Table 1

Evidence of Nipah virus infection in tissue and serum specimens tested during the outbreaks in Malaysia and Singapore. Specimens were obtained from fatal (Y) and nonfatal (N) human cases in Malaysia (M) or Singapore (S) or from euthanized (E) pigs (P), a dog, and a cat from Malaysia. Virus was isolated (Isol) on Vero cells from tissue samples described above. IgM or IgG antibody (Ab) was detected in serum samples by enzyme-linked immunoassays, with Hendra virus antigen prepared as described (8). For RT-PCR, RNA was extracted from human brain tissue (fatal cases only), human cerebrospinal fluid, porcine lung tissue, canine brain tissue, or feline brain tissue. RT-PCR was performed with primers designed to amplify a region of the N gene of Nipah virus (12). In some cases, the nucleotide sequence (Seq) of the PCR products was determined, and the percent identity with the sequence obtained from two cell culture isolates of Nipah virus from M4 and S1 is indicated. Human brain or porcine lung tissue samples were examined by immunohistochemistry (IHC) with the mouse hyperimmune ascitic fluid to Hendra virus; nd, not done.

SourcePCRSeqIsolAbIHCFatal
M1+100++Y
M2+100+ndY
M3+nd+++Y
M4+100+nd+Y
M5, M6ndnd+ndndN
M7–14ndndnd+ndN
S1+100++ndN
S2+100+++Y
S3–6, 8, 9, 13, 15nd+ndN
P1, P5+100+nd+E
P55–56+nd+ndE
P2ndnd+E
P4, P58+ndndndE
Dog+100+ndndE
Cat+100+ndndE