DISEASE | DISEASE TRANSMISSION | POPULATIONS TO CONSIDER FOR VACCINATION | VACCINE PREPARATIONS LICENSED IN CANADA | COMMENTS |
---|---|---|---|---|
Cholera | Ingestion of food or water contaminated by feces or vomitus of infected individuals | Humanitarian relief workers in disaster areas and refugee camps Health care workers in endemic areas | Oral, inactivated traveler’s diarrhea and cholera vaccine | High-risk areas include certain countries in Africa, Haiti, Dominican Republic, Cuba, and Iraq |
TB | Inhalation of Mycobacterium TB– containing microscopic droplets originating from case of active pulmonary TB | Only in certain long-term travelers to areas where TB is highly endemic Consultation with an infectious disease or travel medicine specialist is recommended | BCG vaccine (live, attenuated), derived from Mycobacterium bovis (Connaught substrain) | Contraindicated in pregnant or immunocompromised patients Recent TB cases noted in Nigeria, Madagascar, and Venezuela |
Tick-borne encephalitis | Bite of infected ticks (most commonly Ixodes ticks); occasionally transmitted by ingestion of unpasteurized milk | Travelers to endemic areas during active season (March–November) or those participating in high-risk activities (hiking or camping in forested areas) | Vaccine for the prevention of tick-borne encephalitis (inactivated) | Prevalent in rural forested areas of the Baltic States, Slovenia, the Russian Federation, as well as areas of Eastern and Central Europe |
Japanese encephalitis | Pigs and various wild birds represent the natural reservoir for the virus, which is transmitted to new hosts by mosquitoes | Travelers who spend
| Japanese encephalitis vaccine, inactivated | Transmission occurs throughout much of Asia and parts of the Western Pacific region; however, risk for most travelers is low |
Rabies | Zoonotic disease affecting a range of domestic and wild mammals Virus primarily present in saliva; infection of humans usually occurs through the bite of an infected animal | Travelers at risk of direct contact with infected animals (eg, wildlife professionals, veterinarians, and adventure travelers or cavers); those having considerable exposure to domestic animals (particularly dogs); or those spending a substantial amount of time in high-risk rural areas and participating in activities such as running, camping, or hiking Travelers to rabies-endemic areas where there is poor access to adequate and safe management after exposure Children, particularly those who will be in contact with domestic animals | Rabies vaccine inactivated (DCO) Rabies vaccine (inactivated) | Canine rabies remains highly enzootic in parts of Africa, Asia, and Central and South America |
Meningococcal disease | Transmission occurs via direct person-to-person contact and through respiratory droplets from patients or asymptomatic meningococcal carriers Humans are the only reservoir | Travelers to countries or regions where the vaccine is recommended or required, including travelers to sub- Saharan Africa and pilgrims to the Hajj in Mecca, Saudi Arabia | Monovalent conjugate meningococcal vaccines:
| In the “meningitis belt” of sub-Saharan Africa, large outbreaks and epidemics take place during the dry season (November-June) Recent reports of outbreaks caused by serogroup W-135 strains in Saudi Arabia, sub-Saharan Africa (particularly Burkina Faso, Chad, and Niger), and Chile, and serogroup X in Burkina Faso and Niger |
Hepatitis A | Acquired through close contact with infected individuals or through fecally contaminated food or drinking water | Nonimmune travelers to developing countries, particularly in settings with poor food and drinking water control and poor sanitation | Hepatitis A vaccine inactivated Combined hepatitis A and hepatitis B vaccine Hepatitis A vaccine, purified, inactivated Combined purified Vi polysaccharide typhoid and inactivated hepatitis A vaccine | Vaccines before exposure are at least 85%–90% effective Primary immunization is achieved with 1 dose, with a booster dose given 6 to 36 months later depending on the product |
Hepatitis B | Person-to-person contact with infected body fluids (eg, sexual contact, blood transfusions, use of contaminated needles or syringes) Potential risk of transmission through other skin-penetrating procedures (eg, acupuncture, piercing, and tattooing) Perinatal transmission might also occur | All nonimmunized travelers, particularly if traveling to endemic areas or participating in high-risk activities (occupational exposure to blood products and bodily fluid; unprotected sexual intercourse; exposure to needles through either piercing, tattooing, or injection drug use) | Hepatitis B vaccine (recombinant) Combined diphtheria and tetanus toxoids, acellular pertussis, hepatitis B (recombinant), inactivated poliomyelitis and adsorbed conjugated Haemophilus influenzae type b vaccine Combined hepatitis A and hepatitis B vaccine | Vaccine before exposure is 95%–100% effective Routine immunization is recommended for all children |
Yellow fever | Monkeys are main reservoir of infection, which is transmitted to new hosts via mosquitoes | Travelers to endemic or epidemic areas Vaccine is required by WHO IHRs for those entering certain countries in Africa and South America and other countries with the mosquito vector coupled with previous travel in yellow fever–endemic countries | Yellow fever vaccine (live, attenuated) | In Canada, yellow fever vaccine is only available at Yellow Fever Vaccination Centres designated by the PHAC |
Typhoid fever | Transmitted via consumption of contaminated food or water; occasionally via direct fecal–oral transmission | Travelers who will have prolonged (> 4 wk) exposure to potentially contaminated food and water, especially those VFR or those traveling to small cities, villages, or rural areas in countries with a high incidence of disease Travelers with reduced or absent gastric acid secretion | Parenteral, capsular polysaccharide vaccine:
| Endemic areas include northern and western Africa, South Asia (Afghanistan, Bangladesh, Bhutan, India, Nepal, Maldive Islands, Pakistan, and Sri Lanka), the Middle East (except Israel and Kuwait), Central and South America, the Dominican Republic, and Haiti A recent CATMAT statement advises that the vaccine is only for travelers to South Asia (conditional recommendation)24 Typhoid vaccine does not confer complete protection against disease; therefore, food and water precautions remain of primary importance even in vaccinated travelers |
Traveler’s diarrhea | Caused by bacterial enteropathogens in 80%–90% of cases ETEC is the most commonly isolated bacteria | Only consider in those for whom a brief illness cannot be tolerated (ie, elite athletes, business or political travelers, honeymooners) High-risk, short-term travelers with any of the following:
| Oral, inactivated traveler’s diarrhea and cholera vaccine | Vaccine provides short-term protection only (approximately 3 mo) against ETEC diarrhea; therefore, travelers at ongoing risk might require booster doses Vaccination as a preventive strategy is of limited value and is not routinely recommended for most travelers, as
|
BCG—bacillus Calmette-Guérin, CATMAT—Committee to Advise on Tropical Medicine and Travel, CHF—congestive heart failure, DCO—human diploid-cell culture, DM—diabetes mellitus, ETEC— enterotoxigenic Escherichia coli, IBD—inflammatory bowel disease, IHRs—international health regulations, PHAC—Public Health Agency of Canada, rDNA—recombinant DNA, TB—tuberculosis, VFR—visiting friends and relatives, WHO—World Health Organization.
Data from Centers for Disease Control and Prevention,10 CATMAT,14 WHO,15 PHAC,16 CATMAT,17–23 and Greenaway et al.24