New York, Jun 27 (IANS): Even a moderate Covid-19 infection can increase the risk of chronic pain -- the leading cause of disability in the world --, according to a study. 

Emerging evidence suggests that a Covid infection with a high initial severity may be associated with development of long-Covid conditions such as chronic pain.

"Chronic pain is associated with an increase in depression, anxiety, and sleep disturbance," said researchers from Upstate Medical University in New York.

"It can impact daily living activities, reduce social engagement, and impact the ability to contribute to the workforce," they added in the paper published in the journal Plos One.

At the population level, it is unknown if severity of a Covid infection might be a new risk factor for chronic pain above and beyond the traditional slate of pre-established risk factors.

To understand, researchers examined data from 15,335 adult respondents. They aimed to compare the odds of having chronic pain in the past three months among Covid survivors who had no, mild, moderate, or severe symptoms during their infections and never-infected control participants.

Of all participants, 76.7 per cent reported never having been infected with Covid, 10.7 per cent had no or mild symptoms, and 12.6 per cent had moderate or severe cases. Respondents reporting no or infrequent pain made up 80.3 per cent of the sample, while 19.7 per cent said they had chronic pain.

Chronic pain was more prevalent in the moderate or severe group relative to the never-infected group (25.5 per cent vs 19.4 per cent). Both the adjusted model and matched model showed a higher likelihood of pain for those with moderate or severe Covid than for the uninfected group.

Participants with no or mild symptoms were less likely to report pain in the previous three months than the Covid-naive group.

Adjusted probabilities show that chronic pain was roughly four percentage points more likely among those with more symptoms during infection than among the never-infected group (20 per cent vs 16 per cent).

“A moderate/highly symptomatic Covid-19 infection may be a new risk factor for chronic pain,” the researchers said.

“As the absolute number of severe Covid-19 infections continues to rise, overall prevalence of chronic pain may also increase. While knowledge continues to unfold on long-haul symptoms, prevention of severe infections remains essential,” they added.