Infectious diseases while traveling and tropical diseases abroad

What is bilharzia or schistosomiasis?

• Schistosomiasis is an infection caused by the parasitic worm schistosoma.
• Schistosomiasis was formerly known as bilharzia or snail fever.
• If untreated, schistosomiasis can be fatal due to damage to various organs.
• The schistosoma flatworm is a parasite that lives in freshwater and enters the body through the skin.

Where does bilharzia or schistosomiasis occur?

• Although the parasitic flatworm that causes schistosomiasis occurs in Latin America, the Middle East, and Asia, the risk of infection is by far the greatest in Africa.
• The number of infections is particularly high in freshwater in tropical Africa.

What are the symptoms of bilharzia or schistosomiasis?

• Ingress into the skin itself usually goes unnoticed; travelers' skin often reacts within a day with an itchy or red rash.
• Only after a few weeks do more symptoms usually develop, such as fever, muscle aches, rash, shortness of breath, or an irritating cough.
• When the parasites reach your bloodstream after two to eight weeks, an acute fever (Katayama fever) can occur as your body's immune response.
• The list of nasty conditions grows rapidly if you don't intervene after the first round of symptoms. Depending on the location of the parasites, various organs, your nervous system, and your brain are affected.

What can you do to prevent bilharzia or schistosomiasis abroad?

• Avoid contact with fresh surface water in areas where schistosomiasis is prevalent: do not swim or paddle. Make sure your shower water isn't pumped from open water.
• Have you taken a dip? Dry off quickly to reduce the risk of infection.
• The parasites cannot survive in chlorinated swimming pools.
• There is no vaccine that can prevent schistosomiasis.

Can bilharzia or schistosomiasis be cured?

• Yes, there are excellent treatments available for this parasite.
• Medications only work on adult worms, so taking medication immediately after infection is pointless.

What is cholera?

• Cholera is an intestinal infection caused by bacteria.
• Contaminated water is often the source of the infection.
• Infection often causes symptoms such as diarrhea and vomiting, which can eventually lead to dehydration. This makes the infection very insidious.

Where does cholera occur?

• The cholera vaccination is no longer recommended for any entire country. This is because the infection rate and spread is rapidly declining.
• Outbreaks are often regional in nature and often linked to war or other major disasters, such as floods.
• However, in parts of Africa, a cholera stamp is still occasionally requested, especially during outbreak periods
• The vaccination stamp is requested in exceptional cases at remote African border posts. This is a way local authorities try to generate some revenue

What are the symptoms of cholera?

• In a large proportion of cases, an infection progresses without any real symptoms.
• When symptoms do occur, they often include nausea, vomiting, abdominal pain, and sudden diarrhea.
• The combination of these symptoms can cause patients to develop dehydration, even after 24 hours.
• Dehydration is dangerous and must therefore be treated.
• Symptoms of dehydration include a dry mouth, reduced tear production, sunken eyes, extreme fatigue, and a fishy odor in stool.

Can cholera be treated?

• With proper treatment, the risk of death is minimal.
• Treatment primarily consists of maintaining adequate fluid levels.
• This can be done, for example, by administering fluids orally or through oral rehydration (ORS).
• In the hospital, an IV may be used.
• Finally, in some cases, antibiotics may also be necessary.

What can you do to prevent cholera infection abroad?

• First and foremost: maintain good hygiene.
• This means washing your hands after using the toilet and before eating, not drinking tap water, peeling fruit yourself, and cooking food thoroughly.
• Eating shellfish is particularly risky.

Are there vaccinations against cholera?

• Cholera vaccination isn't offered as part of standard travel vaccinations programs, since prevalence of cholera is absent in tourist areas under normal circumstances.
• People traveling to or working in areas where cholera is endemic and where access to good health care is limited are generally advised to take the vaccination.
• It is important to closely follow general preventive measures, as the vaccine offers on average about 60–80% protection.
• In some destinations, repeated vaccination is recommended for traveling to or visiting locations without access to clean drinking water.
• Once the cholera stamp is in your vaccination record, you never need to get a new one.

