Symptoms of long Covid may vary in people depending on the predominant circulating variant at the time of infection, suggests a new retrospective study from Italy.^1,2

This retrospective, observational study included 428 patients who were treated at the post-Covid OPD of Careggi University Hospital in Florence, Italy between June 2020 and June 2021, when the original SARS-CoV-2 strain and then the alpha variant was circulating. Their mean age was 64 years and men comprised more than half of the study population. Researchers compared long Covid symptoms reported by patients infected with SARS-CoV-2 between March and December 2020, when the ancestral Wuhan strain was the dominant strain with symptoms reported by patients who acquired the infection from January to April 2021, when the alpha variant was the dominant strain. The study participants were instructed to fill in questionnaires regarding persistent symptoms on follow-up at 53 days (median) after discharge.

Review of data obtained from electronic medical records revealed that 38% had moderate symptoms, 23% severe, while 19% were critical. More than 50% of patients received low-flow oxygen, 23% were on non-invasive ventilation, while just 9% did not need supplemental oxygen. Almost 70% of patients were treated with steroids. Hypertension (43%) was the most common comorbid condition in these patients followed by congenital heart disease and diabetes at 19% each.

Overall, 76% patients included in the study complained of at least one symptom on follow-up; the most common being dyspnea (37%), while others included chronic fatigue (36%), insomnia (16%), visual disorders (13%) or brain fog (13%).

When the ancestral strain was predominant, from March to December 2020, fatigue, insomnia, dysgeusia and impaired hearing were the more commonly reported symptoms than dyspnea, brain fog, myalgia and anxiety/depression.

But when the alpha variant was predominant, from January to April 2021, myalgia, dyspnea, brain fog/mental confusion and anxiety/depression were the more frequent symptoms. Anosmia, dysgeusia and impaired hearing were uncommon during this wave.

The study also linked factors like female sex, use of immunosuppressant drugs and need for oxygen support  with greater likelihood of long Covid. A finding of note was that type 2 diabetes patients had reduced risk of developing long COVID symptoms.

This study has for the first time documented the distinction between symptoms reported with different variants of SARS-CoV-2 in the early part of the pandemic such as the original virus and the alpha variant. Researchers have started recruiting patients who were infected during the delta and Omicron waves to study a similar disparity in the long Covid symptoms between these variants as in the present study

References

1. Spinicci M, et al. SARS-CoV-2 variants may induce different long COVID phenotypes. ECCMID 2022; Abstract 02768. https://www.medpagetoday.com/infectiousdisease/covid19/97879.
2. Different variants may cause different long COVID symptoms: Study - Medscape - Mar 25, 2022. https://www.medscape.com/viewarticle/970982.