The Centers for Disease Control and Prevention is preparing to update its COVID-19 isolation guidance, moving from a minimum five-day isolation period to one that is solely determined by symptoms, according to a report from The Washington Post.
Currently, CDC isolation guidance states that people who test positive for COVID-19 should stay home for at least five days, at which point people can end their isolation as long as their symptoms are improving and they have been fever-free for 24 hours.
According to three unnamed officials who spoke with the Post, the CDC will update its guidance to remove the five-day minimum, recommending more simply that people can end their isolation any time after being fever-free for 24 hours without the aid of medication, as long as any other remaining symptoms are mild and improving. The change, which is expected to be released in April, would be the first to loosen the guidance since the end of 2021.
In an email to Ars, a CDC spokesperson did not confirm or deny the report, saying only that, “There are no updates to COVID guidelines to announce at this time. We will continue to make decisions based on the best evidence and science to keep communities healthy and safe.”
The Post notes that the proposed update to the guidance matches updated guidance from California and Oregon, as well as other countries.
The officials who spoke with the outlet noted that the loosened guidelines reflect that most people in the US have developed some level of immunity to the pandemic coronavirus from prior infections and vaccinations.
A report earlier this month found that the 2023–2024 COVID-19 vaccine was about 54 percent effective at preventing symptomatic COVID-19 when compared against people who had not received the latest vaccine. However, the CDC estimates that only about 22 percent of adults have received the updated shot.
Currently, the CDC recommends that people wear a mask for 10 days after testing positive unless they have two negative tests 48 hours apart. The Post reported that it’s unclear if the CDC will update its mask recommendation.
An Oregon resident contracted bubonic plague from their “very sick” pet cat, marking the first time since 2015 that someone in the state has been stricken with the Black Death bacterium, according to local health officials.
Plague bacteria, Yersinia pestis, circulates cryptically in the US in various types of rodents and their fleas. It causes an average of seven human cases a year, with a range of 1 to 17, according to the Centers for Disease Control and Prevention. The cases tend to cluster in two regions, the CDC notes: a hotspot that spans northern New Mexico, northern Arizona, and southern Colorado, and another region spanning California, far western Nevada, and southern Oregon.
The new case in Oregon occurred in the central county of Deschutes. It was fortunately caught early before the infection developed into a more severe, systemic bloodstream infection (septicemic plague). However, according to a local official who spoke with NBC News, some doctors felt the person had developed a cough while being treated at the hospital. This could indicate progression toward pneumonic plague, a more life-threatening and more readily contagious variety of the plague that spreads via respiratory droplets. Nevertheless, the person’s case reportedly responded well to antibiotic treatment, and the person is recovering.
Health officials worked to prevent the spread of the disease. “All close contacts of the resident and their pet have been contacted and provided medication to prevent illness,” Richard Fawcett, Deschutes County Health Officer, said in a news release.
Fawcett told NBC News that the cat was “very sick” and had a draining abscess, indicating “a fairly substantial” infection. The person could have become infected by plague-infected fleas from the cat or by handling the sick cat or its bodily fluids directly. Symptoms usually develop two to eight days after exposure, when the infection occurs in the lymph nodes. Early symptoms include sudden onset of fever, nausea, weakness, chills, muscle aches, and/or visibly swollen lymph nodes called buboes. If left untreated, the infection progresses to the septicemic or pneumonic forms.
It’s unclear how or why the cat became infected. But cats are particularly susceptible to plague and are considered a common source of infection in the US. The animals, when left to roam outdoors, can pick up infections from fleas as well as killing and eating infected rodents. Though dogs can also pick up the infection from fleas or other animals, they are less likely to develop clinical illness, according to the CDC.
While plague cases are generally rare in the US, Deschutes County Health Services offered general tips to keep from contracting the deadly bacteria, namely: Avoid contact with fleas and rodents, particularly sick, injured, or dead ones; Keep pets on a leash and protected with flea control products; Work to keep rodents out and away from homes and other buildings; and avoid areas with lots of rodents while camping and hiking and wear insect repellant when outdoors to ward off fleas.
According to the CDC, there were 496 plague cases in the US between 1970 and 2020. And between 2000 and 2020, the CDC counted 14 deaths.
The Centers for Disease Control and Prevention is putting clinicians on alert about the growing risk of measles cases and outbreaks amid a global surge in transmission.