What is hepatitis A?

• Hepatitis A is a contagious liver disease caused by the hepatitis A virus.
• The virus enters the body through the throat after eating or drinking contaminated food and infects the stomach, intestines, and liver.
• In some cases, the disease is life-threatening; it usually resolves on its own.

Where does hepatitis A occur?

• Hepatitis A occurs worldwide, but mainly in developing regions such as Asia, Africa, and Latin America.
• The risk of infection in North America, Australia, New Zealand, and Western Europe is minimal.
• The disease frequently occurs in poor hygienic conditions. Undercooked or raw shellfish are relatively common sources of infection
• Because it is a highly contagious disease, hepatitis A often occurs in areas where people live in close proximity.
• The risk increases if you have frequent contact with the local population.

What are the symptoms of hepatitis A?

• The virus responsible for hepatitis A ultimately causes inflammation of the liver.
• Symptoms can appear two to six weeks after infection with the virus.
• When the disease follows a typical course, fatigue and nausea often occur initially. This can then be followed by fever, abdominal pain (often in the upper right side), and a significant decrease in appetite. In the following period, the whites of the eyes may appear yellow (jaundice). In addition, urine often becomes darker and stools lighter.
• Although the symptoms often subside after a few weeks, fatigue can often persist for a long time.
• A hepatitis infection very often causes symptoms in adults (80-90% of cases). However, in infants and toddlers, the infection is often inconspicuous.
• The older you get, the more severe the symptoms become. Especially in people over 50, there is a small chance that the disease can become life-threatening.

Can hepatitis A be treated?

• A hepatitis A infection almost always resolves on its own.
• Therefore, there are no medications that accelerate the healing process.
• The most important remedy for the symptoms is rest. The body needs time to recover properly.
• It's also important to realize that you are infectious to those around you for up to one week after the onset of jaundice. Therefore, avoiding public places at that time is recommended.

Are there vaccinations against hepatitis A?

• A vaccine against hepatitis A has been developed that, depending on the brand, protects you against hepatitis A for one or three years.
• It is recommended to get vaccinated at least two weeks before traveling.
• If you get another vaccination within six to twelve months after the first vaccination, it has been shown that you will even be protected for 25 years.

What can you do to prevent hepatitis A abroad?

• Because the hepatitis A virus is often spread in areas with poor hygiene, it is important to pay attention to personal hygiene.
• Some advice therefore includes: washing hands, avoiding contaminated drinking and swimming water, and being careful when preparing food (washing and cooking).

What is Japanese encephalitis?

• Japanese encephalitis is a form of encephalitis caused by a virus.
• The disease is transmitted by mosquitoes. This specific mosquito species generally bites at dusk and at night.

Where does Japanese encephalitis occur?

• Japanese encephalitis occurs primarily in Southeast Asia and the western Pacific region.
• In addition, there are a few small areas where cases are still being reported, such as eastern China, northern Japan, Russia, and also in Australia around Torres State.
• Infections occur in rural areas and on the outskirts of cities.
• This is especially true in areas where pigs are kept in the fields. Pigs often serve as hosts for infected mosquitoes.
• Another very typical location for infection is in rural areas near rice paddies.
• Most travelers to Asia have little chance of infection. Those most at risk are those who spend extended periods in rural areas during a season when the disease occurs. The disease occurs predominantly in children under the age of ten.

What are the symptoms of Japanese encephalitis?

• The vast majority of infected individuals ultimately develop no symptoms.
• If symptoms do develop, they usually begin five to fifteen days after the mosquito bite.
• Symptoms often include fever, headache, behavioral changes, and significant loss of strength.
• In severe cases, symptoms of encephalitis and meningitis develop, with headache, vomiting, and eventually drowsiness, coma, and seizures.
• Paralysis and respiratory problems can lead to death.

Can Japanese encephalitis be treated?

• There is no known official treatment.
• However, supportive therapy can lead to a milder course of the disease.

What to do to prevent Japanese encephalitis abroad?

