Hepatitis A and travel amongst Nova Scotia postsecondary students: evidence for a targeted vs. universal immunization strategy

Abstract

Background: Canadian guidelines recommend hepatitis A virus (HAV) vaccination for high-risk persons, such as travelers to HAV-endemic areas. The US CDC advocates universal immunization.

Objectives: To explore whether a universal strategy for HAV immunization rather than the Canadian targeted approach for travelers is justified by measuring compliance of postsecondary students with Canadian guidelines.

Methods: A cross-sectional study using an electronic survey method elicited HAV risk factors, immunization history, disease status, and factors affecting immunization status from postsecondary students. Seropositivity was determined by measuring HAV antibodies in saliva from a convenience sample of survey participants within each study group. Statistical analysis used Fisher's exact test and logistic regression.

Results: We received 2279 completed surveys (10.6% response) and 235 saliva samples (58.7% response). A total of 1380 (60.6%) participants had traveled to HAV-endemic regions and 1851 (81.2%) were planning to do so within the next 5 years. Less than half who traveled to HAV-endemic areas reported a history of HAV vaccination (48.0%). HAV seropositivity rates were higher amongst those who traveled to (63.6%) or were planning to travel to (55.0%) HAV-endemic areas than those who had never traveled or had no plans to travel to such areas (17.4%). Only 8.9% of unvaccinated students were seropositive (5.3% of Canadian-born students). Amongst unvaccinated, seropositive students, there was a nonsignificant trend for higher seropositivity in those who had previously traveled to HAV-endemic areas (14.7%) than those who had not traveled abroad (4.4%), suggesting an exposure to HAV during travel. Nearly all (96.5%) unvaccinated students, who were willing to be vaccinated based on current knowledge or if their doctor recommended it, indicated a willingness to receive vaccine if it were provided free of charge.

Conclusions: Current Canadian guidelines for HAV vaccination are not being followed within the postsecondary student population. Given high rates of travel to HAV-endemic areas in this population, a universal approach to HAV vaccination may be warranted.