What Is Mpox (Monkeypox)?
Mpox (formerly known as monkeypox) is a viral disease from the same family as smallpox, though its symptoms usually aren't as serious. Scientists have known about it since 1958, when it was found in lab monkeys used for research. Mpox is most common in Central and West Africa. But in May 2022, health officials began reporting an outbreak of the virus in several regions outside Africa.
As of late July 2022, the CDC had confirmed almost 2,900 cases of mpox and a related virus in the U.S. That was up from 35 confirmed cases in early June. The agency had confirmed over 16,800 cases of mpox worldwide as of late July, up from over 1,000 cases reported to the World Health Organization (WHO) in early June.
On July 23, 2022, WHO Director-General Tedros Adhanom Ghebreyesus declared the fast-spreading outbreak to be “a public health emergency of international concern.”
The WHO says an international public health emergency is an “extraordinary event” that poses a serious public health risk. It’s different from a pandemic, like the one caused by the coronavirus. A pandemic is a global outbreak of a virus that infects large numbers of people and causes a high number of deaths, often disrupting daily life and causing general hardship.
Mpox is a zoonotic virus, which means it spreads from animals to humans. In addition to monkeys, it's been found in other primates and certain rodents in Africa. But people can transmit it to each other, too. The first known human infection was in 1970 in the Democratic Republic of Congo.
How Can Mpox Spread?
It can spread from person to person through close contact. Someone who's infected with it can pass it to you through:
- Contact with body fluids like blood or semen
- Contact with mpox lesions on their skin (including inside their nose and mouth)
- Respiratory droplets that you breathe in
- Things that have touched infected body fluids, like bedding or clothing (this happens less often)
During the 2022 global outbreak, mpox spread mainly from person to person, a study in The New England Journal of Medicine suggested. The researchers found that 98% of people who got diagnosed with mpox between late April and late June of 2022 were gay or bisexual men. The researchers suspected that the virus spread through sexual activity in 95% of infected people.
Mpox can also spread from animals to people. Infected animals can pass on the virus if they bite or scratch you. It’s unclear whether dogs and cats can be infected, but the CDC says you should assume that any mammal can catch mpox.
The agency says it’s possible that infected people could spread mpox to their pets through things like:
- Petting
- Cuddling
- Hugging
- Kissing
- Licking
- Sharing sleeping areas
- Sharing food
If you have mpox, stay away from wildlife and pets to avoid spreading it to them. If you have pets, ask someone else to take care of them until you’re fully recovered.
You can also get mpox from eating uncooked contaminated meat.
The virus can get into your body through a break in the skin (which you might not even be aware of) or through your mouth, nose, or eyes. You can breathe it in, but you’d probably have to be in close contact for a fairly long time. That’s because most droplets don’t travel very far.
Mpox isn't technically considered a sexually transmitted infection (STI) since you can get it from other forms of contact. But people infected with mpox can pass it on during sex.
Symptoms of Mpox
It typically takes between 1 and 2 weeks after exposure to get sick from the mpox virus, but it could take as long as 3 weeks.
With the recent outbreak, doctors have noticed a few newer symptoms that don’t quite match the typical description of mpox.
Besides the usual signs, new mpox symptoms may include:
- Painful rash that may start out on your pubic area, genitals, or around your anus
- Fewer bumps (one to two bumps)
- Bumps that look like blisters, pus-filled bumps, or open sores
- Bumps in different stages, even when they’re found around the same area
- Some people may not get a fever or flu-like symptoms before the rash. Some people don’t get a fever at all.
In some cases, people have reported other symptoms such as pain around the anus, the need to poop even though your gut is empty (tenesmus), bleeding in the lower part of large intestine (rectum), and painful inflammation of the anus and rectum lining (proctitis). Doctors have linked these symptoms to the painful bumps in the area.
Experts are not sure what’s causing the shift in symptoms. But research is ongoing. In the meantime, if you notice these symptoms, tell your doctor right away.
Symptoms may also include any of these that were seen in past outbreaks:
- Fever
- Tiredness
- Headache
- Aching muscles
- Chills
- Backache
- Sore throat
- Dry cough
- Swollen lymph nodes
- Trouble breathing (in serious cases)
In previous outbreaks, the following symptoms usually were also seen, and may still be seen now:
- One to 3 days after your fever starts, a rash shows up. It typically starts on your face before spreading to other parts of the body.
- The rash is more common on the hands, feet, arms, and legs. It also tends to follow a particular pattern: Flat, round lesions (macules) grow into slightly raised bumps (papules), then into bumps filled with clear fluid (vesicles).
- People have usually reported anywhere from 10 to 150 bumps on their skin. These then change into bumps with yellowish fluid (pustules) that crust over and fall off. Report any of these symptoms to your doctor right away.
You can spread mpox to others starting a day before the rash shows up. You're contagious for up to 21 days after your first symptoms, or until your lesions have scabbed over and you don't have any other symptoms.
How Serious Is Mpox?
The illness typically runs its course in 2 to 4 weeks. It can be quite serious, especially in children who were exposed to a lot of the virus or in people with other health conditions or weak immune systems.
In some cases, thousands of lesions grow together and cause the loss of large sections of skin at once. Death is rare but possible. In Africa, mpox leads to death in up to 1 of every 10 people who get it. But many people in this region live in areas without adequate medical care. Children are most at risk for serious illness and death.
Possible serious complications from mpox include secondary infections like:
- Encephalitis
- Sepsis
- Bronchopneumonia
- Infection of cornea with possible vision loss
Exposed to Mpox: What to Do
If you think you've been exposed to mpox, call your doctor for instructions. Look out for symptoms for 21 days after your first exposure. You should:
- Check your temperature twice a day.