• Vaccination: The travel vaccine available in the Netherlands prevents outbreaks of Japanese encephalitis in 80 to 90 percent of cases. The vaccine's duration of action has not yet been definitively determined.
• Prevent mosquito bites: Japanese encephalitis can be prevented by wearing long-sleeved clothing, using DEET or another effective mosquito repellent, and using a mosquito net. This is because mosquitoes are most active at dusk and at night.

What is meningitis?

• Meningitis is an inflammation of the meninges and, in some cases, an inflammation of the membranes surrounding the spinal cord.
• The infection can be caused by bacteria, viruses, and, in some cases, fungi.
• Viral meningitis generally does not cause serious symptoms.
• Bacterial meningitis should be treated promptly due to significant health risks.
• Meningitis as a traveler's disease usually refers to bacterial meningococcal meningitis, of which there are several variants, such as types A, B, C, W, and Y.

Where does meningitis occur?

• Meningitis occurs worldwide
• The risk of infection with meningococcal meningitis is highest in Sub-Saharan Africa, especially during the dry season, and to a lesser extent in Asia.
• Meningitis can occur when large groups of people are crowded together under poor hygienic conditions, such as in a slum or during a pilgrimage. The risk of an epidemic is much higher in such cases. Be extra careful in such situations!

How is meningitis caused?

• Bacterial meningitis is caused by bacteria in the nasal and pharyngeal cavities and sometimes in the gastrointestinal tract.
• People who (un)knowingly carry the bacteria can infect others through saliva (sneezing, coughing, kissing, etc.).
• The infection can also be transmitted through feces and/or poor hygiene when using the toilet.
• In healthy people, an infection usually does not lead to illness. In this case, the bacteria are removed by our immune system after some time, and you do not become ill.
• Sometimes the bacteria enter the bloodstream. In that case, we call it sepsis. From the blood, the bacteria can spread to the meninges, where they can eventually cause meningitis.

What are the symptoms of meningitis?

• Meningitis can be accompanied by many different symptoms. The symptoms depend on the cause and the age of the person affected. Meningitis is also called neck spasm, which causes a person to have difficulty bending their head forward. This phenomenon occurs primarily with bacterial strains.
• With meningitis, in addition to neck spasm, you often also feel flu-like. Common symptoms include high fever, severe headache, sore throat, vomiting, and muscle aches.
• Loss of consciousness, loss of balance, photophobia, mild to moderate respiratory distress, convulsions, sepsis, encephalitis, bowel problems, and erectile dysfunction may also occur.

Can meningitis be treated?

• A viral infection can often be treated with rest. In other cases, an antiviral course of medication can provide relief.
• For a bacterial infection, a course of antibiotics is the treatment of choice. Hospitalization is often required, especially in children. In many cases, the antibiotic course is successful, and the symptoms gradually subside.

What can you do to prevent meningitis abroad?

• Good hygiene initially reduces the risk of infection. Wash your hands thoroughly after using the toilet and before and after eating. Avoid contact with potentially infected people.
• There are several forms of meningitis, such as type B and type C. Children have been vaccinated against type B since 1987 and against type C since 2002. Since 2018, types A, Y, and W135 have also been part of the national vaccination program.
• If you have already been partially vaccinated, it may be wise to also be vaccinated against the other forms, depending on the length of your stay and where you are going.
• For example, Saudi Arabia requires meningitis vaccination for pilgrims (Hajj and Umrah) and seasonal workers. You are expected to have received the vaccination at least 10 days before arrival.
• In a large part of sub-Saharan Africa (Senegal to Ethiopia), it is also wise to be vaccinated against the meningitis bacteria during the dry season (November to June).
• A meningitis vaccination consists of a single injection that is effective for three years.

What is rabies?

• Rabies is a viral infection of the brain, caused by lyssaviruses
• The virus is usually transmitted through the bite of an animal (or human) infected with the rabies virus.
• Animals that can transmit it include dogs, raccoons, monkeys, foxes, and bats.
• Rabies is very dangerous and, if untreated, can be fatal.

