David Cox writes:

One of the major challenges for doctors attempting to treat long Covid is that there are likely to be a variety of underlying triggers or causes, depending on the patient.

Recent epidemics have provided one way of gaining crucial clues about what these underlying causes might be. Far from being unique to Sars-CoV-2 – the virus that causes Covid-19 – some scientists believe almost all infectious outbreaks leave behind a proportion of patients who remain chronically unwell with symptom patterns similar to long Covid. This is known as the “long tail” of epidemics. By studying survivors of the Sars coronavirus outbreaks of the early 2000s, and the West Africa Ebola crisis of the past decade, a handful of scientists think they know why it happens.

In 2004, Harvey Moldofsky, a neuroscientist at the University of Toronto, received a call from an old friend. A year earlier, Sars had briefly spread from Asia to Canada, infecting 251 people, mainly healthcare workers in the Toronto area. But more than 12 months later, 50 of them were still unwell, and John Patcai, a consultant at Toronto General Hospital, wanted to try and find out why.

“It was a mystery because even though there didn’t seem to be any evidence of lingering lung inflammation, or the Sars virus, they had all these symptoms,” says Moldofsky. “They felt weak, extremely fatigued, had aches and pains all over their body, and they were completely unable to work. We called it post-Sars syndrome, and because I had a history of studying fatigue, John asked me to have a look at them.”

Moldofsky soon identified that those suffering from the condition were sleeping extremely poorly. He suspected this, along with the other symptoms, was a sign of widespread inflammation in the brain, but lacked the funding to investigate further.

But then came a breakthrough. Scientists in China reported discovering fragments of the Sars virus‘ genetic material in various brain cells in patients with post-Sars syndrome. For Moldofsky, this finding explained much of their malaise. “We know there’s a direct connection from our nose to the brain, called the olfactory nerve, and this is probably how the virus got directly into the circulation of the brain,” he says. “I believe these viral fragments were interfering with how their brains were functioning, which would explain the poor sleep quality and other issues.”

Amy Proal, a microbiologist who runs the PolyBio Research Foundation, which studies the causes of chronic inflammatory diseases, believes that small amounts of pathogens that linger beyond the reach of the immune system in remote pockets of the body, known as reservoirs or anatomical sanctuaries, are at least partially responsible for a whole range of post-infectious syndromes. This includes long Covid, but also a number of mysterious illnesses which have puzzled scientists for decades, such as chronic Lyme disease, and also ME/CFS, a condition which has long been speculated to have infectious origins although some scientists feel there could be a range of potential causes, and bears a number of similarities to long Covid.

“The phenomenon of people developing chronic symptoms after an infectious outbreak is not new,” she says. “If the Sars-CoV-2 virus didn’t do this, it would pretty much be the only documented time where a major pathogen didn’t result in chronic cases. There’s a huge amount of studies, which have been neglected by the mainstream medical community, showing how infectious organisms can persist in tissue, and contribute to disease processes. Some viruses are highly neurotrophic, meaning they can burrow into nerves, and hide out there, and there’s evidence that Sars-CoV-2 is capable of this.” [Continue reading…]