- If you have chills and swollen lymph nodes but no fever or rash, isolate yourself at home for 24 hours.
- If you get a fever and/or rash, self-isolate right away and contact your local health department.
- If chills and swollen lymph nodes don't go away, call your doctor.
- If you have no symptoms, you can go about your daily routine as usual. But don’t donate blood, cells, tissue, breast milk, semen, or organs while you’re monitoring for symptoms.
Call your vet if you think your pet was exposed to mpox. Don’t surrender or abandon them or have them put to sleep. Don’t wipe or bathe them with chemical disinfectants, alcohol, hydrogen peroxide, or other cleaning products.
Diagnosis
Your doctor will look at your lesions and ask you in detail about your symptoms, such as when you likely came into contact with the virus. They’ll try to rule out similar conditions like:
- Measles
- Chickenpox
- Syphilis
- Allergies
- Scabies
- Bacterial skin infections
A laboratory test can tell whether you have mpox.
Mpox Treatment
There's no specific treatment for mpox. Your doctor will likely help keep you comfortable and try to ward off serious complications with rest, plenty of fluids, and over-the-counter meds.
To control an outbreak, doctors could turn to antivirals and vaccinia gamma globulin (made from the blood of people recently vaccinated against smallpox) as well as the smallpox vaccine.
If you’ve had a recent smallpox vaccine (in the last 3-5 years), you have some protection against mpox. Studies show that the smallpox vaccine is 85% effective at preventing mpox.
The U.S. has two vaccines to prevent smallpox: ACAM2000 and JYNNEOS (Imvamune, Imvanex). In 2019, the FDA also approved JYNNEOS to prevent mpox.
The two vaccines contain live virus. ACAM2000 is given by pricking the skin. A small lesion may form, and the virus can grow on it. (This causes the telltale scar of a smallpox vaccine.) Before it heals, the virus could spread to other parts of body or to other people. If you get this vaccine, take care not to spread the virus while the lesion heals.
You get JYNNEOS in two shots taken 4 weeks apart. With this vaccine, there’s no risk of spreading the virus.
While it’s best to get a vaccine before you're exposed to mpox, getting it afterward may still help prevent the disease or make it less serious. The CDC recommends getting the vaccine within 4 days after exposure to mpox. But even if you get it as long as 14 days after exposure, it could still reduce your mpox symptoms.
If you’ve been exposed to mpox and haven’t had a smallpox vaccine in the last 3 years, experts recommend getting vaccinated as soon as possible.
You could have minor reactions from the smallpox or mpox vaccine, such as:
- Mild fever
- Tiredness
- Swollen glands
- Redness and itching at the vaccination site
Mpox and Pregnancy: What to Know
According to the CDC, if you’re pregnant or breastfeeding, you may be at a higher risk of becoming seriously ill if you catch the infection. There’s limited information on the effects of mpox during pregnancy, but the WHO states that it is possible for a mother to pass the virus to an unborn baby before delivery through placenta. The placenta is the organ that connects the baby to the uterus (the womb).
This can increase the odds of complications, such as:
- Miscarriage
- Stillbirth
There’s no information on whether mpox can increase the risk of birth defects. But fever is one of the main symptoms of mpox. And if you catch the infection during your first trimester, a high fever could increase the chances of certain birth defects.
You can also pass the virus to your newborn baby during or after birth through close contact. However, there’s no evidence on whether you can pass on the virus through breastfeeding.
If you have a confirmed infection, tell your doctor immediately. They’ll need to closely monitor you and your baby until birth. If you’re over 26 weeks pregnant or you feel unwell, your doctor might monitor the baby’s heart every 2-3 days. You may also need regular ultrasounds until your doctor can confirm that the baby is growing well and the placenta is working properly.
Your doctor might recommend a C-section if you have mpox or think you do, to reduce the risk of passing on the infection to the baby during birth. After birth, your baby might be isolated to protect them until there’s no risk of infection.
As for prevention, the JYNNEOS mpox vaccine has not been specifically approved for pregnant women. But a study of 300 pregnant women who got the shot found no side effects or failed pregnancies linked to the vaccine. If you’re pregnant, planning to get pregnant, or breastfeeding, and you’ve been exposed to the mpox virus, talk to your doctor about whether the vaccine is right for you.
Should You Wear Masks?
According to the CDC, if you have mpox, you should wear a surgical mask, especially if you have respiratory issues like cough, shortness of breath, or a sore throat. This can reduce the risk of infection.
If you’re unable to wear a mask, then it’s best if those around you wear a mask to protect themselves.
Can Condoms Help Prevent Infections?
If you or your partner has a mpox rash on your genitals or anus, using condoms alone probably won’t prevent you from spreading or catching mpox during sex.
It’s much safer not to have sex if you think or know you or your partner has the virus. Instead you could have cybersex over the computer or phone, or masturbate at the same time while staying at least 6 feet away from your partner.
If you decide to risk having actual sex, the CDC recommends that you:
- Consider having sex with your clothes on or with your clothes covering body parts with a rash.
- Use condoms.
- Don’t kiss.
- Wash your hands, bedding, towels, clothes, and any sex toys or fetish gear afterward.
How Else Can You Avoid Catching Mpox?
To avoid catching mpox:
- Stay away from animals that might have the virus, especially dead animals in areas where mpox is common.
- Stay away from bedding and other materials that have touched a person with mpox or a sick animal.
- Separate infected persons or animals from others at risk for infection.
- If you have to be close to an animal or person with the virus, wash your hands with soap and water often.
- Use protective gear like masks, safety goggles or glasses, and gloves if you can’t avoid contact.