“This is not going to be a short-term battle.”
- Anne Rimoin, Ph.D., Professor of Epidemiology, Center for Global Health and Immigrant Health, UCLA
“Our institutions are poised to repeat the mistakes of COVID-19.”
- Jerusalem Demsas, staff writer, The Atlantic
The number of cases of monkeypox has mushroomed since May 25, 2022 when I wrote the Germ Gems post, “Monkeypox Arrives in the U.S.: Concern? Yes. Panic? No.” On July 23, 2022, the World Health Organization (WHO) reported more than 18,000 cases from 78 countries. At the same time, the Centers for Disease Control and Prevention (CDC) was tracking 4,639 monkeypox cases in the U.S.
Despite the recent surge in case numbers, on July 30, 2022 The Lancet reported: “The clade of monkeypox that seems to be responsible for the outbreak largely causes mild self-limiting illness, although patients have been admitted to hospital, mainly for pain.” Moreover, deaths from monkeypox remain exceedingly rare.
According to both the WHO and CDC, the spread of this virus can be controlled: “this is an outbreak that can be stopped if countries, communities and individuals inform themselves, take the risks seriously, and take the steps needed to stop transmission and protect vulnerable groups.” In this week’s Germ Gems post, I focus on who’s at risk of getting infected and on measures that can be taken to prevent infection.
Change in transmission of monkeypox. Monkeypox is one of the classic “emerging infectious diseases.” (See last week’s Germ Gems post, “Why Are Infectious Diseases Emerging Faster Than Ever?”) It is a zoonotic infection, that is, the infectious agent (monkeypox virus) is transmitted from animals to humans.
In 1958, scientists discovered the monkeypox virus in colonies of monkeys kept for research. Monkeys are not, however, the natural animal reservoir for the virus; rodents (squirrels, rats, and mice) in central and West Africa are. (A move is afoot to change the name of the virus.)
In 1970, researchers identified the first human case of monkeypox in a 9-month-old boy in the Democratic Republic of Congo. Until 2017, most cases of monkeypox were linked to animal exposure in Africa, and it appeared that the riskiest behavior for acquiring monkeypox was handling an infected animal (or preparing contaminated “bushmeat”).
That all changed in 2017 when Nigerian scientists reported an outbreak of about 200 cases of monkeypox occurring mainly in men between 20-40 years old who had engaged in high risk sexual behavior including multiple partners and sex with prostitutes. The scientists determined the virus was spread through skin-to-skin contact during sexual intercourse or by transmission via genital secretions. The Nigerian scientists’ reports on monkeypox transmissibility went virtually unnoticed until the current 2022 multinational monkeypox outbreak.
With this outbreak, scientists confirmed that the monkeypox virus can be transmitted from person-to-person: (1) through direct contact with the skin lesions (resembling pimples or pustules and appearing predominantly in the genital or perianal areas of the body) and or body fluids; (2) by respiratory secretions during prolonged, face-to-face contact; (3) through sharing items of an infected person, such as bedding or clothing; or (4) during intimate physical contact, such as kissing, cuddling, or sex. Anyone—man, woman or child—who has been exposed to the virus in any of the above ways is at risk of developing monkeypox.
Monkeypox is not considered a sexually transmitted disease, but transmission of the virus in this outbreak is strongly associated with sexual activity. Reports of clusters of monkeypox cases associated with sex parties or saunas underscore the potential role of sexual contact as a promoter of transmission. To date, 98% of cases of the 2022 monkeypox pandemic are in men who have had intimate contact with men. By July 25, 2022, in the U.S. only 13 women and two young children had been diagnosed with the virus.
How to prevent monkeypox. Despite the fact that monkeypox has grown into a global threat, the virus does not spread easily. While this is good news, we should all be aware of how to avoid it and take the necessary precautions to do so.
