As of Wednesday, the US has detected 84 cases of MPXV, according to CDC data
, and 2,027 cases have been detected across 36 countries. While the virus cannot reach the level of infectiousness of COVID-19, the US has upped its efforts to detect, diagnose, and treat people who have been infected, many of whom are gay and bisexual men who have contracted it during casual sexual encounters.
According to the CDC’s new guidance
, MPXV is not a sexually transmitted infection (STI)
and is likely spreading due to the close physical contact that happens during sex. However, many of the early symptoms look somewhat similar to STIs
such as syphilis and gonorrhea, and part of the CDC’s new guidance is for doctors to more rigorously test people with rashes or lesions that they believe can be explained by an STI.
Since it was discovered in Liberia in 1970, MPXV has generally caused symptoms in patients that are extremely similar to the virus’ much deadlier cousin, smallpox. However, according to the CDC, the newest variant of the virus spreading across Europe and the Americas since last month has some new features, including a persistent rash in the mouth, genitals or anus, and lesions that remain localized instead of spreading across the body. The health agency also notes that multiple types of lesions can be present on a single person, including fluid-filled ones, pus-filled ones, and raised ones.
The lesions remain the most infectious aspect of the virus and touching the skin or the contents of a lesion is enough to cause an infection. Thus, bedding or clothing that has touched the lesions can also cause infection, much as it does in smallpox.
The risk to the public remains low, the CDC said, noting that people exposed to people who were infected, or who traveled to countries with an outbreak, should be extra-vigilant of early symptoms. If someone tests positive for orthopoxvirus, the family of viruses that includes MPXV, they are advised by the CDC to isolate themselves from others until their scabs have fallen off and a fresh layer of skin has formed. The symptoms typically last between two and four weeks.
The World Health Organization (WHO), a UN-affiliated global health agency, referred to the change
in viral symptoms as “an unusual situation.”
The MPXV version spreading is a West African variant with a mortality rate of 1% and has caused no deaths in the present outbreak outside of the virus’ endemic range in Central and West Africa. Other variants of the virus can have a mortality rate of as high as 10%, which still pales in comparison to the 30% death rate of the now-eradicated smallpox, a close relative of MPXV.
Because of its origins in Africa, coverage of the MPXV outbreak has often featured imagery of Africans bearing its trademark lesions, which African doctors have denounced as discriminatory and stigmatizing. As a result, the WHO announced earlier
this week that it would rename the virus.