Where does rabies occur?

• Rabies occurs almost everywhere in the world.
• However, there are areas where the risk of infection is higher, such as South Asia, particularly India, and parts of South America.
• Be especially careful with stray dogs or aggressive guard dogs in rural areas. Working with wild animals also carries an increased risk of infection.

What causes rabies?

• After a bite, it takes some time, depending on the location, for symptoms to appear.
• The virus is transmitted through the saliva of infected animals. The virus can enter the body through wounds or mucous membranes.
• The virus multiplies in the muscles and then travels through the nervous system to the brain.
• The closer the bite is to the brain, the faster symptoms develop.
• This time can vary from two weeks to several months.

What symptoms can you experience with rabies?

• It usually begins with vague symptoms; nausea, headache, loss of appetite, a mild fever, and a sore throat are common.
• The first symptoms appear between 20 and 90 days.
• In later stages, these symptoms are followed by irritability, convulsions, and hypersensitivity to bright light and loud noises.
• Ultimately, without early treatment, the disease is always fatal.

Are there vaccinations against rabies?

• Vaccination is the primary means of preventing a fatal infection.
• If you were vaccinated before a bite, you must receive additional, shorter treatment after the bite. You will then need two more regular vaccinations after the bite or scratch. These are usually available in the country where you contracted rabies.
• If you were not vaccinated before a bite, you will need antibodies. These antibodies are difficult to obtain in some countries. If you are going to a specific volunteer project or a fixed location, check in advance whether they are available there.

What does a rabies vaccination cost?

• In the EU, a rabies vaccination costs an average of 90 euros per shot. Vaccinations administered just under the skin can be less expensive; check with your vaccination doctor, as this is not possible for everyone.
• Abroad, the price can vary considerably, from approximately 10 euros per shot in Thailand to 200 euros in the US.

How long is a rabies vaccination valid?

• If you've only had one shot, it's generally valid for three years. If you're bitten, you'll need an additional shot with the antidote within 24 hours.
• If you've had two or three shots, you have basic protection for life. If you're bitten, you'll need two additional shots within 48 hours, but not with the antidote. The antidote, in particular, isn't always available or of sufficient quality in many locations and countries.
• Previously, the rabies vaccination was only valid for about three months, making it relatively expensive.

When should you get a rabies vaccination?

• If you're going on a cycling holiday, a rabies vaccination is recommended because there's a higher risk of being bitten by dogs.
• If you're going to a volunteer project with animals that can transmit rabies and there aren't enough vaccines or care facilities near the project site.
• If you're traveling where there's a high risk of being scratched or bitten by an animal that can transmit rabies.
• If you frequently travel where you might come into contact with rabies-carrying animals.

What can you do to prevent rabies abroad?

• It's important to avoid being bitten, licked, or scratched by potentially infected mammals.
• Petting stray dogs, for example, isn't exactly Russian roulette, but it comes pretty close in some destinations and locations. Petting pet monkeys can also be much more exciting than you might think. It's best to first check with the owner whether the animal in question has been vaccinated against rabies, and if that's not possible, try to keep your hands to yourself.
• Avoid contact with injured or dead animals in any case.
• If you are volunteering with dogs, monkeys or other rabies-sensitive animals, check with your organization to what extent the animals are vaccinated before you allow them to come very close to you.

How can you treat rabies?

• If you have been bitten, always rinse the wound thoroughly with soap and water, or just with water, and then disinfect with iodine or 70% alcohol.
• If you have been bitten by an animal suspected of being rabies-infected and there are no symptoms yet, it is important to get treated with the additional vaccinations within 48 hours. If you have not had any vaccinations beforehand, a 24-hour period is recommended.
• Therefore, contact your travel insurance emergency center immediately for assistance as quickly as possible, and go directly to a local doctor or medical center if possible.
• Once symptoms appear, treatment is virtually no longer possible, and the disease is almost always fatal.
• Approximately 60,000 people die from rabies worldwide. A lot of attempts are currently being made, but an effective treatment has not yet been found.