The best way to protect yourself against monkeypox is by avoiding the risks associated with acquiring the virus. The WHO and CDC highly recommend avoiding skin-to-skin contact with someone who has a rash and exhibits other monkeypox-related symptoms (fever, headache, muscle aches, swollen lymph nodes, exhaustion, or respiratory symptoms, e.g., sore throat, nasal congestion, or cough). (To see what the monkeypox rash looks like, click here) If you are exposed to someone with monkeypox or develop a suspicious rash after such exposure, contact your health care provider.
Who Should Get Vaccinated Against Monkeypox? The CDC provides on-line guidance regarding who should be vaccinated (see the CDC’s June 2, 2022 post “Monkeypox and Smallpox Vaccine Guidance”). The CDC does recommend vaccination for those who have a known exposure to the virus.
Two currently licensed monkeypox vaccines are available in the U.S.: ACAM2000 and JYNNEOS (also known as Imvamune or Imvanex). When administered before an exposure, these vaccines may be effective at protecting people against monkeypox. While the efficacy of these vaccines is not clearly established, demand for the vaccines is rapidly outpacing supply, especially among the gay male and bisexual populations. (See for example the July 13 Associated Press article, “Demand for Monkeypox Vaccine Overwhelms NYC System”).
Researchers and health care workers in certain settings can still get the smallpox vaccine. For laboratory personnel, researcher workers, and certain healthcare and public health responders who work with or may be exposed to monkeypox virus, the CDC recommends pre-exposure vaccination to prevent monkeypox. For any people in these high-risk groups who have not received smallpox vaccine within the last three years, another smallpox vaccination or monkeypox vaccination is recommended.
Note that, if you are over the age of 50, you may already have some protection against this virus. Monkeypox virus is a cousin of variola virus that caused smallpox. Until 1972, smallpox vaccinations were routine in the U.S. but were stopped when the disease was eliminated in the U.S. (Due to an extraordinary global vaccination campaign, in 1980 the WHO announced the worldwide eradication of smallpox.) But smallpox vaccine is unusual in that it keeps on giving, that is, if you’ve been vaccinated against smallpox, you have about an 85% chance of being protected against monkeypox.
Treatment options. Tecovirimat (also known as TPOXX) is the only drug with potential efficacy for treating monkeypox. But cumbersome access to proper testing and then treatment have hampered management of the disease. To address these shortcomings, on July 28 the CDC issued an “Update for Clinicians on Testing and Treatment for Monkeypox” via its Health Alert Network.
Can the spread of monkeypox in the U.S. be contained? Some scientists claim that the U.S. is losing the fight against monkeypox. (See, for example, the July 8, 2022 New York Times article “The U.S. May Be Losing the Fight Against Monkeypox, Scientists Say.”) Yet, CDC and WHO officials contend that the spread of monkeypox can be controlled, that is, we still have a window of opportunity to stop this pandemic.
With all the scientific, public health, and medical experience gained battling COVID-19 over the past two-and-one-half years, the U.S. should have a leg up, so to speak, on controlling this virus. Monkeypox presents many of the same challenges as COVID-19 did (such as proper testing, distribution of vaccines and an antiviral drug, providing trustworthy information, and preventing “reverse zoonosis,” that is, spillover of the virus from humans to other animals).
But monkeypox virus is not COVID-19. Unlike the novel coronavirus SARS-CoV-2 that emerged in2019, the monkeypox virus has been around for decades. Its R0 (R naught), a measure of transmissibility, is around 1 whereas the R0 of the Omicron subvariant BA.5 is estimated at 18 (similar to measles virus). Monkeypox virus means of transmission is entirely different: skin-to-skin contact versus airborne (aerosol) transmission and it is not causing an untoward number of deaths. Moreover, there is a treatment and a vaccine for monkeypox.
We have the tools to wage battle against this virus. It may, however, mean that some people will need to change their life style for a while. But the main message of my May 25, 2022 Germ Gems post still holds—monkeypox is a cause for concern but not panic.
