More than half number of people diagnosed with COVID-19 experience post-COVID symptoms, known as long COVID, up to six months after recovering, according to a study.
The researchers at Penn State College of Medicine in the US noted that governments, health care organisations and public health professionals should prepare for the large number of COVID-19 survivors who will need care for a variety of psychological and physical symptoms.
During their illnesses, many patients with COVID-19 experience symptoms, such as tiredness, difficulty breathing, chest pain, sore joints and loss of taste or smell, they said.
The study, published in the journal JAMA Network Open, reviewed 57 reports that included data from 250,351 unvaccinated adults and children who were diagnosed with COVID-19 from December 2019 through March 2021.
Among those studied, 79 per cent were hospitalised, and most patients (79 per cent) lived in high-income countries. Patients' median age was 54, and the majority of individuals (56 per cent) were male.
The researchers analysed patients' health post-COVID during three intervals at one month (short-term), two to five months (intermediate-term) and six or more months (long-term).
According to the findings, survivors experienced an array of residual health issues associated with COVID-19. Generally, these complications affected a patient's general well-being, their mobility or organ systems.
Overall, one in two survivors experienced long-term COVID manifestations. The rates remained largely constant from one month through six or more months after their initial illness.
The researchers noted several trends among survivors. More than half of all patients reported weight loss, fatigue, fever or pain. Roughly one in five survivors experienced a decrease in mobility.
Nearly one in four survivors experienced difficulty concentrating or were diagnosed with generalised anxiety disorders.
Six in ten survivors had chest imaging abnormality and more than a quarter of patients had difficulty breathing.
Chest pain and palpitations were among the commonly reported conditions. Nearly one in five patients experienced hair loss or rashes. Stomach pain, lack of appetite, diarrhoea and vomiting were among the commonly reported conditions.
"These findings confirm what many health care workers and COVID-19 survivors have been claiming, namely, that adverse health effects from COVID-19 can linger," said study co-lead investigator Vernon Chinchilli from Penn State.
"Although previous studies have examined the prevalence of long COVID symptoms among patients, this study examined a larger population, including people in high-, middle- and low-income countries, and examined many more symptoms," Chinchilli added.
The researchers noted that the mechanisms by which COVID-19 causes lingering symptoms in survivors are not fully understood.
These symptoms could result from immune-system overdrive triggered by the virus, lingering infection, reinfection or an increased production of autoantibodies -- antibodies directed at their own tissues, they said.
The SARS-CoV-2 virus, the agent that causes COVID-19, can access, enter and live in the nervous system, the researchers said.
As a result, nervous system symptoms such as taste or smell disorders, memory impairment and decreased attention and concentration commonly occur in survivors, they added.
