What Is Monkeypox? The New Viral Infection in the United States

Monkeypox is the latest viral infection on the public health radar. However, it’s a lot different than COVID-19. Rash, not respiratory illness, is the key monkeypox symptom. Monkeypox is not nearly as widespread or lethal as COVID-19, and it isn’t new. As of early August, over 7,000 cases have been reported in the U.S. — out of the more than 28,000 confirmed cases globally.

Vaccines already exist and are currently being recommended by the Centers for Disease Control and Prevention for anyone who has been exposed to the virus and for people who are more likely to contract the virus.

Health experts are increasingly concerned about the monkeypox virus. Globally, the appearance of monkeypox in 81 countries where the virus doesn’t typically circulate has caused the World Health Organization Director-General Dr. Tedros Adhanom Gehebreyesus to declare monkeypox to be a “public health emergency of international concern.”

In his July 23 statement, Gehebreyesus warned that the virus has “spread around the world rapidly, through new modes of transmission, about which we understand too little.”

Following that announcement by the WHO, U.S. Department of Health and Human Services Secretary Xavier Becerra declared the spread of the monkeypox virus to be a public health emergency on August 4. Becerra called ending the outbreak a “critical priority,” and this declaration is intended in part to help bolster vaccine production and access.

High rates of transmission in New York, California and Illinois have also caused those states’ governors to declare public health emergencies. Governor Jay Robert Pritzker of Illinois noted in his emergency declaration that the current disease situation “requires the full mobilization of all available public health resources to prevent the spread.”

[SEE: How to Describe Medical Symptoms to Your Doctor.]

Monkeypox Symptoms

After someone is infected with monkeypox, the incubation period lasts 7 to 14 days on average, but can range from 5 to 21 days, according to the CDC. The person is not contagious and doesn’t have any symptoms during this time.

For monkeypox in humans, symptoms tend to follow a pattern. “In the classic presentation of monkeypox, people just start off not feeling well,” says Dr. Bobbi Pritt, governor of the College of American Pathologists. “And then they develop a fever. Interestingly, they also have swollen lymph nodes. Then the rash comes out.”

The early onset of symptoms, or prodrome, for monkeypox is usually pretty consistent, says Pritt, who is also a professor of laboratory medicine and pathology and chair of clinical microbiology at the Mayo Clinic in Rochester, Minnesota. “Although in this current outbreak, there have been some people who just got the rash,” she notes.

Monkeypox Rash

The monkeypox rash has these features, Pritt explains:

— Numerous lesions appear mostly on the arms, legs and head, and less so on the abdomen.

— The rash starts as little red spots that are flat on the skin, or macules.

— Next, these spots begin to swell and become hard, solid papules.

— These papules then fill with clear liquid, entering the vesicle stage.

— That fluid turns cloudy and turns into pus — at this point, the lesions are called pustules.

— Lesions eventually scab and dry up, and then the crust falls off.

— “At this point, that’s the end of the rash,” Pritt says. “That person is no longer infectious.”

Once the rash appears, the process takes about one week to two weeks for pustules to crust and scab over, according to the CDC. Scabs then remain another week or so before beginning to fall off, and once they all have, a person is no longer contagious.

Another monkeypox feature: “Lesions tend to be the same across the whole body,” Pritt says, unlike chickenpox, where different rash stages can appear on the body at the same time.

[See: Ways to Boost Your Immune System.]

How Monkeypox Spreads

Today, it’s almost impossible to avoid making COVID-19 comparisons when a viral infection crops up. But the scope, danger and spread of COVID-19 and monkeypox are quite different.

“Our previous experience with monkeypox has demonstrated that it is less transmissible than the current variants of the COVID-19 virus circulating,” says Amira Roess, a professor of global health and epidemiology in the College of Health and Human Services at George Mason University in Fairfax, Virginia. “But it is transmissible through close contact with infected individuals. A large number of individuals involved in the current outbreak were exposed to sexual partners who were infected.”

