New study highlights inconsistencies in defining long COVID
Do you suspect you have long COVID, but aren't sure?
The answer you get will largely hinge on whom you ask, a new study says.
The medical field still lacks a clear answer as to what constitutes long COVID, despite hundreds of published studies and millions of sufferers worldwide, researchers reported Tuesday in JAMA Network Open.
The definition of long COVID varies so widely that the percentage of people identified as having the ailment can differ dramatically, making it harder to properly diagnose and treat patients, researchers said.
"The findings highlight the need for a standard definition for long COVID," lead researcher Lauren Wisk, an assistant professor of medicine at UCLA's David Geffen School of Medicine, said in a news release.
A number of major organizations like the National Academies of Sciences, Engineering, and Medicine have advanced their own definitions for long COVID, but none has stuck and all feature some flaws, researchers said in background notes.
For example, the National Academies' definition, released in 2024, is extremely broad and does not require lab confirmation that a person actually had an initial COVID-19 infection, researchers said.
For the study, researchers applied five published long COVID definitions from previous studies to a group of more than 4,500 COVID patients being tracked as part of an ongoing research project. The prior studies took place in the U.S., U.K., Netherlands, Sweden and Puerto Rico.
The five definitions differed by symptom duration, ranging from four weeks to six months, researchers said. The definition also varied by the number of potential symptoms, from nine to as many as 44.
The percentage of patients with long COVID varied from 15% to 42%, depending on which definition had been used, results showed.
These differences can lead doctors to miss legitimate long COVID cases while misdiagnosing others who actually don't have the syndrome, said senior researcher Dr. Joann Elmore, a professor at David Geffen School of Medicine.
"Without a shared definition, we risk mislabeling patients and misguiding care," she said in a news release. "This is more than an academic debate -- it affects real people."
These differences are also hampering medicine's ability to figure out long COVID, Wisk said.
"If every study on long COVID uses a different definition for identifying who has it, the scientific conclusions become harder to compare across studies and may lead to delays in our understanding of it," she said.
"In the absence of an objective measure, like a blood test, or a uniform standard for measuring long COVID, researchers and clinicians will need to decide which definition is best suited for their scientific question and be more transparent about the potential limitations of using a more versus less restrictive definition," Wisk added.
More information
The U.S. Centers for Disease Control and Prevention has more on long COVID.
Copyright © 2025 HealthDay. All rights reserved.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
UPI
2 hours ago
- UPI
Argentina raises death toll from tainted fentanyl to more than 100
The government of Argentine President Javier Milei blamed blamed a local laboratory, HLB Pharma Group S.A., for the deaths of more than 100 people from contaminated fentanyl. Photo by Juan Ignacio Roncoroni/EPA Aug. 15 (UPI) -- More than 100 people are believed to have died from a batch of medical fentanyl that may have been contaminated, Argentina's government said in a statement from the presidential press office. The government blamed a local laboratory, HLB Pharma Group S.A., for the incident. The tragedy, described as one of the most serious in the country's public health history, began with the distribution of vials contaminated with multidrug-resistant bacteria -- including Klebsiella pneumoniae and Ralstonia pickettii -- used in public and private hospitals across several regions since early 2025. Although the first cases were detected in May, the death toll has continued to rise in recent days, reaching 96 confirmed deaths with at least nine more under investigation. From the presidential palace, President Javier Milei's government said the company responsible, led by businessman Ariel García Furfaro, engaged in "criminal conduct" by allowing the defective product to be distributed. The presidential press office said more than 300,000 vials of the drug were produced, about 45,000 of which were administered before recall protocols were activated. Unlike other critical medications, clinical-use fentanyl was not fully integrated into the national electronic tracking system, making it harder to detect the problem early and identify the health centers that received the contaminated vials. In a public appearance, Milei turned the health emergency into a political issue by accusing the Kirchnerist movement of having "covered up" for the laboratory's owners for years. Kirchnerism is a left-wing populist movement that blends Peronist nationalism with progressive social policies, economic interventionism and an emphasis on human rights "This is a longtime partner of the previous regime. We will not allow impunity," Milei said. He also warned that his government will seek the recusal of the federal judge handling the case if the businessman is not immediately taken into custody. The National Administration of Drugs, Food and Medical Technology said it had revoked the laboratory's authorization in February, but acknowledged there were failures in subsequent distribution controls. So far, 24 people linked to the production and distribution of fentanyl have been identified as suspects in the court case. All are barred from leaving the country and have had their assets seized, though no formal charges have been filed. At the same time, the victims' families are demanding justice. Patient organizations and health professionals have called for urgent reforms to the drug tracking system and a full audit of the health system's operations to prevent similar incidents in the future. In a press release, HLB Pharma Group said it is "at the disposal of the courts" and accused political and economic sectors of "opportunism" in carrying out a "media smear campaign" against the company. The company also said that "contamination such as that reported by some media -- involving one or more multidrug-resistant bacteria typically found in a hospital setting in the same batch -- is simply not possible in a laboratory setting."
