Vaccination priorities.
Selection of immunizations should be based on requirements and on risk of infection. According to the International Health Regulations, many countries require yellow fever vaccination and proof thereof as the International Certificate of vaccination. Additionally selected countries require proof of vaccination against cholera and meningococcal disease. A consultation for travel health advice is always an opportunity to ascertain that routine immunizations have been performed. Recommended immunizations often are more important for traveller's health than the required or routine ones. The most frequent vaccine preventable infection in non-immune travellers to developing countries is hepatitis A with an average incidence rate of 0.3% per month; in high risk backpackers or foreign-aid-volunteers this rate is 2.0%. Many immunizations are recommended for special risk groups only: there is a growing tendency in many countries to immunize all young travellers to developing countries against hepatitis B, as it is uncertain who will voluntarily or involuntarily get exposed. The attack rate of influenza in intercontinental travel is estimated to be 1%. Immunity against poliomyelitis remains essential for travel to Africa and parts of Asia. Many of the 0.2-0.4% who experience an animal bite are at risk of rabies. Typhoid fever is diagnosed with an incidence rate of 0.03% per month among travellers to the Indian subcontinent, North and West Africa (except Tunisia), and Peru, elsewhere this rate is 10-fold lower. Meningococcal disease, Japanese encephalitis, cholera and tuberculosis have been reported in travellers, but these infections are rare in this population. Although no travel health vaccine is cost beneficial, most professionals will offer protection against the frequent risks, while most would find it ridiculous to use all available vaccines in every traveller. It is essentially an arbitrary decision made on the risk level one wishes to recommend protection--but the priorities need to be set correctly.
Steffen
Robert
R
World Health Organization Collaborating Centre for Travellers' Health, Institute of Social and Preventive Medicine, University of Zurich, Sumatrastrasse 30, CH-8006 Zurich, Switzerland. travclin@ifspm.unizh.ch
Baños
Ana
A
deBernardis
Chiara
C
D015981:Epidemiologic Factors; D006506:Hepatitis A / Q000453:epidemiology / Q000517:prevention & control; D006509:Hepatitis B / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D012307:Risk Factors; D014195:Travel; D014611:Vaccination; D015004:Yellow Fever / Q000453:epidemiology / Q000517:prevention & control