Men who have sex with men have been among those infected with monkeypox in the current U.S. outbreak. However, monkeypox is not a sexually transmitted infection in the strict sense of the definition, Roess says. “For an infection to be sexually transmitted, we expect that the infectious virus would be transmitted through semen and vaginal fluids,” she explains. “So far, we have not detected virus in these fluids — but we also have severely understudied this topic.”

Close contact of any kind could potentially transmit monkeypox.

“There have been cases in men who have sex with men,” Pritt says. “But other forms of sexual contact between a man and a woman could also spread the infection. Close contact with any lesions in the rash of monkeypox can also spread the disease — so it can be nonsexual in origin. Close contact of any sort, and respiratory secretions. Those are the primary ways that the virus spreads.”

Additionally, the CDC warns that monkeypox can be spread through contact with shared objects or shared surfaces. Avoid touching any unsanitized clothing, bedding, towels or other surfaces that an infected person has used to reduce your risk of contracting the virus.

[Read: Infectious Disease Nurse: COVID-19 in Some Ways Scarier Than Ebola.]

Monkeypox Origins

Monkeypox was originally discovered in laboratory monkeys. “We’ve dealt with numerous monkeypox outbreaks over the last few decades since the monkeypox virus was first identified in the late 1950s,” Roess says. Among animals, monkeypox is seen in monkeys, apes, rabbits and several types of rodents, including rats, mice and squirrels, and can spread from animal to animal. Among humans, monkeypox is currently endemic in certain parts of Africa.

Monkeypox is classified as a zoonotic virus, which means it’s typically transmitted from animals to humans through close contact — such as a bite, scratch, direct contact with the rash or with material like clothing or linens contaminated from monkeypox lesions — according to an article published online on May 27 in the medical journal JAMA.

The disease was first identified in humans in 1970. Contact through lesion substances or respiratory droplets is thought to be the main way that monkeypox is transmitted from person to person.

“When we saw outbreaks in West and Central Africa, and in the U.S., in 2003, what often happened was that an individual became exposed to monkeypox from handling an infected animal and then became infected themselves,” Roess says. “The infected individual went on to infect household members through close contact and even health care workers who were caring for them. We are seeing something similar now in many countries.”

In the U.S., sporadic monkeypox cases aren’t new, Pritt points out. “It’s not that cases don’t ever occur, but usually you can trace the person who has the infection to West or Central Africa, where it’s really endemic,” she says. “Usually, the isolated cases that we see in the United States are in people with direct travel exposure. That’s what makes what we’re calling this current outbreak unique — because these are people who haven’t traveled to Africa.”

U.S. Monkeypox Outbreak

The CDC is actively tracking cases in the U.S. as the numbers continue to rise and is urging health care providers to be aware of patients who present with monkeypox symptoms. “At this point, the most important aspect is just awareness in case someone does develop signs or symptoms consistent with monkeypox,” Pritt says.

“Thankfully, the specific strain that is circulating right now is the West African strain,” Pritt says. “It’s the milder of the two strains that have been identified.” As of August 8, the WHO is reporting 12 deaths globally, with none occurring in the U.S..

At the same time, as of August 5th, the CDC reports 7,510 confirmed monkeypox cases in the U.S., with New York, California and Florida having the highest total case counts.

Pinpointing Monkeypox Cases

If you think it’s even remotely possible that you could have monkeypox, don’t hesitate to speak up. “It’s important for the United States to identify the cases so people can be isolated and prevent the spread of infection,” Pritt says. “So, if anyone has symptoms that may be suggestive of monkeypox they should go to their physician. And the physician should contact the CDC, so they can safely collect a specimen from the patient and send it to the CDC for testing.” (You should call to alert your doctor’s office in advance that you suspect you might be infected.)

Most U.S. testing for monkeypox is being performed at the CDC, Pritt notes. “But there are also some larger laboratories that are developing their own tests,” she adds. “So I think within the next few weeks we will see other laboratories offering testing.” As of this week, commercial labs are now testing as well.

