1. Tropical Section,1
2. Servei Microbiologia,2 and
3. Unitat d'Epidemiologia i Bioestadı́stica,3 Hospital Clı́nic Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain, and
4. Ifakara Health Research and Development Center, National Institute for Medical Research,4 and
5. Saint Francis Designated District Hospital,5 Ifakara, Tanzania