Travel abroad immunizations and medications

All areas of the world have particular health risks. When you travel, it's important to know in advance what risks to expect at your destination. Taking the recommended precautions can help ensure a safe and healthy trip. Immunizations against certain diseases, as well as medications to prevent malaria, can considerably decrease the risk of acquiring disease during travel.


Health risks
Some health risks are common to most areas of the world, while others are limited to only a few. A first-class hotel in an urban area of a developing country generally poses fewer health risks than one in a rural area, for example. The risk increases the longer you stay abroad. While you're traveling, you may be exposed to viruses, bacteria or parasites that cause infectious diseases if you:
consume contaminated food or water
are bitten by an infected insect or disease-carrying animal
bathe or swim in contaminated water
walk barefoot or sit on soil or sand containing parasites
contact contaminated blood or body fluids
breathe air contaminated with bacteria and viruses

Prevention tips
Become informed. Find out as much as possible about the region you plan to visit. Up-to-date, specific information about health risks around the world is readily available from the Centers for Disease Control and Prevention (CDC) through the Internet, fax or phone. Information is also available on the Internet from the World Health Organization (WHO). For information about the general safety of a region, you can also contact the U. S. State Department.

If you're pregnant, breastfeeding or have a diagnosed health condition, especially HIV, discuss travel plans with your doctor ahead of time. Be sure to carry documentation about your condition. List the medications, vitamins and herbal supplements you take, and note any medication allergies you have.

Obtain necessary immunizations. Receiving immunizations before you travel can prevent a number of infectious diseases. When you're immunized, you're given a vaccine or toxoid by injection or mouth. Vaccines contain a weakened or dead disease germ, while toxoids contain a harmless version of the poison the germ produces. Your body produces antibodies to fight the weakened or dead germ or poison. These antibodies remain in your body, ready to protect you from illness if you're later exposed to the real disease germ or poison.

The Advisory Committee on Immunization Practices (ACIP), a committee of national experts, has developed immunization recommendations for all adults and children in the United States. These recommendations include immunizations against hepatitis A, hepatitis B, diphtheria, tetanus, whooping cough, polio, measles, mumps, rubella (German measles), chickenpox, pneumococcal illnesses and influenza (the flu). Make sure these immunizations are current before you travel. Although some of these illnesses are rare in the United States, they may be prevalent in other parts of the world.

Depending on your travel route and destination, additional immunizations against various diseases may be required. When possible, plan to receive your immunizations three to six months ahead of time -- some require a series of shots. Immunizations you may need include cholera, hepatitis A and B, influenza, Japanese encephalitis, meningococcal meningitis, rabies, plague, typhoid fever and yellow fever. These immunizations are discussed below in alphabetical order. Some of these vaccines may need to be postponed if you're ill or have a fever.

Another note of caution: If you're pregnant or breastfeeding, discuss the following vaccines with your doctor before traveling. The same rule applies for children.


Immunizations
Cholera
Cholera is an intestinal bacterial infection caused by the bacterium Vibrio cholerae. It spreads through contaminated food or water. Cholera usually causes mild diarrhea, but it can also cause severe, profuse watery diarrhea, vomiting and leg cramps. Rapid loss of body fluid can quickly cause dehydration that can be fatal without prompt treatment. The cholera vaccine is not currently required for entry into any country, but local authorities may have other recommendations. The cholera vaccine that was previously given in the United States is no longer manufactured or sold. When it was given, it provided only limited and incomplete immunity. Two more recent and apparently more effective vaccines are available in other countries, but are not recommended for travelers. The best precaution is safe food and water.

Hepatitis A
Hepatitis A (infectious hepatitis) is a viral infection of the liver that's often transmitted through food or water contaminated with stool that contains the virus. If you're traveling to a country where the disease is prevalent and you may have contact with the virus, get the hepatitis A immunization. The vaccine is given in two injections in the upper arm. The first dose should be given at least four weeks before traveling, and the second is given six to 12 months later. The length of immunity or whether a booster shot is needed is not yet known.

For people over 18, a combined hepatitis A and hepatitis B vaccine is available. You'll need three doses. The second dose is given one month after the first, and the third dose is given six months after the first. (This is the same schedule as the hepatitis B vaccine.)

Adverse reactions to the hepatitis A vaccine are relatively minor and commonly include pain, soreness, redness and swelling at the injection site, fever, headache and a general feeling of discomfort. Rarely, a serious allergic reaction may occur.

