Scientists have identified four new strains of human adenovirus in Singapore and found an increase in two strains linked to severe respiratory diseases. Researchers from the Duke-NUS Medical School discovered the new strains after the virus caused severe respiratory disease among children and adults in recent years in Singapore and Malaysia. They were, however, unaware whether or not these outbreaks were caused by new or re-emerging virus strains that infect people of all ages with symptoms including the common cold, sore throat, and fever.
The research, using a genotyping algorithm to examine human adenovirus (HAdV) infections among patients from two large public hospitals in Singapore, found the new strains were closely related to a strain isolated from an infant in Beijing during an epidemic in 2012–2013. Scientists tested more than 500 clinical samples from pediatric and adult patients, said lead author Kristen Coleman, Emerging Infectious Diseases (EID) Programme at Duke-NUS Medical School, and highlighted an increase in HAdV types four and seven among the pediatric population over time.
The results published in Medical Xpress suggested patients with "weakened immune systems and those with HAdV types 2, 4 or 7 were more likely to experience severe disease," including conjunctivitis, pneumonia or more life-threatening conditions such as organ failure. According to the Centres for Disease Control and Prevention (CDC), there are no approved antiviral medicines for adenovirus infections, which can be transmitted from an infected person to another through close personal contact and air by coughing and sneezing.
The researchers said public health officials and clinicians in Singapore should consider using antiviral therapies, as well as, routine adenoviral genotype surveillance to collect the data needed to make informed and evidence-based decisions. Gregory Gray, a professor in the EID Programme at Duke-NUS and a member of the Duke Global Health Institute, said HAdV type 4 upon its discovery in the 1950s was largely considered restricted to and controlled by the vaccine in the US military population, with rare detection among civilians.