DETECTION OF RESPIRATORY SYNCYTIAL VIRUS NUCLEIC-ACID IN ARCHIVAL POSTMORTEM TISSUE FROM INFANTS

Archival lung tissue from 99 cases of sudden infant death syndrome (SI DS) and from 58 matched comparison cases with known causes of death wa s studied. Sections were examined by in situ hybridization (ISH) using a cocktail of three synthetic oligonucleotides with sequences chosen from the published sequence of the nucleoprotein gene of respiratory s yncytial virus (RS virus). The oligonucleotides were end-labelled with dinitrophenyl (DNP) or digoxigenin (DIG) and hybrids were detected im munocytochemically. RS virus nucleic acid was detected in 24 cases of SIDS (24%) and in 11 (19%) of the comparison group. Specificity was co nfirmed using a DIG-labeled cloned probe covering the whole of the nuc leoprotein gene sequence. With one exception, th same results were obt ained. Reverse transcriptase-polymerase chain reaction (RT-PCR) was us ed to confirm the specificity of these results. When matched for age a nd month and year of death, 76 SIDS cases and 38 controls could be com pared. Twenty-one SIDS cases (27.6%) and seven comparison cases (18.4% ) contained detectable RS virus sequences by ISH, with a higher detect ion rate in winter in both groups. The differences were not significan t and reflected the seasonal pattern of RS virus infection in the comm unity rather than a causal relationship of RS virus with SIDS. Detecti on of RS viral mRNA through the summer months suggests that persistenc e is possible.