For the first time since the first US cases were reported last year, the US has not recorded any new cases of smallpox for more than a week, according to the Numbers Published Wednesday by the Centers for Disease Control and Prevention.
This achievement comes after cases of smallpox, which were previously called Monkeypoxlast year, after a summer peak of about 500 infections per day across the country.
It is unclear how many weeks new cases do not need to appear before an outbreak can be officially declared in the United States. Biden administration he moved Late last year to end the public health emergency it declared for smallpox, when it was averaging 16 cases per day.
A CDC spokesperson did not immediately respond to a request for comment.
Mpox has resulted in painful lesions that last for weeks for most people infected with the virus. More than 30,000 cases and 42 deaths of smallpox have been found registered by the CDC since the outbreak began in May 2022.
Mpox cases have been largely among men who have sex with men. Severe cases disproportionately affected communities of color: 87% of deaths were in black men, the CDC reports. during MarchMany immunocompromised patients with advanced HIV.
Why have smallpox cases slowed?
Scientists said so-called “network immunity” may have helped end smallpox outbreaks, in which people die or develop immunity from infection through the sexual networks that first spread the virus.
put the theory d. Christophe van Dijk of the Institute of Tropical Medicine in Belgium: earlier this monthin a statement discussing the research presented at the European Congress of Clinical Microbiology and Infectious Diseases.
Authorities previously attributed the slowdown to other factors as well, such as changes in behaviour or put up Jynneos vaccinationsand he estimated to curb infections.
However, officials also admitted that these did not explain the whole story. Behavioral changes have not been uniform, and cases have declined even in countries without any vaccines.
Center for Disease Control analysis Presented at the agency’s Epidemic Intelligence Service conference this week, it found that transmission of smallpox “was slightly reduced” after cases peaked in several middle- and high-income countries that rolled out vaccines, compared to those that did not.
This difference was statistically significant, though they cautioned that more data was needed to confirm “causation about the effect of vaccination campaigns” on the outbreak.
“An alternative explanation could be that countries that got vaccinated also mounted more aggressive responses in general, with aggressive campaigns to change behavior and raise awareness,” CDC’s Andrea Stewart told the conference.
Stewart said others at the CDC are working on “more advanced modeling” that might also control for whether the pace of case inflation early in an outbreak affected how infections slowed later.
“Countries that experienced more aggressive outbreaks early on may have been more likely to implement vaccine campaigns earlier as well. Their outbreaks could have declined rapidly due to population dynamics,” Stewart said.
Danger of a resurgence?
US health officials warned That the country could still see a rebound over the coming months, with renewed outbreak With increased travel and large gatherings in the warmer months.
The CDC designers concluded that “If reintroduction of chronic smallpox disease occurs and no additional vaccination or sexual behavior adaptations occur, the risk of reintroduction of chickenpox is greater than 35% in most jurisdictions in the United States.” . in April.
Still new cases reported abroad. And at least one site in the US – located in central Virginia – continued to have “consistent detection” of smallpox in wastewater samples. Collected by the Centers for Disease Control of sewers there as recently as mid-April, though no new cases have been reported for months.
Sheryl Rodriguez, a spokeswoman for the state health department, said in an email that Virginia’s sewage monitoring has not detected smallpox in any other parts of the state across the 36 monitoring sites set up in March.
She said the ongoing detection in Central Virginia could be the result of previously diagnosed smallpox infections that have not yet been resolved, or new infections that have not been reported to state authorities.
“The most recently reported case of smallpox occurred in the central region of Virginia in November 2022,” Rodriguez said.
[ad_2]
