Rise in mpox cases in Chicago raises concerns of possible summer spread

A recent spike in mpox diagnoses in Chicago, including some in people vaccinated against the virus, has raised concerns about a possible spike in cases among gay and bisexual men over the summer.

On Monday, Howard Brown Health, an LGBTQ-focused clinic in Chicago, reported eight new cases of mpox, formerly known as monkeypox, since April 17. By comparison, only one case, also diagnosed in Howard Brown, was reported to the Chicago Public Health Department in the previous three months.

Public health experts have expressed measured concern that, as with other cases of infections transmitted through sexual contact, mpox cases could increase during the summer, especially as gay and bisexual men go to Pride parties and other major LGBTQ events.

“Without renewed vaccination and prevention efforts, we risk a resurgence of mpox,” said Dr. Demetre Daskalakis, deputy White House national mpox response coordinator. “The vaccine is a really important tool, even if it’s not perfect.”

Diagnosed cases have “increased slightly” in eight countries over the past three weeks, including France and several countries in East Asia, said Dr Rosamund Lewis, technical manager of mpox at the World Health Organization. health. About half of recent French cases have been in vaccinated people.

Otherwise, number of cases worldwide have continued to decline since the peak in early August. Since mid-April, Lewis said, only 21 of the 111 countries that reported cases during the outbreak have reported new diagnoses. However, many cases may go undetected, she said.

The weekly rate of mpox cases in Chicago is the highest since early November. According Data from the Centers for Disease Control and Preventionwhich is updated every two weeks, the United States has had a seven-day rolling average of no more than 17 diagnoses since mid-February.

The Howard Brown Clinic is analyzing new cases to determine if they are part of a cluster of related infections.

Mpox vaccination rates are insufficient

Seven of the eight newly diagnosed patients were gay or bisexual men, said Dr. Leanna Gordon, medical director of preventive medicine at Howard Brown. One person was unvaccinated, one had received one dose of the two-dose Jynneos vaccine and six were fully vaccinated.

All eight cases were mild, with none requiring treatment for pain. Even with a breakthrough infection, the vaccine is still likely to reduce the severity of an infection, Gordon said.

Gordon stressed the importance of people at substantial risk of mpox receiving both doses of the Jynneos vaccine to protect themselves and their sexual partners.

“One of our main concerns is that our at-risk population is under-vaccinated,” Gordon said. “We haven’t had as much interest in the vaccine as we would like.”

According to the CDC, more than 1.2 million doses of the Jynneos vaccine have been administered across the country to 725,000 people, 90% of them men. The agency estimates that only 1 in 4 of those most at risk, including gay and bisexual men and transgender people, have been fully vaccinated.

Two doses of the Jynneos vaccine reduced the risk of mpox disease by 69%, and that one dose was 37% effective, the The CDC reported in December. Updated figures are expected next week.

Public health experts have expressed concern that mpox could spread more widely across the country after Chicago hosted the Mr. Leather International Festival, a popular destination for gay men, at the end of the month.

Daskalakis said the CDC is working with Howard Brown and other local partners to leverage the event to promote mpox prevention and awareness.

Dr Jeffrey Klausner, an infectious disease physician at the University of Southern California, said: “We need to maintain vigilance and promote and provide free vaccination.”

Symptoms of mpox

Mpox, which has an incubation period of around three to 17 days, usually manifests such as rash and lesions. Other potential symptoms include:

• Fever.
• Chills.
• Swollen lymph nodes.
• Exhaustion.
• Muscle aches.
• Headache.
• Sore throat.

In France, the national health authorities recently reported that of the 19 diagnoses this year until April 3 in the Centre-Val de Loire region, 16 were made after March 1 and all but one concerned men who have sex with men. Ten of the cases were in fully vaccinated people: six who had received two doses of the Jynneos vaccine and four who had received the smallpox vaccine as children and a recent dose of Jynneos.

Could the mpox return this summer?

Last summer mpox outbreak decreased following a combination of vaccination, immunity after infection, and behavior change in gay and bisexual men.

Infectious disease experts believe that existing immunity from previous infection and vaccination would likely prevent mpox from spreading at the same level as last year.

But questions remain about the duration of immunity and whether homosexuals, many of whom have reported reducing their number of sexual partners or even practicing abstinence last summer, returned to their basic behavioral patterns after the dramatic decrease in mpox cases.

“Everyone’s efforts have helped control the outbreak, but it hasn’t gone away,” Lewis said. She noted that there is evidence that mpox can be spread both before symptoms start and by people who never develop symptoms.

Dr. Marc C. Shamier, resident in clinical microbiology at University Medical Center Rotterdam in the Netherlands, reported that in September around 45% of gay and bi men who attended sexual health centers in Rotterdam and Amsterdam had antibodies. detectable against orthopoxviruses, the family to which mpox belongs.

“However,” Shamier said in an email, “this level of immunity is not sufficient to completely stop viral circulation, so sporadic clusters of monkeypox are to be expected.”

Shamier continued: “Large-scale events such as annual Pride parties could increase the number of sexual contacts among the risk group, which could lead to increased viral circulation and infections.”

With testing, case isolation and higher levels of mpox immunity among at-risk groups, Shamier expects case numbers to be relatively low compared to last year.

Daskalakis said the recent cases in Chicago amounted to “a call for action as opposed to a call for panic.”

“We have the tools to deal with it,” he said. “We just have to do it.”