A study of patients admitted to hospitals between October and January in Kamituga, eastern Congo, indicates that recent genetic mutations in smallpox stem from its sustained transmission among humans.

The Republic of Congo is facing challenges in controlling its largest smallpox outbreak to date, with scientists indicating that a newly identified strain of the disease in a mining community may have increased potential for human-to-human transmission.

Since January, Congo has documented over 4,500 suspected cases of smallpox and close to 300 fatalities, marking a threefold increase compared to the same period last year, as reported by the World Health Organization. Recently, Congo declared the nationwide outbreak a public health emergency.

An examination of patients hospitalized between October and January in Kamituga, located in eastern Congo, indicates recent genetic alterations in smallpox resulting from ongoing transmission among humans, particularly in an area where inhabitants have limited interaction with the wildlife believed to be the natural carriers of the disease.

Dr. Placide Mbala-Kingebeni, the lead researcher of the study, remarked, "We are witnessing a new phase of smallpox," noting that the findings will soon undergo submission to a scientific journal for publication. Dr. Mbala-Kingebeni oversees a laboratory at Congo's National Institute of Biomedical Research dedicated to studying disease genetics.

Mbala-Kingebeni noted that most patients are reporting milder lesions primarily on the genitals, posing challenges for diagnosis. In contrast to previous outbreaks in Africa where lesions were predominantly observed on the chest, hands, and feet, this new form appears to have a lower fatality rate.

In its recent assessment of the global smallpox situation, the WHO highlighted the potential need for a revised testing approach to detect the mutations in this new variant of the disease.

With concerns raised by experts regarding the limited testing of less than half of smallpox cases in Congo, Mbala-Kingebeni emphasized, "The concern is that without proactive patient reporting, there could be silent transmission of the disease, leaving it undetected."

Mbala-Kingebeni and his team have identified a novel variant of clade 1, associated with smallpox, potentially linked to over 240 cases and at least three fatalities in Kamituga. This area sees a notable influx of transient individuals traveling across Africa and beyond.

Dr. Boghuma Titanji, an infectious diseases specialist at Emory University not involved in the study, expressed concern over the new mutations, stating, "This indicates that the virus is evolving to effectively transmit among humans and could lead to significant outbreaks with serious consequences."

While the West managed to contain smallpox epidemics with vaccines and treatments, Congo has had limited access to such resources. Cris Kacita Osako, coordinator of Congo’s Monkeypox Response Committee, stated that Congo's health minister has authorized vaccine use in high-risk provinces and is negotiating with donor countries like Japan to procure vaccines.

Kacita Osako added, "Once an adequate supply of vaccines is secured, vaccination will be integrated into our response efforts."

Dr. Dimie Ogoina, an expert on smallpox at Niger Delta University, expressed concerns about the parallels between the current situation and earlier outbreaks, likening the spread among sex workers to the initial stages of HIV. He emphasized the importance of addressing prejudices surrounding sexually transmitted infections and the reluctance of smallpox patients to seek medical attention.

Dr. Michael Ryan, WHO's emergencies chief, recently noted that despite the ongoing spread of smallpox in Africa and elsewhere, there has been a lack of investment from donors in combating the disease.