Roess also emphasizes the importance of tracing monkeypox cases. “Right now we need to prioritize tracing as far back as possible for potential and actual cases so that we can vaccinate their close contacts, health care workers who interacted with them and possibly close contacts of health care workers,” Roess says. “We are very lucky to have a durable and effective vaccine in this case.”

Medical Follow-Up

Should testing confirm that you actually have monkeypox, you would need to be followed by specialists. “An infectious disease physician would be the best suited,” Pritt says. “It’s fine to start with your primary care physician — that’s the person who the patient has access to in the health care system. But very quickly there would be a team of people brought in, including those focused on infection prevention.” The infectious disease physician would likely be part of the team administering your care, she adds.

For those who develop monkeypox, the majority will do well on their own and won’t need any specific treatment, Pritt says. Most people will get better in two to four weeks or so, she says, and their illness will completely resolve, although they may be left with scars from the rash.

However, for those who might be considered at high risk — like people who are immunocompromised — treatment might be indicated, such as off-label use of drugs that have been used to treat monkeypox in other countries, she notes.

Monkeypox Vaccine and Treatment

Two FDA-approved vaccines are available in the U.S., although in limited supply. Vaccine doses are recommended for people who have been exposed to monkeypox, as well as people who are at a higher risk of contracting the virus. A recently developed vaccine for monkeypox is available for people at high risk of occupational exposure to a group of viruses called orthopoxviruses.

High-risk individuals include: people identified as a contact of someone with monkeypox, people who are aware that one of their sexual partners in the past two weeks has been diagnosed and people who have had multiple sexual partners in the past two weeks in an area with known monkeypox.

Additionally, the CDC recommends vaccination for people at high risk of occupational exposure to a group of viruses called orthopoxviruses. For instance, some laboratory workers, health care workers or military personnel in certain parts of the world may risk close exposure to animals or people infected with monkeypox.

The two FDA-approved vaccines are called JYNNEOS and ACAM2000, both of which are live virus vaccines. JYNNEOS was licensed by the Food and Drug Administration in 2019 to prevent smallpox or monkeypox disease in adults ages 18 and older, as an alternative to ACAM2000, which was already in use. (Routine smallpox vaccination in the U.S. was discontinued in 1972 and the disease is considered eradicated.)

While it’s unclear exactly how effective these vaccines are in preventing the disease, receiving the vaccine within four days after exposure to the monkeypox virus may prevent disease onset, and vaccination between 4 and 14 days after exposure may still reduce symptoms.

“Smallpox and monkeypox are related and the smallpox vaccine gives us a very strong and lasting immunity against monkeypox,” Roess says. “That is very good news (and) there are medications that help with some of the symptoms of monkeypox once a person is infected.”

Tecovirimat (Tpoxx) is the only antiviral drug currently approved by the FDA to treat monkeypox specifically. Given as pills or intravenously, tecovirimat is made by SIGA Technologies, a New York-based pharmaceutical company.

Public Health Implications

For now, monkeypox awareness is the primary public health message. “Our previous experience suggests that because monkeypox is less transmissible than COVID-19, that it will not be necessary to impose stay-at-home orders or restrict movement at the scale we have seen,” Roess says. “What can change all of this is if we find that we are now dealing with a more transmissible strain or a more virulent strain of monkeypox than what we have dealt with previously.”

Monkeypox infection is extremely rare, Pritt emphasizes. “It’s easy to get excited about these things; it’s this exotic virus coming over from Africa,” Pritt says. “People just need to be aware of this and if they are to develop a rash that meets this description, they should go to their physician. That’s going to be essential for containing the outbreak, and identifying cases and keeping infected people away from others so it doesn’t spread.”

More from U.S. News

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What Is Monkeypox? The New Viral Infection in the United States originally appeared on usnews.com

Update 08/11/22: This story was published at an earlier date and has been updated with new information.

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