The hepatitis A vaccine is not recommended if you've had serious reactions or allergies to either a prior hepatitis A immunization or preservatives. The vaccine is not appropriate for children under age 2.

An immune globulin injection (ISG) is recommended if you can't be vaccinated against hepatitis A or you must travel to a high-risk area in less than four weeks, before your body has had time to develop immunity from the vaccination. The immune globulin injection contains antibodies that protect against several infectious diseases. It provides peak protection within 48 to 72 hours and lasts from two to five months, depending on the dose. The injection is given in a large muscle -- such as the leg in a child or the arm in older children and adults. After receiving the immune globulin, you must wait five months to receive a measles, mumps and rubella (MMR) or chickenpox vaccine. If you've already been given these vaccines, wait two to three weeks before receiving immune globulin.

Adverse reactions to immune globulin are usually mild and may include pain at the injection site, flushing, headache, chills and nausea. A serious allergic reaction to the vaccine is possible, but rare.

Hepatitis B
Hepatitis B is a viral infection of the liver that can become chronic and lead to liver failure or liver cancer. The virus is found in the fresh or dried blood and body fluids (such as the semen, saliva or vaginal fluids) of an infected person. Hepatitis B develops after contact with infected body fluids, such as through sexual, household or occupational contact or sharing infected needles.

A hepatitis B vaccination is recommended for all children and all young adults who have not previously been immunized. The hepatitis B vaccine is recommended if you'll be traveling to or living in a country where hepatitis B is prevalent or if you'll be engaging in certain high-risk activities, such as:

sexual activity
drug use
blood exposure during professional health care activities
needle exposure through dental or medical care, drug use, body piercing, tattooing or acupuncture
receiving a transfusion of blood not screened for hepatitis B
The hepatitis B vaccine is given in three injections to the upper arm and protects 80 to 100 percent of people from hepatitis B. The second dose is given one to two months after the first, and the third four to six months later.

Again, for people over 18, a combined hepatitis A and hepatitis B vaccine is available. You'll need three doses, following the hepatitis B vaccine schedule.

For maximum protection, the vaccine series should be completed before travel, although some protection is provided after one or two doses. It's unknown exactly how long immunization lasts, but current studies suggest a series of shots provides more than 15 years of protection. Booster shots are not currently recommended for healthy people.

Adverse reactions to the vaccine are typically minor, possibly including soreness, redness, warmth or swelling at the injection site and a low-grade fever, fatigue, headache and irritability. The symptoms may appear within 24 hours of the vaccine and usually disappear within 48 to 72 hours. Rarely, a serious allergic reaction occurs.

The hepatitis B vaccine is not appropriate if you've had an allergic reaction to baker's yeast or a serious reaction or allergy to a prior hepatitis B immunization.

Influenza (flu)
The flu is a viral infection of the throat, bronchial tubes and lungs that can sometimes lead to serious complications. If you contract the flu while traveling, it could significantly change your plans.

Two types of influenza vaccine are now available.

The inactivated influenza vaccine, commonly called the flu shot, has been used for many years. This vaccine is given by injection.
A nasal spray (FluMist) was licensed in 2003. FluMist is a weakened live vaccine that's sprayed into the nostrils rather than injected into the muscle. It's approved for healthy children and adults from ages 5 to 49.
The influenza vaccine is up to 90 percent effective in preventing the flu and provides protection one to two weeks after a single dose. If you do catch the flu after receiving the vaccine, the severity of symptoms and risk of complications are likely to be reduced.

There's a risk of developing the flu while traveling in the Northern Hemisphere from November through March, in the Southern Hemisphere from April through September, and in the tropics at any time of the year. If you're traveling to these areas during these months, consider getting a flu shot if you didn't receive it during the most recent fall or winter season or are at risk for severe illness, such as if you:

are over age 50
have medical problems such as heart disease, lung disease (including asthma), diabetes or other metabolic diseases, kidney problems or diseases that cause abnormal red blood cells, such as sickle cell anemia
have an impaired immune system (due to cancer, HIV or long-term treatment with steroids, for example)
live in a nursing home or a facility that cares for the chronically ill
are between ages 6 months and 18 years and receive long-term aspirin therapy (due to the link to Reye's syndrome, a rare but serious illness involving the brain and liver, following the use of aspirin during the flu or other viral illness)
Health care workers, volunteers, household members, or other caregivers of someone included in the above high-risk groups should also be vaccinated.