Between December 1, 2023, and January 23, 2024, there have been 23 confirmed measles cases in the US, including seven direct importations by international travelers and two outbreaks with more than five cases each, the CDC noted. Most of the cases were in unvaccinated children and teens.
Measles outbreaks in the US are typically sparked by unvaccinated or undervaccinated US residents who pick up the infection abroad and then, when they return, transmit the disease to pockets of their communities that are also unvaccinated or undervaccinated.
Globally and in the US, vaccination rates against measles—via the measles, mumps, and rubella vaccine (MMR)—have fallen in recent years due to pandemic-related health care disruption and vaccine hesitancy fueled by misinformation.
“The increased number of measles importations seen in recent weeks is reflective of a rise in global measles cases and a growing global threat from the disease,” the CDC’s outreach message, titled “Stay Alert for Measles Cases,” read.
According to data from the World Health Organization, the European region saw an over 40-fold rise in measles cases in 2023 as compared with 2022. The region tallied over 42,200 measles cases last year, compared with just 941 in 2022.
This week, the WHO reported a rapid escalation of measles cases in Kazakhstan (which the WHO considers part of the European region). Kazakhstan has recorded the highest incidence of measles cases in the region, with 13,677 cases in 2023. That corresponds to over 639 cases per million in the population. In the news release Tuesday, Kazakhstan’s health minister reported that there are “currently 2,167 children in hospital with measles, 27 of them in a serious condition.”
The outbreak is largely spurred by unvaccinated children who missed their routine immunizations during the pandemic. Sixty-five percent of the reported measles cases are in children under age 5, the WHO noted. The country is now trying to catch children up on their vaccines to curb the outbreak.
“Measles is highly infectious, but fortunately, can be effectively prevented through vaccination,” WHO’s Regional Director for Europe, Hans Henri P. Kluge, said in the news release. “I commend Kazakhstan for the urgent measures being taken to stop the spread of this dangerous disease.”
Meanwhile, measles is flaring up in many other places. Last week, the UK Health Security Agency warned of the potential for an ongoing measles outbreak to spread. As of January 18, there were 216 confirmed cases and 103 probable cases in the West Midlands region since October 2023. Authorities warned that any areas with low MMR vaccination rates are at risk of an outbreak.
The vast majority of Americans have received their MMR vaccines on schedule. In this case, the two standard, recommended doses are considered 97 percent effective against measles, and the protection is considered for life. But anyone who is unvaccinated or undervaccinated is at high risk of infection in the event of an exposure. The virus can linger in air space for up to two hours after an infected person leaves the area, the CDC notes, and is highly infectious—up to 90 percent of unvaccinated people exposed will fall ill. Once infected, people are infectious from four days before the telltale measles rash develops to four days afterward.
Enlarge/ The influenza virus from an image produced from an image taken with transmission electron microscopy. Viral diameter ranges from around 80 to 120 nm.
Key indicators of seasonal flu activity declined in the first week of the year, signaling a possible reprieve from the high levels of respiratory virus transmission this season—but the dip may only be temporary.
On Friday, the Centers for Disease Control and Prevention released its latest flu data for the week ending on January 6. Outpatient visits for influenza-like illnesses (ILI) were down that week, the first decline after weeks of rapid increases. Flu test positivity and hospitalizations were also down slightly.
Enlarge/ Percent of outpatient visits for respiratory illnesses by week.
But transmission is still elevated around the country. Fourteen states have ILI activity at the “very high” level in the current data, down from 22 the week before. And 23 states have “high” activity level, up from 19 the week before. (You can see the week-by-week progression of this year’s flu season in the US here.)
The CDC says it is monitoring for “a second period of increased influenza activity that often occurs after the winter holidays.”
Flu isn’t the only virus that seems to be letting up a little in the data, at least for now. COVID-19 data also showed some dips, with the CDC reporting that “Despite test positivity (percentage of tests conducted that were positive), emergency department visits, and hospitalizations remaining elevated nationally, the rates have stabilized, or in some instances decreased, after multiple weeks of continual increase.”
The CDC speculates that some of the declines in indicators could be due to people not seeking medical care during the holidays as they would otherwise. COVID-19 wastewater activity levels remain “very high,” with all regions showing high or increasing levels. The South and Midwest have the highest levels in the latest data, but there are some early indications that rises in the Midwest and Northeast may be slowing down.
Meanwhile, RSV activity remains elevated, though some areas are starting to see declines.
