Fatigue is the most common persistent symptom of COVID-19 in different variants of the virus

A study by the Rey Juan Carlos and Complutense universities of Madrid has compared symptoms during the acute phase and six months after infection with the Wuhan, alpha and delta variants of SARS-CoV-2. The Wuhan variant had more persistent symptoms, which follow a potential downward trend as different variants of the disease appear and progressive vaccination.

Newsroom

For the first time, a research group led by the Rey Juan Carlos University (URJC) and in which the Complutense University of Madrid (UCM) participates, has compared the symptoms at the beginning and six months later of three groups of patients infected with different variants (Wuhan, alpha and delta) of SARS-CoV-2 that required hospitalization.

One of the main conclusions, published in Pathogens, is that fatigue is a symptom that affects patients in a similar proportion regardless of the variant of the virus.

"By remaining constant through the variants, it may be one of the key clinical criteria for defining this disease," says César Fernández de las Peñas, Professor of the Department of Physiotherapy, Occupational Therapy, Rehabilitation and Physical Medicine at the URJC. However, the large number of symptoms associated with SARS-CoV-2 "makes it difficult to establish a single diagnostic criterion," he adds.

According to the study, patients infected with the Wuhan variant had on average more symptoms in the acute phase of the disease than the other variants, with fever, dyspnea -difficulty breathing- and gastrointestinal symptoms being the most common, while with the delta variant had more headache and anosmia -loss of smell-. According to Fernández de las Peñas, “the presence of anosmia in the delta variant determines that one should not speak of SARS-CoV-2 flu infection.”

"These differences have been observed in the clinic throughout the different waves, but we have been the first to compare them systematically" in a scientific study, highlights Dr. Fernández de las Peñas.

Telephone follow-up six months later

To carry out the study, the researchers reviewed the data of the 200 patients during their hospitalization.

Six months after the acute condition, telephone interviews were conducted to learn about the situation and symptoms of these people after hospitalization. Fatigue had a similar persistence in the three groups of patients, although there were multiple symptoms with all variants of the virus.

Those infected with the Wuhan variant had a greater number of persistent symptoms (3 versus 2 for the rest of the variants), and dyspnea was the most frequent. Patients with delta reported more alopecia.

"It seems that the incidence of persistent COVID may be lower as time goes by and in the presence of new variants such as omicron, probably conditioned by vaccination, but it is still a serious problem given the large number of infections that occur," says Juan Torres. Macho, researcher at the UCM Department of Medicine and co-author of the work.

In addition to the URJC and the UCM, the San Carlos Clinical Hospital, the University of Valencia, the Infanta Leonor-Virgen de la Torre University Hospital and the University of Aalborg (Denmark) have participated in the research.