FRIDAY, April 28, 2023 (HealthDay News) – For the first time since the mpox outbreak began last spring, no new cases have been reported in more than a week, fresh government data shows.

At the peak of the outbreak, there were 500 new infections reported daily, but by late last year that number was 16, CDC statistics show.

While the Biden administration ended the public health emergency for the virus that was previously called monkeypox late last year, it’s not clear how much time is required with zero cases to declare the outbreak over, CBS News reported.

And a resurgence is still possible, public health officials have warned.

"If mpox reintroduction occurs and no additional vaccination or sexual behavior adaptations occur, the risk of a resurgent mpox outbreak is greater than 35% in most jurisdictions in the United States," modelers for the U.S. Centers for Disease Control and Prevention reported in April.

Other countries continue to report new cases, while a site in central Virginia that tests wastewater continues to detect the virus in samples. This could be because of unresolved but previously reported infections, CBS News reported.

"The most recently reported case of mpox in the Central Region of Virginia occurred in November 2022," Cheryle Rodriguez, a spokesperson for the state's health department, told CBS News.

The reason for the slowed case numbers may because people have died or developed immunity from infections. Other reasons may include changes in behavior and availability of a vaccine called Jynneos.

The virus typically has been seen in men who have sex with men during the outbreak. Deaths have disproportionately been among Black men, CBS News reported. About 87% of deaths were in Black men, many of whom had advanced HIV, the CDC reported.

"Infection-induced immunity of the individuals at the core of the sexual network generated 'network immunity,' which halted the epidemic," Dr. Christophe Van Dijck, of the Institute of Tropical Medicine in Belgium, suggested earlier this month during the European Congress of Clinical Microbiology and Infectious Diseases, CBS News reported.

"An alternate explanation could be that countries with vaccination also mounted more aggressive responses overall, with strong campaigns to change behavior and raise awareness," the CDC's Andrea Stewart said recently during the Epidemic Intelligence Service conference, CBS News reported.

"Countries that experienced more aggressive outbreaks early may have been more likely to implement vaccine campaigns early as well. Their outbreaks could have declined quickly due to population dynamics," Stewart said.

Since the outbreak began last May, more than 30,000 people have been infected with the virus, which causes painful lesions, and 42 people have died, according to CDC data.

More information

The World Health Organization has more on mpox.

SOURCE: CBS News