CDC warns that mpox cases may increase this spring, summer: 'The outbreak is not over'

The Centers for Disease Control and Prevention is warning U.S. residents about a possible increase in mpox, formerly known as monkeypox, this spring and summer, according to a memo from the health agency.

The increase could come as people ditch their homes in favor of crowded festivals and events, the health agency said Monday.

In fact, the CDC is looking into 12 confirmed mpox cases and one possible case in the Chicago area. The cases were reported between April 17 and May 5 to the Chicago Department of Public Health.

The cases in Chicago were reported by the CDC just days after the World Health Organization said the mpox public health emergency was over.

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What is mpox, formerly known as monkeypox?

Mpox is an uncommon disease that's triggered by an infection from the mpox virus and, in rare cases, can be fatal, the CDC says.

The disease was known as monkeypox, but the World Health Organization renamed it to get rid of the stigma that associated the disease with monkeys. (Monkeys don't spread the virus, but it was first identified in them decades ago, hence the name.)

A global mpox outbreak started in May 2022, and as of May 10, more than 30,000 cases had been reported in the United States. In July 2022, WHO Director-General Tedros Adhanom Ghebreyesus declared an mpox global emergency.

Mpox cases are down but may not stay that way, CDC says

Cases of mpox peaked in August and have dropped since then, but "the outbreak is not over," the CDC said Monday.

In reference to cluster of cases in Chicago, the CDC said all of them were among symptomatic men. None of the people involved were hospitalized.

The CDC also said that among the 13 cases confirmed or probable cases in the Chicago area:

  • Nine out of 13 were among men who had received multiple vaccine doses.

  • Nine were non-Hispanic white men, two were non-Hispanic Black men, and two were Asian men.

  • The median age was 34 (between 24 and 46 years old).

  • Four people had recently traveled to areas including New York City, New Orleans and Mexico.

Experts from Northwestern University Feinberg School of Medicine in Chicago encouraged people in the area to be cautious.

“Clearly, this gives us pause that vaccine immunity may not be lasting long in some patients despite full vaccination,” said Dr. Alexandre Carvalho, an infectious diseases fellow at Northwestern, in a news release. “People will likely let their guards down in this first post-pandemic summer, go out to meet others, have fun. However, with the virus circulating, we must encourage people to take precautions and practice safe sex.”

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What are the symptoms of mpox?

Symptoms include a rash, possibly on the hands, feet, chest, face, mouth and near the genitals, the CDC says on its website. The agency says the mpox incubation period is three to 17 days, and during this period, people won’t have symptoms and may feel OK.

The rash starts off by looking like pimples or blisters and may be itchy and painful. Before the patient heals, the rash will undergo several stages, the CDC said, including scabbing.

Some people also have flu-like symptoms before the rash sets in, the CDC says, while others may develop a rash first and then suffer other symptoms.

According to the CDC, other symptoms include:

  • Fever

  • Chills

  • Swollen lymph nodes

  • Exhaustion

  • Muscle aches and backache

  • Headache

  • Respiratory symptoms such as sore throat, nasal congestion or cough

Patients may experience some symptoms but not all, the agency said.

How long do symptoms last, and how is the disease transmitted?

Once a person develops symptoms, they’re capable of spreading mpox, the CDC said. Spreading can continue until the rash has fully healed.

The CDC also cited new data showing that as of February 2023, some people can spread mpox one to four days before their symptoms begin.

“There is currently no evidence showing that people who never develop symptoms have spread the virus to someone else,” the CDC said.

What should I do if I think I have mpox?

The CDC says people who believe they have the disease or have been in contact with someone who tested positive should contact a doctor. From there, the doctor can determine if they need to be tested.

Until that happens, the CDC recommends avoiding close contact such as sex until they have been seen by a doctor.

For those without health insurance, public health clinics are an option.

What the CDC says about mpox vaccines

The CDC says it does not recommend routine immunization against mpox for the general public and instead urges health care providers to offer it to people at high risk for exposure to the disease.

Those at higher risk include people who were exposed to someone who tested positive or people who have had sexual contact in the past two weeks with someone was diagnosed with mpox.

Licensed Vocational Nurses (LVN) Gabriela Solis (L) and Adrian Gutierrez prepare doses of the Jynneos monkeypox vaccine at an L.A. County vaccination site in East Los Angeles on August 10, 2022 in Los Angeles, California.
Licensed Vocational Nurses (LVN) Gabriela Solis (L) and Adrian Gutierrez prepare doses of the Jynneos monkeypox vaccine at an L.A. County vaccination site in East Los Angeles on August 10, 2022 in Los Angeles, California.

The CDC also says the list of potentially high-risk mpox patients includes gay people, bisexual people, men who have sex with men and transgender or nonbinary people who have been diagnosed with a sexually transmitted disease in the past six months.

People who have sexual contact at commercial sex venues and sex workers are also at risk, the CDC said.

“To help prevent a renewed outbreak during the spring and summer months, CDC is urging clinicians to be on alert for new cases of mpox and to encourage vaccination for people at risk,” the CDC said in its announcement Monday.

“If mpox is suspected, test even if the patient was previously vaccinated or had mpox. Clinicians should also refamiliarize themselves with mpox symptoms, specimen collection, laboratory testing procedures, and treatment options.”

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This article originally appeared on USA TODAY: What is mpox? What to know about symptoms, vaccines, cases