Mary Altaffer / AP
More than three months into the US monkeypox outbreak, there’s a new and welcome phrase coming from the lips of health officials who are spearheading the country’s response: cautious optimism.
The change in tone reflects early signs that the rate of new infections is slowing in some major cities where the virus arrived and spread rapidly, particularly in New York City, Chicago and San Francisco.
Federal officials have warned that it is too early to make announcements about the length and breadth of the country. Still a slowdown in parts of the US – coupled with data about how those most at risk are protecting themselves and getting vaccinated – are promising signs.
“Our numbers are still increasing, [but] “The rate of growth is low,” Dr. Rochelle Valensky, director of the Centers for Disease Control and Prevention, told reporters on Friday. “We’re really hopeful that many of our harm reduction messages and our vaccines are out there and working.”
Based on the NPR analysis of the data, the number of cases reported since mid-August is decreasing CDC released on Wednesday, Overall, the 7-day average of new cases has dropped by about 25% in the past two weeks.
However, health officials caution that lag in data reporting may present an incomplete picture of outbreaks in recent weeks, making it difficult to know whether cases have really peaked.
The decline in parts of the US is already being seen in some European countries, where the virus was first detected a few weeks ago. In both the UK and Germany, there has been a steady decline in the number of daily cases since the end of July. The number of new cases has decreased in many other countries, including the Netherlands and Italy.
Slow pace of cases in big cities
In New York City – one of the epicenters of the outbreak – the number of new people being infected has dropped by 40% in the past month. San Francisco health officials are also seeing a drop in the rate of new cases.
“I am cautiously optimistic,” says Dr. Susan Phillip, health officer for the City and County of San Francisco. “We know, however, that it is going to take a lot of work and effort to maintain that downward curve and ensure that cases continue to decline.”
Janna Kerins, medical director of the Chicago Department of Public Health, says key metrics — such as the average number of cases and the time it takes for cases to double — have decreased over the past few weeks. “I’m not sure we’re ready to say that this outbreak is really ending,” Kerins says, “but all those things are encouraging.”
Changes also track with Modeling released this week This suggests that the national outbreak is declining.
“We are seeing a substantial bearish sign and forecasts suggest that it is going to move in the right direction,” at least in the next four weeks, he says. Gerardo Chovel-Puenteprofessor of epidemiology and biostatistics at Georgia State University modeling monkeypox outbreaks
a change in behavior leads to a decline
Given the size and diversity of the US, there is still considerable uncertainty about how outbreaks will unfold in different parts of the country, but infectious disease experts are broadly concerned with changing the behavior of gay, bisexual and other men who have sex. He attributes the slowdown to the efforts. Along with men – a group that accounts for the majority of cases.
“Most of us in public health who work on this disease are pretty confident that the majority of the deficit is due to behavioral changes,” says Dr. Jai Verma Director of the Cornell Center for Epidemic Prevention and Response at Weill Cornell Medicine,
More than 94% of monkeypox cases in the US are linked to sexual activity. And on Friday, CDC officials highlighted new data showing the gay and lesbian community is modifying their sexual behavior in response to the messaging around monkeypox.
In an online surveyNearly 50% of respondents said they had reduced “their number of sexual partners, one-time sexual encounters” [or] Use of dating apps due to monkeypox outbreak. modeling studies The release by the CDC showed that “a 40% reduction in outright sexual partnerships can delay the spread of monkeypox and reduce the percentage of people infected” by about 30%.
“It means that LGBTQIA+ people are doing things that are actually reducing their risk, and it’s working,” White House monkeypox response deputy coordinator Dr. Demetre Daskalakis said in a press briefing Friday. .
It’s not entirely surprising that the virus is slowing in the US as it is in Europe, says Dr. Jeffrey KlausnerProfessor of Medicine and Infectious Diseases, Population and Public Health Sciences at the Keck School of Medicine at the University of Southern California.
,Most cities will see a drop in cases – the decline may not be as steep or as steep as the climb,” Klausner says.
Klausner notes that monkeypox has mostly resided within a few relatively small sexual networks — making it harder for the virus to keep pace as vaccinations increase, people build up immunity to infection and those most at risk change their behavior. Huh.
“Those who expressed concern about the spread of infection on college campuses and daycare and other types of settings where there is close personal contact to the point, this has not happened,” he says.
But other experts are not as optimistic about the trajectory of the outbreak – at least not yet.
“It’s great to see some declines,” says anne rimon, an epidemiologist at UCLA who has studied monkeypox for years. “But if the downward trend is due to changes in behavior and vaccination, it is not clear how long the behavioral change can be maintained, and how well vaccination actually works to prevent infection.”
Health officials are urging members of affected communities to take precautions to slow the spread of monkeypox.
“Let me be clear,” Daskalakis said on Friday. “The Advice on how to reduce risk The risk of monkeypox is for now, not forever, and is an important part of our public health and community response as we urgently increase vaccination to control this outbreak.”
Still, there is no real world data on how well the monkeypox vaccine, approved by the Food and Drug Administration in 2019, protects against infection and transmission. Further complicating the picture is that vaccine shortages have prompted the Biden administration to pursue a new strategy of offering shots intravenously to bolster supplies.
“The laboratory data we have on the vaccine shows that it’s going to be very effective in humans,” says Verma. “But what we do know in medicine is that we never know for sure until we see what happens in the real world.,
NPR’s Micheline Doukleff contributed to this report.