Almost a fifth of Covid-19 patients without symptoms went on to experience conditions consistent with long Covid a month after their initial diagnosis, according to a huge study published on June 15 (2021).
The analysis by US non-profit organisation FAIR Health encompassed insurance claims from 1.96 million Americans – the largest population of patients ever studied for long Covid – from February 2020 to February 2021.
Long Covid refers to symptoms of the disease that persist more than four weeks after being diagnosed.
The study found that across all ages, the most common post-viral conditions were, in order of frequency:
- Breathing difficulties
- High cholesterol
- General discomfort and fatigue, and
- High blood pressure.
The odds of dying 30 days or more after initially being diagnosed with Covid-19 were 46 times higher for patients who were hospitalised and discharged, compared to those who weren’t hospitalised.
Overall, 0.5% of Covid-19 patients who were hospitalised then discharged, died 30 days or more after their initial diagnosis.
Meanwhile, 19% of asymptomatic Covid-19 patients experienced long Covid symptoms 30 days out from their initial diagnosis.
This figure increased to 27.5% for those who were symptomatic, but not hospitalised, and 50% of those who were hospitalised.
The order of most common long Covid conditions varied by age group, e.g. for children and adolescents, intestinal issues replaced high cholesterol as the third most frequent problem.
Most long Covid conditions were associated more with females than males, but some, such as cardiac inflammation, were more common in males.
A quarter of all such cases occurred among individuals aged 19-29.
Among the four mental health conditions evaluated after 30 days, anxiety was the most common, followed by depression, adjustment disorders and tic disorder.
The biggest drawback of the new study is that it lacks a control group of people who never got Covid-19, which would help determine the extent to which Covid-19 caused the conditions as opposed to being coincidental.
The causes of long Covid, which is also known as post-Covid syndrome or post-acute sequelae of Covid, remain unknown.
“Theories include persistent immune activation after the acute phase; initial damage from the virus, such as damage to nerve pathways, that is slow to heal; and persistent presence of low-level virus,” the study said. – AFP Relaxnews