Children Up To Age 14 Can Experience Long Covid Lasting At Least Two Months: Study In Lancet

Long Covid: Children with a positive Covid-19 test are more likely to experience at least one symptom lasting longer than two months, than children who never tested positive for SARS-CoV-2.

The study published in The Lancet Child & Adolescent Health found that children diagnosed with Covid-19 in all age groups are more likely to experience at least one symptom for two months or longer than the control group. | Representative Photo

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Long Covid symptoms in children aged zero to 14 can last at least two months, a new study published in The Lancet Child & Adolescent Health has found. It is the largest study to date of long Covid symptoms in children aged zero to 14. Researchers used national level sampling of children in Denmark and matched Covid-19 positive cases with a control group of children with no prior history of a Covid-19 infection.

What Is Long Covid?

While a Covid-19 patient is declared ‘recovered’ after a negative test, it does not mean he or she is fully recovered as far as overall health is concerned. Hence, a nutritious diet, light exercise, and adequate rest are recommended for some time. Since SARS-CoV-2 is known to damage memory cells, doctors also advise brain exercises, such as playing puzzles or memory games, to regain cognitive thinking abilities.  

However, when the symptoms persist even after several weeks and months, despite testing negative for SARS-CoV-2, the condition is called ‘long Covid’. 

According to an article on the Harvard Health website, the points that should be taken into consideration to define ‘long covid’ are, a medical diagnosis of Covid-19 on the basis of symptoms and/or diagnostic testing for the virus, the patient not having returned to the pre-Covid level of health and function even after a period of six months, and a patient suffering from symptoms suggesting long Covid but not evidently suffering from permanent damage to the heart, kidneys, and lungs.

What Was The Overall Aim Of The Study

In a statement released by The Lancet, Professor Selina Kikkenborg Berg, one of the authors on the paper, said the overall aim of the study was to determine the prevalence of long-lasting symptoms in children and infants, alongside quality of life, and absence from school or day care. She further said the results reveal that although children with a positive Covid-19 diagnosis are more likely to experience long-lasting symptoms than children with no Covid-19 diagnosis, the pandemic has affected every aspect of all young people's lives. According to Berg, further research into the long-term consequences of the pandemic on all children will be important going forwards.

The Study Analysed Children Up To Age Of 14 Who Tested Positive For Covid-19

While most previous studies of long Covid in young people have focussed on adolescents, the new study analysed infants, toddlers and other children up to the age of 14 who had tested positive for Covid-19 between January 2020 and July 2021. 

There Were Almost 11,000 Children With Positive Covid-19 Test

Responses for almost 11,000 children with a positive Covid-19 test result were obtained. The children were matched by age and sex to over 33,000 children who had never tested positive for Covid-19.

23 Most Common Symptoms Of Long Covid Were Considered

According to the statement, the participants were asked about the 23 most common symptoms of long Covid in children, as part of surveys. These symptoms were identified by the Long COVID Kids Rapid Survey January 2021. 

Covid Symptoms Lasting For More Than Two Months Are Long Covid Symptoms

The surveys used the World Health Organization (WHO) definition of long Covid as symptoms lasting more than two months. 

Most Commonly Reported Symptoms In Different Age Groups

Mood swings, rashes, and stomach aches were the most commonly reported symptoms among children aged zero to three years

Among children aged four to 11 years, the most commonly reported symptoms were mood swings, trouble remembering or concentrating, and rashes.

The most commonly reported symptoms among children aged 12 to 14 years were fatigue, mood swings, and trouble remembering or concentrating.

Important Findings Of The Study

The study found that children diagnosed with Covid-19 in all age groups are more likely to experience at least one symptom for two months or longer than the control group. According to the study, 40 per cent of the children aged zero to three years who were diagnosed with Covid-19 experienced symptoms longer than two months, compared to 27 per cent of controls. There were 1,194 children in the zero to three years age group, and of these, 478 children experienced long Covid symptoms longer than two months. The control group for the zero to three years age group had 3,855 children. 

Meanwhile, for the four to 11 years age group, the ratio was 38 per cent of cases compared to 34 per cent of controls (6,189 of 18,372 children). There were 5,023 children in the four to 11 years age group, and of these, 1,912 children experienced long Covid symptoms for more than two months compared to 34 per cent of the controls.

According to the study, the ratio was 46 per cent of cases in the 12-14 years age group compared to 41 per cent of controls. There were 2,857 children in the 12-14 years age group and 10,789 children in the control group. The study found as many as 1,313 cases in the 12-14 age group, and 4,454 children in the control group who experienced long-lasting symptoms.

Non-Specific Symptoms Associated With Long Covid

Children who are otherwise healthy often experience non-specific symptoms associated with long Covid. These include headache, mood swings, abdominal pain, and fatigue. These are all symptoms of common ailments that children experience which are unrelated to Covid-19.

Were Long-Lasting Symptoms A Representation Of Covid-19?

The study found that children with a positive Covid-19 diagnosis were more likely to experience long-lasting symptoms than children who had never had a positive diagnosis. This suggests that these symptoms were a presentation of Covid-19. 

The finding is supported by approximately one-third of children with positive Covid-19 tests experiencing symptoms that were not present before the SARS-CoV-2 infection. According to the study, with increasing duration of symptoms, the proportion of children with those symptoms tended to decrease.

Children Diagnosed With Covid Reported Less Psychological Problems Than Kids In Control Group

The study found that children diagnosed with Covid-19 reported less psychological and social problems than children in the control group. The cases in older age groups often felt less scared, had less trouble sleeping, and felt less worried about what would happen to them.

The increased pandemic awareness in older age groups could explain why they reported less psychological and social problems than children in the control group. The latter experienced fear of the unknown disease and more restricted everyday life due to protecting themselves from catching the virus.

Importance Of Knowledge Of Long-Term Symptom Burden In Covid Positive Children

Berg said the opportunity to undertake such research is rapidly closing as the vast majority of children have now had a Covid-19 infection. For instance, 58 per cent of children in Denmark had lab-confirmed infection between December 2021 and February 2022. She added that the knowledge of long-term symptom burden in SARS-CoV-2 positive children is essential to guide clinical recognition, parental caregiving, and societal decisions about isolation, lockdown, non-pharmaceutical interventions, and vaccine strategies. 

Berg explained that the findings of the study align with previous studies of long Covid in adolescents showing that, although the chances of children experiencing long Covid is low, especially compared to control groups, it must be recognised and treated seriously. She further said that more research will be beneficial to treat and better understand these symptoms and the long-term consequences of the pandemic on children going forward.

Limitations To The Study

The authors noted some limitations to the study. These include a long recall period between diagnosis and taking the survey. Recall period is the period of time patients are asked to consider in responding to a question. Also, the research was dependent on parent reported data which is less accurate for psychological symptoms, leading to selection bias as the mothers and guardians of children with more severe symptoms are often keener to respond. This leads to the results representing the most affected children.

Moreover, public testing for Covid-19 was only available from August 2020. This means that some children in the control group could have had undetected asymptomatic infections. 

Covid Might Not Be Responsible For Non-Specific Symptoms 

Maren Rytter from the University of Copenhagen, Denmark, who was not involved in the study, wrote in a linked comment that the study found that symptoms of any kind were slightly more frequent in children who had been infected with SARS-CoV-2. However, the overall impact on children of having had Covid-19 is probably small, and likely much less than the impact of the indirect effects of the pandemic. 

Rytter added that for most children with non-specific symptoms following Covid-19, the symptoms are more likely to be caused by something other than Covid-19. If these symptoms are related to Covid-19, they are likely to pass with time.