The mpox outbreak in Africa is still not under control, the Africa Centres for Disease Control and Prevention (Africa CDC) has warned, adding that cases were still increasing in several countries.
Reuters reports that countries on the continent are struggling to respond to the major outbreak, coming on the heels of the Covid-19 pandemic that exposed weak health systems hugely unprepared to deal with a major public health crisis.
The number of mpox cases in Africa has surged 177%, and deaths have increased 38.5% compared with the same period a year ago, data from the Africa CDC showed.
“We can say today that mpox is not under control in Africa. We still have this increase of cases that is worrying for all of us,” Jean Kaseya, director-general of Africa CDC, told a weekly briefing on the outbreak.
In just one week, 2 912 new cases were reported compared with the previous week, including a new country, Morocco, where a case was reported, confirming the spread of the disease in all four regions of the continent.
So far, 15 of the 55 member states of the African Union have reported cases, Africa CDC said.
“We still have people dying from mpox in Africa. In one week, we lost 14 people,” he added.
In some countries, like Cameroon and the Democratic Republic of Congo, two strains of the disease were in circulation, but because surveillance and testing systems were not robust enough, it was impossible to tell if that were the case in other countries.
Kaseya said Rwanda had started its vaccination campaign, while the Democratic Republic of Congo, the epicentre of the outbreak, will start vaccinations in early October.
Questions remain
The startling spread of the virus in Africa raises concerns that it may now be more infectious and more severe than anticipated, a delayed conclusion that is partially to blame for the slow arrival of vaccines on the continent.
When the virus that causes mpox jumped on to the international stage in 2022, countries worldwide, including the US, turned to vaccines targeting the closely related smallpox virus to curb its spread.
Yet, reports ScienceNews, it wasn’t until 2024 that Africa, from where the virus emerged and first began spreading among people, received its first doses.
On 13 September, the WHO authorised the smallpox vaccine Jynneos, made by Bavarian Nordic, to tackle growing mpox outbreaks, an administrative move meant to escalate distribution.
Weeks earlier, on 27 August, Nigeria had received 10 000 doses as part of a donation from the US, and another 99 000 shots arrived in the Democratic Republic of Congo on 5 September.
But other countries in Africa are still waiting, and millions more doses are needed to address growing outbreaks in Central Africa, even as researchers rush to learn more about the virus and its spread.
Congo is at the centre of the surge. The sometimes deadly disease has long been a problem here, causing symptoms including fever, muscle aches and a hallmark rash that looks like pimples or blisters.
Since the first case in 1970, others have popped up sporadically in children, usually after exposure to wild animals like rodents or primates infected with the virus, and sometimes sparked small outbreaks.
But the Congo has had a steady rise in cases over the past decade, driven by viruses belonging to a subgroup called clade I. Behind the latest health emergency are clade I versions spreading person-to-person in a growing number of countries, including through sexual networks.
“As scientists, we’re not surprised this is happening because we’ve been ringing the bell for some time,” said Jean Nachega, an epidemiologist at the University of Pittsburgh. “But it looks as if not too many people were listening.”
Scientists are trying to catch up on missed decades of vaccine, drug and diagnostic research for a long-neglected disease.
The first mpox-related public health emergency that hit the Americas and Europe hard in 2022 – caused by viruses from a different branch of the family tree called clade II – ultimately faded and officially ended in May 2023 after global cases declined.
But few resources made it to Africa, and the spread there wasn’t resolved. Now, clade Ib has emerged in the DRC, and appears to spread more easily among people.
“Viruses thrive on opportunity,” said Boghuma Titanji, an infectious diseases physician at Emory University School of Medicine in Atlanta. As viruses spread, they can pick up genetic changes that help them adapt in ways that endanger people.
“Should we really be waiting for a new variant to emerge before we suddenly play catch-up again with a public health emergency declaration to respond to mpox – when we could have done that in 2022?”
In the wake of the latest public health emergency declaration, several countries including Japan, Spain and the United States, have pledged vaccine donations to affected places.
Meanwhile, nearly 6 000 mpox cases are confirmed in 15 African countries as of 13 September, with tens of thousands more suspected: at least 724 people have died.
Difference between clade I and clade II
“Clade” refers to groups of close relatives that cluster together on the viral family tree. The viruses that cause mpox can be sorted into clade I and clade II; each circulate in different parts of Africa.
Historically, clade II viruses jumped from animals to people in parts of West Africa, including Sierra Leone and Nigeria. But around 2014, a clade II virus began spreading among people, researchers said.
Public health officials first detected cases in humans in 2017. Five years later, in 2022, the outbreak went global, mostly spreading among sexual networks of men who have sex with men. Clade II viruses still circulate in Nigeria, and cause sporadic cases elsewhere.
Two groups of clade I viruses, called clade Ia and clade Ib, both usually found in the DRC, are the focus of the new public health emergency. Clade Ia primarily affects children, part because kids like to play in forests, where they might come into contact with infected animals, Nachega says, though there is occasional transmission among people.
