Paratyphoid fever epidemiology and demographics

Overview
Infections with S. Paratyphi A are common in Africa, they follow a course similar to typhoid but rose spots are more abundant and larger. Paratyphoid B is more frequent in Europe. Paratyphoid C is a rare infection, generally seen in the Far East.

An estimated 22 million cases of typhoid fever and 200,000 related deaths occur worldwide each year; an additional 6 million cases of paratyphoid fever are estimated to occur annually. Approximately 300 cases of typhoid fever and 150 cases of paratyphoid fever are reported each year in the United States, most of which are in recent travelers. The risk of typhoid fever is highest for travelers to southern Asia (6–30 times higher than for all other destinations). Other areas of risk include East and Southeast Asia, Africa, the Caribbean, and Central and South America. The risk of paratyphoid fever is also increasing among travelers to southern and Southeast Asia.

Travelers to southern Asia are at highest risk for infections that are nalidixic acid–resistant or multidrug-resistant (resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole). Travelers who are visiting friends and relatives (VFRs) are at increased risk. Although the risk of acquiring typhoid or paratyphoid fever increases with the duration of stay, travelers have acquired typhoid fever even during visits <1 week to countries where the disease is endemic.