With pride event planned worldwide in the coming weeks, U.S. officials are preparing for the return of mpox, the infectious disease formerly known as monkeypox that has struck tens of thousands of gay men and hermaphrodites worldwide by 2022. A combination of behavioral changes and vaccinations have quelled that outbreak, but a large portion of those at risk remain unvaccinated.
On Thursday, the Centers for Disease Control and Prevention warned of a deadlier version of mpox ravaging the Democratic Republic of Congo and urged people at risk to get vaccinated as soon as possible. No cases of that subtype were identified outside Africa hitherto. But experts say the escalating epidemic in Congo still poses a global threat, just as infections in Nigeria caused the 2022 outbreak.
“This is a very important example of how infection anywhere is likely to be transmitted everywhere, and why we need to continue to improve disease surveillance globally.”
Dr. Rimoin has studied mpox in Congo for more than 20 years and first warned about its potential for global spread in 2010.
CDC is focusing on encouraging Americans most at risk to get vaccinated before the virus surges again. The agency’s outreach efforts include engagement with advocacy groups and social media influencers who have broad appeal in the LGBTQ community. In December, the agency Call for clinicians to stay alert for possible cases in travelers from Congo.
There are two main types of mpox: Clade I, the dominant type in Congo, and Clade II, a version of which caused the 2022 global outbreak. (A clade is a group of viruses that are genetically distinct and clinical.) Both clades have been circulating in Africa for decades, occasionally breaking out in outbreaks.
People with mpox may experience fever, severe headaches, and back pain, followed by a rash. Many patients also develop painful ulcers, often at the site of infection. People with weak immune systems, including people with HIV, will most likely become seriously ill and die.
The mpox version that caused the 2022 outbreak, known as Clade IIb, caused more than 30,000 cases in the United States that year. The epidemic subsided in 2023 with only about 1,700 cases but is now showing signs of a resurgence: The number of cases in the US this year is nearly double the number of cases at this time last year.
In Congo, as of April 14, Clade I virus had caused about 20,000 infections and nearly 1,000 deaths since January 2023. Clade I infections have a mortality rate of about 5%, compared with less than 0.2% of Clade IIb.
Most cases in children in Congo are thought to be caused by direct contact with infected animals such as monkeys, prairie dogs, squirrels and shrews or by eating contaminated bush meat. Children may live in crowded households and have poor health.
The country is troubled by armed conflict, floods, poverty, malnutrition and many infectious diseases, including cholera, measles and polio.
“There is just one difference in living in the DRC that could drive higher transmission among children,” said Dr. Jennifer McQuiston, deputy director of the High Consequence Pathogens Division at CDC.
Cases in adults in Congo have also been attributed to contact with infected animals or close, prolonged contact with infected people. But last year, for the first time, scientists discovered sexual transmission of Clade I mpox between male and female prostitutes and their contacts.
During an outbreak in Kamituga, a mining town in Congo, heterosexual prostitution in the bar appears to be the main form of transmission. Genetic analysis shows that, around September, the virus mutated, allowing it to spread more easily among humans.
Marion Koopmans, a virologist at Erasmus Medical Center, said the chain of transmission appeared to be a second, distinct outbreak in the country, caused by a new version of the virus called Clade Ib, with Cases are equally divided among young men and women. Rotterdam, Netherlands.
“I really think there is more than one outbreak going on, and it’s important to continue to evaluate what that means,” Dr. Koopmans said. “We cannot assume” that all forms of mpox work the same way, she said.
This development also alarmed scientists because miners and prostitutes in the area only work temporarily and could transmit the virus to neighboring countries such as Rwanda, Burundi, Uganda and Tanzania.
In many of these countries, limited access to tests, vaccines and treatments has created opportunities for the virus to grow and evolve. The majority of mpox cases are diagnosed based on symptoms alone.
Some countries rely on tests that detect only Clade I or only Clade IIb. According to one report, those tests may not cover Clade Ib, the new version that appeared in September. recent research.
Dr. Rosamund Lewis, head of the WHO’s mpox response team, said that finding prompted the World Health Organization to warn countries to review their testing procedures “and make sure they are not missing out.” any diagnosis”.
In the United States, a test approved by the Food and Drug Administration detects all versions of mpox but cannot distinguish between them. A positive result on that test must be followed by more specific tests to be able to identify the branch, Dr. McQuiston said.
At least for now, currently available vaccines and antiviral drugs are expected to be effective against all forms of the virus. The 2022 outbreak began in Europe in May and flared up in the United States during Pride Month in June and beyond.
From the beginning of the outbreak there was one shortage of two-dose mpox vaccine, called Jynneos. But many gay and bisexual men, accustomed to paying attention to public health messages about HIV, restrict their sexual activityprecipitate one number of cases decreased even before vaccines were widely available.
However, the decline in numbers may have created a false sense of security.
“The sense of complacency is that this really isn’t something that people need to worry about constantly, and we saw that vaccination rate decrease rapidly.
Dr. Titanji said behavioral changes are difficult to maintain, so vaccination is important for long-term control of the virus.
Two doses of the vaccine are more powerful than one dose, with up to 90% effectiveness. an analysis final month of 16 studies. Even if the vaccine does not prevent infection, it reduces the severity and duration of the illness.
However, less one in four Americans at risk of receiving two doses.
“We continue to saturate the space with messaging and uptake hasn’t really changed much,” said Dr. McQuiston, suggesting that more creative approaches are needed.
As of 2022, the vaccine is only available in the United States through federal agencies and is hampered by problem with delivery, limiting its availability; it is now available on the market. WHO, which recommends the vaccine to African countries, has been slow to approve it and has not even started the approval process.
However, the WHO’s advisory group on immunization has recommended that if available, the vaccine could be used to protect adults and children at risk of mpox, Dr. Lewis said.
In addition to preparing for mpox’s return to the United States, CDC also supports Congo’s efforts to provide vaccines, drugs, and disease containment.
“It would be much better to help them control this outbreak before it spreads to other areas and becomes a more global threat,” Dr. McQuiston said. “And, ethically, it was the right thing to do.”