In 2023 and 2024, clade Ia cases have also popped up in the Central African Republic and the DRC.
Then in September 2023, there was an mpox outbreak with human-to-human transmission in Kamituga, a mining area in eastern Congo. Like those caused by clade II viruses, the outbreak was linked to sexual contact, this time including sex workers and their clients. The new viral clade behind the outbreak, which Nachega and colleagues dubbed clade Ib, has mutations indicative of human-to-human transmission, they reports in Nature Medicine.
“It was the first scientific confirmation that something new had happened with this virus,” Nachega said.
To date, clade Ib viruses have spread to four of the Congo’s neighbouring countries – Burundi, Kenya, Rwanda and Uganda – and some travel-related cases have appeared in Sweden and Thailand.
Spread has also seemingly expanded beyond sexual networks to move through households, probably through close contact. In Burundi, around 30% of cases confirmed by 17 August have been in children under five.
Clade I viruses may be deadlier than clade II versions, says the WHO. But the data are murky. Because the clades affect different populations, it’s possible that factors like age or quality of healthcare cloud the picture, making the disease seem deadlier in some places than in others.
Why is mpox spreading so widely now?
After the WHO declared smallpox – a closely related virus – eradicated in 1980, and ceased vaccinations, people have gradually become more susceptible to mpox outbreaks. Now, with immunity that once protected against both viruses declining in Africa and globally, mpox cases are on the rise.
But researchers have questions about how specifically clade Ia and Ib viruses are spreading.
For instance, more than half of 5 000 confirmed mpox cases in Congo as of 5 September have been in children under 15, says the Africa CDC.
While clade Ib has hit adults hard, children in this age group have faced worse outcomes than adults after getting infected with viruses from either clade.
It’s unclear how many cases are in infants, young children or teenagers, and it’s possible that different activities are behind the virus’s spread in each group, Titanji said.
Caregivers might expose children through close contact as they carry infants in their arms. Older children may be exposed while working in mines and being in contact with other adults.
Some transmission could be happening through respiratory droplets that get released through talking or breathing. Although most transmission happens through close contact, overcrowded households, where children mingle with family, could offer the virus multiple routes to spread fast.
“If you don’t understand these transmission dynamics, it makes it harder to predict what could happen when the virus makes the jump to another country or continent where lifestyles differ,” Titanji said.
If there were an outbreak outside central Africa, for instance, “would we see a disproportionate impact on children?”
The virus is also spreading through sexual networks in adults, Titanji said. She’d like to know whether the virus hangs around in some parts of the body, making some forms of contact riskier than others, or whether people can transmit the virus to others even when they don’t have symptoms.
Are vaccines essential to control spread?
Vaccines are among the best tools available. Africa CDC has said that the continent needs around 10m vaccine doses to bring the mpox outbreaks under control. But given previous difficulties in getting shots in hand, and hurdles to manufacture enough doses, that is a tough bar to meet.
“Also, we still need hard data to understand how effective existing smallpox vaccines are at protecting people from clade Ib viruses,” Nachega said.
Researchers are developing mpox-specific vaccines (though those aren’t yet ready to test in humans so aren’t useful in the current outbreak). One candidate outperformed the smallpox shot Jynneos at protecting rhesus macaques from mpox, researchers reported recently in Cell.
Vaccinated animals had fewer lesions and fewer days of symptoms than those given either Jynneos or a placebo.
“We can’t have another vaccine-based strategy,” said Ayoade Alakija, an infectious diseases physician and chair of the African Union’s Vaccine Delivery Alliance, during an August briefing on mpox at the WHO Regional Committee for Africa Meeting. “We must do primary healthcare. We must do the basic things. It’s not just about vaccines.”
A handful of drugs exist to treat smallpox, for instance. But it’s unclear how effectively those antivirals fare against mpox. A recent test of the drug tecovirimat showed that the rashes of treated people infected with clade I viruses didn’t resolve any faster than those given a placebo.
Helping people understand how to change behaviour in ways that help curb transmission is also important, Titanji said.
During the 2022 outbreak, activists led the messaging that mpox was spreading among men who have sex with men, and that limiting sexual encounters could protect people from getting mpox.
“And that worked,” Titanji said.
Still, without enough shots to protect high-risk groups in affected countries, the outbreak will probably continue for some time, Nachega said. “Nobody is safe until Africa is safe.”
This week, meanwhile, the US government placed an order worth $63m with Bavarian Nordic to produce additional bulk product and the final freeze-dried doses of its Jynneos vaccine.
As per the contract, the Danish biotech company will manufacture 1m freeze-dried vaccines to be delivered by 2026, it said.
Reuters reports that the additional bulk product, representing the majority of the contract value, will help replenish the inventory used to manufacture vaccines in response to the mpox outbreak in 2022.
Reuters article – Mpox is not under control in Africa, warns Africa CDC (Open access)
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