Journal of travel medicine
-
Enteric fever (EF) has become a travel-related disease in industrialized countries. The possible effects of vaccination on typhoid epidemiology in travelers are unknown. We compared the incidence and clinical and microbiologic findings in travelers returning with EF, according to pretravel vaccination status and vaccine type. ⋯ Among Israeli travelers S. typhi infection is declining whereas S. paratyphi A is increasing, with most cases occurring in vaccinated travelers. Prior typhoid vaccination did not modify the course of the disease. S. paratyphi A infection in travelers is not milder than S. typhi infection. Although this is not a prospective, controlled, randomized trial, it appears that the Ty21a vaccine may be less effective for S. typhi but may offer some protection against S. paratyphi A. Sequential vaccination with the available oral and Vi vaccine may merit consideration. A more effective vaccine for S. typhi and S. paratyphi A is urgently needed.