Affiliations: * National Institute of health, Department of Medical Science, Ministry of PublicHealth, Nonthaburi 11000 Thailand
** Institute for Animal Experimentation, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
***Bureau of General Communicable Disease, Department of Disease Control, Ministry of Public Health, Nonthaburi 11000, Thailand
Source: Presented at: The 6th International Conference on Hantavirus (HFRS and HPS), Seoul, Korea, 23-25 June 2004
Hemorrhagic fever with renal syndrome (HFRS) and hantavirus
pulmonary syndrome (HPS) are rodent borne viral zoonosis caused by hantavirus. So far 23 virus species has been registered in the hantavirus genus. Among them, the etiologic agents of HFRS are Hantaan (HTNV), Seoul (SEOV), Puumala (PUUV), and Dobrava (DOBV) viruses whereas Sin Nombre (SNV) and related viruses are leading causes of HPS. In Thailand, observations of Hantann-like virus infection have been reported since 1985 in rodents as well as in humans without clinical symptoms. More recently, there were patients hospitalized for pyrexia of unknown origin, who had specific immune reactions to agents related to leptospira, rickettsia, influenza, dengue, and hantaviruses.
We, therefore, demonstrated serological evidence of hantavirus infection among 519 serum specimens from seronegative cases for leptospirosis in Surin, Thailand. The human sera were screened for indirect immunofluorescence antibody (IFA) with HTNV and PUUV followed by Western blotting (WB). Three of 519 human sera shown to be positive. One of the serum (#277) was strongly positive for IgG and IgM antibody to HTNV by ELISA but having lower titer to PUUV. The other two sera showed lower titers to both antigens. The #277 serum was further examined by FRNT with HTNV, SEOV and Thailand virus (THAIV). It showed the highest FRNT titer to THAIV (1 : 160) but was negative (<40) to HTNV and SEOV.
In addition, a total of 48 rodent sera (15, Bandicota indica ; 2, B. savilei; 19, Rattus rattus; 7, R. exulans; 5, R. norvegicus) were collected in Burirum, which is close to Surin, were examined in 1999. We found that (2, B. indica; 1, R. rattus) of the 48 rodent sera were positive by IFA, ELISA and WB. Furthermore, one of the B. incica sera showed FRNT titer of 1 :80 to THAIV but negative to HTNV and SEOV.
Although the THAIV was isolated from Bandicota indica in Thailand, no virological evidence for human infection has been reported so far. The present study showed that THAIV infection is exising in both humans and rodents in Thailand. Since the patient (#277) Showed high IgM antibody and developed symptoms compatible with HFRS, such as high fever, conjunctival suffusion, proteinuria, high blood level of transaminase (SGOT and SGPT), it is suggested that THAIV is the causative agent of this case of HFRS.