Doctors in India are struggling to diagnose and treat the unexplained and persistent symptoms of long-standing Covid patients because of limited guidelines, while researchers have flagged inadequate studies of the condition.

With the World Health Organization declaring the end of COVID as a global health emergency in May 2023, focused efforts are underway worldwide to estimate the long-term burden of COVID among the population.

The condition refers to a set of persistent symptoms affecting different parts of the body that persist well beyond the period of acute infection with COVID, including cough, muscle and joint pain, fatigue, brain fog, and difficulty concentrating. The viral disease is caused by the SARS-CoV-2 virus.

While studies have suggested that about a third of those moderately or severely infected are likely to suffer from long-term Covid, however, depending on the region, the incidence could vary.

A study by researchers, including those from Harvard Medical School, USA, estimated that 31% of previously infected people in North America, 44% in Europe and 51% in Asia have had COVID for a long time, which “causes the health system. , but there are limited guidelines for its treatment”. It was published in the International Journal of Infectious Diseases in September.

In India, however, studies on long-term COVID are few and far between.

One such study by the Maulana Azad Medical College in New Delhi, conducted from May 2022 to March 2023 on 553 patients who recovered from COVID, found that about 45% had persistent symptoms, with persistent fatigue and a dry cough being the most common. more frequent.

“There is limited exploratory research on long-term COVID syndrome, with limited data on long-term outcomes,” the authors wrote in the study published in the journal Cureus in May of this year.

Understanding the long-term effects of the virus is important for developing management strategies, optimizing healthcare delivery and providing support to recovered Covid patients in the community, they said.

Dr Rajesh Sagar, Professor of Psychiatry, All India Institute of Medical Sciences (AIIMS), New Delhi, said: “Looking at the current state of long-term Covid studies in India, it is too early to say that we understand the condition well enough to know how to diagnose or treat it.” Animesh Samanta, assistant professor at Shiv Nadar University’s School of Natural Sciences, Greater Noida, said: “While studies in India highlight the growing recognition of neurological complications in patients with long-term Covid, more focused research is needed on neuroinflammation”. Doctors have also reported an increase in patients complaining of symptoms they didn’t have pre-Covid.

“People who have never had asthma in the past, post-Covid, with every viral infection, have a prolonged cough, difficulty breathing and wheezing, which requires the use of inhalers or nebulizers,” senior consultant Dr Neetu Jain, who runs a Post-Covid Care Clinic at Pushpawati Singhania Hospital and Research Institute, New Delhi, said.

Dr Arun Garg, Chairman, Neurology and Neurosciences, Medanta-The Medicity, Gurugram, said he has seen an increase in stroke cases among young patients who do not suffer from known risk factors such as diabetes, hypertension and obesity.

“Similarly, we see more cases of encephalopathy (swelling of the brain) for no reason and having a confused state of mind after one or two days of fever. Their MRI scans show no change. These patients have grown significantly after Covid,” he said. he said. said.

In the absence of medical guidelines to diagnose long-term Covid, doctors are forced to resort to broad, non-specific tests and questionnaires to assess a patient’s “quality of life”.

Studies have shown that the fatigue felt in long-term Covid is similar to that of cancer patients, with a quality of life similar to that of Parkinson’s patients.

“We don’t really have any test to diagnose long-term Covid, even though it’s certainly a clinical diagnosis. We diagnose long covid for people who have had at least moderate to severe infection, after which they were never able to regain their pre-covid quality of life. Checking inflammatory markers like C-reactive protein (CRP) can support the diagnosis,” said Dr Jain.

“In addition to routine blood tests that measure inflammation, we do antibody tests to look for direct markers. In many of these patients, we are finding rare antibodies that are very new to us and did not exist before Covid,” said Dr Garg.

Inflammation that persists despite recovery from acute Covid infection is thought to be at the heart of long-term Covid. However, tests to measure this specific immune response are lacking, even though researchers have been working in this direction around the world.

One such effort comes from Shiv Nadar University, where a team led by Samanta has developed a fluorescent probe capable of detecting inflammation in brain cells that can occur due to Covid infection.

The probe measures nitric oxide levels in brain cells, specifically in human microglia cells, where increased levels of NO are linked to SARS-CoV-2 infection. Microglia are immune cells in the brain that fight disease and help maintain brain health.

Lysosomes in microglia, which help eliminate foreign disease-causing agents such as the SARS-CoV-2 virus, produce nitric oxide as part of an immune response to infection. The probe detects nitric oxide produced in lysosomes in response to infection and therefore allows a measurement of inflammation levels.

This screening method can provide “qualitative information about the state of the infection,” said Samanta, corresponding author of the study published in the journal Analytical Chemistry in the American Chemical Society.

He explained that patients with pre-existing conditions such as Alzheimer’s disease, Parkinson’s disease or multiple sclerosis (an autoimmune disorder) could experience prolonged neuroinflammation and brain cell loss following Covid infection.

Although the probe has shown efficacy in cell cultures, animal studies should be done before testing it in humans, Samanta said.

Analyzing the World Health Organization’s International Clinical Trials Registry Platform, the Harvard Medical School study found that 587 clinical trials had been conducted on long-term Covid, of which around 53% (312) were testing potential treatments.

Most of these were found to have been carried out in the US (58), followed by India (55) and Spain (20). Studies have looked at interventions including exercise, psychotherapy and pharmacological ones such as paxlovid and fluvoxamine.

However, “to date, only 11 of these 312 studies have published results that were not confirmatory,” the researchers wrote.

The team called for studies looking at sleep disorders, which have rarely been included in registered clinical trials. In addition, interventions targeting the biological processes responsible for prolonged Covid are needed but currently lacking, they said.