[1] St Lukes Episcopal Hosp, Dept Internal Med, Internal Med Serv, Houston, TX 77030 USA
[2] Univ Texas, Sch Publ Hlth, Ctr Infect Dis, Houston, TX 77030 USA
[3] Goa Med Coll, Dept Microbiol, Bambolin, Goa, India
[4] Univ Zurich, Travel Clin, Inst Social & Prevent Med, Div Epidemiol & Prevent Communicable Dis, CH-8006 Zurich, Switzerland
[5] Baylor Coll Med, Div Infect Dis, Houston, TX 77030 USA