Travelers are at risk for a large number of infectious diseases depending upon
travel destination, time of year, local weather factors, lifestyle of the traveler
and duration of travel.
Among the most important diseases that travelers are likely to encounter are:
Influenza A and B
Many of the Infections that travelers are likely to encounter can be prevented by immunizations or vaccines.
The major diseases that can be prevented include:
What is Hepatitis A?
Hepatitis A is a potentially serious viral Infection of the liver caused by the Hepatitis A Virus. Viral Infection is very common in developing countries. It is spread by close personal contact through contaminated food and water.
Hepatitis A can cause a mild “flu-like illness.”
More commonly it causes fatigue, abdominal pains, diarrhea, and jaundice with yellow discoloration of skin and eyes.
Twenty percent of infected people will require hospitalization.
Immunization is quite effective in preventing disease.
Hepatitis immunization is recommended with few exceptions for travelers age 1 year and older traveling to countries where Hepatitis A is common.
Start immunization one month before traveling to achieve the best protection.
A second dose of the vaccine should be given at least 6 months after the first dose to ensure lasting protection.
Use strict food and water precautions while traveling.
Use canned or commercially bottled water and drinks.
Avoid ice cubes.
Avoid raw and undercooked meat and seafood.
Eat fruits and vegetables only if you wash or peel them yourself.
What is Hepatitis B?
Hepatitis B is a serious viral infection of the liver caused by the Hepatitis B Virus. Hepatitis B can cause acute or Chronic Liver infection and may lead to liver cancer or death. It is spread by intimate or sexual contact with an infected person. It can also be transmitted by exposure to blood or blood-contaminated fluids.
Hepatitis B typically causes a short-term illness with loss of appetite, fatigue, diarrhea and vomiting, muscle and joint pain, and abdominal pain.
Acute infection may lead to chronic long-term disease resulting in liver damage with cirrhosis or liver cancer.
In the United State 3,000 to 5,000 people die each year from cirrhosis or liver cancer caused by Hepatitis B.
Immunization is safe and can prevent Hepatitis B and its serious consequences of acute and chronic disease, cirrhosis, and liver cancer.
Hepatitis B immunization ideally should be started at birth.
Unimmunized children, adolescents, and adults with few exceptions traveling to countries where Hepatitis B is common should be immunized.
Unimmunized adults at greatest risk for Hepatitis B infection include sex partners of infected persons, people who inject street drugs, household contacts of infected people, and anyone with exposure to human blood.
Avoid unprotected sex with an infected person.
Avoid contact with blood or body fluids including sharing toothbrushes or razors.
Do not share needles when injecting prescription or non-prescription drugs.
Avoid exposure to any used needle.
If you are in a non-emergency situation requiring blood transfusion during travel, request to be flown home to avoid exposure to improperly screened blood.
What is Influenza?
Influenza is a highly contagious respiratory infection caused by Influenza B or one of two types of Influenza A Virus. Everyone is at risk of Influenza infection which may lead to hospitalization and sometimes even death. Infection can be transmitted by hand or respiratory contact with an infected person or by touching a contaminated surface or object.
Influenza symptoms typically include high fever, cough, headache, and generalized aching lasting for 5-10 days.
Serious complications requiring hospitalization include pneumonia, respiratory failure, renal disease and death.
Seasonal Influenza immunization protects against the three viruses that are expected to be the most common in any year.
The most common Influenza immunization uses a killed virus preparation. Less commonly a live virus nasal-spray preparation is used.
Protection against Influenza develops approximately two weeks after immunization.
Immunization should be considered for all travelers who visit the tropics or the southern hemisphere between April and September.
International surveillance of Influenza outbreaks pemits estimates about which virus types will circulate in a given year.
Contrary to popular opinion Influenza immunization does not cause Influenza disease.
Avoid direct contact with infected persons by avoiding crowded locations.
Wash your hands often with soap and water and avoid contact with ill persons.
Influenza immunization is required annually since the virus changes frequently.
What is Japanese Encephalitis?
Japanese encephalitis is a serious viral infection that causes swelling of the brain. It occurs in certain rural areas of Asia and is spread through the bite of infected mosquitos. It cannot be transmitted from one person to another.
Some infections cause only mild symptoms of fever and headache.
A much more severe form of infection .my occur causing high fever, severe headache, neck stiffness, disorientation and abnormal movements.
With severe infection convulsions, coma, and paralysis may occur.
The mortality rate from severe infections can be as high as 25%.
Immunization with Japanese encephalitis vaccine is highly effective and can prevent a majority of infections.
Travelers one year of age and older visiting selected rural parts of Asia for 30 days or longer should be immunized.
Maximal protection is provided by three doses of vaccine. The second and third doses are given 3 and 30 days after the first immunization.
The last dose of vaccine should be given at least 10 days before travel.
Avoid exposure to mosquitoes by wearing clothes that cover most of the body.
Remain in well-screened areas.
Use an effective insect repellent such as DEET on skin and clothing.
Use permethrin on clothing to help prevent mosquito bites.
What is Meningococcal Disease?
