Researchers uncover the link between Human Adenovirus and respiratory diseases
Duke-NUS researchers have identified two new HAdV strains in Singapore that contribute to serious illnesses when in greater amounts.
Singapore | 24 October 2019
Duke-NUS researchers have recently discovered four new human adenovirus (HAdV) strains in Singapore, with two of them found to have a correlation to serious illnesses when in greater amounts.
Strains of viruses are, in essence, genetic variations or subtypes of a gene. This is due to a mutation of the gene of the virus when they replicate, which can infect a new cell that synthesises another 50,000 copies of the new mutated gene—as the human immune system does not know how to stop the synthesis of the mutation, it leads to a new strain of virus.
HAdV infections in Singapore and Malaysia have resulted in critical respiratory diseases among both children and adults, and while scientists have not been able to find out the cause of the outbreak. Not knowing whether it is a new or re-emerging virus strain, they have started conducting large-scale investigations in Singapore. During these investigations, scientists methodically classified HAdV strains present in patients in Singapore, and they managed to identify four strains of HAdV strains, two of which are found to contribute to acute diseases when in larger amounts.
The scientists led by Duke-NUS Medical School used a genotyping algorithm to analyse the HAdV infections that affected patients residing in two large public hospitals in Singapore. They ran tests on more than 500 clinical samples, which comprised of a combination of samples from both paediatric and adult patients.
“We detected four new HAdV strains closely related to a strain isolated from an infant in Beijing during an epidemic in 2012-2013,” said the study’s lead author, Dr Kristen Coleman, from the Emerging Infectious Diseases (EID) Programme at Duke-NUS Medical School. “Our results also highlight an increase in HAdV types 4 and 7 among paediatric population over time. Importantly, patients with weakened immune systems and those with HAdV types 2, 4 and 7 were more likely to experience severe disease.”
Adenoviruses are a family of viruses with more than 50 known strains, and it can have several detrimental effects on the patient, no matter the age. For example, it can result in common cold-like symptoms such as sore throat and fever, and in patients with an already weak immune system, it can even cause acute respiratory illnesses (such as pneumonia) and organ failure.
“The high prevalence and severity of HAdV type 4 infections identified in our study is intriguing,” stated Dr Gregory Gray, senior and corresponding author of the study. He is also a professor in the EID Programme at Duke-NUS and a member of the Duke Global Health Institute at Duke University, USA. “Upon its discovery in the 1950s, HAdV type 4 was largely considered restricted to and controlled by vaccine in the US military population, with rare detections among civilians. Singapore would benefit from more frequent studies of clinical HAdV genotypes to identify patients at risk for severe diseases and help guide the use of new antiviral therapies.”
Based on the results of the study, the authors recommended public health officials and clinicians in Singapore to start using antiviral therapies and adenovirus vaccines to treat the symptoms caused by the virus and to prevent the virus from becoming more and more widespread. They also advocate for adenoviral genotype surveillance to be conducted more regularly at fixed time intervals worldwide. This is especially important for countries that are seeking new HAdV therapeutic options and actions that they can undertake to mitigate the severity of the virus. These actions include measures to prevent the virus from expanding throughout the country.
Genetic surveillance is essential so that the researchers can collect the data required for informed and evidence-based decisions regarding HAdV infections.
The research paper was publish in September 2019 on The Journal of Infectious Diseases
This article was contributed by Ling Yi, an editorial intern at World Scientific Publishing Co. and a contributing writer for Asia-Pacific Biotech News. She is from Nanyang Girls' High School, has keen interest in learning more about life sciences and exploring literature, in both English and Chinese. She also enjoys studying different languages such as Japanese and Korean, and has a passion for dancing and reading.