Long-term Covid can affect children of all ages, including babies, study says

In January of this year, the boy Carlos Eduardo, 14, from Curitiba (PR), was diagnosed with Covid-19, along with the whole family. The teenager had the mildest condition, with only a sore throat and low-grade fever.

In May, the boy began to have tremors as if he were having a seizure. Days later, he started to have a fever, a lot of tiredness, stomach pain, diarrhea and decreased strength in his legs.

“We thought it was bullying, a problem at school, he entered high school, he is more demanding”, says his mother, nurse Mara Neiva Nunes Machado.

After going through two pediatricians, came a possible diagnosis: long Covid, possibly exacerbated by a new viral H1N1 infection. After being medicated, the boy now undergoes a series of tests. “He has already started to improve, the tiredness is decreasing”, says the mother.

Carlos is no exception. There is an increasing amount of scientific evidence about the effects of long-term Covid also on children of all ages. One of the most extensive research on this impact was published last month in The Lancet Child & Adolescent Health.

The study evaluated data from 44,000 children in Denmark aged between zero and 14 years, of which 11,000 were diagnosed with Covid-19 between January 2020 and July 2021. Data from children who had the disease (with PCR confirmation) were compared with those that did not. Both groups had similarities in age, sex and prevalence of preexisting comorbidities.

The results show that the symptoms varied according to the age group of the child. Between zero and three years old, 40% of children who were positive for Covid presented at least one symptom after two months or more of infection (against 27% of the control group), in the age group between 4 and 11 years old, 38% (against 33.7%) and between 12 and 14 years old, 46% (against 41%).

Among children up to three years old, mood swings, skin rashes and stomach pains were the most common symptoms. In the group aged 4 to 11 years, in addition to mood swings, difficulty remembering or concentrating and skin lesions were reported. Between 12 and 14 years old, they mainly mentioned fatigue, mood swings and difficulties in memorization and concentration.

According to the researchers, although the symptoms associated with long-term Covid are general complaints that children can experience even without the disease — such as headaches, mood swings, stomach problems and tiredness — those who were diagnosed with coronavirus infection were more likely to have symptoms.

It is still unclear what percentage of children may develop prolonged Covid symptoms and how long they may last. Other smaller studies have already found rates between 30% and 50% of long-term Covid in the child population, a condition that can affect even those who had mild cases of the infection, such as Carlos Eduardo. There are no specific tests for long Covid.

Pediatrician Victor Horácio da Costa Souza Júnior, a pediatric infectious disease specialist at Pequeno Príncipe Hospital, in Curitiba (PR), the largest pediatric institution of the SUS in Brazil, says that, in general, children treated with long-term Covid have persistent cough, sometimes without fever, and many already had comorbidities before Covid – they were transplanted or had neurological diseases, for example.

Souza Júnior says that the hypothesis is that, with the ômicron variant and its intense transmissibility, patients have had a high viral load for a longer time in the body. This can induce the immune system to produce antibodies for a long time, producing a kind of self-harm in various systems of the body.

“In the musculoskeletal system, the patient feels weakness, muscle pain; in the nervous system, tingling, decreased strength; in the respiratory system, a persistent dry cough and tiredness; in the vascular system, it can cause thrombosis; in the brain, anxiety and depression.”

The Instituto da Criança at Hospital das Clínicas de São Paulo has been monitoring a group of children who had Covid since the beginning of the pandemic and several studies are underway to understand the impact of the infection on children.

One of them, already published, shows that four out of ten children and adolescents continued with the prolonged effects of Covid in the 12 weeks following infection. Among them, headache (19%), tiredness (9%), dyspnea (8%) and difficulty concentrating (4%). Muscle and joint pain, in addition to poor sleep quality, were also reported (4%).

Of this total, a quarter of the children continued to have at least one of the symptoms after 12 weeks and were classified as having long-term Covid, according to pediatrician Clóvis Artur Almeida da Silva, a professor of pediatrics at USP and coordinator of the studies.

Another study evaluated the impact of Covid on quality of life, comparing children and adolescents who were diagnosed with Covid (53), compared to those who did not (52). Both groups, made up of children who are monitored at the institute and who, therefore, already have comorbidities, had similar profiles.

“Both physical domains (such as mobility) and school domains (learning, for example) were more affected among those who had Covid compared to those who did not”, explains Silva.

Another study showed that among children who had pediatric multisystem inflammatory syndrome (SIM-P), due to Covid, continued with changes in the blood vessels that nourish the heart muscle.

“This will have an impact on the patient’s life, public health and pediatrics. We will have to monitor these patients carefully. Covid is a disease that can generate medium and long-term sequelae for these children. Therefore, vaccination is extremely important “, says the doctor.