Meningococcal disease is a serious bacterial infection most commonly causing inflammation of the brain and spinal cord coverings (meningitis). It is the most common cause of bacterial meningitis in children and can affect adults as well causing seizures, mental retardation or even death . It may also cause infection of the bloodstream.
Symptoms of meningitis include fever, headache, neck stiffness, changes in mental status, and seizures.
Skin rash and muscle pains occur commonly.
Some people will develop a blood stream infection without involvement of the brain.
1 out of 10 people who get the disease will die from it and many others are affected for life with loss of arms or legs, deafness, recurring seizures, or strokes.
Travelers to parts of Africa or the Middle East where meningococcal disease is common should be immunized.
Two kinds of meningococcal vaccine are available in the United States.
Both vaccines work well and protect up to 90% of people immunized.
The Meningococcal conjugate vaccine (MCV4) is used for people 2 through 55 years of age. The Meningococcal polysaccharide vaccine (MPSV4) is recommended for people older that 55 years of age.
Stay away from crowded places to avoid direct contact with infected people.
Do not share water bottles, drinking glasses or personal care items.
Wash hands frequently and especially after contact with oral secretions.
Receive vaccinations before traveling to areas of the world where meningitis is common.
What is Pneumococcal Disease?
Pneumococcal disease is a potentially serious infection caused by Streptococcus pneumoniae bacteria. The organism commonly affects the lung causing pneumonia. It can also cause blood stream infections or inflammation of the covering of the brain causing meningitis. Anyone can acquire the disease but the risk is greatest in the elderly, the very young, and persons with weakened immune systems.
Pneumococcal disease can cause a mild “flu-like” illness.
More commonly it involves the lungs causing a cough, high fever, shaking chills, excessive sweating, and shortness of breath.
When infection affects the covering of the brain it results in headache, neck stiffness, and changes in mental status.
Serious infection of the brain can result in death of as many as 30 of 100 infected people.
All travelers 65 years of age and older should be immunized with a pneumococcal vaccine.
Travelers age 2 through 64 with any condition that lowers the body’s resistance to infection should be immunized.
Most healthy adults develop protection against infection within 2 to 3 weeks of immunization which lasts for 5 years before requiring a booster injection.
Two types of pneumooccal vaccine are available in the United States, both of which are highly effective.
Avoid direct contact with infected persons.
Avoid crowded locations.
Receive immunizations with either of the two protective vaccines.
What is Rabies?
Rabies is a highly fatal and fortunately rare viral infection in humans. Rabies primarily is a disease of animals transmitted to humans by a bite.
Initially there may be no symptoms except for pain at the site of the animal bite.
Several weeks or months after a bite symptoms of fever, fatigue, headaches, and irritability develop.
Seizures, hallucinations, and paralysis develop and death follows shortly thereafter.
International travelers who are likely to come into contact with animals in parts of the world where rabies is common should be vaccinated.
What is Typhoid Fever ?
Typhoid Fever is a serious bacterial infection acquired through ingestion of contaminated food or water or by close contact with a Typhoid carrier. Fortunately it is uncommon in the United States but is common throughout the world affecting more than 20 million people a year.
High fever, headache, abdominal pains and loss of appetite are commonly seen.
Skin rash can also occur.
As many as 30% of infected persons will die from the disease.
The most commonly used vaccine is a weakened live vaccine taken by mouth.
Typhoid immunization is not 100% effective and is not a substitute for being careful about food and water ingestion.
Four doses given every other day are needed to provide protection.
A booster dose is needed every 5 years for travelers who remain at risk.
A second type of vaccine is a polysaccharide vaccine for injection that does not contain live organisms. This vaccine consists of one injection and booster injections every 2 years.
Anyone with a weakened immune system should not get the live vaccine. This includes people with cancer, those with HIV/AIDS or other diseases that affect the immune system, and those being treated with mediations that depress immunity.
Oral typhoid vaccine should not be given within 24 hours of taking certain antibiotics.
The intramuscular vaccine should be used for patients with a weakened immune system.
What is Yellow Fever?
Yellow Fever is a frequently severe viral disease transmitted to humans by the bite of an infected mosquito. It is a rare cause of disease in U.S. travelers. No specific treatment is available.
The initial symptoms include the sudden onset of fever, chills, severe headache, back pain, body aches, nausea, vomiting, fatigue, and weakness.
Most people improve after the initial illness but approximately 15% of people will have a remission of several hours to a day and then develop more a severe illness with high fever, bleeding, jaundice, and failure of many body organs.
No specific treatment is available.
Yellow fever is preventable by a relatively safe, effective vaccine.
Only one vaccine is available in the United States which is a life-attenuated preparation.
Vaccination is recommended for persons 9 months of age or older traveling to or living is areas at risk for the disease.
Yellow fever is found in tropical and subtropical areas in South America and Africa.
The best way to avoid infection is to avoid mosquito bites.
Minimize areas of exposed skin by wearing long-sleeved shirts, long pants, boots, and socks.
Wearing closed shoes instead of sandals may reduce the risk of mosquito bites.
Use repellents or insecticides such as permethrin applied to clothing and gear.
Sleep in adequately screened or air conditioned areas if possible. If these are not available use bed nets.