What is typhoid fever?

• Typhoid fever is an intestinal infection caused by the Salmonella bacteria.
• When the bacteria travel through the intestines into the lymphatic system, the rest of the body is often infected through the bloodstream. In this case, an infection can lead to life-threatening situations.

Where does typhoid fever occur?

• Typhoid fever occurs primarily in (sub)tropical regions.
• The risk of infection is highest in Asia, especially in Bangladesh, India, and Pakistan.
• You are also at risk in Africa and the Caribbean.
• The disease occurs primarily in poor hygienic conditions combined with a (sub)tropical climate. Consider regions with poor sewage systems, which can also contaminate drinking water.

What are the symptoms of typhoid fever?

• After a typhoid infection, it can take up to two weeks before you experience any real symptoms.
• If you become seriously ill, it can take several weeks to several months for the infection to clear.
• Typhoid fever has a mild onset but can worsen over time. The most common symptoms are: rising fever, decreased appetite, headache, muscle aches, abdominal discomfort, and red spots on the skin. Initially, you often experience constipation and a dry cough, and in some cases, diarrhea with blood.
• Aside from the usually severe symptoms in adults, the symptoms in young children are often much milder.

Can typhoid fever be treated?

• With immediate treatment with antibiotics, more than 99% of all people treated recover. This usually involves a course of antibiotics lasting 4 to 6 weeks.
• In some cases, even with treatment, recovery can take several weeks to several months.
• The more advanced the disease, the lower the chance of recovery and the greater the risk of persistent symptoms.

Are there vaccinations against typhoid fever?

• In countries where the risk of infection is increased, typhoid vaccination is recommended for stays longer than two weeks.
• In areas where the risk is not significantly increased, but are in the danger zone, typhoid vaccination is recommended for stays longer than three months.
• Approximately 70% of all vaccinated people are fully protected. If the vaccination is effective, you are protected for three years. Therefore, keep in mind that even with vaccination, you are not 100% certain of complete protection.
• Therefore, vigilance is just as important as vaccination.

What else can you do to prevent typhoid abroad?

• Typhoid is often transmitted through water or food contaminated with Salmonella bacteria. Good personal hygiene, as well as that of the people who prepare your food, is very important in preventing typhoid.
• Travelers visiting areas where typhoid fever is prevalent are advised to minimize their consumption of raw leafy vegetables and other food served at room temperature.
• Other recommendations and precautions include: drinking only bottled or boiled water, avoiding raw vegetables, raw shellfish, peeled fruit, or food with (many) flies on it. Food that is freshly prepared and then served hot or chilled is generally safe.
• Also, pay close attention to hygiene when using the restroom.

What is Zika fever?

• Zika fever is an infectious disease caused by a virus.
• This infectious disease has many similarities with dengue fever.
• The disease is transmitted by infected mosquitoes, which are primarily active during the day.
• Outbreaks occur regularly in all tropical regions.
• Zika fever is particularly dangerous for pregnant women because the virus can harm the unborn child. For other adults, it is primarily a "normal" and unpleasant illness.

What are the symptoms of the Zika virus?

• The symptoms of Zika fever are usually mild and short-lived (2 to 7 days). Symptoms include fever, inflammation of the lining of the eye, temporary joint pain, and a rash.
• The most dangerous aspect of the Zika virus is the birth defects that babies of infected mothers can develop.

What to do to prevent Zika abroad or while traveling?

• There is no vaccine available yet, so preventing mosquito bites is the key to preventing the disease.
• Stay informed about local outbreaks, especially during pregnancy.
• If you live or work in a (sub)tropical area where Zika is present, try to avoid stagnant water in areas such as bowls, flowerpots, puddles, and car tires.
• Use DEET and mosquito-repellent clothing to prevent bites.
• Read more about DEET and pregnancy.

What to do if you get Zika?

• The disease usually clears up on its own within a week.
• Treatment focuses primarily on managing pain and fever, for example, with paracetamol.