Scientists from Imperial College London have riddled out the cause of one of the most pervasive viruses on earth: the enterovirus.
“There are many different types of enteroviruses that infect humans,” Dr. Margarita Pons-Salort, co-author of the research from Imperial’s School of Public Health, said. “Some cause epidemics every year, while others cause epidemics every two or three years. However, until now we didn’t know what determined the frequency of these outbreaks, or why some viruses seemed to cause large outbreaks in certain years.”
Enteroviruses infected 50 million children in the United States alone annually. There is only one vaccine for enteroviruses currently available and others are in development.
Pons-Salort’s team has developed a mathematical model that could allow for prediction of outbreaks up to two years ahead of time. Focusing on 14 years of Japanese enterovirus surveillance data for its initial build and testing, the team simulated epidemic patterns for each of the 20 most common types of enterovirus and successfully predicted outbreaks in 2015 and 2016. Tests based on other countries’ data are ongoing.
“The accuracy of our model to explain the data means we now understand why these outbreaks occur, and that they are actually highly predictable,” Pons-Salort said. “This information could allow medical staff to prepare ahead of the outbreak. Our model will also help design vaccination strategies (i.e. who should be vaccinated and when), and anticipate the impact of the vaccine.”
The findings, published in the journal Science, also indicate that frequency of enterovirus outbreaks over time are linked to birth rates. There are over 100 different types of enterovirus which can infect people, and the scientists found that outbreaks of the varying types were mostly determined by the number of children born in a given year, as well as the development of immunity against that specific type in the wake of infection. That infection tends to lead to development of immunity to further infections of that virus.
The team also found that each outbreak tends to be followed by a group of children born without encountering the virus, which leads to further infections down the road, and another resulting outbreak. These outbreaks can manifest in all sorts of ways: cold symptoms, sore throat and fever, viral meningitis, or even encephalitis.