The flu shot is a single yearly injection, typically given in the upper arm. Adverse reactions are typically mild and may occur during the first six to 48 hours after the vaccination. The most common reactions are tenderness and redness or a lump at the injection site that may last up to two days. Less common reactions include fever, a generalized feeling of discomfort and aching muscles. Rarely, a serious allergic reaction after the vaccine may occur.

The flu shot is not appropriate if you've had an allergic reaction to a previous dose of the vaccine, to other vaccine components, or to chicken or eggs. Since the composition of the vaccine varies from year to year, discuss allergies with your doctor each year.

Again, the FluMist vaccine is only approved for healthy children and adults ages 5 to 49. The most common reactions are mild, including runny nose or nasal congestion, fever, cough, headache and muscle aches.

Japanese encephalitis
Japanese encephalitis is a viral infection contracted through the bite of an infected mosquito in certain areas in Asia. It starts as a flu-like illness and may develop into a serious brain infection. The infection is fatal in up to one-third of cases. It's more common during the mosquito season, and you're at greater risk in rural areas where the disease is prevalent. The vaccine is not usually recommended if you plan to stay in major urban areas of the region for less than 30 days.

The vaccine is given in the arm in three doses to people age 1 or older. The second dose is given seven days after the first, and the third is given 14 to 30 days later. The final dose must be given at least 10 days before travel.

Some vaccine recipients may experience fever, headache or muscle aches. Redness, swelling and pain at the injection site may also be noted. Rarely, serious allergic reactions may occur within minutes to one week after the vaccination. These include hives (rash), swelling of the throat and mouth, and difficulty swallowing or breathing.

Most reactions occur during the first 48 hours, but some may take as long as 10 days to appear. Due to the serious potential reactions, you will be observed for at least 30 minutes after the injection and should be vigilant for any allergic reaction symptoms for several days after the injection. If they occur, seek medical help immediately. Allergic reactions to the vaccine are more common in people who've had allergic hives or reactions to other drugs or bee stings. If you have a history of allergic reactions, discuss the benefits and possible risks with your doctor before receiving this vaccination. Don't have the vaccine if you've had an allergic reaction to it in the past.

Meningococcal meningitis
Meningococcal meningitis is a serious bacterial infection of the lining of the brain and spinal cord, as well as the surrounding fluid. The infection is caused by the Neisseria meningitides bacterium, which spreads through close contact with the respiratory secretions of an infected person (through contact with droplets sneezed or coughed into the air, for example).

The meningococcal vaccine is recommended if you will be in an area where the disease is prevalent. The vaccine protects against the four most common strains of meningitis bacteria. It's given in one dose in the upper arm to people age 2 and older, 10 to 14 days before travel. For those who were vaccinated before age 4, revaccination is recommended after two to three years. Otherwise, revaccination is recommended after three to five years for those who remain at risk of infection. How long protection lasts is unknown.

Adverse reactions to the vaccine are mild and infrequent. They may include fever or a few days of redness at the injection site. Rarely, a serious allergic reaction occurs. Don't have this vaccine if you've had a serious reaction or allergy to a prior meningococcal immunization or any of its components, including thimerosal (an organic, mercurial ingredient used in pharmaceutical compounds).

Plague
The plague is a serious infection caused by the Yersinia pestis bacterium. It can spread from wild rodents to people through rodent flea bites or direct contact with an infected rodent or other animal. The plague can be fatal.

The plague vaccine is currently unavailable in the United States. It's best to avoid travel in areas where plague is prevalent. If this isn't possible and you may be exposed to insects or rodents who may carry the disease, your doctor may prescribe an antibiotic (such as a tetracycline) to help prevent the plague infection while you travel. It's also important to protect yourself from insect bites and avoid handling rodents, including their habitats and remains.

Polio
Polio is a serious infectious disease that can cause disabling paralysis of the arms and legs and breathing difficulty. It spreads through fecal-oral contact, such as eating or drinking contaminated food or having oral-anal sex. In some cases, it may be fatal. A worldwide vaccination program has led to the eradication of polio in many countries.

If you're traveling to a country where polio is prevalent, you should be fully immunized. In the United States, the recommended vaccine is the inactivated polio virus vaccine (IPV), which contains dead poliovirus and is given in a shot. Children are routinely immunized against polio with four injections of the vaccine. For adults who have not been immunized or are uncertain of their immunization status, the recommended IPV series is usually three doses, with the first and second dose given four to eight weeks apart, and the third dose given six to 12 months after the second. An accelerate schedule may be recommended if there isn't enough time to complete this series. Adults who have been partially immunized in the past should finish the series. Adults and children who have completed the series may need a booster dose. Check with your doctor for details.

