June 29, 2020

Review study details clinical features of children infected with SARS-CoV-2 and perinatal outcomes of infants born to women infected with SARS-CoV-2

By Denise Baez

NEW YORK -- June 29, 2020 -- A review article published in The Pediatric Infectious Disease Journal summarised the epidemiologic and clinical features of children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the perinatal outcomes of neonates born to women infected with SARS-CoV-2 in pregnancy.

Petra Zimmermann, MD, Fribourg Hospital HFR and Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland, and colleagues analysed data from 11 published case series from China comprising 333 infants and children aged 1 to 16 years (55% male) with confirmed SARS-CoV-2 infection.

The researchers noted that in 2 of the studies, there were patients that overlapped and further duplicate reporting of patients could not be excluded in 2 other studies. They did not include single case reports, publications which did not give enough clinical details or studies that were retracted.

The majority of diagnoses were made by real-time reverse transcriptase-polymerase chain reaction on nasopharyngeal or other respiratory samples. Overall, 83% of the children had a positive contact history, mostly with family members.

Three studies reported incubation periods between 2 and 25 days. Several studies reported that the nasopharyngeal or throat swabs can be positive before the onset of symptoms; however, false-negative swabs have also been described. In 4 studies, respiratory samples remained positive between 1 and 22 days and in stool between 5 and over 30 days. Viral shedding from the gastrointestinal tract might last longer and also be greater than that from the respiratory tract.

Up to 35% of children were asymptomatic. The most common symptoms were cough (48%), fever (42%), and pharyngitis (30%). Further symptoms were nasal congestion, rhinorrhoea, tachypnoea, wheezing, diarrhoea, vomiting, headache, and fatigue. Laboratory test parameters were only minimally altered. Radiologic findings were unspecific and included unilateral or bilateral infiltrates with, in some cases, ground-glass opacities or consolidation with a surrounding halo sign.

Children rarely (3%) needed admission to the intensive care unit (ICU), and to date, only a small number of deaths have been reported in children globally. Of these 9 children requiring intensive care, only 2 were described to have a pre-existing condition (leukaemia and hydronephrosis).

“Unpublished data suggests that the clinical features of coronavirus disease 2019 in children varies in different countries,” the authors wrote. “While in Asian countries and Europe children have been reported to have milder disease, recent data from the United States reports that, by March 27, 2020, at least 35 children needed mechanical ventilation and one infant died.”

“The majority of children included in this review had a reported adult or family contact infected with SARS-CoV-2,” the authors added. “It is still uncertain whether asymptomatic children transmit the virus and therefore the role of children as a reservoir for SARS-CoV-2 and for transmission of the virus remains unclear.”

“This review confirms that, compared with adults, children with SARS-CoV-2 infection have milder clinical symptoms and fewer laboratory and radiologic abnormalities,” the authors concluded.

The researchers also examined perinatal outcomes of infants born to women infected with SARS-CoV-2 during pregnancy. They found 9 case series and 2 case reports (all from China) comprising 65 women and 67 neonates. Most of the women became infected during the third trimester and most delivered between 30 and 40 weeks of pregnancy, mostly by caesarean section (88%); 37% delivered preterm. Fetal distress was reported in 31% of pregnancies.

Maternal complications included premature rupture of membranes (12%), pre-eclampsia (3%), gestational hypertension (6%), gestational diabetes (5%), hypothyroidism (3%), tachycardia (2%), and abnormal umbilical cord (3%). Two women were admitted to the ICU for mechanical ventilation, 1 of whom developed multi-organ failure.

Neonatal complications included respiratory distress or pneumonia (18%), disseminated intravascular coagulation (3%), asphyxia (2%), and 2 perinatal deaths. Four neonates (3 with pneumonia) have been reported to be positive for SARS-CoV-2 despite strict infection control and prevention procedures during delivery and separation of mother and neonates. Additionally, three neonates whose mother presented with COVID-19 infection 23 days before delivery were found to have immunoglobulin M and G against SARS-CoV-2 at birth. Therefore, vertical transmission could not be excluded.

“The influence of SARS-CoV-2 infection on pregnancy and neonatal outcomes is also unclear,” the authors wrote. “SARS- and MERS-CoV cause more severe disease in pregnant women compared with non-pregnant women,” they added. 

However, the authors noted that there is no evidence that SARS-CoV or MERS-CoV can be vertically transmitted to the fetus. Nonetheless, “maternal infections have been associated with intrauterine growth retardation, preterm delivery, stillbirths and perinatal deaths in SARS-CoV and MERS-CoV”. Similarly, the authors noted that low birth weight, preterm delivery and 2 perinatal deaths have been reported in association with SARS-CoV-2. They added that “it is unclear if some of the reported maternal and neonatal complications are due to the virus or were iatrogenic (eg, decision for a Cesarean leading to preterm delivery and neonatal respiratory problems). Nevertheless, 1 case-control study reported that the number of preterm deliveries were higher in SARS-CoV-2-infected women compared with non-infected women. Furthermore, fetal distress and preterm ruptures of membranes have been reported in women with SARS-CoV-2 infection.”

The authors noted that there is no evidence for the presence of SARS-CoV-2 in genital fluids. However, it was reported that the virus can be isolated from feces, suggesting the possibility of a greater risk for infection of the infant via vaginal delivery. They added that most of the women reported in these case series and case reports delivered by Cesarean section as recommended in Chinese guidelines.

SOURCE: The Pediatric Infectious Disease Journal