Mpox is spreading faster, showing new modes of transmission and affecting different populations, with scientists warning that the disease needs to be brought under control urgently, reports SciDevTech.
An international researcher from the University of Manitoba, Canada, who is playing a key role on a global team working to track and understand the shifts in how mpox is spreading throughout the Democratic Republic of Congo (DRC), has called the expansion of the virus extremely concerning.
“Viruses don’t have passports – and they don’t respect international borders. We need to get things under control urgently,” said team member Dr Jason Kindrachuk, UM Canada Research Chair in molecular pathogenesis of emerging viruses and associate Professor of medical microbiology and infectious diseases at the Max Rady College of Medicine, Rady Faculty of Health Sciences.
One of the team’s studies, published in The Lancet this year, examined 13 years of data and revealed that mpox has spread to almost every part of the DRC.
In 2010, 18 out of 26 provinces reported cases, but by 2023, that number had risen to 24.
“Its spread has changed rapidly over the past couple of years,” said Kindrachuk, who travels regularly to Africa. “Cases had been fairly focused within specific regions that were largely rural. Now the virus has become a much broader problem across most of the DRC in both urban and rural locations.”
Shift from wildlife to human transmission
Before 2023, most mpox infections were associated with direct contact with wildlife, particularly rodents, he said. The virus primarily affected children under 15.
However, a second study published in The Lancet earlier this year revealed a shift in transmission patterns in South Kivu province. The researchers identified the emergence of a new variant – subclade Ib – which showed signs of sustained human-to-human transmission and a rise in cases among people aged 15 to 34.
Kindrachuk, who also works with the Children’s Hospital Research Institute of Manitoba, noted that many of these adult cases involved numerous skin and genital lesions. This pattern suggests that the infections were probably linked to sexual activity, with several affected individuals identifying as sex workers or engaging in sex work, he said.
New trends in severity, urban spread
The study also found that the overall disease severity was relatively low in South Kivu. They saw two deaths out of 403 hospitalised patients – a fatality rate of less than 1%.
“The reality is that what we were seeing in South Kivu among those cases was actually different from what we’ve seen historically,” he said.
Previously, there typically weren’t many mpox cases in Kinshasa, the capital of DRC with a population of 17m. This also changed.
“However, it’s now in Kinshasa, according to our research published last month in The Lancet. And this becomes an even bigger predicament in terms of response efforts because you’re not only dealing with spread across most of the DRC, but you also now have it embedded in this very large metropolis that is a major network for many other countries in Africa.”
Transmission during pregnancy
In a fourth study published in The New England Journal of Medicine in June, the team found that in three women, mpox was transmitted between mother and baby in utero, resulting in pregnancy loss or infection.
The findings support the significance of preventive interventions, including vaccinations, in pregnant women.
“We now need to conduct large-scale studies to better understand the outcomes associated with mpox in pregnancy and to help guide clinical management,” he said.
See more from MedicalBrief archives:
DRC fights mpox-measles co-infections
Most mpox cases can’t be tracked, says Africa CDC