A Survey of Recent Adenoviral Respiratory Pathogens in Hong Kong Reveals Emergent and Recombinant Human Adenovirus Type 4 (HAdV-E4) Circulating in Civilian Populations.

Jing Zhang,Donald Seto,Patrick Woo,Susanna Lau,Shoaleh Dehghan,Qiwei Zhang,Junxian Ou,Siddharth Sridhar,June Kang

doi:10.3390/v11020129

Abstract

Human adenovirus type 4 (HAdV-E4), which is intriguingly limited to military populations, causes acute respiratory disease with demonstrated morbidity and mortality implications. This respiratory pathogen contains genome identity with chimpanzee adenoviruses, indicating zoonotic origins. A signature of these “old” HAdV-E4 is the absence of a critical replication motif, NF-I, which is found in all HAdV respiratory pathogens and most HAdVs. However, our recent survey of flu-like disease in children in Hong Kong reveals that the emergent HAdV-E4 pathogens circulating in civilian populations contain NF-I, indicating recombination and reflecting host-adaptation that enables the “new” HAdV-E4 to replicate more efficiently in human cells and foretells more potential HAdV-E4 outbreaks in immune-naïve civilian populations. Special attention should be paid by clinicians to this emergent and recombinant HAdV-E4 circulating in civilian populations.

Highlights

An increase in pediatric patients with influenza-like symptoms in Queen Mary Hospital (July to October 2014) led to a question as to whether the putatively host-adapted human adenovirus type 4(HAdV-E4) [1] is circulating in Hong Kong
inverted terminal repeats (ITRs), i.e., they have the NF-I binding site that is found in all human respiratory adenoviruses (Figure 1)
This motif is missing in simian adenoviruses (SAdVs) ITRs [18], as well as the “old”