common in animals (such as jungle habitats), and where there is no access to prompt, reliable and safe medical care.
• Anyone traveling for less than one month to an area where rabies is common in animals, but who may be exposed to rabies because of their travel activities. For example, those working with animals.

Rabies vaccine cannot be given to children under 2 months old.

There are currently two rabies vaccines available. Vaccination normally requires a course of three doses for protection. The second dose is normally given seven days after the first, with the third dose given 21 or 28 days after the first, depending on the vaccine used.

Vaccination should be completed before your departure to allow your body to develop full immunity.

Depending on the vaccine used, a booster dose is needed every 2-3 years, or 2-5 years, for continued protection.

If you are bitten or scratched by any animal when you are abroad, you should wash the wound thoroughly with soap and water and seek immediate medical attention, even if you have been vaccinated against rabies. If you do not seek immediate medical attention, or you are unable to obtain medical attention while you are abroad, you should still seek it when you return, even if that is some time after the injury.

Tick-borne encephalitis

Tick-borne encephalitis is a serious infection of the brain caused by a virus known as a flavivirus. The infection can cause flu-like symptoms and inflammation of the brain (encephalitis), and can be fatal. Tick-borne encephalitis is usually spread by tick bites, although unpasteurized milk is also thought to be a source of the disease.

Tick-borne encephalitis is found in forested areas in most countries in Western and Eastern Europe, Scandinavia, the former Soviet Union and some parts of China. Those most at risk include those who intend to walk, camp or work during late spring or summer in heavily forested areas in countries where the disease is found.

Tick-borne encephalitis vaccine is recommended for:

• Anyone traveling during late spring or summer to an area where tick-borne encephalitis is found, particularly if doing a travel activity likely to put them at increased risk, such as camping, hiking or backpacking.

Tick-borne encephalitis vaccine cannot be given to children under 1 year of age.

Vaccination against tick-borne encephalitis requires a course of three doses for protection. The second dose is given 1-3 months after the first, and gives immunity for about one year. A third dose given 5-12 months after the second gives immunity for up to three years. A booster dose can be given up to three years after the third dose for continued protection.

If there is not enough time before you travel to complete a normal course of vaccination, you may be able to have an accelerated course of two doses given two weeks apart.

You can reduce the risk of tick-borne encephalitis by taking some simple precautions to avoid insect bites:

• Wear clothing with long sleeves and long trousers tucked into socks, and apply your clothes with insecticide spray.
• Apply insect repellent to any exposed areas of skin.
• Check your body for ticks regularly. Common areas for ticks attach are at the hair-line, behind the ears, elbows, backs of the knees, groin and armpits.
• Remove any ticks you find as soon as possible by using a pair of tweezers. Place the tweezers as close as possible to the skin and then pull the tick slowly, ensuring the mouth parts are removed completely. Take care not to squeeze the tick's stomach contents into the site of the bite, as this increases the risk of infection.