Traveling has become very common, also to far-away countries. While traveling, it is possible that you come into touch with diseases that dont exist in your country and for which you are, therefore, more susceptible. It is good to remember this and to take your precautions. If you get a doctors opinion you will probably be adviced to undergo some vaccinations. We wish to line up which vaccines are advisable and how significant they are.
Yellow fever is a viral disease which is spread, just like malaria, through mosquitos. Especially Middle-Africa and South-America are hit by the disease. The World Health Organization counts around 300 cases yearly around the world. The symptoms of the disease reveal about 3 to 6 days after infection. Mostly the disease is running a satisfactory course, like a kind of flu. But in rare cases where the disease takes a serious course the deathrate might rise considerably. For some countries vaccination is mandatory, otherwise you will be refused to enter the country. Even after traveling through infected area a vaccination certificate can be required. The only way to avoid vaccination is to choose an other country for destination. East and Southern Africa, for instance, are mostly saved from the disease and, therefore, dont require vaccination against it.
The vaccine is mostly administered in specialized centres at least ten days before departure. This needs to be registered in an official vaccination booklet. The certificate is valid for 10 years. The vaccine contains a living weakened organism administered through a hypodermic injection.
The vaccine-efficiency is considered to be pretty high: 93% for adults, 60% for babies.
The vaccine may cause encephalitis, especially to babies under 9 months old. Multiple sclerosis appeared with a 22-year old man after vaccination. Other side-effects are: generalized nettle-rash, bursitis, jaundice, neuritis, muscular pain and slight fever. About a fourth of all people vaccinated show reactions and 11% has diffuse pains all over the body and fever. Once gangrene was diagnosed in the vaccinated arm a few hours after inoculation. Five of these patients went into a coma and died. Yet, according to another study, administration to pregnant women should have no effect on the newborns. The vaccine is not given to pregnant women (if really necessary this is possible from the sixth month), to children younger than 12 months, to persons hypersensitive to the antibiotics neomycine or polymyxine B (Arylvax) or to persons with decreased immunity (cancer or cancertherapy; cortisone treatment, HIV-infection).
This is an infection of the digestive tract caused by food or drinks contaminated with Salmonella. You can carry the disease-germs and eliminate it through motion without yourself being sick. The risk to get infected while travelling is very low (6 cases per million travelers). Thyphoid fever is an illness that in our country almost only occurs through import from other countries, especially Peru, India, Chili, Indonesia and North-Africa. The most important measure is a hygienic handling of food. The treatment of the illness is no problem, but without treatment the deathrate might rise up to 15 %.
Vaccination can be done as well with a living as with a dead vaccine.
Studies about the effectiveness of the vaccine are rather unreliable, because they are mostly executed in an area where the disease occurs. Therefore it was often impossible to determine whether a person had the antibodies from the vaccine or from the disease itself. In several studies even no protection at all was diagnosed, especially not for travelers or for little children. In a Dutch hospital 18 out of 39 thyphoid patients were certainly vaccinated and one could not be sure about another 10. Besides, immunity, if any, is only obtained against infection with a small amount of bacteria, while in case of foodcontamination exist a lot of bacteria and therefore the protection wont do. Also, the oral vaccine (taken through the mouth) needs to be stored in a refrigerator, otherwise it loses its effectiveness.
Complications of the vaccinations include: local swelling and redness, pain, fever, paralysis, neuritis, tiredness, articular pains, meningitis.
Antibiotics can only be given one week after vaccination, polio (OPV) only after 3 days, anti-malaria drugs after 24 hours.
The vaccine should not be given in case of serious intestinal disease or infection, fever, lowered immunity or pregnancy.
Malaria, the lasting scourge of many tropical countries, worries many travellers. Suffering an infection with this plasmodium is not a hoax. But what to do in order to avoid the problem?
1°: Avoid to visit infected areas;
2°: make sure to use a good mosquito net after sunset since that is the time when the mosquitoes that spread the disease appear;
3°: use repellents, also at daytime;
4°: if you hang around in the city, no need not take further measures. If, on the opposite, you intend to move on into the woods or the land, chemoprophylaxis is to be advised. One or more anti-malaria drugs should be started before departure and cintinued until a few weeks after returning home.
