Physician assistant Susan Eng-Na, right, administers smallpox vaccine to monkeys in a vaccination clinic in New York. New cases are beginning to decline in New York and some other US cities.
Mary Altaffer / AP
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Mary Altaffer / AP
Physician assistant Susan Eng-Na, right, administers smallpox vaccine to monkeys in a vaccination clinic in New York. New cases are beginning to decline in New York and some other US cities.
Mary Altaffer / AP
More than three months after an outbreak of monkeypox in the United States, there’s a new – and welcome – phrase emanating from the lips of health officials who are directing the country’s response: optimism careful.
The change in tone reflects early signs that new infection rates are slowing in some major cities where the virus arrived early and spread quickly, notably New York City, Chicago and San Francisco. Francisco.
Federal officials warn that it is still too early to make a statement about the country’s entering a corner. Still a slowdown in some parts of the US – along with data on how those most at risk are protecting themselves and getting vaccinated – are promising signs.
“Our numbers are still growing, [but] The rate of increase is lower,” Dr Rochelle Walensky, director of the Centers for Disease Control and Prevention, told reporters Friday.
The number of reported cases has been on a downward trend since mid-August, based on NPR analysis of the data CDC released on Wednesday. Overall, the 7-day average of new cases has fallen by about 25% over the past two weeks.
However, health officials warn that delays in data reporting could give an incomplete picture of the outbreak in recent weeks, making it difficult to know if cases have really peaked. point or not.
The decline in parts of the US mirrors what has been seen in some European countries where the virus had been detected weeks earlier. In both the UK and Germany, the number of daily cases has been steadily decreasing since the end of July. In several other countries, including the Netherlands and Italy, the number of new cases has dropped.
Cases slow down in major cities
In New York City – one of the epicenters of the outbreak – the number of new cases has dropped 40% in the past month. San Francisco health officials are also seeing a drop in the rate of new cases.
“I’m cautiously optimistic,” says Dr. Susan Philip, health workers of the city and county of San Francisco. “However, we know it will take a lot of work and effort to maintain that downward curve and ensure that cases continue to go down.”
The picture is also improving in other cities such as Los Angeles, Houston and Chicago, where local health leaders say there are signs that infections are leveling off.
Janna Kerins, chief medical officer at the Chicago Department of Public Health, said key indicators – such as the average number of cases and the time it takes for cases to double – have fallen over the past few weeks. “I’m not sure we’re ready to say this outbreak is really over, but it’s all encouraging,” Kerins said.
Changes also track with model released this week that suggests the nationwide outbreak is decreasing.
“We are seeing signs of a significant slowdown and the forecasts suggest that this will be on track,” at least for the next four weeks, Gerardo Chowell-Puenteprofessor of epidemiology and biostatistics at Georgia State University who is modeling smallpox outbreaks in monkeys
Changes in behavior that lead to decline
Given the size and diversity of the United States, there is still uncertainty about how outbreaks have spread in different parts of the country, but infectious disease experts largely attribute this slowdown to efforts force to change the behavior of gay, bisexual, and other sexually active men. with men – a group that makes up the vast majority of cases.
“Most of us in the public health industry who work with this disease are pretty confident that much of the decline is due to behavior change,” he said. Dr. Jay Varma, director of the Cornell Center for Pandemic Response and Prevention at Weill Cornell Medicine.
More than 94% of monkey pox cases in the US are related to sexual activity. And on Friday, CDC officials highlighted new data showing the gay and gay community is modifying their sexual behavior in response to the message around monkeypox.
In an online surveyabout 50% of respondents said they have reduced “the number of sexual partners, one-time sex sessions [or] using dating apps because of the monkeypox outbreak. ” model study published by the CDC found that “a 40% reduction in one-time sex can delay the spread of monkeypox and reduce the proportion of people infected” by up to about 30%.
“This means that LGBTQIA+ people are doing things that really help reduce their risk,” said Dr. Demetre Daskalakis, deputy coordinator for the smallpox response at the White House. their disease risk and it’s working properly.
It’s not entirely surprising that the virus seems to be slowing down in the US as it is in Europe, say Jeffrey Klausner Drprofessor of medicine and infectious diseases, population science, and public health at the Keck School of Medicine at the University of Southern California.
“According to Klausner, most cities will have a decline — that decline may not be as rapid or as steep as going up.
Klausner notes that monkeypox is mostly in some relatively small sex webs – which makes it harder for the virus to stay motivated as vaccinations increase, humans build up immunity from infection. and those most at risk of changing their behavior.
“Those who raise concerns about the spread of communicable disease on university campuses and daycare and other types of environments where there is close personal contact, at this point in time, are that didn’t happen.
Uncertainty remains
But other experts are not optimistic about the trajectory of the outbreak – at least not yet.
“It’s great to see some drop,” Anne Rimoin, an epidemiologist at UCLA who has been studying smallpox in monkeys for many years. “But if the downward trend is due to changes in behavior and vaccination, it’s not clear how long the behavioral changes can last and how effective vaccination really is to prevent infection.” match.”
Health officials are urging members of affected communities to continue taking precautions to slow the spread of monkeypox.
“Let me be clear,” Daskalakis said Friday. “The tips on how to reduce risk for monkeypox exposure is now, not forever, and is an important part of our public health and community response as we urgently ramp up vaccinations to control this outbreak. “
However, there is no strong actual data on how effectively 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 led the Biden administration to pursue a new strategy of delivering intradermal injections to prolong supply.
“The laboratory data we have on the vaccine shows that the vaccine will be very effective in humans,” Varma said. “But what we do know in medicine is that until we see what happens in the real world, we never know for sure.. ”
Michaeleen Doucleff of NPR contributed to this report.
