Investigation of a potential zoonotic transmission of orthoreovirus associated with acute influenza-like illness in an adult patient

Bats are increasingly being recognized as important reservoir hosts for a large number of viruses, some of them can be highly virulent when they infect human and livestock animals. Among the new bat zoonotic viruses discovered in recent years, several reoviruses (respiratory enteric orphan viruses) were found to be able to cause acute respiratory infections in humans, which included Melaka and Kampar viruses discovered in Malaysia, all of them belong to the genus Orthoreovirus, family Reoviridae. In this report, we describe the isolation of a highly related virus from an adult patient who suffered acute respiratory illness in Malaysia. Although there was no direct evidence of bat origin, epidemiological study indicated the potential exposure of the patient to bats before the onset of disease. The current study further demonstrates that spillover events of different strains of related orthoreoviruses from bats to humans are occurring on a regular basis, which calls for more intensive and systematic surveillances to fully assess the true public health impact of these newly discovered bat-borne zoonotic reoviruses.

Broad reactive monoclonal antibodies for rapid identification of enteroviruses show cross-reactivity with chikungunya virus infected cells

In the past decade, enterovirus 71 (EV71) and chikungunya (CHIK) virus have re-emerged periodically causing serious public health problems in Malaysia, since their first emergence in 1997 and 1998 respectively. This study demonstrates that CHIK virus causes similar patterns of cytopathic effect in cultured Vero cells as some enteroviruses. They also show positive cross-reaction on direct immunofluorescence staining using monoclonal antibodies meant for typing enteroviruses. Without adequate clinical and epidemiological information for correlation, CHIK virus isolated from patients with acute febrile rash can be wrongly reported as untypeable enterovirus due to its cross-reactivity with commercial pan-enterovirus monoclonal antibodies. This is due to the diagnostic laboratory being unaware of such cross-reactions as it has not been reported previously. Final identification of the virus could be determined with specific antibodies or molecular typing using specific oligonucleotide primers for the CHIK virus.

Isolation of measles virus from clinical specimens using B95a and Vero/hSLAM cell-lines

The clinical presentation of acute measles is normally quite typical, especially in the presence of Koplik's spots, that laboratory test is seldom required to confirm the diagnosis. However, with wide measles vaccination coverage and the extensive use of immunosuppressive chemotherapy, the diagnosis of atypical manifestations of acute measles may require laboratory confirmation. When compared with B95a cell-line, this study shows that the Vero/hSLAM cell-line is sensitive and is recommended for use in the primary isolation of wild-type measles virus from clinical specimens. Throat swab and urine specimens are the clinical specimens of choice and both are recommended for optimal isolation of measles virus from patients suspected of acute measles virus infection.