Eight out of 10 COVID-19 patients had at least one persistent symptom from 14 days to 16 weeks after acute infection, although some effects could last longer. This is the main conclusion that we have drawn from a meta-analysis that can be found in this prepublication of medRxiv .
In this work, we analyzed almost 19,000 studies that uncovered 55 persistent effects after acute infection. The data was drawn from the records of 47,910 people aged 17 to 87 who participated in 15 studies that had evaluated symptoms or long-term laboratory parameters. Each study had a minimum of 100 patients. Nine studies were from Britain or Europe, three were from the US, and the rest were from Asia and Australia. Six studies focused only on people hospitalized for COVID-19; the others included mild, moderate, and severe cases.
A previous study in Wuhan (China) and published in The Lancet showed that 76% of patients who required hospitalization reported at least one symptom 6 months later, and the proportion was higher in women. The most common symptoms were muscle fatigue or weakness and difficulty sleeping. Additionally, 23% reported anxiety or depression during follow-up.
What we know about the previous coronaviruses, SARS and MERS, is that they both share clinical characteristics with covid-19, including persistent symptoms. People who survived SARS showed lung abnormalities months after infection, and 28% of people had lung dysfunction up to two years later.
Regarding psychological symptoms, high levels of depression, anxiety and long-term post-traumatic stress disorder have also been reported in patients previously infected with other coronaviruses. For MERS survivors, 33% of people with pulmonary fibrosis were also seen, as well as long-term post-traumatic stress and anxiety disorders.
The most commonly identified long-term effects of COVID-19 were fatigue (58%), headache (44%), attention deficit disorder (27%), hair loss (25%), dyspnea (24%). ) or anosmia (24%).
Other persistent symptoms were pulmonary (cough, chest tightness, decreased lung diffusion capacity, sleep apnea, pulmonary fibrosis), cardiovascular (arrhythmias, myocarditis), neurological or psychiatric (memory loss, depression, anxiety, sleep disorders) . During follow-up, 34% of the patients had an abnormal chest X-ray. Elevated blood markers were also observed that could be used as a prognosis for the disease.
Hair loss is found in 25% of cases after COVID-19 and could be considered telogen effluvium, defined as diffuse hair loss after a major stressor or systemic coronavirus infection. It is caused by premature follicular transitions from the active growth phase to the resting phase, lasts about 3 months, but can cause emotional distress and trigger neurological diseases.
The loss of taste or smell is transitory during the acute phase of COVID-19, but it is true that the records we found indicate that it can be persistent in approximately 20% of cases and last up to at least 4 months. Experts recommend treating olfactory dysfunctions caused by the coronavirus through vitamin A drops, steroids, but mainly with olfactory training, which regenerates the olfactory neurons damaged by covid-19 and helps them recover earlier.
SARS-CoV-2 neuroinvasion can affect the brain and leave neurological sequelae. In addition to the direct entry of the coronavirus into the nervous system, either through the olfactory nerve, or by its circulation through the blood system, there are other neurological problems that arise from the inflammation and hypercoagulation that occurs in the development of this disease .
Neurocognitive disabilities associated with viral diseases that cause dysfunction in the immune and metabolic system, as occurs in covid-19, have already been observed. People who suffer from neuropsychiatric problems have a high risk of mortality from covid-19, but there are also factors that can be the answer to subsequent neuropsychiatric problems. An early diagnosis of psychiatric problems is very important to be able to receive treatment, and to be considered as risk groups in this disease.
There is a need for prospective studies. The Centers for Disease Control and Prevention aims to identify how common these symptoms are, who is most likely to have them, and if they eventually resolve. More studies are also needed to determine if some of the symptoms, especially the psychological ones, are due directly to the virus or to the stressful situation of facing the pandemic or to the side effects of intubation and treatments.
To date, there is no established diagnosis for the persistent condition of covid-19. Therefore, preventive measures, rehabilitation techniques, and clinical management strategies designed to address long-term effects are urgently needed. From a clinical perspective, the need for multidisciplinary teams with comprehensive patient perspectives to address long-term covid-19 care, monitoring the duration and treatment of each symptom and following up to determine whether these long-term effects term complicate previous illnesses, are a continuation of covid-19, or may trigger other illnesses in the future.
Sonia Villapol, Assistant Professor, Houston Methodist Research Institute
This article was originally published on The Conversation. Read the original.
