The model aligns with the World Health Organization’s assessment of the disease’s transmissibility
RESEARCH TRIANGLE PARK, N.C. — A new study by researchers at RTI International, a nonprofit research institute, finds that the introduction of monkeypox in a population resembling a high-income European country would likely result in a relatively low number of secondary cases, even without public health interventions. However, the study also shows that quick public health interventions would drastically reduce an outbreak’s cases and duration.
The researchers simulated an outbreak using a unique mathematical modeling framework that accounts for interactions at the individual level and has been applied to investigate the transmission of measles, Ebola and COVID-19. It is the first individual-based model to be applied to estimate monkeypox cases in non-endemic countries.
“Our model aligns with the World Health Organization’s assessment that monkeypox in various countries is unlikely to cause major outbreaks,” said Donal Bisanzio, Ph.D., a senior epidemiologist at RTI and the study’s lead author. “This does not mean that countries should abandon public health interventions to control currently observed monkeypox case clusters, as they have the potential to substantially reduce transmission.”
The model results estimated that the introduction of 3, 30 and 300 monkeypox cases, without interventions, would cause approximately 18, 118 and 402 secondary cases, respectively. The first scenario would have a duration of about 23 weeks, while the latter two outbreaks would last about 37 weeks, according to the model.
Conducting contact tracing with isolation of symptomatic cases would reduce the number of secondary cases by between 69-72%, the researchers found, and adding ring vaccination to contact tracing efforts would increase the reduction to 78-89%.
“Fortunately, the current evidence points to monkeypox having low human-to-human transmissibility,” said co-author Richard Reithinger, Ph.D. “Symptoms of monkeypox tend to emerge soon after infection and are usually obvious, so unlike COVID-19, asymptomatic transmission is rare.”
The model assumed a high-income country of 50 million people where the disease is not endemic. The socioeconomic and demographic characteristics of the population were determined by an average of the 27 European Union countries.