According to research, Mpox was in circulation for five years before experiencing a worldwide explosion in 2022.
According to researchers, the illness previously referred to as monkeypox experienced a widespread outbreak in 2022 and had been present in human populations for over five years prior to the sudden increase in cases that led to a worldwide public health crisis.
The revelation of long-standing, concealed spread among people has prompted demands for enhanced worldwide monitoring of the MPXV virus in order to eradicate the illness, now known as mpox, from the human population and prevent its resurgence.
Dr. Áine O’Toole, an evolutionary biologist at the University of Edinburgh, warned that any emerging outbreak has the potential to become a global threat. She emphasized the importance of early detection and containment, even when case numbers are low, in order to prevent the spread of the virus among humans.
In the 1950s, Mpox was initially identified after outbreaks occurred in laboratory monkeys used for research. The Democratic Republic of the Congo (DRC) recorded the first documented human case in 1970. Over the next five decades, sporadic cases primarily occurred in the DRC and Nigeria.
Prior to 2020, the majority of human infections were attributed to direct contact with rodents who are known carriers of the virus in regions where the illness is prevalent. In the few instances where the infection was transmitted between people, it usually occurred among family members residing in the same household.
The mpox outbreak that occurred worldwide was unique. In the publication Science, O’Toole and her team detail how the viruses taken from patients in 2022 had significantly more mutations than anticipated. The normal rate for the mpox virus to acquire a mutation is once every three years, but when compared to the virus collected in Nigeria in 2018, the mpox from 2022 patients had a striking 42 mutations.
Upon further examination, it was discovered that most mutations were a result of clashes with the human immune system, specifically due to an antiviral enzyme known as apobec3. This indicates that the evolution of the virus is being influenced by the human immune system, marking the transition to its ongoing spread among humans. According to the frequency of mutations, scientists predict that mpox has been present in the human population since at least 2016.
The worldwide spread of mpox was caused by a specific group known as B.1. Thanks to public health measures and targeted vaccination efforts directed towards men who have sexual relations with other men, the number of cases has been decreasing. However, experts note that several countries, including the UK, US, Portugal, India, and Thailand, are still reporting other strains of the virus that can be traced back to Nigeria. This suggests that the initial outbreak in 2022 is still ongoing without any signs of slowing down.
According to Dr. Emma Hodcroft, a lead researcher at the Swiss Tropical and Public Health Institute in Switzerland, the virus was likely circulating among humans well before 2022, which may have contributed to its potential for causing a worldwide outbreak.
“Being aware that the virus has been present and continues to spread among humans, alters our approach in preventing and eradicating it. This serves as a reminder that unnoticed alterations in viral behavior can result in increased danger in terms of virulence and transmission. According to Hodrcroft’s statement to the Guardian, in order to effectively monitor these viruses worldwide, we must continue to strive for fairer training, funding, and distribution of equipment.”