A concern for global health security, the US CDC have issued an alarm about a surge in cases of monkeypox. In its Morbidity and Mortality Weekly Report, the CDC notes a “recent apparent increase in human monkeypox cases across a wide geographic area”.

It is similar to smallpox. Primary infection is caused by contact with the bodily fluids of sick animals, but cases of human-to-human transmission have also been documented.

After an incubation period of up to three weeks, victims experience up to five days of intense fever, headache and muscle pain. This is followed by a rash, typically on the face, palms and soles of the feet, and sometimes across the entire body. The rash period lasts for around three weeks, after which recovery or death occurs.

Monkeypox is fatal in about 10% of cases.

The CDC warning targets several countries in Africa.

Altogether, the CDC says, there have been monkeypox cases reported in more countries during the past decade than in the preceding 40 years.

Smallpox is an entirely human disease, a crucial factor in its vaccine-led eradication. Monkeypox, however, is zoonotic – meaning that it exists outside humans in one or more animal species that serve as reservoirs.

There is no specific treatment available for monkeypox, the smallpox vaccination offers cross-protection.