The presence of Nipah virus in respiratory secretions and urine of patients during an outbreak of Nipah virus encephalitis in Malaysia

Objectives: To study the excretion of Nipah virus in the upper respiratory secretions and urine of infected patients in relation to other clinical fea tures. Methods: Isolation of Nipah virus from the respiratory secretions and urine was made in Vero cells and identified by indirect immunofluorescence assay using anti-Hendra specific hyperimmune mouse ascitic fluid and FITC-conjug ated goat anti-mouse IgG. Results: During the peak outbreak of Nipah virus encephalitis in Malaysia, Nipah virus was isolated from the upper respiratory secretions and urine in eight of 20 patients who were virologically and/or serologically confirmed to be infected with the virus, From these eight patients, Nipah virus was isolated from sire throat swab specimens, three urine specimens and only on e nasal swab specimen. The positive virus isolation rate was related to the collection of these specimens during the early phase of the illness (P = 0 .068). The presence of serum anti-Nipah specific IgM appeared to reduce the chance of isolating the virus (P = 0.049). There was no significant differ ence in the isolation rate with respect to the age, gender, ethnic group an d clinical features associated with grave prognosis and mortality outcome o f the patients. Conclusion: This study shows that it is possible to be infected from secret ions of infected patients, but epidemiological survey on close contacts so far did not suggest that human-to-human transmission is common. (C) 2001 Th e British Infection Society.