Molecular typing of adenoviruses associated with respiratory illness among humans and poultry, Pakistan

Objectives: This pilot study sought to examine the distribution of circulating adenovirus types among humans and other animals in Pakistan. Methods: Patients with influenza-like illness or pneumonia at seven hospitals were enrolled and sampled (oropharyngeal or nasopharyngeal swabs), and their epidemiological data were collected. Concomitantly, livestock with respiratory symptoms in live bird markets and farms were also sampled. These specimens were screened for evidence of adenovirus infection. Results: Of 1705 total samples, 96 (8.8%) of 1084 humans and 15 (4%) of 385 poultry had molecular evidence of adenovirus. Infection in humans was significantly associated with wheezing, coughing, fever, and sore throat, and prevalence was greatest among participants residing outside Punjab. Genetic sequencing identified co-circulation of human-like adenovirus (HAdV-7) and HAdV-3 strains among humans. Further sequencing identified HAdV-C1, HAdV-5, HAdV-89, HAdV-12, and HAdV-56. Bovine adenovirus 2 was unexpectedly detected in a human nasal swab. Among poultry, fowl aviadenovirus (FAdV)-4 and FAdV-11 were identified. Conclusions: Compared with other studies, there was a relatively high prevalence of adenoviruses among sick humans and poultry, with the unusual discovery of bovine adenovirus in a sick human's airway. There was considerable diversity among detected adenovirus strains. Given periodic adenovirus outbreaks in Pakistan, monitoring types in respiratory illness is key.