VIABLE

Aim/goal of project
The primary question of this project is “Do respiratory viruses explain high rates of acute otitis media with perforation (AOMwiP) in young Aboriginal children in remote Australia?”

Background
The VIABLE study is a retrospective analysis of clinical trial specimens and data.  We are using stored nasopharyngeal swabs collected at monthly visits from children less than 18 months of age with AOM with perforation and from children without AOM to determine the prevalence of respiratory viruses (influenza A and B; respiratory syncytial virus; parainfluenza 1,2 & 3; rhinovirus, adenovirus, human metapneumovirus).  We will also quantify the AOM-pathogen-specific load (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis), and total bacterial load prior to and at the time of perforation.  Mathematical models of bacterial load and viral infection will be applied to test the hypothesis that viral infection directly or indirectly increases the risk of AOM.

Results
M. catarrhalis (96%), H. influenzae (91%), S. pneumoniae (89%) and respiratory viruses (59%) were common; including rhinovirus (HRV) (38%), polyomavirus (HPyV) (14%), adenovirus (HAdV) (13%), bocavirus (HBoV) (8%) and coronavirus (HCoV) (4%). Geometric mean bacterial loads were significantly higher in children with acute otitis media (AOM) compared to children without evidence of otitis media. Children infected with HAdV were 3 times more likely (p<0.001) to have AOM with or without perforation.

Interesting information
Conclusions: This study confirms a positive association between nasopharyngeal bacterial load and clinical ear state, exacerbated by respiratory viruses, in Indigenous children. HAdV was independently associated with acute ear states.

Links/newsletters
http://www.ncbi.nlm.nih.gov/pubmed/21649905
http://www.ncbi.nlm.nih.gov/pubmed/20357093