Adverse reactions to IPV are rare. Some people develop soreness at the injection site. Very rarely, it is possible to have an allergic reaction to the vaccine or its individual components. Don't have this vaccine if you've had a severe allergic reaction to a prior dose of the vaccine or any of its components, including the medications neomycin, polymyxin B and streptomycin.

Rabies
Rabies is a serious, usually fatal viral disease of the nervous system that's transmitted through the bite of an infected animal. Rarely, rabies can be transmitted without a bite if infected saliva enters a mucous membrane or a cut in the skin. The rabies vaccine may be recommended before travel to an area where rabies is prevalent, particularly when you're at an increased risk of unprotected exposure to animals in rural areas or when access to medical care after an exposure may be delayed.

To prevent rabies before exposure, three injections of the vaccine are given in the upper arm. The second shot is given seven days after the first, and the third 21 or 28 days later, preferably before travel. Booster shots are needed if you have frequent possible exposure to rabies.

The vaccine may also be given as an emergency measure after potential exposure to the virus, but the schedule and number of shots differs from pre-exposure vaccination.

Adverse reactions to the vaccine are usually mild, including pain, redness and swelling at the injection site, headache, nausea, abdominal pain, muscle aches and dizziness. Rarely, a serious allergic reaction occurs.

If you've previously had an allergic reaction to the vaccine, discuss the potential benefits and risks with your doctor. If the vaccine is necessary even if you've had an allergic reaction, it may be given with medication to help prevent harmful reactions.

Typhoid fever
Typhoid fever is a life-threatening bacterial infection caused by Salmonella typhi. It's contracted through food or drinking water contaminated with the bacteria. In the developing world, there are as many as 12.5 million cases of typhoid fever each year. There are only about 400 cases each year in the United States, many contracted by people traveling abroad.

The typhoid vaccine is 50 to 80 percent effective and is recommended if you'll be traveling to a country where typhoid fever is prevalent. Since the vaccine is not 100 percent effective, it's essential to avoid contaminated food and water.

Two typhoid vaccines -- one oral vaccine and one injectable vaccine -- are available in the United States. Both vaccine series must be completed at least one week before travel. The oral vaccine, Ty1a, is a four-dose regimen that takes seven days to complete. It can be given to people age 6 or older and a booster dose is required every five years. The injectable vaccine, ViCPS, can be given to people age 2 or older. It requires only one injection, with a booster dose every two years.

Adverse reactions are minimal for both vaccines. For the oral vaccine, common reactions include abdominal discomfort, nausea, vomiting, headache and rash. For the injectable vaccine, common reactions include fever, headache and redness and swelling at the injection site.

These vaccines are not appropriate if you've had a severe reaction to an earlier dose of the vaccine. In addition, the oral vaccine is not appropriate if your immune system is impaired (due to cancer, HIV or long-term steroid therapy, for example). You may also need to postpone the vaccination if you're taking certain antibiotics or antimalarial medications.

Yellow fever
Yellow fever is a potentially fatal viral infection transmitted through the bite of an infected mosquito in certain areas of Africa and South America. It is the only disease where immunization may be required before you can enter certain countries. Some countries require all travelers to be vaccinated against this disease. Others require immunization only if you're traveling from a country where yellow fever is found -- even if your visit in the country was brief or you never left the airplane.

The yellow fever immunization must be given at an authorized U.S. Public Health Service Yellow Fever Vaccination Center. For help locating the center nearest you, contact your local or state health department. When you receive the yellow fever vaccination, it will be recorded on an International Certificate of Vaccination (yellow card). This document will be required for entry into any country where yellow fever immunization is mandatory. The certificate can also be used to record all other vaccinations you've received, as well as prescriptions for medications and eyeglasses.

The yellow fever vaccine is a live vaccine that's given in one upper arm injection. Immunity lasts 10 years. The vaccine must be given at least 10 days before your departure. Adverse reactions to the vaccine are infrequent and may include mild swelling and pain at the injection site. Five to 10 days after the vaccination, you may experience a mild headache, muscle pain or fever.

Rarely, two vaccine-associated conditions may develop. A type of encephalitis (inflammation of the brain) called yellow fever vaccine-associated neurotropic disease was thought to occur only in young infants following vaccination, but adult cases have now been reported. A new, serious adverse reaction syndrome has recently been described as well. It was previously reported as febrile multiple organ system failure and is now called yellow fever vaccine-associated viscerotropic disease.

