KUALA LUMPUR, May 4 – A study by the University of Malaya (UM) found that women and people with severe Covid-19 have a higher chance of developing long Covid, or persistent symptoms beyond the acute illness.
Women have been found to have a 58 per cent higher chance of experiencing long Covid compared to men, while patients with moderate and severe levels of acute Covid-19 are 3 to 3.6 times more likely to acquire long Covid, compared to those without symptoms.
The preprint UM study, which has not been peer-reviewed, involved 732 respondents who survived Covid-19 and was conducted from July to September 2021 during the Movement Control Order (MCO).
Of the total 732 Covid-19 survivors, 21.1 per cent reported experiencing long Covid symptoms, most commonly fatigue, “brain fog” (feeling mentally fuzzy or sluggish thinking), depression, anxiety, insomnia, arthralgia (joint stiffness), or myalgia (muscle aches or pain).
Lead researcher Prof Dr Moy Foong Ming said the higher prevalence of long Covid in women could be explained by the autoimmune hypothesis, which suggests that women have stronger immune responses than men, due to genetic and hormonal factors.
“This contributes to a more active immune response, where activation of white blood cells and production of inflammatory markers and antibodies are stronger than in men.
“This could be seen as a double-edged sword, as while it appears to confer better protection against severe symptoms and deaths, it could also bring about the emergence of autoimmune inflammatory symptoms that lead to long Covid,” said Dr Moy, who is a professor of epidemiology and public health at UM.
Respondents who had moderate to severe acute Covid-19 infection also had higher odds of experiencing long Covid at 26.7 per cent and 30.4 per cent, respectively.
Dr Moy said this may be explained by the immune response to the SARS-CoV-2 virus, which stimulates the production of cytokines and other inflammatory mediators, with higher concentrations found in those with more severe Covid-19 conditions.
The multi-systemic inflammatory response to the virus may also be responsible for persistent Covid-19 symptoms in survivors.
Those without symptoms or with mild symptoms also reported experiencing long Covid at 10 per cent and 17.5 per cent, respectively. Dr Moy said the available evidence on the occurrence of post-Covid symptoms in individuals with mild Covid-19 infection is minimal.
“The majority of patients with mild Covid infections are usually treated as outpatients at home or in clinics, with minimal care devoted in comparison to those who are admitted to the hospital with serious infections.
“Therefore, the post-Covid or long Covid symptoms may not be captured by health authorities if the patients did not seek treatment. These patients should be educated on long Covid symptoms and to seek treatment if needed.
“The Ministry of Health (MOH) has a protocol on the management of long Covid for primary health care facilities. With that, it is hoped that the primary care physicians will take appropriate action among Covid-19 survivors who reported post-Covid symptoms,” Dr Moy said.
Previous studies on long Covid suggests that sex, body mass index (BMI) categories, comorbidities, and severity of acute Covid-19 were reported to be associated with long Covid. However, the UM study found only sex and severity of acute Covid-19 to be significant factors for long Covid.
Age group was not found to be associated with long Covid in the UM study as most of its respondents were young. The study was conducted through an online survey among Covid survivors.
In a separate UK study, the prevalence of long Covid increased with age, almost doubling the prevalence of long Covid for those more than 70 years old compared to those 18 to 49 years old. As an individual ages, one’s ability to manage the viral load also deteriorates.
Other studies also found that obese Covid survivors usually take longer time to resolve abnormalities on chest radiographs, which is linked to long Covid symptoms such as fatigue, cognitive decline, and shortness of breath.
However, the UM study did not find an association between BMI categories with long Covid, though probably because its sample involved young respondents with lower rates of comorbidities.
Long Covid or post Covid-19 disease is defined as a condition that occurs in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually three months from the onset of Covid-19, with symptoms that last for at least two months and cannot be explained by an alternative diagnosis.
Health Minister Khairy Jamaluddin recently announced that the Batu Gajah Hospital is the first public facility in Perak to provide treatment and rehabilitation for long Covid patients in a ward that officially opened on January 1 this year.
In Malaysia, most long Covid treatment programmes are currently concentrated in the Klang Valley, such as university hospitals University of Malaya Medical Centre and Universiti Teknologi Mara Medical Centre; MOH facilities Cheras Rehabilitation Hospital, Kuala Lumpur Hospital, and Sungai Buloh Hospital; as well as private facilities such as ReGen Hospital, Daehan Sunway, Prince Court and others.
Sunway Medical Centre also plans to establish a post-Covid recovery clinic.