As concerns rise over a more severe strain of Mpox spreading across Africa, experts in infectious diseases are cautiously optimistic that this variant will not pose the same level of threat in the U.S. The potential risk to the U.S. could be reduced by several factors, including existing immunity from vaccinations and previous infections from a different variant that emerged in 2022, the absence of viral circulation in wild animals, and better healthcare access, living standards, and public health infrastructure.

On Wednesday, the World Health Organization reclassified mpox (formerly known as monkeypox) as a public health emergency of international concern due to a significant outbreak of Clade I in the Democratic Republic of Congo (DRC), which has since spread to other African countries.

On Thursday, Sweden reported the first case of clade I outside of Africa. Dr. Boghuma Titanji, an infectious disease specialist at Emory University, noted, “It was only a matter of time before we saw this extend beyond the African continent.”

Following this, Dr. Pamela Rendi-Wagner, director of the European Centre for Disease Prevention and Control, announced on Friday that the risk level of clade I for the general European population was raised from “very low” to “low.” She emphasized the need for vigilance due to Europe’s close connections with Africa and the possibility of more imported cases.

The CDC confirmed on Friday that there have been no reported cases of clade I in the U.S. so far. Clade I is considered more transmissible and severe compared to clade II, which was responsible for the global mpox outbreak that peaked in August 2022 with a death rate of 0.2%. People with compromised immune systems, particularly those with untreated, advanced HIV, were at the highest risk of severe outcomes from clade II. Currently, the U.S. is experiencing low-level transmission of clade II.

Anne Rimoin, an epidemiologist at UCLA and a leading expert on mpox, stressed the importance of context when evaluating how mpox might behave differently in Western countries compared to Africa. “We must be very cautious about labeling clade I as more dangerous,” Rimoin remarked. “The data on its severity and mortality are limited, and there are many factors, such as population immunity, transmission routes, and infectious dose, that could affect perceived severity.”

The National Institutes of Health reported on Thursday that the antiviral TPOXX did not reduce the duration of symptoms for clade I in a clinical trial conducted in the DRC. However, the death rate among participants was 1.7%, significantly lower than the typical 3.6% or higher seen for clade I in the DRC. NIH experts attributed this to the improved medical care available to the study participants.

Dr. Jennifer McQuiston, who leads the CDC’s response to clade I, indicated that the study results provide hope that high-quality healthcare in the U.S. could mitigate deaths from the disease. Dr. Dan Barouch from Harvard Medical School noted that while the U.S. will likely see clade I cases, the immediate risk remains low. “We need to stay vigilant,” he advised.

The CDC first alerted healthcare providers to be on the lookout for clade I in December and updated its advisory on August 7. Testing for mpox includes checking for specific clade types, with some labs performing direct screenings and others sending samples to the CDC. All positive results must be reported to the CDC, which also monitors wastewater across the nation for signs of the infection.

Dr. McQuiston emphasized that clade I presents a greater concern than clade II, prompting ongoing vigilance. The CDC recently noted that receiving both doses of the Jynneos vaccine appears to reduce the risk of mpox and is expected to offer protection against both clades.

During the ongoing low-level outbreak of clade II, mpox has primarily spread through sexual contact among men. The CDC continues to recommend that men with multiple male partners receive both doses of the Jynneos vaccine. Currently, only about 25% of those at significant risk in the U.S. have been fully vaccinated.

In the DRC, clade I has been widely transmitted through sexual contact among both gay men and female sex workers. Notably, children have made up two-thirds of the approximately 20,000 suspected cases and three-quarters of the 975 suspected deaths in the DRC since January 2023.

Recent mutations in the virus may have increased its transmissibility. Rimoin noted that close physical contact—whether sexual or nonsexual—is likely necessary for transmission. Living conditions in the DRC, which are often more cramped than in the U.S., may also contribute to the spread. “We don’t hear reports of transmission from markets,” McQuiston said, adding that household spread might be facilitated by caregivers lacking protective measures and the ability to isolate infected individuals.

The vaccine remains scarce in the DRC, whereas it is sufficiently available in the U.S., where those exposed to infected individuals can seek prophylactic vaccination. In rural areas of the DRC, mpox may be contracted from unknown wild animal hosts, possibly rodents, while no animal reservoirs are known in the U.S.

Dr. Jeffrey Klausner from the University of Southern California suggested that differences in sexual behavior between gay men and heterosexuals in the U.S. might limit mpox’s broader spread. He noted that the gay and bisexual male population includes a smaller subgroup that engages in behaviors capable of sustaining an outbreak. Klausner argued that natural immunity from previous infections might have been underestimated and, combined with vaccination, is likely sufficient to prevent a major outbreak.

However, Dr. Chloe Orkin from Queen Mary University of London cautioned that the extent to which immunity from clade II protects against clade I remains uncertain. Emory’s Dr. Titanji also warned against complacency, highlighting that clade I could potentially spread in heterosexual networks in the U.S. as well.

Source

The post Could the new mpox threat cause significant harm in the U.S.? appeared first on Foxton News.