Hepatitis A, typhoid and malaria among travelers--surveillance data from Québec (Canada)

Analysis of epidemiological data on health problems related to international travel helps put into perspective preventive interventions for travelers. To document the epidemiological context of travel health interventions in Québec, we reviewed surveillance data for three infectious diseases. The analysis included data collected in the notifiable diseases surveillance system for hepatitis A, typhoid, and malaria cases reported from 2000 to 2002. Additional data were obtained from the provincial hepatitis risk factor database as well as from regional public health departments. More than 40% of cases of hepatitis A for which risk factor information is available are associated with international travel; 20% of these cases were contracted in Mexico and 22% in the West Indies. The risk of acquiring hepatitis A seems to be higher among travelers under 35 years of age; also, given the number of Quebecers traveling to all regions of the world, this risk is proportionally higher in Africa. Data gathered for typhoid indicate that the risk to travelers from Québec is proportionately higher for Quebecers traveling to the Indian subcontinent and whose purpose is to visit family and friends, and for those who stay abroad for 4 weeks or longer. The risk of malaria is greater in Africa (where contracted cases are mostly caused by Plasmodium falciparum). Over half of malaria cases involve individuals traveling abroad for business (including volunteerism), and almost 75% contracted the disease during a stay of a month or more. Nearly half of the cases had not taken chemoprophylaxis. Available data have limitations for infectious disease surveillance among Québec travelers: imprecise number of cases (underdiagnosis and underreporting), imprecise denominators (number of travelers), and lack of data on the characteristics of trips taken. However, despite its limitations, this profile of infectious diseases among travelers from Québec provides interesting data for preventive intervention.