Corona Daily 013: Long Covid: Part Two

In 2004, SARS had posed a similar riddle. Twelve months after contracting it, some patients continued to be unwell. There was no evidence of any lingering lung infection or the presence of the SARS virus. Still the patients were weak, extremely fatigued, with a constant body-ache, unable to work. Rather than long SARS, it was called the “post-SARS syndrome”. Harvey Moldofsky, a fatigue researcher from Toronto, found out that most of these patients were sleeping badly. He suspected it meant inflammation in the brain. However, he had no funds to investigate further.

A breakthrough came from China. Chinese scientists discovered SARS virus’s genetic material in the patients’ brain cells. The olfactory nerve connects our nose to the brain. Dr Moldofsky felt this was the route the virus had taken to reach the brain. The viral fragments interfering with the brain functioning probably caused sleep disruption and other issues.

Amy Proal, a microbiologist, believes viruses linger in the remote pockets of our bodies that are beyond the reach of the immune system. They cause several post infectious syndromes including CFS (Chronic Fatigue Syndrome) and long covid. Dr Proal says every major pathogen results in chronic cases. A huge number of studies show infectious organisms can persist in tissue, and contribute to diseases. Some viruses are highly “neurotrophic”, meaning they invade the nerves and hide out there. There is evidence the covid-19 virus is capable of this.

In the past, Dr Proal adds, many doctors thought those symptoms to be psychological. In the last ten years, though, survivors of Ebola, Zika and Covid-19 have suffered long-term illnesses that were real and not psychological.

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Scientists found that the Ebola virus can linger in the body for months or years. Dr Georgios Pollakis, a British microbiologist works with hospitals in Africa to monitor Long Ebola. One study found the antibody levels in Ebola survivors rising after a year. Dr Pollakis and others discovered the virus hidden in the body’s reservoirs, from the eye to the lymph nodes, and even in body fluids like breast milk and semen.

A paper this year suggested that an Ebola survivor recently caused an outbreak in Guinea. He had contracted the infection around 2015. The Ebola virus was dormant in his testes for over five years. The man infected his sexual partner with that hidden virus.

Dr Pollakis believes Long Covid just like Long Ebola happens because the body is unable to eradicate the virus within. The remaining hidden fragments of the virus periodically get back into the bloodstream, causing an immune reaction and other symptoms. Covid-19 virus is shown to be capable of infecting a wide range of tissues, from the brain to the testes. The virus can reside in the semen for a long time.

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Dr Heightman thinks that in some patients Covid provokes the immune system to attack the body’s own tissue. This is similar to autoimmune diseases like rheumatoid arthritis or multiple sclerosis. This theory may explain the higher proportion of women suffering from Long Covid. (Though more men are infected and die of covid itself). In Heightman’s clinic, 66% of the long covid patients are women.

Another hypothesis is Covid-19 triggering re-activation of other viruses hidden in our bodies. Viruses causing Chickenpox or the EBV from the Herpes family are known to lie dormant in human bodies for years or decades. A group of scientists speculates that covid may re-activate such viruses that result in the new chronic symptoms.

Currently, there are no approved medicines for long covid.

The good news is that many long Covid patients simply get better through natural recovery. Since covid-19 is only 18 months old, we don’t yet know how long the Long Covid can be. Despite death rates falling, the risk of Long Covid remains alive. UK has so far awarded scientists at the University of Birmingham £2.2 million to study Long Covid. Far more has been requested in the USA and Europe. A significant number of Long Covid patients are health care workers. It is in societies’ interest to make them healthy and productive faster.

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(Continued tomorrow)

Ravi