The CDC notes that it’s not too late to get vaccinated against COVID-19, flu, and (for those ages 60 and over) RSV. So far, 21 percent of adults have received the 2023–2024 COVID-19 vaccine, including 41.5 percent of people ages 65 and up. Around 363,000 people have died from COVID-19 in the US since September.
For flu, about 47 percent of adults have received their annual shot, including 74 percent of people ages 65 and up. On Thursday, researchers in Canada published the first estimates of flu vaccine effectiveness this season, finding the current annual shots are 61 percent effective against the most common strain of flu circulating in the US (influenza A(H1N1)pdm09) and 49 percent effective against the less common influenza A(H3N2) and 75 percent effective against influenza B.
The CDC estimates that there have been at least 14 million flu cases, 150,000 hospitalizations, and 9,400 deaths from flu so far this season so far, the agency reported. In the first week of this year, 13 children died of flu, bringing this season’s total to 40.
Enlarge/ A vial of the updated 2023-2024 formula of Pfizer’s COVID-19 vaccine at a CVS Pharmacy in Eagle Rock, California, on September 14, 2023.
Staying up to date on COVID-19 vaccines can cut the risk of COVID-related strokes, blood clots, and heart attacks by around 50 percent in people ages 65 years or older and in those with a condition that makes them more vulnerable to those events, according to a new study from the Centers for Disease Control and Prevention.
The finding, published this week in the CDC’s Morbidity and Mortality Weekly Report, should help ease concerns that the shots may conversely increase the risk of those events—collectively called thromboembolic events. In January 2023, the CDC and the Food and Drug Administration jointly reported a preliminary safety signal from their vaccine-monitoring systems that indicated mRNA COVID-19 vaccines may increase the risk of strokes in the 21 days after vaccination of people ages 65 and older. Since that initial report, that signal decreased, becoming statistically insignificant. Other vaccine monitoring systems, including international systems, have not picked up such a signal. Further studies (summarized here) have not produced clear or consistent data pointing to a link to strokes.
In May, the FDA concluded that the evidence does not support any safety concern and reported that “scientists believe factors other than vaccination might have contributed to the initial finding.”
But, the statistical blip could potentially cause lingering concerns. While clinicians had noted lower rates of thromboembolic events among vaccinated people, the authors of the new study noted that, until now, there were no rigorous estimates of how effective COVID-19 vaccines are at preventing those events.
For their analysis, they primarily looked at two groups of patients: A group of 12.7 million Medicare beneficiaries ages 65 and older and a group of around 78,600 Medicare beneficiaries ages 18 and older with end-stage renal disease (ESRD) on dialysis, a condition that increases their risk for thromboembolic events, including COVID-19-related thromboembolic events. Using medical claims records from September 2022 to March 2023, the researchers compared rates of thromboembolic events among the people in those groups that had gotten a bivalent COVID-19 booster dose and those who had only gotten the original monovalent COVID-19 vaccine in the past. To be considered a COVID-related thromboembolic event, the event had to occur within a week of or a month after a COVID-19 diagnosis.
Protective effect
In the group of 12.7 million patients ages 65 and older, about 5.7 million (45 percent) had gotten the bivalent booster, making them up to date on their COVID-19 vaccinations at the time. The remaining 7 million (55 percent) had only gotten the original vaccine.
During the study period, 17,746 patients who were not up to date on their COVID shots got COVID-19 and experienced a COVID-related thromboembolic event. Of the bivalent boosted patients, there were 4,255 COVID-related thromboembolic events. The researchers adjusted for confounding factors, such as age, race, and time of vaccination, and estimated that the bivalent booster was overall 47 percent effective at preventing COVID-related thromboembolic events, which again include strokes, blood clots, and heart attacks.
A sub-analysis including the time since vaccination indicated that the estimated effectiveness waned about two months after receipt of the vaccine, dropping early effectiveness of 54 percent down to 42 percent at 60 days or more.
Among the 78,600 patients ages 18 and up with ESRD, 23,229 (29.5 percent) received a bivalent dose and thus were up to date on their COVID-19 vaccines. The remaining patients (70.5 percent) had only received an original vaccine, and of those, 917 experienced a COVID-19-related thromboembolic event after getting the pandemic virus. Among the up-to-date patients, there were only 123 events. After adjustments, the researchers estimated that the vaccines’ effectiveness against thromboembolic events was 51 percent in this group, which also waned slightly over time.
