How monkeypox could affect Bay Area

A new global virus outbreak is making headlines, and it’s not related to COVID.

Cases of the viral infection known as monkeypox, which is related to smallpox, have been reported worldwide. One case has been identified so far in Massachusetts while another is under investigation in New York, and a handful of other cases have been reported in Canada, the U.K. and several European countries.

This is what we know so far about monkeypox and how it could affect Bay Area residents.

What is monkeypox? Monkeypox is in the same family as smallpox, but it’s less severe. Symptoms generally start with fever, swollen lymph nodes, muscle aches, chills and fatigue.

Peter Chin-Hong, a UCSF infectious disease expert, said the “dead giveaway” is a rash in the form of pus-filled blisters that develop after the initial symptoms.

“The hallmark of the disease is a characteristic ‘pox’ rash ... that starts on the torso and then moves to the extremities,” Chin-Hong wrote in an email. “Nothing else looks like it.”

Is monkeypox deadly? Chin-Hong said monkeypox can kill up to 10% of those infected, but it depends on the strain. He said the currently circulating version is thought to carry a less than 1% mortality rate.

Seth Blumberg, an assistant professor of medicine at UCSF who specializes in infectious diseases, said monkeypox can cause severe disease and death, but it’s not as “severe as smallpox in terms of mortality risk.”

He said the level of mortality depends on a number of factors including the “strain one gets, background of one’s general health, nutrition status as well as access to modern healthcare including antibiotics.”

Blumberg added that a majority of cases occur in rural villages in Africa, which often don’t have the same health care access as more developed countries, and this can affect the mortality rate.

How is monkeypox transmitted? According to the Centers for Disease Control and Prevention, monkeypox was first discovered in 1958 when two outbreaks of the disease occurred in research monkeys, which is how it got its name. The first human case was reported in 1970 in the Democratic Republic of Congo. Monkeypox has mostly been localized to central and western African countries, but past cases have been reported around the world. In the U.S., an outbreak was caused by imported mammals in 2003, and there were two travelrelated cases in 2021.

Blumberg said calling it “monkeypox is a bit of a misnomer,” because “it mostly affects rodents like squirrels and rats.”

How do humans get it? UCSF’s Chin-Hong said humans usually get monkeypox via contact with infected animals, such as through bites or scratches. “Human-to-human transmission is rare, as the virus does not traditionally favor humans as a host,” he said, but added that it “can be spread by exchange of body fluids in prolonged kissing or potentially sex, and like influenza can also be spread by droplets.”

Blumberg said studies from the 1980s showed that the potential for human-to-human transmission has a reproductive number of less than 1, meaning each infected person would infect fewer than one other person. Therefore “human-to-human transmission is not self-sustaining,” he said.

But this current outbreak “spans a big geographic region” so the crossover is greater now, Blumberg said, which means the virus could “potentially be self-sustaining.”

What do we know so far about this current outbreak? Chin-Hong said it “doesn’t follow the normal obvious rules of transmission,” which is usually a traveler coming from west or central Africa, or exposure to infected animals.

“Either there was a lot of close contact and these cases were linked by a social or sexual network, or the virus has evolved to transmit more efficiently from human to human,” he said. “The outbreak could grow larger . ... But I would be surprised if it spread to large epidemic numbers.” On May 7, the World Health Organization was notified of a confirmed monkeypox case in an individual who recently traveled to Nigeria. Now there are nine confirmed cases, and most have been detected in men who are gay or bisexual and who had not recently traveled to Africa. This prompted a U.K. Health Security Agency official to urge any gay or bisexual men who notice lesions or rashes to alert a sexual health clinic.

In the U.S., one case was identified in a Massachusetts man who had recently traveled to Canada. Currently, health officials in Montreal are investigating 17 suspected monkeypox cases, and an official there said the first reported cases were by sexual health clinics, mostly in men who have sex with other men.

Chin-Hong explained that the idea is some of these patients in the different clusters “might have been linked by a social and sexual network,” or “several networks” for those who don’t know each other.

“It is not being gay or bisexual that is the risk factor, rather the focus should be on the sexual behaviors (such as) exchange of bodily fluids, prolonged kissing, respiratory droplets, and contact with potentially exposed people,” ChinHong said. He added that people don’t need to change their behavior or be scared, but to “just be aware to alert medical providers if you come down with consistent symptoms.”

Given the stigma that the gay community has faced with HIV/AIDS, and that Asian Americans have faced during the COVID-19 pandemic, Chin-Hong stressed that messaging is crucial.

“It is so important not to demonize groups, but rather focus on the biology of how disease is spread,” he said. “This has had lethal consequences in so much of infectious diseases history, and time and time again this has proven to be the wrong approach. Both from stigmatizing groups thought to be purveyors of disease, but also from making people not in those groups assume that they are protected, and never think of themselves at risk.”

Spain is currently investigating 22 suspected cases, and Italy has one confirmed case, according to CNN.

How is it similar to and different from COVID? Blumberg said among the main similarities is one shared by many infectious diseases: “the initiation of monkeypox involved animal-to-human transmission.”

Some of the initial symptoms are similar to COVID: fever, headache muscle aches, chills and fatigue.

Like COVID, there is a vaccine that can be protective against monkeypox. According to the CDC, past data from Africa suggests the smallpox vaccine is 85% effective in preventing monkeypox.

Blumberg said the mode of monkeypox spread “is less dependent on respiratory transmission.” Evidence so far shows that unlike COVID-19, monkeypox “is not thought to be aerosolized like SARSCoV-2,” Chin-Hong said. Should we be concerned? Experts say there is no cause for alarm yet.

Blumberg doesn’t think on an individual level that people should worry as “there really have not been many cases.”

“The transmission potential is not that significant based on previous studies,” he said.

He added that developing a fever and rash could be a sign of other, more common illnesses, such as chicken pox, shingles or herpes simplex, and it’s recommended to go see a doctor with any worrisome symptoms.

“It’s unlikely to be monkeypox unless you travel to an area,” where it’s spreading, he said.

But he added as a community, we “need to be humble in acknowledging the potential impact of pathogens and their ability to change over time, and treat the potential threat of monkeypox seriously so it doesn’t become a big issue.”

Chin-Hong doesn’t think people need to be concerned yet. “Like with many strange and emerging infections, we should all be curious, but not fearful,” Chin-Hong said. “Most patients so far do well without any antiviral or antibody treatment . ... The virus does not generally like being in humans and prefers rodents.”

He added that he wouldn’t change his behaviors, particularly travel plans, due to this outbreak. Rather, he said people “should be on the lookout for illness.”