The vaccine is not recommended for children under age 6 months, pregnant women, anyone who's had a serious reaction or allergy to eggs or a prior yellow fever immunization, or those who have an impaired immune system (due to cancer, HIV or long-term steroid therapy, for example). If you have HIV but have no current symptoms, the vaccine may be recommended in some situations. If you're in any of these groups and must travel to areas where yellow fever is prevalent, consult your doctor. In most countries, a medical waiver is accepted for people who should not receive the vaccine. You can get details concerning waivers from the U.S. Embassy or Consulate before you travel.


Antimalarial medications
Malaria is a common, serious tropical illness spread through the bite of the Anopheles mosquito. The disease begins as a flu-like illness with fever, chills, headache and muscle aches. It can lead to serious, life-threatening anemia (a condition characterized by a decreased number of red blood cells or hemoglobin, a substance in the red blood cells that contains iron), as well as liver and central nervous system damage. The symptoms of malaria can develop as early as six days after a bite or several months later. The disease can also recur periodically after the first episode.
For pregnant women, malaria can be especially severe. It can increase the risk of pregnancy complications, such as miscarriage, premature birth and stillbirth. During pregnancy, it's best to avoid travel to areas where there is a risk of malaria. If travel is necessary, discuss the use of antimalarial medications with your doctor.

Even if you take antimalarial medications, malaria can sometimes develop anyway. Travelers are also advised to use preventive measures against mosquito bites. If symptoms such as persistent headaches, muscle aching, weakness, vomiting or diarrhea occur, seek medical care immediately. If treatment is delayed, malaria can be fatal.

If medical care will be unavailable, you may also want to bring along medication to help prevent or treat malaria. These medications should always be taken as recommended and kept out of children's reach. An overdose of any of the antimalarial drugs can be fatal.

Chloroquine (Aralen)
One of the most commonly used drugs to prevent malaria is chloroquine. This highly effective antimalarial drug is taken once a week, starting one to two weeks before departure, continuing through the trip and four weeks after returning home.

Side effects are rare but may include an upset stomach, headache, dizziness, blurred vision and itching. These side effects usually don't require discontinuation of the drug. Sometimes, side effects can be eased by taking the drug with meals or dividing the dose in half and taking it twice a week. Discuss side effects and possible solutions with your doctor. Hydroxychloroquine, a drug very similar to chloroquine, may be better tolerated.

If you choose to take chloroquine to prevent malaria, your doctor may suggest bringing a supply of pyrimethamine-sulfadoxine (Fansidar) in case you develop a fever and are more than 24 hours from medical care. One dose is enough to help prevent a potentially fatal illness, but it's only a temporary treatment and medical care must be sought as soon as possible. This medication is not appropriate if you have a history of allergy to pyrimethamine or sulfadoxine, a sulfa medication.

Mefloquine (Lariam)
In areas where the malaria parasite is resistant to chloroquine, the antimalarial drug mefloquine is often used. Mefloquine is taken once a week, also starting one to two weeks before departure, continuing through the trip and four weeks after returning home.

Side effects are usually mild and short-lived, potentially including upset stomach or dizziness. Mefloquine is not appropriate for anyone who has a history of epilepsy, psychiatric disorders or a known allergy to the medication. The risks and benefits of the drug should be discussed with a doctor before it's taken.

Doxycycline (Vibramycin)
Travelers who can't take mefloquine may take doxycycline. Doxycycline is taken once a day beginning one to two days before departure, continuing through the trip and four weeks after returning home.

Side effects can include an upset stomach, vomiting, diarrhea, rash and increased sensitivity to the sun, which can lead to sunburn. Women taking the drug have an increased risk of vaginal yeast infections. The risks and benefits of the medication should be discussed with a doctor before it's taken. If you choose to take doxycycline, be sure to wear protective clothing and use plenty of sunscreen.

Atovaquone-proguanil (Malarone)
Atovaquone-proguanil is another medication that can be used in areas where the malaria parasite is resistant to chloroquine. Atovaquone-proguanil is taken once daily, starting one to two days before departure, continuing through the trip and for seven days after returning home.

Side effects can include abdominal pain, nausea, vomiting and headache. The risks and benefits of the medication should be discussed with a doctor before it's taken.

Your doctor may prescribe atovaquone-proguanil for self-treatment if you're traveling to certain areas of the world and are not already taking the drug to prevent malaria. If you develop a fever and are more than 24 hours from medical care, taking one dose of atovaquone-proguanil for three days can help prevent a potentially fatal illness. However, it's only a temporary treatment and medical care must be sought as soon as possible.