According to Oriol Mitjà, a researcher in infectious diseases at the Germans Trias I Pujol University Hospital in Barcelona, Spain, who co-authored one of the recent studies published in The Lancet1, "When you put all these studies together, we see that the clinical presentation everywhere is similar—but also surprising." This is due to the fact that the signs and symptoms, as well as the pattern of dissemination, differ from what scientists had previously seen in West and Central Africa, where the monkeypox virus has been responsible for long-lasting, isolated outbreaks.
Since early May, monkeypox has infected more than 32,000 people in more than 90 countries, with roughly one-third of those infections occurring in the United States. The rapid spread of the virus prompted the World Health Organization to declare its highest public health alert on July 23. US President Joe Biden followed suit by announcing a US public health emergency on August 4.
The majority of cases have so far involved males who have sex with men (MSM), particularly those who have several sexual partners or who engage in anonymous sex, despite the fact that some women and children have been infected since May. According to Mitjà, the virus has undoubtedly used the MSM community's extensive sexual networks to its advantage in order to propagate quickly. The virus will have additional opportunity to infect other populations as it spreads, including wild animals, who could develop viral reservoirs that could repeatedly infect humans, according to scientists.
Viruses abounding
Flu-like symptoms, swollen lymph nodes, and characteristic fluid-filled lesions on the skin can all appear in a person with monkeypox. Mitjà and his colleagues report that samples taken from skin lesions at the time of diagnosis contain significantly more viral DNA than those taken from the throat1. This is despite the fact that some researchers have hypothesized that the monkeypox virus could spread through respiratory droplets or airborne particles, similar to how SARS-CoV-2 does. According to Boghuma Titanji, MD, an infectious-disease specialist at Emory University in Atlanta, Georgia, who was not involved in the study, the lesions appear to be relatively "teeming with virus."
A number of studies2, 3, including Mitjà's, demonstrate that few people get the illness from a household member who is sick but with whom they haven't had sexual contact. This discovery, along with the information on viral load, leads Titanji to surmise that respiratory droplets and airborne particles are probably not the main means of transmission. If confirmed by additional research, it may raise the question of whether individuals should remain in isolation for the duration of an infection, which may be challenging given that the sickness appears to take up to a month to resolve, she says.
Refer to sex
It is currently unknown if monkeypox is sexually transmitted in the strictest sense, meaning that it can spread from one person to another through blood, semen, or other bodily fluids during sex. However, numerous investigations have discovered that weeks after infection, monkeypox virus DNA can still be identified in a person's semen. Additionally, one study discovered an infectious virus in one person's semen six days after their symptoms started.
Even if the virus is sexually transmissible, it is unclear how significant a role this route of transmission plays in comparison to simple skin-to-skin contact or breathing in respiratory particles, both of which happen during sex. Knowing how long an infectious virus can survive in semen will be crucial if additional research reveals it there. The fact that viruses like Ebola can linger in semen for months or even years after infection has hindered attempts to stop epidemics. The UK Health Security Agency advises people to continue using condoms for eight weeks following infection until researchers learn more.
The researchers found that having more lesions in the mouth and throat was associated with oral sex, whereas having more lesions in and around the anus was associated with anal-receptive sex. Given all of these findings, Titanji believes it's imperative that public health experts discuss sex openly in their recommendations and be clear about the different methods of protection that are available.
There is a desperate need for more data from carefully planned trials, according to Justman. Given the news of limited vaccine stocks, unavailable antiviral medications, and poor testing, several researchers already worry that the outbreak is past the point of being contained. Compared to COVID-19, she says, monkeypox research is less funded and less motivated. As there was a "Operation Warp Speed" to speed up US vaccine development during the pandemic, she continues, "We don't have one."
