The World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus declared mpox a public health emergency of international concern on Aug. 14 following the uptick in cases in the Democratic Republic of Congo and the spread of the virus across surrounding African countries.
On Aug. 15, the public health agency of Sweden confirmed that strain Clade Ib of mpox reached outside of Africa to Sweden, where a traveler picked up the virus after visiting one of the countries affected by mpox. Since then, cases have been reported in Thailand and the Philippines, according to the New York Times. At the moment, the risk to Wisconsin and the general U.S. public is very low, according to the U.S. Department of Health and Human Services.
What is mpox?
Mpox, previously called monkeypox, is a virus similar to smallpox, though less severe and less contagious. There are two different strains of the virus, and the current strain is mostly caused by Clade Ib, a mutant of Clade I, according to the WHO. Typically endemic to central Africa, Clade Ib is more severe and more deadly than the genetically distinct strain that caused an outbreak in 2022, Clade II.
“Whether the mortality or death rate would be similar in DRC versus somewhere else like the U.S. is unknown. But, obviously, we have to be hesitant upfront and watch very closely because it does have this increased mortality compared to the other version,” Dan Shirley, an infectious disease physician and medical director for infection prevention at UW Health, told The Daily Cardinal.
Were the virus to spread, the mortality rate is expected to be lower in the U.S. than in the DRC. Unlike in the DRC, the U.S. Food and Drug Administration (FDA) has already approved use of two vaccines against mpox.
The fatality rate for Clade Ib is around 10% in children and five percent in adults, compared to a fatality rate of one percent or lower in both populations for Clade II. The virus is also more deadly for those with comorbidities such as HIV.
The virus is zoonotic — transmittable from animals to humans — and was discovered in 1958 in a monkey, though monkeys are not the infection source. It was first discovered in humans in the DRC in 1970. It belongs to the Orthopox family, along with 12 other DNA viruses. The family includes smallpox.
“[Orthopox] is a group of viruses that all cause a pox disease, pustules that are on your skin,” Emma Mohr, an assistant professor in the Department of Pediatrics, told the Cardinal. Mohr’s research focuses on the transmission of Clade IIb mpox from mother to fetus during pregnancy.
Mpox can also be spread person-to-person via physical contact, and Clade Ib can be transmitted sexually and through contaminated objects, as well as to a fetus through an infected mother. Those affected can experience a variety of symptoms, including swollen lymph nodes, fever and, most notably, skin lesions, which generally take weeks to heal.
“The skin lesions can be all over your body, including in your mouth and down by your bottom, and can impact your ability to swallow liquids, keep liquids down and stay hydrated. Sometimes the infection is so severe that it infects the lungs and infects the brain, and that's why people die,” said Mohr.
This outbreak comes on the heels of a 2022 outbreak of the Clade II strain of the virus, which affected 95,000 people across 115 countries, and over 32,000 in the U.S. alone, including 97 in Wisconsin, according to the CDC.
Both Mohr and Shirley agreed there will likely be cases of Clade Ib in the U.S.
Whereas the previous outbreak affected primarily sexually active gay and bisexual men, the new outbreak primarily affects children. Around 70% of the now over 20,000 cases in DRC are in children under 15, and case numbers are likely underreported due to limitations in contact tracing, testing and surveillance, according to the WHO.
More than 95% of all cases of the new strain originate from DRC, although the virus has affected 13 countries in total, according to the New York Times. So far, 975 deaths have been reported in DRC alone. Besides vaccines, social distancing can slow the disease’s spread. But some places in DRC, particularly displacement camps, are so crowded that they make distancing difficult or impossible.
“I hope that the global community is able to help intervene now that the WHO has called it a public health emergency of international concern and really help to get medical care and vaccines to these impacted populations in the civil unrest in that area,” said Mohr.
Recently, the WHO Director-General initiated the process for Emergency Use Listing of mpox vaccines. This listing allows companies to submit vaccines for approval and distribution by partners such as Gavi and UNICEF.
Although the Emergency Use Listing of the vaccine has been initiated, it has not yet been approved, and the WHO has not officially approved the two available vaccines for use. This complicates the process for vaccines to be transported into DRC — it is estimated that around 10 million vaccines will be needed to quell the virus.
Lindsay Pfeiffer is the science editor for The Daily Cardinal.