The study has limitations, such as that it can’t account for previous COVID-19 infections, which could alter people’s risk of developing complications from COVID-19, including thromboembolic events. It relied on medical claims, which have limitations, and it’s possible there are other confounding factors, such as the use of Paxlovid and behavioral differences. Last, Medicare beneficiaries are not representative of the whole population.
But, given the data available, the study authors concluded that it appears the bivalent vaccine dose “helped provide protection against COVID-19–related thromboembolic events compared with more distant receipt of original monovalent doses alone.” The authors recommend that, “to prevent COVID-19–related complications, including thromboembolic events, adults should stay up to date with recommended COVID-19 vaccination.”
In the FDA’s announcement, the agency noted that “The lead-to-chromium ratio in the cinnamon apple puree sample is consistent with that of lead chromate (PbCrO4).” This is a notorious adulterant of spices used to artificially bolster their color and weight.
Lead chromate is a vibrant yellow substance that has frequently turned up in turmeric sourced from India and Bangladesh. In a 2017 study by public health researchers at Boston University, 16 of 32 turmeric products bought in markets in the Boston area had lead levels over the FDA’s allowable lead level for candy (the FDA does not have guidelines for lead levels in spices, specifically). Two samples, the only two samples sourced from Bangladesh, exceeded the allowable lead level by two orders of magnitude. The researchers had conducted the study after a string of lead poisoning cases in US children were linked to contaminated spices, including turmeric. Other studies have also identified spices as a source of lead exposure in US children.
The 2017 study highlighted the reason that lead chromate is used as an adulterant. A media outlet in Bangladesh quoted one turmeric trader’s explanation: “Traders use the artificial color [lead chromate] to hide the marks of pest attacks and other spots on raw turmeric. It is used during boiling and polishing to make the spice look brighter to attract big buyers, including spice processing firms.”
The FDA’s testing does not definitively conclude that lead chromate was in the contaminated cinnamon, which was sourced from an Austrofoods manufacturing facility in Ecuador and used in the recalled applesauce pouches. But it does bolster the FDA’s suspicion that the poisonings were the result of “economically motivated adulteration,” a specific category of food fraud defined by the FDA.
Jim Jones, FDA’s deputy commissioner for human foods, told Politico in December that the agency believed then that the contamination was economically motivated. “My instinct is they didn’t think this product was going to end up in a country with a robust regulatory process,” Jones said. “They thought it was going to end up in places that did not have the ability to detect something like this.”
Health effects
For the hundreds of US children poisoned by the applesauce pouches, the finding of chromium adds yet more nightmarish uncertainty of possible long-term health effects. Lead is a potent neurotoxic metal that can damage the brain and nervous system. In developing toddlers and younger children, the effects of the acute exposures could manifest as learning and behavior problems, as well as hearing and speech problems in the years to come.
The effects of chromium exposure are less clear. Chromium is a naturally occurring metal and an essential trace nutrient. But there are two notable forms: chromium III and the more toxic chromium VI. The FDA’s testing couldn’t identify which form of chromium was present in the cinnamon applesauce pouches, but the more toxic chromium VI is what’s present in lead chromate. Chromium VI is considered a carcinogen, and chronic, prolonged inhalation and skin exposure is associated with chronic lung disease and ulceration of skin and mucous membranes, the CDC notes. But the effects of eating chromium VI are not well studied or understood beyond the immediate, nonspecific effects of an acute exposure—which might include abdominal pain, nausea, vomiting, diarrhea, anemia, and kidney and liver dysfunction.
The CDC and the FDA note that it’s possible that even if chromium VI contaminated the applesauce pouches, the acidity of the applesauce and the stomach may have converted the chromium VI to chromium III.
The FDA recommends that the families of children exposed to the recalled pouches—especially those with elevated blood lead levels—should inform their health care providers of potential chromium exposure. The CDC provided clinical guidance for doctors on how to test and care for children with exposure.
The recalled cinnamon applesauce pouches include WanaBana apple cinnamon fruit puree pouches (sold nationally and through multiple retailers, including Amazon and Dollar Tree), Schnucks-brand cinnamon-flavored applesauce pouches and variety packs (sold at Schnucks and Eatwell Markets grocery stores), and Weis-brand cinnamon applesauce pouches (sold at Weis grocery stores).
According to the CDC’s latest numbers, which, as of the time of publication, were last updated on December 29, there have been a total of 287 cases identified across 37 states.
