PUNE: A first-of-its-kind genetic study of a newer and more stubborn Mpox variant detected in Kerala has linked those cases to international travel and reported signs of continued human-to-human transmission. The study of Mpox Clade Ib, which has been driving outbreaks in parts of Africa and has since showed up in several countries outside the continent, showed that it is prone to spreading faster and wider than older variants of the virus, necessitating enhanced surveillance.The study, led by researchers from Pune’s ICMR-National Institute of Virology and teams from Viral Research and Diagnostic Laboratories across India, focused on 10 lab-confirmed cases of Mpox Clade Ib in Kerala between Sept 2024 and March 2025. The findings, published in the journal Virology, indicate active viral evolution with implications for disease surveillance and public health preparedness. “The study confirmed the Mpox virus is indeed mutating, as we found a distinctive mutational pattern that signals sustained human-to-human transmission,” a researcher said.Scientists found the mutation pattern stronger in Clade Ib than in older forms of the virus, suggesting it continues to adapt while circulating. “The sequences also carried mutations in several genes that had earlier been identified as hotspots in Clade Ib strains from the Democratic Republic of Congo, pointing to evolutionary convergence across different regions,” a scientist involved in the study said.A new mutation was detected in six of the 10 cases. The researchers studied patients’ symptoms, viral load, immune response and the full genetic sequences of the virus. The findings showed that the virus arrived in India not through one carrier but as part of a wider regional spread linked to international travel. Epidemiological analysis showed nine of the 10 patients had travelled abroad prior to testing positive for the strain. Local transmission was noted in one person.
