New Delhi: The latest variant of Mpox clade 1b that is causing infections across the globe, particularly in Africa, is not only more infectious but also raises a high risk of miscarriage, according to a study led by international researchers.
The study based on genetic analyses of clade 1b — first detected in September 2023 in Kamituga, Democratic Republic of the Congo (DRC), showed that this variant has since undergone mutations making it more easily transmissible between humans.
In the study, published in the journal Nature Medicine, the scientists identified three new subvariants, one of which has spread beyond Kamituga to other cities in the DRC, neighbouring countries, and even internationally — Sweden and Thailand. Separately, Clade Ib has also spread to the US, causing 4 mpox infections in the US since November, last year.
The research team from six different countries including DRC, Denmark, the UK, and Spain, noted that the “new data may also suggest that clade 1b entails a high risk of miscarriage”. Of the 670 patient samples analysed in the study, 52.4 per cent infected with mpox were women, while 47.6 per cent were men.
The majority of infections were transmitted through sexual contact, but three cases were recorded among healthcare personnel. While seven patients died, eight out of 14 pregnant women suffered miscarriages.
“For clade 1b, we see that one particular subvariant appears to have become better at transmitting between humans, and it has now been detected in several countries outside East Africa. In addition, the number of infected pregnant women who miscarry is high among those we have tested,” said Professor Frank Moller Aarestrup from DTU National Food Institute in Denmark.
Originally, mpox was considered a zoonotic disease that primarily spread from animals to humans. However, in 2022, the world witnessed an outbreak primarily affecting men who have sex with men. The new clade 1b differs as both men and women are now contracting the virus.
In addition, an increasing number of infections are being reported among healthcare workers and children, said the team.
Aarestrup said that although “there is some international spread, we do not yet expect a large outbreak outside the epicentre in East Africa”.
However, the researchers urged the need to “avoid close contact, particularly sexual contact, in high-risk areas”; and expand cross-border cooperation to track disease transmission, treat patients, and disseminate health education, particularly among sex workers.
