Understanding Rotavirus: Introduction, Discovery, and Impact

Posted by Janice on July 2nd, 2021

Rotavirus is one of the main pathogens that cause diarrhea in babies and young children. It mainly infects the epithelial cells of the small intestine, which can cause cell damage and eventually lead to some symptoms. The name rotavirus comes from its wheel-like appearance observed under an electron microscope. The Latin word for wheel is "rota", which explains why the virus got its name. The rotavirus belongs to the Reoviridae family and is a genus of double-stranded RNA viruses. There are nine species of rotavirus, referred to as A, B, C, D, F, G, H, I and J. Infections in humans are caused by serogroups A, B and C, with serogroup A being the most common.

Rotavirus infection is highly contagious. Rotavirus is transmitted mainly by the faecal-oral route, which can be transmitted directly from person to person, and indirectly through contaminated surfaces and hands and respiratory spread. Rotavirus can generally be found in the stool of an infected person, from two days before the onset of symptoms to up to 10 days after symptoms disappear. Children under the age of two are vulnerable to develop serious diseases after being infected with rotavirus. Adults sometimes become infected, but the symptoms in adults are usually mild and will not develop serious diseases. According to public data, rotavirus gastroenteritis episodes in young children cause more than 500,000 deaths, and nearly two million people become severely ill worldwide each year. The vast majority of these infected children live in low-income countries.

Although rotavirus was first identified by Ruth Bishop in 1973 and has caused more than 50% of hospitalizations of infants and young children with severe diarrhoea, it has not been widely recognized by the public health community, especially in developing countries. Rotavirus infection usually starts within two days of exposure to the virus. It can cause a wide variety of clinical presentations, ranging from asymptomatic infections and mild, watery diarrhea to severe, life-threatening gastroenteritis requiring hospitalization. Severe dehydration is responsible for death in rotavirus infections.

Since 2006, WHO has launched a global vaccination program against rotavirus. Vaccinations have significantly improved the health of children and greatly reduced hospitalization rates. However, rotavirus is easy to mutate or produce new strains because of its double-stranded RNA replication mechanism and the possibility of gene recombination between different virus species. Therefore, there is still a chance of infection after vaccination. But even if infected after vaccination, there is an 80% chance of avoiding severe illnesses.

There is currently no specific medicine to treat rotavirus infection. Recently, biomedical sciences researchers at Georgia State University found that the combination of two substances (known as cytokines) secreted by the immune system can cure and prevent rotavirus infection. They also investigated how these cytokines inhibit rotavirus infection. In addition, scientists at the University of Tokyo have developed transgenic rice with anti-rotavirus antibodies that can fight against rotavirus, providing a cost-effective way to protect children in developing countries from rotavirus infection. These discoveries could prove valuable in offering new venues for the development of novel antiviral strategies.