New York Post
3 hours ago
- New York Post
Three babies die amid ‘concerning rise' of syphilis in New York — what to know about the dangerous disease
At least three babies have died of presumed congenital syphilis in New York state this year, prompting health officials to warn about the risks of the preventable infection. A pregnant woman can pass syphilis, a sexually transmitted infection, to her fetus. Left untreated, congenital syphilis can lead to miscarriage, premature birth, skeletal abnormalities, neurological problems, developmental delays, stillbirth or infant death shortly after birth. 3 There's been a 'concerning rise' in congenital syphilis cases in New York this year, state health officials said this week. HENADZY – Advertisement 'Detecting syphilis early in pregnancy with a simple blood test is important to ensure rapid diagnosis and treatment, so you have a healthy baby,' State Health Commissioner Dr. James McDonald said in a statement this week. New York has reported 21 cases of congenital syphilis in counties outside of NYC this year. Authorities did not disclose where the three infant deaths happened, except that they weren't in the city. There were 36 cases in the region outside of NYC last year, including five stillbirths and one infant death. Eight infant deaths presumptively linked to syphilis were recorded in the area between 2019 and 2023. Advertisement 'The highest rates we're seeing are in Native Americans, American Indians, Alaska Natives, Hispanic populations and black populations,' Kristin Wall, an associate professor of epidemiology at Emory University's Rollins School of Public Health, told ABC News about national congenital syphilis trends. 'And I think it's really important to think about access to care barriers as one of the big reasons that we're seeing these increasing rates in certain populations.' 3 A newborn in 1963 displays signs of congenital syphilis. Getty Images Unsurprisingly, there has been a 'concerning' rise in infectious syphilis cases among female New York residents, contributing to a nationwide surge. Advertisement Researchers have speculated that the increase could be due to decreased condom use, a disruption in healthcare routines because of the COVID-19 pandemic, inadequate sex education and disparities in access to testing and screening services. New York officials observed that substance use and hepatitis C were notable threads throughout congenital syphilis cases in the state. Last year, New York implemented a requirement for syphilis screening during the third trimester. Advertisement Pregnant women must now be tested for syphilis at their first prenatal appointment, in their third trimester (between weeks 28 and 32) and at delivery. Penicillin is the recommended treatment for syphilis, though some people may be allergic. In those cases, desensitization may be necessary. Unfortunately, there's been a nationwide penicillin shortage for months, compounding syphilis concerns. 3 A syphilis rash often appears as reddish-brown spots on the palms of the hands and soles of the feet. Stock Media Labs – Syphilis is spread by vaginal, anal or oral sex. Symptoms typically emerge 10 to 90 days after exposure, starting with a painless sore that appears at the site where the bacterium Treponema pallidum entered the body. The sore can heal on its own in three to six weeks, even as the infection persists. In the next stage of infection, symptoms can include a rash, fever, fatigue, sore throat, swollen lymph nodes and hair loss. Advertisement Syphilis is typically diagnosed with a blood test. New York's health department reminded residents that they have access to at-home testing options for sexually transmitted infections. If not addressed, syphilis can devastate the brain, heart and nervous system, leading to blindness, paralysis and even death.
UPI
3 hours ago
- UPI
PFAS chemicals tied to weight loss difficulties in teens
"Forever" PFAS chemicals might hamper a teenager's ability to drop excess weight, even if they've undergone weight-loss surgery, University of Southern California researchers said in a new study. File Photo by Diego Azubel/EPA "Forever" PFAS chemicals might hamper a teenager's ability to drop excess weight, even if they've undergone weight-loss surgery, a new study says. Teens with high blood levels of per- and polyfluoroalkyl substances were more likely to regain weight lost after bariatric surgery, researchers reported Aug. 14 in the journal Obesity. "Our study shows a clear association between PFAS exposure and weight-related outcomes in bariatric surgery for adolescents," lead researcher Brittney Baumert said in a news release. She's a postdoctoral research fellow in population and public health sciences at the Keck School of Medicine of USC. PFAS are called "forever chemicals" because they combine carbon and fluorine molecules, one of the strongest chemical bonds possible. This makes PFAS removal and breakdown very difficult. PFAS compounds have been used in consumer products since the 1940s, including fire extinguishing foam, nonstick cookware, stain-resistant furniture, waterproof clothing and food wrappers, researchers said. Previous studies have shown that PFAS chemicals disrupt hormones in the human body, potentially affecting metabolism and weight gain, researchers said in background notes. "With the growing use of weight loss interventions around the world, it's critical for us to understand the association between PFAS and successful weight loss management, including what this means for long-term outcomes," Baumert said. For the study, researchers tracked 186 teenagers who underwent bariatric surgery between 2007 and 2012. Blood samples were taken before surgery and tested for seven types of PFAS, and the participants were tracked for up to five years after surgery for weight, body mass index and waist size. (BMI is an estimate of body fat based on height and weight.) Results showed that teens with higher PFAS blood levels before surgery regained more weight and had greater increases in waist circumference than those with lower levels. The strongest links between the chemicals and excess weight were observed in a class of PFAS known as sulfonic acids, which includes perfluoroctaansulfonaten, or PFOS, and perfluoroheptanesulfonic acid, or PFHpS, researchers said. For example, teenagers with the highest levels of PFOS regained about 47 pounds on average within five years of their surgery, compared with about 36 pounds for those with the lowest exposure levels, results showed. And teens with highest PFHpS exposure regained an average 4.3% of their body weight per year following surgery, compared with 2.7% per year in the lowest exposure group. These results add to mounting evidence that PFAS need stronger regulation, researchers said. This particularly applies to public water supplies, which are the greatest source of PFAS exposure in the U.S. "PFAS are a modifiable risk, which is why protective policies are so important to reduce exposure and safeguard public health -- especially for vulnerable populations," Baumert said. Researchers next plan to explore whether PFAS exposure might affect the impact of other weight-loss methods, such as GLP-1 drugs like Ozempic and Zepbound. They also want to investigate whether PFAS chemicals increase risk of metabolic conditions like type 2 diabetes or fatty liver disease. However, they noted the current study is observational and cannot draw a direct cause-and-effect link between PFAS and weight gain. More information The Environmental Working Group has more on PFAS chemicals. Copyright © 2025 HealthDay. All rights reserved.
