Molecular characterization of Nipah virus from Pteropus hypomelanus in Southern Thailand

Abstract

BackgroundNipah virus (NiV) first emerged in Malaysia in 1998, with two bat species (Pteropus hypomelanus and P. vampyrus) as the putative natural reservoirs. In 2002, NiV IgG antibodies were detected in these species from Thailand, but viral RNA could not be detected for strain characterization. Two strains of NiV (Malaysia and Bangladesh) have been found in P. lylei in central Thailand, although Bangladesh strain, the causative strain for the outbreak in Bangladesh since 2001, was dominant. To understand the diversity of NiV in Thailand, this study identified NiV strain, using molecular characterizations, from P. hypomelanus in southern Thailand.FindingsPooled bat urine specimens were collected from plastic sheet underneath bat roosts in April 2010, and then monthly from December 2010 to May 2011 at an island in southern Thailand. Five in 184 specimens were positive for NiV, using duplex nested RT-PCR assay on partial nucleocapsid fragment (357 bp). Whole sequences of nucleocapsid gene from four bats were characterized. All 5 partial fragments and 4 whole nucleocapsid genes formed a monophyletic with NiV-MY.ConclusionsOur study showed that P. hypomelanus in southern Thailand and from Malaysia, a bordering country, harbored similar NiV. This finding indicates that NiV is not limited to central Thailand or P. lylei species, and it may be a source of inter-species transmission. This indicates a higher potential for a widespread NiV outbreak in Thailand. NiV surveillance in Pteropus bats, the major natural reservoirs, should be conducted continuously in countries or regions with high susceptibility to outbreaks.

Pteropus lylei primarily forages in residential areas in Kandal, Cambodia

“…Similar to observations for P. vampyrus (Epstein et al, ) and P. medius (Epstein, unpublished), visits to four other roosts including one 105 km from the study site were observed. These frequent exchanges between roosts are consistent with a regional circulation of different NiV strains in Southeast Asia suggested in previous studies (Epstein, ; Wacharapluesadee et al, ). From a conservation perspective, they also suggest that P. lylei in Cambodia is likely a metapopulation and that conservation strategies should be planned on a regional scale.…”

Emergence and adaptive evolution of Nipah virus

“…Analysis based on a large number of N coding sequences (Figure b) revealed human and bat‐derived NiV in Bangladesh lineage and a more complicated structure in the Malaysia lineage including viruses derived from multiple hosts (bat, swine and human), which is corresponding to the different transmission modes of two lineages (Av et al, ). Of note, NiV belonging to different lineages was observed in local bat population of Thailand and Cambodia, and this phenomenon in Thailand was previously reported while NiV from Cambodia bats was formerly thought to only belong to Malaysian lineage, which could be the result of the analysis of additional Cambodia bats sequences obtained in 2013 (Lo et al, ; Reynes et al, ; Wacharapluesadee et al, , , ). In addition, NiV could be divided into these two lineages based on ML trees reconstructed based on other coding sequences (Fig S1), which is similar to the results of previous studies (Lo et al, ).…”

Enhancing preparation for large Nipah outbreaks beyond Bangladesh: Preventing a tragedy like Ebola in West Africa

“…In southern Thailand, Nipah virus has been found in bats; however, no human infections have been documented. Sequencing of the N gene (1599 bp) from this Nipah virus showed 99.1-99.4% identity with the Malaysian strain of Nipah (Wacharapluesadee et al, 2016).…”