Drug resistance, however, is an increasing problem. The products available must be adapted to the region to be visited, and even then they do not provide complete guarantee for protection.
5°: The only anti-malarial vaccine available is useless because ineffective.
Cholera is also an intestinal infection caught through infected food or drinks. Here, too, the message is to adapt scrupulous hygienic measures as to nourishment when travelling in infected areas. A limited infection must not necessarily lead to a disaster: a healthy person can carry over a bilion germs without even getting ill.
There are different vaccines, but none of them is any good. Either they only work for a short time, or only in people with a certain blood type, or only against specific bacteria. Most vaccination centres, therefore, no longer advise the vaccine.
Moreover, vaccination does not prevent anybody from becoming a carrier, so every vaccinated individual may spread the disease anyway. From 1973 on, no country is allowed anymore to mandate vaccination against cholera. If vaccination takes place anyway, there should be at least three weeks between the yellow fever vaccination and the one against cholera, or the efficacy of both go down. Protection is assumed to be present seven days after vacciation.
Adverse effects observed after vaccination are: spinal paralysis, pancreatitis, hepatitis B, immune disorders, sudden death, lesions of the cardiac muscle, and psychiatric disturbances. The risk for side-effects to occur is greater if administered together with the thyphoid vaccine.
Even after antibodies disappeared, clinical immunity against polio remains sufficient without boosters. A booster before your journey is, therefore, redundant. Moreover, if the oral vaccine is used, the vaccinated person is himself a source of infection to his environment.
The oral vaccine is not to be administered during acute intestinal problems, during pregnancy, in case of neomycin allergy or immune deficiency.
If the oral typhoid vaccine is given as well, both must be separated at least 2 weeks. The injected (Salk) vaccine must not be given to people with a streptomycin allergy.
The risk for infection is not greater travelling than at home. A journey, therefore, is not a reason to booster the vaccine. One should be careful with tetanus boosters because of the allergic reactions which are more prevalent after too much boostering. The minimum span between two administrations is 10 years, but a booster after 20 years will do as well.
After a small epidemic in the former USSR, a few years ago, the risk for infection with diphtheria is by far exaggerated in western countries. Diphtheria is a not so very contagious disease which florishes in a context of alcoholism and poverty. Vaccination should be limited to those who are bound to come in close contact with infected subjects.
MEASLES - MUMPS - RUBELLA
In tropical countries contact with these diseases is feasable. Since virtually everybody has antibodies to the diseases, we see no need to vaccinate.
Hepatitis A is more common in the third world than it is in western countries. Whether this is a good reason to vaccinate all travellers is a different question. Sufficient general hygiene (food, stool) as discribed further on in this page, and a responsible attitude as to sexual contacts (abstinence or preservatives!) suffice to keep the risks within reasonable limits. If, for some reason, an injection is necessary, one should assure that only sterile disposable needles are used. It would be smart to take some with you!
The same goes for hepatitis B and C and...
If infection should occur anyway it is always possible to inject antibodies (gammaglobulines).
The influenza vaccine has never proven to be of any value, as little abroad as it is with us. To be avoided.
PNEUMOCOCCUSThis infection can cause a serious form of pneumonia. The vaccine is too recent to be sure it is safe. Persons who are recommended to have the vaccine most probably are so weak they should not travel in tropical countries anyway.
Group A meningococci may cause meningitis. In Africa, the disease is centered as a belt around the equator, between December and July. A vaccine is recommended for people who will stay near the local population at this time of the year. For pilgrims to Mekka the vaccine is mandatory. In all other situations there are no valid arguments to vaccinate. Administration of the vaccine must take place at least 10 days before departure. The vaccination remains valid for 2 years.
Fever may occur after vaccination within 24 hours after administration. Systemic reactions also have been observed.
contra-indications are: fever, an allergy to phenol, and pregnancy.