Leptospirosis in Taiwan, 2001–2006

Persistent symptomless human metapneu-movirus infection in hematopoietic stem cell transplant recipients. metapneumovirus infection in lung transplant recipients: clinical presentation and epidemiology. Characterization of multidrug-resistant in-fl uenza A/H3N2 viruses shed during one year by an immunocompromised child. et al. Virological features and clinical manifestations associated with human metapneumovirus: a new paramyxovirus responsible for acute respiratory tract infections in all age groups. To the Editor: Leptospirosis is a zoonotic disease that has now been identifi ed as an emerging infectious disease (1,2). It is caused by pathogen-ic spirochetes of the genus Leptospira. The natural hosts for Leptospira spp. come from a variety of species (2–4), of which the rodent is the most important reservoir (4,5). The incubation period range for leptospirosis is usually 5–14 days, with a range of 2–30 days (4). Leptospirosis is a disease of humid tropical and subtropical countries. According to the World Health Organization (4), probable leptospirosis incidence ranges from ≈0.1–1 case/100,000 population/year in temperate climates to 10–100 cases/100,000 population/ year in humid tropical climates. Lep-tospirosis epidemics are often related to heavy rainfall and fl ooding (1,6,7). Because of its climate, Taiwan may be at high risk for leptospirosis. We therefore investigated human leptospirosis in Taiwan and the relationship between leptospirosis incidence and rainfall pattern. Taiwan is a medium-sized archipelago in East Asia; the Tropic of Cancer runs through its center. The northern part of Taiwan is subtropical; the southern part is tropical. Taiwan lies in the path of many tropical storms and typhoons that bring extremely heavy rainfall usually during July–Septem-ber. The annual " plum rain " season in May and June also brings a lot of precipitation. Because of its tropical and subtropical marine climate, Taiwan enjoys rich agricultural productivity throughout the year, which is favorable for rodent infestations (8,9). In Taiwan, reported cases of lep-tospirosis have been investigated by the Centers for Disease Control since 2001. Leptospirosis should be suspected in patients who have fever; headache; myalgia; abdominal pain; prostration; conjunctival suffusion; meningeal irritation and aseptic meningitis ; anuria, oliguria, or proteinuria; jaundice; acute renal insuffi ciency; or gastrointestinal or lung hemorrhage. Patients with suspected leptospirosis are reported by physicians to Taiwan's Centers for Disease Control through the Notifi able Disease Surveillance System, after which local health bureaus collect urine and blood samples for confi rmation by serologic testing. Urine and blood samples from patients with clinically suspected leptospiro-sis are inoculated into Ellinghausen-McCullough-Johnson-Harris culture medium …