Typhoid fever in the United States, 1985-1994: changing risks of international travel and increasing antimicrobial resistance.

BACKGROUND: Typhoid fever is a potentially fatal illness common in the less industrialized world. In the United States, the majority of cases occur in travelers to other countries.
METHODS: We reviewed surveillance forms submitted to the Centers for Disease Control and Prevention, Atlanta, Ga, for patients with culture-confirmed typhoid fever between 1985 and 1994.
RESULTS: The Centers for Disease Control and Prevention received report forms for 2445 cases of typhoid fever. Median age of patients was 24 years (range, 0-89 years). Ten (0.4%) died. Seventy-two percent reported international travel within the 30 days before onset of illness. Six countries accounted for 80% of cases: Mexico (28%), India (25%), the Philippines (10%), Pakistan (8%), El Salvador (5%), and Haiti (4%). The percentage of cases associated with visiting Mexico decreased from 46% in 1985 to 23% in 1994, while the percentage of cases associated with visiting the Indian subcontinent increased from 25% in 1985 to 37% in 1994. The incidence of typhoid fever in US citizens traveling to the Indian subcontinent was at least 18 times higher than for any other geographic region. Complete data on antimicrobial susceptibility to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole were reported for 330 (13%) Salmonella Typhi isolates. Isolates from 1990 to 1994 were more likely than isolates from 1985 to 1989 to be resistant to any of these antimicrobial agents (30% vs 12%; P<.001) and to be resistant to all 3 agents (12% vs 0.6%; P<.001).
CONCLUSIONS: American travelers to less industrialized countries, especially those traveling to the Indian subcontinent, continue to be at risk for typhoid fever. Antimicrobial resistance has increased, and a quinolone or third-generation cephalosporin may be the best choice for empirical treatment of typhoid fever.