Scars from the mpox pustules are still visible on seven-year-old Grace Kabuo’s face, as well as on a handful of her playmates at a camp for displaced people near Goma, in the Democratic Republic of Congo.

Grace has otherwise recovered from the virus.

Her mother Denise Kahindo says she is still unsure how her daughter was infected earlier this month.

“I just helplessly noticed the symptoms on her body,” she said.

For disease experts, Grace's case embodies a new concern about mpox, which was first identified over 50 years ago.

Her infection was caused by a new variant that appears to be more capable of transmitting between people than previous strains.

Local doctors say they have seen 130 suspected mpox cases, almost entirely in children and adolescents, in the last four weeks at a nearby facility that treats displaced people from the camps in the last four weeks.

“Fifty percent [of the 130 cases] are even less than five years old,” said Dr. Pierre-Olivier Ngadjole, a medical adviser for Medair, a charity helping with treating and transporting patients from the camp near Goma to the nearby medical centre in Munigi.

An estimated 750,000 people have fled to the area due to fighting between the M23 rebel group and the Congolese government.

“You know the children, they play together… and in the displaced person camps, people are side-by-side,” he added.

Mpox, a viral infection that can spread through close contact is usually mild but can lead to death in some cases.

It causes flu-like symptoms and pus-filled lesions on the body.

The current mpox outbreak in Congo has already seen around 27,000 cases, and claimed more than 1,100 lives, most of them children, since the beginning of 2023.

It began with the spread of an endemic strain, known as Clade I. But the new variant, known as Clade Ib, appears to spread more easily through routine close contact, as seems to be the case among children.

“Mpox is a public health problem – not only for endemic countries but also for others. So, we must act now,” said microbiologist Jean-Jacques Muyembe-Tamfum, head of Congo’s Insitut National pour la Recherche Biomedicale (INRB).

Another mpox variant, Clade IIb, prompted an international health emergency when it spread globally in 2022, mainly through sexual contact among men who have sex with men.

Public health officials in the United States and Europe launched campaigns to promote safe sex practices and vaccinated at-risk populations to curb the spread.

In Congo, there are no vaccines or specific treatments for mpox available outside of clinical trials.

Stigma, regulatory hurdles, and a lack of money, along with measles and cholera outbreaks in the displacement camps have made it a challenge for people to access medical tools, especially in the densely packed locations.

Last month, the country approved the use of two mpox vaccines, but funding remains a significant challenge.

Only a few countries have offered to donate shots to Congo and WHO approval regulations remain a hurdle for international vaccine organisations.

At the Munigi treatment center, some children are assigned to isolation rooms used in past Ebola outbreaks, to help stop the spread of mpox.

They too have lesions on their faces and bodies.

“She had rashes on her arms, abdomen, and even on her tongue,” said Jacqueline Musengimana, mother of Sandrine Sibomana, 5, who is also recovered.

Doctors at the centre said they have discharged 82 patients and have not seen any deaths yet.

Scientists have only sequenced a handful of the cases and found Clade Ib.

There are also likely more cases going undetected, two experts said.

Cris Kacita, head of the mpox response for the Congolese government visited Goma last week to assess the situation.

“What we fear is that when investigations are not carried out properly ... there is no follow-up of contacts of confirmed cases,” he said.

Muyembe-Tamfum and other health officials said work was underway by INRB and others to access vaccines and to investigate the new variant's transmissibility and severity.

The endemic Clade in Congo has a fatality rate of between four percent and 11 percent.

The mortality risk for children posed by the new variant is unknown.

“Children will be exposed; they will be affected. At the moment they are few in number, but we wouldn’t be surprised if that number grows,” said Rosamund Lewis, mpox lead at the WHO in Geneva.