Quite true. To support this, I can share my (N=1) experience.
I first fell ill while traveling in Southeast Asia during the summer of 1997.
I was diagnosed with an unknown tropical infection. From my background in Infectious Disease, I already knew that very few infections were detectable with modern diagnostic technology, so from the start I gave up trying to diagnose the exact infection via diagnostic tests.
Instead, I decided to narrow down the universe of pathogens by listing the known categories of human infections, and trying broad-spectrum agents aimed at each category. I started with a year of broad-spectrum antibiotics, in various combinations. No effect on my symptoms. Then antifungals, again with no effect. The symptoms persisted, despite pharmacotherapy. Then I tried various anti-parasitic agents, again with no effect.
This left viruses. Since herpes viruses are often claimed to be reactivated in ME, I tried various anti-herpetic antivirals, again for a whole year, in various combinations. Although my laboratory reports strongly suggested that there were reactivated infections that had been suppressed, there was no change to any of my ME symptoms. Again, the ME symptoms persisted despite the combined effects of the immune system and pharmacotherapy.
Then I turned to RNA viruses. The only broad-spectrum anti-RNA-virus pharmacotherapy currently approved is Ribavirin. Within days of starting Ribavirin, I broke out in prominent hand-foot-mouth blisters and herpangina at the back of the throat. A literature search for these symptoms only revealed enteroviruses as a possibility. Although these symptoms may suggest an enterovirus is present, they did not mean the virus is related to my ME symptoms.
So I increased the dosage, carefully, steadily, until there was a sudden disappearance of all my ME symptoms at a certain dosage. I shared this surprising finding with a few colleagues. One wisely pointed out that Ribavirin is an anti-inflammatory at the dose I was using, and ME symptoms are known to be alleviated with anti-inflammatories, so my improvement may be a side-effect of the Ribavirin rather than due to suppression of a virus. Since continued use of the Ribavirin resulted in bone marrow suppression, I stopped the Ribavirin and my ME symptoms returned.
(FOR THE RECORD: Do NOT try Ribavirin. At the doses needed to see an effect, you will likely suffer serious, and potentially life-threatening, toxicity. Please, do NOT try Ribavirin.)
So I wondered if there might be another broad-spectrum anti-RNA-virus drug that does not have anti-inflammatory properties. I found Favipiravir, a drug with the same antiviral mechanism of action as Ribavirin, but without any anti-inflammatory or immunosuppressive effects. Again, I increased the Favipiravir dosage, carefully, steadily, until there was a sudden disappearance of all my ME symptoms at a certain dosage. This time, when I consulted with colleagues, there was a consensus that my ME symptoms had to be caused by some persistent RNA virus. Unfortunately, since continued use of the Favipiravir lead to signs of liver toxicity, I stopped the Favipiravir and my ME symptoms returned.
(FOR THE RECORD: Do NOT try Favipiravir. At the doses needed to see an effect, you may suffer serious, and potentially life-threatening, toxicity. Please, do NOT try Favipiravir.)
Later, I searched the literature to see if there was a known outbreak in Southeast Asia in the summer of 1997, when and where I fell ill. The only outbreak I found was an outbreak of Enterovirus 71. If you’re interested in learning about Enterovirus 71, I’m attaching the slides from a small talk on the subject I gave at Berkeley a few years ago. My apologies that the slides are a bit out-of-date; there have been some fascinating developments in the last couple of years. (For privacy reasons, I have removed my name from the slides.)
Thank you again for all your time and effort.