Many countries, including the US, are not doing enough to contain monkeypox, which can spiral into a large-scale global outbreak, an infectious disease epidemiologist warned.

The viral disease, once centred in countries in central and west Africa, has now spread to countries that are not endemic to the virus.

"This is a unique outbreak where we know this virus, but it's causing a very large outbreak in a number of countries around the world," Dr Syra Madad, senior director of the special pathogens programme at New York City Health + Hospitals, was quoted as saying to CNBC's "Squawk Box Asia".

"It's not an outbreak to take lightly. What is a really big concern is that it becomes an established virus in the US, as well as in other countries that this virus is not endemic to," she added. Madad said "it is really unacceptable," especially in the wake of the COVID pandemic, for countries to be struggling to contain the spread of monkeypox.

"Having all the lessons learned with COVID-19, we should not be dealing with an outbreak of this scale and are not doing enough to ensure that this does not become endemic," she added.

While cases have, so far, been concentrated primarily within gay and bisexual communities, the World Health Organization warned that there is little evidence to suggest that the disease will remain confined to those groups. In fact, it has already started to spread to a more vulnerable group: children - two in the US and one in the Netherlands.

"In the US, two children contracted monkeypox through the household transmission of someone that has monkeypox. We know those cases may start to increase over a period of time as more transmissions happen in the community," Madad said.

More than 16,000 cases of monkeypox have been reported across over 75 countries this year, so far, and the number of confirmed infections rose to 77 per cent from late June through early July, as per WHO data.

Madad said the best way to cut chains of transmission is to vaccinate people who are at risk and may have been exposed to monkeypox, the report said.