RSV, adenovirus most common viral coinfections among young children
Concurrent respiratory infections are common among young children, and recent study findings from Egypt indicate that respiratory syncytial virus and human adenovirus were the most common causes.
Respiratory syncytial virus (RSV) and human adenovirus were the most common respiratory viruses detected from nasopharyngeal aspirates of 450 children aged younger than 5 years who presented with a lower respiratory tract infection at a Cairo hospital during a 1-year period.
Caroline F. Shafik
Caroline F. Shafik, of the Viral and Zoonotic Diseases Research Program, US Naval Medical Research Unit No.3, Cairo, and colleagues used direct fluorescence assay, real-time reverse-transcriptase polymerase chain reaction, and shell vial culture to identify the viral causes of the lower respiratory tract infection. They tested for eight major respiratory viruses, which included human adenovirus; influenza A; influenza B; human metapneumovirus; human parainfluenza (HPIV)-1; HPIV-2; HPIV-3; and RSV.
Of the 450 isolates, 269 patients (59.9%) had a viral infection, among whom 10.8% had a coinfection with two or more viruses. RSV was the most predominant virus isolated by all three methods; HPIV-2 and influenza B were the least predominant.
The mean age of the children was 1.1 years and 40% of the cases were aged 6 months or younger; 57% were boys.
The researchers said development of the PCR has enabled scientists to detect coinfections at a level not previously possible in Egypt; however, it is unclear which virus(es) contribute to disease.
PCR is the most useful method to detect coinfections representing near-past and current infections because of its ability to detect very low viral titers and/or lingering nucleic acid still present later in the infection course, according to the study researchers.
The difference in testing methods should be considered when designing surveillance studies “to estimate the burden of viral etiologies of respiratory diseases,” the researchers said.
Picornaviruses, coronaviruses, bocaviruses and polyomaviruses were not assessed in this study, so their contribution to respiratory disease etiology and rates of coinfection in Egypt remain unknown.
Disclosure: The researchers report no relevant financial disclosures.