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What is monkeypox and how worried should we be?

A Q&A with Dr. John Swartzberg

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Monkeypox was declared a public health emergency in the United States last week, with cases exploding to over 7,500 between May (when there were only two cases reported) and August 2022. We asked John Swartzberg, clinical professor emeritus of infectious diseases and vaccinology at UC Berkeley School of Public Health, to give us his perspective on the virus: where it came from, how it spreads, and what individuals can do to protect themselves from contracting it.

What is monkeypox and where did it originate?

Monkeypox is a virus in the same family as smallpox, but fortunately it doesn’t cause nearly as severe disease as smallpox does. We’ve known about it for over 70 years. Prior to the 1970s, it had been exclusively found in central and western Africa, causing human cases in a scattered fashion with some significant morbidity and some mortality. The mortality rates ranged anywhere from 1-10%.

So it’s not a benign disease, but we hadn’t seen it outside of central and western Africa until some scattered cases in the ’70s. And then there was an outbreak [47 confirmed and probable cases, according to the CDC] here in the United States in 2002 associated with the importation of some rodents from Africa getting into the prairie dog population. We’ve seen cases occur outside of Africa, but nothing like what we’re seeing now.

How does one contract monkeypox and how does it spread?

It’s frustrating to talk about that because, as I said, we’ve known about this disease for over half a century, yet we haven’t put a lot of effort into understanding it really well. And one of the things we just don’t understand is how it’s transmitted. What we do know is that the primary means of transmission is by skin-to-skin contact. If somebody’s got monkeypox and they’ve got lesions and you rub up against that skin, that’s the way you can get it. It’s clear that that’s a very important means of transmission.

We also know that the virus is found in oral secretions because you can get lesions inside your mouth as well, and those oral secretions can get distributed in the air. So there’s the concern that maybe this plays a role in transmission.

But there are some big question marks about transmission that aren’t really answered yet.
One is, can somebody transmit it who’s infected but not diseased? That is, they have the virus—but they either don’t yet have skin lesions or they have the virus and it just isn’t causing any symptoms—what we call asymptomatic infection. And can these folks transmit it? We just don’t know if we have an answer to that.

How does the virus impact those who contract it? 

Worst case scenario is that this virus can extend beyond the skin or what we call the mucous membranes like in your mouth and can get into your bloodstream and go elsewhere in your body, causing very severe disease and even death. That’s pretty rare. We’ve only seen very few cases. I think four to six deaths have been reported outside of Africa with this outbreak out of thousands and thousands of cases.

But we have seen people requiring hospitalization. That’s not common, but it does certainly happen. It’s because some of these lesions can be very, very painful and can cause difficulty with bowel movements or difficulty with urination. Skin lesions can get secondarily infected with bacteria. So it can be very serious in that regard.

And for those people who don’t require hospitalization, it means that they’re going to suffer from two to four weeks with very uncomfortable and sometimes painful lesions and difficulty with urination or with defecation. So it’s not just a run-of-the-mill, benign disease.

Can someone be asymptomatic and possibly be a carrier?

Well, we don’t know. There’s no good evidence for that at this point. But there’s just not a lot of good evidence, that is really the problem. We’re not doing enough testing to know if there are people out there who are asymptomatically infected. We don’t even know if it’s an issue at this point.

But having a being in the midst of a major outbreak and not having this kind of information is very reminiscent of the early days of COVID-19.

How can people protect themselves from contracting the virus, whether it’s by getting vaccinated or preventative behavioral measures they can take?

Well, here’s the good news. We do have vaccines against this virus. The bad news is they’re not as available as we need them to be right now, but that is going to get fixed over time. We also have medications that work. In particular, there’s a medication called Tecovirimat (TPOXX is the brand name) that works very well.

So these are things we didn’t have at the beginning of the COVID outbreak. The other thing that’s terribly important is that you don’t have to worry about getting monkeypox going into the grocery store or going out to dinner in a restaurant

So the important thing is to recognize that, unlike COVID-19, where you can just be minding your own business and get infected; with monkeypox, you just don’t have to worry about getting infected unless you’re going to be having very close contact, intimate contact with others.

Who should think about getting the vaccine? 

Right now, 94–96% of the cases are occurring in men who have sex with men. So this is currently the high risk group, though we’ve seen some cases of spillover now to females and we’ve seen some cases of spillover to children.

This is the group (men who have sex with men) that needs to have a priority to get the vaccine. Though those in a monogamous relationship are not at high risk.

How does the vaccine work?

