In the medical community, a patient with an illness has two common routes — they recover, or they die. But what about that third category of patients, that improves but never fully recovers? These patients often mystify doctors, who lack a standard treatment for people battling long–haul symptoms with no end in sight.
Doctors recommend physical therapy to treat weakened muscles, pain management to treat headaches or nerve pain, or pulmonary rehabilitation to re–train the heart or lungs following respiratory issues. However, treatments may be highly individualized and expensive for patients who believe they have long–haul symptoms. Given that symptoms can be extremely varied, patients often find it difficult to convince doctors to believe them or refer them to the proper channel for treatment and recovery.
“These patients often mystify doctors, who lack a standard treatment for people battling long–haul symptoms with no end in sight.”
COVID–19 and the abundance of “long–haul COVID” patients has exacerbated the need for doctors to broaden their understanding of chronic illnesses resulting from acute infections by a pathogen (a virus or bacteria). Following the COVID–19 pandemic, approximately 30% of adults in the U.S. who reported contracting COVID also reported experiencing long COVID at any point.
COVID–19 is not alone in causing symptoms the body just can’t seem to overcome. Other viruses, such as those that cause West Nile, Zika, Ebola, and H1N1 (swine flu) have all reportedly caused long–haul symptoms. Certain bacteria, including those that cause Lyme disease and Q fever, can also create chronic symptoms.
The difficulty with diagnosing patients as long–haulers stems from the variety of symptoms that can occur. Long–haulers may report symptoms ranging from consistent fatigue and shortness of breath to “brain fog” and loss of smell or taste. More general symptoms, such as newly developed anxiety or depression and stomach pain, have also been reported. With symptoms that range across body systems and fluctuate in severity, doctors have difficulty attributing symptoms to a previously acquired pathogenic infection. If the patient has other comorbidities — like being overweight or having poor sleep — it can be extremely challenging to convince a doctor the symptoms do not stem from those problems.
There are several proposed hypotheses to explain recurrent or persistent symptoms in patients, but none definitively explain this phenomenon. One hypothesis proposes that infectious pathogens remain at low levels in patients’ tissues, potentially including the gut and brain. This stock of pathogenic particles may cause symptoms and flare an immune response. Another hypothesis suggests that those with long–haul symptoms may have developed an autoimmune disorder as a result of the initial invasion. After a pathogenic invasion, “soldier molecules” — such as white blood cells — which normally fight invaders, may instead attack the very bodily systems they are supposed to protect. These antibodies may attack other immune defenses or specific proteins in key organs, according to Yale researchers. Another theory suggests that even if the pathogen itself may be flushed from the patient’s system, its building blocks, such as RNA or proteins, may remain. These floaters could be enough to activate the patient’s immune response, resulting in long–haul symptoms.
“With symptoms that range across body systems and fluctuate in severity, doctors have difficulty attributing symptoms to a previously acquired pathogenic infection.”
Another idea suggests that it is not the invading pathogen, but the overall process of invasion which lowers the body’s defenses and allows dormant pathogens to reactivate. Some pathogens can linger for years, and may morph into a new disease when the immune system is stressed. For example, the virus causing chickenpox can lay in wait for decades before causing shingles, often in elderly folks with compromised immune systems. Likewise, the bacteria that cause salmonella or listeria can persist in the body and reactivate in a weakened immune system. In the case of COVID, it may not be the COVID pathogens themselves causing long–haul symptoms, but rather the overall weakened immune system reawakening other dormant pathogens.
While exact causes are unknown, it is clear that long–haul symptoms affect a significant slice of those who have experienced a pathogenic invasion. More research into the link between pathogenic infection and chronic symptoms is needed to effectively treat the long–haul patient epidemic.