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KP Science Corner: Focus on the monkeypox outbreak

By Shannon Lee

Monkeypox is a disease caused by infection with the monkeypox virus, a distant relative of smallpox in the family of DNA viruses known as Poxviridae. These viruses are not related to chicken pox (varicella zoster), which is of the family Herpesvirus. The first U.S. case in this current monkeypox outbreak was reported on May 18 on the East Coast. As of July 20, there are 2,323 cases in the country, 356 from California. Globally, there are 14,000 cases.

Aligning this virus with monkeys is a bit of a misstep because the most common animal reservoirs are rodents. Viruses that can readily jump from animal to human, and back into an animal reservoir, present a difficult control landscape for healthcare professionals. Viral experts are saying it is very important to track and attempt to squelch pandemics of this type to prevent expanding the pockets of animal reservoir communities.

The previous monkeypox outbreak that touched the United States was in 2003, when 47 people in the Midwest contracted the virus from pet prairie dogs who had become infected when housed near some small, imported African mammals. During that outbreak, no person-to-person transmission cases occurred. Many experts felt the United States “dodged a bullet” because the 2003 outbreak was not worse, and there was no evidence the virus had established residence in a new wild animal population.

Monkeypox presents with similar symptoms to smallpox and other rash-based diseases, including some other sexually transmitted diseases. Most people recover quickly and have a mild course of disease, but for some the process is very painful, and it is not unusual to have the skin manifestations persist for up to two to four weeks. Children, those who are pregnant, and immunocompromised people are the most vulnerable. Severe cases can lead to skin scarring, extended hospitalization, blindness, and enduring disability.

The monkeypox virus is most easily transmitted from an infected human, or animal, by skin-to-skin contact when pustules are present. However, the virus is quite surface stable and has also been readily detected in semen, urine, saliva, feces, and via nasal, throat, and rectal swabs. Close contact with an infected individual, especially intimate contact, is considered the most likely pathway of spread and is the target of prevention measures.

The predominance of cases in the United States at present are in the “men who have sex with men” (MSM) community. As such the federal government is strongly recommending that members of the MSM community minimize numbers of sexual partners and engagement with anonymous partners until the outbreak has subsided.

For those of us who were alive in the early 1980s, this feels like deja vu. In the early days of the human immunodeficiency virus (HIV) pandemic, many incorrectly said that virus was a “gay” disease and dismissed it as something they personally didn’t need to think about. There was also terrible discrimination and ugly rhetoric. We would be very wise to not make these mistakes 40 years later. This outbreak will not be specific to one slice of our diverse society.

The case fatality rate for monkeypox in previous outbreaks has typically been 3–6 percent (World Health Organization), with some variants as high as 10%. Thankfully, the virus group (clade) of this current outbreak appears to be demonstrating a case fatality rate of 1 percent, which is lower but still of great concern to epidemiologists familiar with this disease. For comparison, the seasonal flu has a case fatality rate of 0.1 percent.

Reasons for concern are the long trajectory of infection (multiple weeks), the considerable stretch of transmission before skin lesions are obvious, symptoms being overlooked or misdiagnosed, and the increased surface stability in this new virus clade. That last bit is very worrying. This could translate to spread via surface contact and not just person-to-person intimacy.

It is important to understand that intimate spread need not include only sexual behavior, but also could include grooming, bathing, sharing contaminated objects, etc. There are now several cases in children from suspected household transmission. Cohousing situations, such as in college dorms and military barracks, and close-contact situations, such as in day care, preschool, and other school settings, may prove centers of spread this fall.

Due to the ease of spread, and the potential for both high mortality and morbidity (the persistence of symptoms), monkeypox is listed as a virus group of bioterrorism concern by many of the world’s top health agencies. A network of surveillance exists, and epidemiologists are vigilant, alert, and rather concerned about the current outbreak being in so many countries so rapidly. On July 23, the World Health Organization declared monkeypox a Global Health Emergency.

One bit of good news is that, unlike COVID-19, monkeypox is not a novel (new) virus, and rapid testing and a vaccine already exist.

“Unlike the early days of the COVID-19 pandemic, when we did not have a vaccine to mitigate the spread, in the case of monkeypox we do have an approved vaccine that should be effective,” said Dr. Mark Ghaly, California Health and Human Services secretary. “It is critical for us to work together and across government — federal, state, and local — to mitigate the spread and protect those disproportionately impacted by the virus.”

On July 20, a state of California press release indicated that an official request for 600,000 to 800,000 additional JYNNEOS vaccine doses has been filed with the Centers for Disease Control and Prevention. As prevention, two doses of this monkeypox-specific vaccine are recommended (two weeks apart) and can even be administered after a diagnosis has been rendered. If you suspect exposure or have any unusual rash, avoid close contact with other people and reach out to your healthcare provider for guidance.