A promising drop in new MPX cases in Los Angeles County is likely the result of vaccination efforts, behavioral changes in those at higher risk and a growing natural immunity for survivors, officials said.
The country’s most populous county publicly reported just 53 new cases of the disease for the seven-day period that ended Thursday. At the apparent peak of the outbreak, August 19-25, 313 cases were publicly reported.
A similar trend can be seen when looking at cases by episode date — a slower but more accurate process that tracks infections based on when someone first tested positive for MPX or experienced symptoms. Using this method, LA County peaked at about 288 weekly cases in the seven days ended Aug. 20, compared to 62 weekly cases observed at the end of September.
“We continue to be encouraged that we continue to see this steady decline in cases in LA County,” said Dr. Rita Singhal, senior medical director for the Los Angeles County Department of Health, during a briefing Thursday.
Similar trends can be observed elsewhere. In mid-September, California was seeing about 260 weekly cases, down from a peak of about 680. San Francisco had nine weekly cases through late September, after peaking at 145 in late July.
Citing a recent report from the US Centers for Disease Control and Prevention, Singhal said likely factors contributing to the slowing down of new infections include vaccination, a reduction in risky behavior “and possibly infection-acquired immunity in networks.” with high transmission” of monkeypox.”
MPX, as California health officials refer to the disease because of widespread concerns that its original name is stigmatizing and racist, behaves very differently from COVID-19. In the latter, it is possible to become reinfected – sometimes within weeks – and hyperinfectious variants can easily become airborne.
But in the current MPX outbreak, the virus was much less transmissible and generally requires close skin-to-skin contact to spread. And scientists suspect MPX survivors might have long-lasting immunity after infection.
Amid widespread concerns that the name “monkeypox” is racist and stigmatizing, the World Health Organization and other public health agencies have pledged to find a replacement. The Times will refer to it as MPX, used by the California Department of Health and Human Services.
“When that immunity builds up on certain networks, it reduces the risk of transmission. You won’t have as many people for the virus to get to then,” Singhal said.
dr Peter Chin-Hong, an infectious disease specialist at UC San Francisco, said the number of patients with MPX in the hospital has “dropped drastically” since the summer. The number of people seeking Tpoxx, an antiviral treatment for severe MPX cases, has also fallen — from about 15 a week to just one or two, he said.
According to the state Department of Public Health, nearly 200 people across California have been hospitalized for MPX at some point, but fewer than 30% of those have emerged in the last month.
California has reported just over 5,000 probable and confirmed cases, the most of any state, since the outbreak began.
LA County has more cases than any other county, with 2,213 as of Thursday. San Francisco is second with 813, followed by San Diego County with 421; Riverside County, 296; and Alameda County, 238.
But taking population into account, San Francisco was the hardest-hit of California counties, with a cumulative per capita rate of 93 MPX cases per 100,000 people. LA County is second with 22 cases per 100,000 people; and San Diego, Riverside, and Alameda counties have comparable rates between 12 and 14.
Forty-one of California’s 58 counties have reported at least one MPX case, state data shows.
Cases of this outbreak have spread primarily among gay and bisexual men and some transgender people, but anyone, regardless of gender or sexual identity, can contract the virus. Although MPX is not considered a sexually transmitted disease, it is most easily spread through close skin contact, which may include sex.
In LA County, 96% of the cases were males. According to the district, 90% of people whose sexual orientation is known describe themselves as gay or bisexual.
Of the nearly 3,800 California MPX cases for which information is available, the vast majority — about 95% — were not hospitalized during their illness, according to the California Department of Health.
However, the disease can have serious health consequences. Authorities in Ohio recently reported one death from MPX, the second confirmed such death nationwide. The first was reported in LA County in mid-September.
Another death – of a severely immunocompromised adult who had been diagnosed with MPX – was reported in Texas in late August. But officials didn’t say definitively at the time whether this death was caused by the disease.
“This latest death is an important reminder that while most people with monkeypox have had mild to moderate illness, some people can develop severe illness,” Singhal said. “Given this risk, immunocompromised individuals with monkeypox should seek medical attention and treatment early and be cared for by a provider throughout the course of the disease.”
Chin-Hong said the number of hospital admissions or people seeking treatment doesn’t necessarily reflect the full viral landscape as MPX is now disproportionately hitting black and low-income communities in both the Bay Area and LA
By the beginning of the summer, MPX cases were particularly prominent among white residents in LA County. But case numbers among black residents rose to levels significantly higher than among white residents. By late summer, MPX case rates among Latino residents exceeded those of white residents.
Case numbers for these three racial or ethnic groups have all declined, but the rate for Black residents has been significantly higher than that for White or Hispanic residents throughout most of this outbreak, Singhal said.
“At its peak, the case rate among African-American residents was nearly twice the peak rate among white residents,” she said.
Nonetheless, trends are showing a sure sign of improvement. Case numbers for black residents peaked around the same time as for Hispanic residents — around late August — and declined at the same pace as other groups, Singhal said.
“I think we shouldn’t be fooled into thinking that it’s necessarily gone, but it’s a lot better than it was,” Chin-Hong said. “We have to keep the energy up”
He said he would like to see more funding, outreach and education around the virus, which he doesn’t expect will go away completely. But he said those who have already had MPX and have recovered should rely on their immunity, which he expects will be “for life, if not for a long time”.
“Maybe we’ll see some torches at some point because they’re still in the background,” Chin-Hong said. “We’ve probably resigned ourselves to always thinking about MPX.”
Another area of concern is obtaining vaccines for higher-risk people of color. Although black residents have the highest case rate, white residents remain the racial or ethnic group most likely to have received a vaccine.
Because the MPX outbreak is global — and LA County regularly welcomes visitors from around the world — “even if we shut down local transmission, there’s still likely to be an impact from cases coming in from outside as well,” Singhal said.
“I think that risk will always be there, at least for a few months if not longer. And so I think we’re in it for the longer term,” she said, adding that it’s important to continue educating residents about vaccinations and other measures that can prevent transmission of MPX.
But even if MPX continues to circulate to some extent, Singhal said, “We hope it will be a very low number of cases and will not spike again.”
https://www.latimes.com/california/story/2022-10-07/mpx-cases-decline-los-angeles MPX cases falling dramatically in California. Is the outbreak ending?