It works like any vaccine, it gives us protection, it educates our immune system to not allow the virus to replicate in the body. So if you get the vaccine before you’re exposed, which is the ideal situation, it should prevent you from getting infected at all.

The incubation period for this virus is long; the average is about 10 days or so. So if you’ve had an exposure, and you learn about it the next day, if you can get vaccinated in the first four days, it will probably prevent you from becoming sick. And if you can take it before you become ill, it’s going to moderate how seriously ill you become.

The vaccine is really very helpful, we just need to make them available.

What are some misconceptions that you’ve seen about monkeypox?

I think the biggest misconception is that there are certain people who are more predisposed to getting monkeypox. And that’s just not true. We all have the potential to get monkeypox depending upon if we’re exposed or not. So that’s a major misperception we need to dispel.

I think there are also misconceptions about the role of the vaccine. I don’t think people understand clearly how effective this vaccine can be and when they should be getting it.

I think that there’s also a misconception, just from the name of the virus itself, monkeypox, which is a horrible name. The virus was first found in monkeys, but the monkeys got it probably from rodents. And this is probably a rodent virus, not a monkey virus. And so we ought to really change the name of this virus to get that misconception away.

There’s also the role of inanimate objects and transmission. We know, for example, if somebody has monkeypox that the virus is hardy and can live on, for example, the sheets of a bed. And so if you’re sleeping in the same bed with somebody, the virus could get transmitted that way. But just shaking hands with somebody is not going to spread this virus.

Monkeypox has been declared a public health emergency. How will that impact resources and management of the virus?

(Declaring monkeypox a national emergency) is going to make things a lot better very quickly. It gives the government authority and the ability to not only collect more data and more accurate data from the states, but it also gives the government greater ability to make vaccines available, and make medication more available.

So I think it is going to facilitate things greatly and we’ll see the fruits of this pretty quickly.

If you had a crystal ball, would you see the trajectory of this virus being more like COVID-19 or more like HIV?

Like neither. It’s certainly not going to be like COVID-19. We didn’t know anything about COVID, obviously, because it entered the human population at the end of 2019. So we had to learn very quickly about that virus. We now know it’s incredibly transmissible.

HIV is transmitted in a very different way. It’s easier to prevent getting infected with HIV in many respects because it’s not transmitted via the air like SARS-CoV-2, the virus that causes COVID-19. People who have HIV are asymptomatic for long periods of time—they don’t know they’re infected. When you don’t know when you’re infected, it’s much easier to transmit the virus.

So with HIV, it does require intimate contact, it’s a sexually transmitted infection, although it’s transmitted in certainly other ways as well, like blood. Monkeypox is very different. The predominance of transmission occurs in people who already have sores. Sores typically are, although not always, visible. So one knows when they’re infected and are clearly contagious at that point.

And of course, as I mentioned earlier, the availability of both the drug and the vaccine can dramatically stop transmission. So we have all the tools right now at the beginning of this pandemic to stop it. Whereas with COVID-19, we didn’t have the vaccine for 11 months. If we could aggressively get people who are at high risk vaccinated [for monkeypox], get people who are exposed vaccinated very quickly, and get people treated very quickly, I think we can prevent a significant spillover into the general population and maybe prevent this from becoming an endemic disease.

Unfortunately, because there’s been such a delay in getting things done to prevent the spread of this virus, we may already be too late to prevent it. We’ll just have to wait and see. But if we’re really aggressive now, we can knock this down to a very low level.

Do you have any other thoughts that you’d like to share?

You know, it’s been so hard dealing with COVID-19 over these two-and-a-half–plus years and now to be dealing with another virus that is spreading pretty quickly, it’s really hard on the general population, certainly hard on me.

I think all of this is a clear statement that we’ve been neglecting the scientific and public health view on what we call the neglected infectious diseases, diseases that are occurring elsewhere in the world. We’re just not paying enough attention to them. We could have controlled monkeypox in central and western Africa, because we had the vaccine for a good while, but we hadn’t bothered to use it.

And this is the price you pay for it. It’s also a commentary on the fact that the United States has been trying to do public health on the cheap for at least three to four decades. We’re paying a dear price for that right now during the COVID-19 pandemic and now dealing with the pandemic with monkeypox. And surely we’re going to be dealing with pandemics going forward.

We’ve been lecturing about the need to fund public health and the need to have a robust public health system for decades. You feel like Cassandra: She sees the future, but nobody will listen to her.


This interview has been edited for clarity and length.