Nearly from the starting of the Covid pandemic, experiences have accrued of persistent, bizarre, disabling signs in survivors, a syndrome that’s come to be generally known as lengthy Covid. The complicated of fatigue, confusion, coronary heart arrhythmias, intestine problems, and different issues—which can persist months after an an infection begins, or come up months after it appears to have concluded—has attracted consideration and sympathy, intense affected person activism, substantial analysis curiosity, and large authorities funding. Final December, the US Congress voted in $1.15 billion to fund 4 years of analysis into lengthy Covid, and this February, the US Nationwide Institutes of Well being introduced it could use these funds to create a nested set of enormous research analyzing grownup and baby experiences of the syndrome.

What makes lengthy Covid analysis pressing can also be what makes it, at this level, so difficult. Nobody has but been capable of decide its trigger, past the affiliation that it happens in individuals who have had Covid—or who suppose they did however weren’t capable of get a take a look at to show it. This makes it obscure and subsequently to foretell who’s susceptible: why one affected person develops lasting signs and one other doesn’t.

A new research of lengthy Covid sufferers in France, revealed in November in JAMA Inside Drugs and accomplished by researchers at a number of universities and medical facilities in France and Italy, is complicating that downside. The researchers surveyed 26,283 sufferers about their experiences with Covid and any long-lasting signs, and likewise analyzed samples of their blood for antibodies that may verify their infections. Their findings: The factor that the majority predicted whether or not sufferers developed lengthy Covid signs was whether or not they believed they’d been contaminated, not whether or not their an infection may very well be lab-confirmed.

“Additional analysis on this space ought to take into account underlying mechanisms that will not be particular to the SARS-CoV-2 virus,” the authors wrote. “A medical analysis of those sufferers could also be wanted to forestall signs as a consequence of one other illness being erroneously attributed to ‘lengthy COVID.’”

This research hasn’t upended analysis into lengthy Covid: The sphere is just too new for that. However for scientists engaged on the issue, it emphasizes the problem of carving out a analysis agenda for a syndrome so new, multifarious, and widespread. And it raises the unsettling prospect of getting to broach to sufferers, with out being dismissive, that the signs they’re experiencing will not be attributable to Covid in any respect.

There’s a lengthy historical past of latest illnesses being dropped at medical consideration by sufferers—usually by ladies, who between month-to-month menstruation and routine GYN visits are usually extra in tune with their our bodies than males are—after which dismissed by medication as imagined. Lyme illness is one such instance; myalgic encephalomyelitis/continual fatigue syndrome, one other. Researchers are decided that lengthy Covid not go down that street.

“As a doctor, but additionally as a girl, I’ve seen so many of those poorly outlined syndromes get dismissed, and seen sufferers haven’t any different apart from quackery, when there actually is a pathophysiologic foundation for his or her signs,” says Megan Ranney, a doctor and affiliate dean on the Brown College of Public Well being and co-director of a brand new lengthy Covid initiative there. “As an emergency doctor, I’ve seen, firsthand, sufferers with persistent signs after Covid an infection which have dramatically shifted their life. They deserve us to deliver scientific rigor to the query—and for folk for whom a few of these signs could exist and will not be as a consequence of Covid, they deserve some type of a proof and remedy as properly.”