Mpox (monkeypox) 101: Insights for cancer patients and caregivers

Last updated Dec. 1, 2022.

If you’ve seen the headlines about mpox (formerly called monkeypox) and are wondering if you need to be concerned, you’re not alone. 

To learn more about this contagious disease, we went to Chief Infection Control Officer Roy Chemaly, M.D. Here’s what he wants cancer patients and their caregivers to know about mpox, which the World Health Organization (WHO) has declared a global health emergency and the United States has declared a public health emergency. 

What is mpox (formerly called monkeypox)? 

It’s a virus that belongs to the same family of viruses as smallpox. It was discovered in 1958 in colonies of monkeys kept for research. However, the source of the disease remains unknown. The first documented infection of a human with monkeypox was in 1970.

How is mpox transmitted? Do you have to be bitten by an animal?

No. People can get mpox through close contact with an infected animal or animal products. But this year’s outbreak is primarily spreading through direct contact with a person who’s infected. 

That could mean either intimate sexual contact or exposure to bodily fluids. The lesions that are hallmarks of this disease initially appear as a skin rash, and their contents can also contaminate bedding, clothing and upholstery.

There’s some evidence that mpox may also be spread through droplet transmission, but right now, we believe it’s rarely airborne.

Where has this virus been found? 

Thanks to global travel, mpox cases have now been confirmed on almost every continent. There are cases across the United States, which is why it has been declared a public health emergency.

What are the symptoms of mpox (formerly called monkeypox)? 

In the early stages of the disease, people may have:

• fever 
• chills 
• fatigue 
• muscle aches 
• oral lesions 

A few days later, they usually develop a painful, itchy rash that turns into open skin lesions or pus-filled blisters that burst. Sometimes, people experience the rash first, or only a rash and no other symptoms.

Mpox can be confused with the rashes caused by herpes, syphilis, and varicella. It’s also possible that someone is infected with both mpox and a sexually transmitted disease. During this recent outbreak, isolated areas of rash involvement have been observed in the genital, peri-genital, peri-anal, oral and palm areas.

How long do people remain contagious with mpox?

People are most contagious when the rash is active, and they remain so until the open lesions have resolved, the scabs have fallen off, and a fresh layer of intact skin has formed.

So, if you think you’ve been exposed to mpox, monitor yourself for symptoms for 21 days. 

And, if you think you’ve been infected with mpox, isolate yourself immediately and contact your doctor and local health department for guidance.

What should cancer patients know about the mpox vaccine?

Until 2019, there was no vaccine specific to mpox (formerly called monkeypox). But the Food and Drug Administration (FDA) approved one that year called Jynneos. It was designed to prevent both smallpox and mpox. The U.S. government will begin distributing supplies of it to states soon, for use in adults age 18 and older who’ve been exposed to mpox. Priority will be given to high-risk groups, such as gay and bisexual men.

An older smallpox vaccine called ACAM2000 may offer some cross-protection, because the viruses are related. But it’s not available to the general public, and it can have some pretty harsh side effects. So, we wouldn’t recommend it. In the U.S., it’s typically only provided to military personnel and people who may be exposed to it through laboratory work, like by handling cultures infected with pox viruses. 

Talk to your care team if you think you might be eligible to receive the Jynneos vaccine.

Are there any special precautions cancer patients or other immunocompromised people should take to avoid catching or spreading mpox? 

Avoid direct contact with anyone who has an unexplained rash. Wash your hands frequently, and, if possible, avoid going to countries with a high level of transmission.

If you develop an unexplained rash, don’t feel well, and had close or intimate in-person contact with someone with a similar rash or suspected of having mpox, assume you have monkeypox, isolate yourself and contact your doctor for guidance.

What should cancer patients do if they think they’ve been exposed to or infected with mpox? 

Contact your care team for guidance on next steps. Most people recover without any long-term problems. But no one knows yet how cancer patients or immunocompromised people are going to react, or what kinds of complications they might have.

Unless it's an emergency, you should not come directly to the hospital without warning if you believe you may be infectious.

What’s the one thing you want people to know right now about mpox? 

We’re taking steps to educate our frontline workers health care workers on when to suspect monkeypox and what to do if they encounter it.

Request an appointment at MD Anderson online or by calling 1-877-632-6789.