It seems impossible that we have to confront the rapid spread of a new virus when we’re still dealing with the effects of COVID-19. But for monkeypox, we didn’t have to respond “from scratch.” After decades of research and clinical work on smallpox, a related but considerably more lethal virus, testing protocols and vaccines were already available for use in monkeypox.
Nearly 20,000 cases of monkeypox have been reported around the world since May, with more than 5,000 infections reported in the U.S. There are probably many more undiagnosed and unreported cases.
Variations in presentation.
In New York City, where more than 1,000 cases of monkeypox have been reported, clinicians are seeing variations from “classic” presentations of monkeypox. The NYC Department of Health and Mental Hygiene reports that many people with monkeypox are not experiencing prodromal symptoms such as fever or lymphadenopathy before the appearance of a rash. Incubation periods have been as short as two to five days. Some people are experiencing fewer or scattered lesions, and initial lesions are often in the anogenital area rather than on the face and extremities. These atypical presentations can lead to misdiagnoses of varicella zoster or genital herpes.
The virus can be transmitted by close contact with lesions or anything that has touched them (towels, clothing, bedsheets), or after prolonged face-to-face contact with respiratory secretions. Neither current patterns of transmission nor past outbreaks in monkeypox-endemic areas suggest that the virus travels easily by air. It’s not yet known whether the infection can be transmitted from an infected person who is asymptomatic, or whether saliva, semen, or vaginal fluids contain the virus.
It’s possible for an infected pregnant woman to transmit virus to the fetus. Miscarriages and stillbirths have been reported during past outbreaks in endemic areas. All mammals are considered to be susceptible to monkeypox, and infected people may be able to transmit the virus to household pets through close contact.
The CDC recommends that patients be placed in a private room (with the door closed, if possible), and that staff don gown, gloves, eye protection, and an N95 respirator to enter. Isolation precautions should continue until all lesions have crusted over, the crusts have separated, and new skin has formed over the area. Most people with monkeypox infection don’t need hospitalization; the CDC provides detailed recommendations for home infection control on their website.
Asymptomatic people can’t be tested for monkeypox; material from monkeypox vesicles is swabbed for testing.
Treatment for monkeypox is supportive. Drugs for the pain, itching, and nausea or vomiting may be used. (The lesions, which can be on mucous membranes as well as skin, can be very painful.) Tecovirimat (TPOXX) is available under Investigational New Drug regulations for people with severe disease, or those who are immunocompromised and therefore at risk of severe disease.
People who have been exposed to a known or suspected case of monkeypox should be assessed for their level of risk (which depends on the type and duration of exposure), and monitored daily for 21 days from the date of their last exposure to monkeypox.
The use of currently limited vaccine supplies.
The JYNNEOS smallpox and monkeypox vaccine can be administered to close contacts of an infected person, especially those at risk for severe disease. It is not a treatment and shouldn’t be used for people who are already infected. The vaccine is given as a two-dose regimen, with the second dose administered at least four weeks after the first.
Because limited vaccine supplies are currently available, many states (NY, MI, others), Canada, and the UK are prioritizing the administration of the first dose to as many at-risk people as possible in order to provide at least partial protection to more people. Full vaccine-induced immunity against monkeypox occurs two weeks after the second vaccine dose is given.
Other preventive measures.
Although sexual intimacy is not recommended for someone with monkeypox infection, the CDC does provide detailed suggestions for “safer sex” on its website.
The reasons for the fast-moving spread of monkeypox from central and west Africa, where it has long been endemic, to countries all over the world in a short period of time are not yet known.