The World Health Organization has once more named mpox as a public health emergency of international concern.
There are four versions, or clades, of mpox, which have appeared in different locations and have different characteristics. For example, where Clade Ia is endemic to Central Africa, Clade IIa is endemic to West Africa. These two clades are both zoonotic, meaning that they can be transmitted to humans from infected animals. This could be from bites or scratches, or from activities such as cooking or eating infected animals. While there have been cases of Clade 1a in the Democratic Republic of Congo for over a decade, these figures are surging in the western and northern regions of the country. Those who are infected can pass on mpox to others and it is children who have been particularly impacted. Where outbreaks of Clade 1a have reportedly killed up to 10 percent of those sick in the past, more recent outbreaks have been less deadly.
Clade IIb is the result of a genetic mutation of Clade IIa. This subclade is highly transmissible from human-to-human through physical contact. It was this clade that led to an epidemic in 2022, spreading to countries that were not previously endemic, particularly affecting (although not only), gay, bisexual and other men who have sex with men, having largely spread through sexual networks. This outbreak is still ongoing.
The third clade which is currently seeing outbreaks is Clade Ib. This subclade is believed to be more lethal than the one of the 2022 epidemic and is also highly transmissible from person-to-person. These outbreaks of cases are particularly in the east of the DRC as well as neighboring countries, with reports of it having been spread along trucking routes, mainly transmitted by heterosexual sex and non-sexual contact. According to the New Scientist, there has been high transmission between mothers and other carers and children, with the mortality rate of clade 1B is around 5 per cent in adults and 10 per cent in children (based on people who have been treated in hospitals).
One of the reasons cited for the increase in mpox now is that we are seeing new generations of people who have not been vaccinated against smallpox. This is important because vaccines for smallpox are effective against the disease.
According to the WHO, the duration of the illness usually lasts between two to four weeks and symptoms include a rash, pustiles, a fever, sore throat, headaches, muscle and back ache, low energy and swollen lymph nodes.
