Do you remember the Mpox virus, formerly known as the monkeypox virus, the virus that made a lot of headlines in 2022? While overall news coverage of the virus may have decreased somewhat this year, the Mpox virus has continued to spread in 2023, bringing even more bad news. As of January 1, 2023, the Democratic Republic of Congo has more than 12,569 suspected Mpox cases, resulting in 581 deaths, according to a November 25 World Health Organization situation report. That translates to an estimated 4.6% of those infected ultimately dying. That is the highest number of reported Mpox cases the DRC has ever had and there is still a month to go in 2023. Furthermore, the specific version of the virus spreading in the DRC – namely the clade I MPXV – spread in a away in 2023 that has apparently never been seen before.
The MXPV has also increasingly affected parts of the DRC. This year marked the first time that there were suspected cases in the Kinshasa, Lualaba and South Kivu areas of the DRC. In fact, in recent years the virus has gone from being endemic in 11 of the DRC’s 26 provinces to being detected in 22 of the country’s provinces. You may have noticed that the WHO has used the word “suspect” instead of “confirmed” when describing many of these Mpox cases. That’s because not everyone who became ill and showed clinical symptoms of Mpox – such as showing the pus-filled lesions typically associated with Mpox – has been tested for the virus. Only 9% of reported cases in the DRC have been confirmed by laboratory testing, as many people in the country do not even have access to such tests.
Note that the version of the virus spreading in the DRC is from a different clade than the clade that caused the global outbreak that started in 2022. The word ‘clade’ rhymes with ‘shade’ and is defined as a group of organisms that all descended from one common ancestor. The MPXV has two known clades: clade I, formerly known as the Congo Basin clade, and clade II, formerly known as the West African clade. Scientists have further divided clade II into two subclades: clade IIa and clade IIb. If you’re wondering which clade is the cause of the global outbreak that started last year, it’s clade IIB. But during this global outbreak, the DRC has not reported a single case of clade IIb MPXV. To date, all Mpox cases in the DRC are attributable to clade I MPXV.
As you may recall, before 2022, public health officials didn’t actually associate Mpox transmission with sexual contact. Instead, reported transmission typically occurred between people who lived together or otherwise had close contact. However, that all changed last year with the global outbreak. Many of the cases that have occurred in Europe, the US and other parts of the world over the past two years involved people who had sex with someone else infected with the clade IIb MPXV. However, before you label Mpox as purely a sexually transmitted infection, keep in mind that you don’t have to have sex with someone to contract MPXV. Transmission can still occur through close, non-sexual contact.
Now, before April 2023, there were no formally documented cases of clade I MPXV being sexually transmitted. That all started to change this year after a man from Belgium who already had connections to the DRC arrived in Kinshasa on March 15. That same day, he began experiencing anal itching and discomfort, which developed into painful blisters around his anus over the next two days. and sexual organs. His torso and buttocks also began developing skin lesions. After the man first visited a doctor for these symptoms on March 23, investigations revealed that he was indeed infected with clade I MPXV.
Since the man already had symptoms on the day he arrived in the DRC, it is likely that he was exposed to the MPXV while still outside the DRC – probably somewhere in Belgium. After all, the incubation period for the MPXV is usually one to two weeks, meaning this is the time it normally takes for you to start experiencing symptoms after you are first infected. But while in the DRC, this man frequented clubs where men had sex with men and had several such encounters. That meant public health officials had to identify those with whom the man had had sexual or non-sexual contact and continue to monitor them over time. As you can imagine, that’s no small task. Ultimately, of the 27 such contacts identified, six were tested for MPXV, with five of these sexual contacts testing positive. Of these five – four of whom were men – three eventually developed Mpox symptoms.
Several months later, on July 28, there was another reported and confirmed case of a man in the DRC who developed Mpox after having sex with other men, this time in Kenge. This case seemed completely separate from the cases related to the man from Belgium.
What is seen in the DRC in 2023 could significantly influence the rest of the world. The Democratic Republic of Congo is not a small country. The population is estimated at over 102 million people, which would constitute approximately 1.27% of the entire world population and place the country 15th in the world in terms of population size. Therefore, if MPXV is not adequately controlled in the DRC, many more people could become infected. And what happens when an infectious disease is not well controlled in one country usually does not persist in that country. Furthermore, having two clades that can spread through sexual contact is obviously worse than having only one clade.
So no news is not necessarily good news. Just because a virus doesn’t get the same attention from news media and political leaders as it did in 2022 doesn’t mean the pathogen will no longer cause problems. Pathogens don’t listen to the news and political rhetoric. The MXPV situation is certainly dynamic with new developments in 2023 that could change the dynamics of the MXPV spread in the future – possibly in a bad way.