Severe pneumonia in a 7-month-old infant with COVID-19

A 7-month-old male infant, otherwise healthy, presented with a 5-day history of fever, seizures, cough and runny nose. Seven days before the presentation, he had contact with a relative who was later confirmed to be SARS-CoV-2 infected. On admission, his body temperature was 39.4ºC. Laboratory studies showed leukocytosis (19.88×10⁹/L; normal range: 6-16×10⁹/L) with a slight increase in neutrophil, lymphocyte and monocyte counts, as well as d-dimer concentration (386μg/L; normal range, 0-230μg/L). The RT-PCR test for SARS-CoV-2 was positive.

AP chest x-ray (CXR) obtained at the admission showed bilateral diffuse infiltrative opacification, without appreciable lobe predominance (Fig. 1).

Non-enhanced chest computerized tomography (CT) scan was performed on day 1 after admission, due to worsening of patient conditions with onset of dyspnoea and hypoxemia. It revealed diffuse multifocal ground-glass opacities and interstitial prominence, with bilateral and symmetric distribution, slightly more pronounced in lower lobes and not exclusively peripheral, suggesting central dissemination by contiguity. CT also showed areas of atelectasis in the dependent portions of the lungs. No consolidations were noted. (Fig. 2a-c).

AP chest x-ray on day 5 of admission showed a partial reduction of the diffuse infiltrative shadows (Fig. 3).

On day 8 of admission, the radiographic evaluation revealed an almost complete resolution of the infiltrative lung involvement (Fig. 4).

The radiographic findings followed the patient's progressive clinical improvement.

Background:

A review of 2.000 COVID-19 pediatric cases defined the severity of the disease based on clinical features, including asymptomatic, mild, moderate, severe and critical cases. Over 90% of pediatric patients integrate the first three levels with mild and moderate manifestations including fever, cough, diarrhoea and runny nose. About 5% are severe cases, with dyspnoea or hypoxemia, and 0.6% progress to critical respiratory distress syndrome - substantially lower rates than those reported for adults.[1] Compared to other children, infants are more likely to have a severe form of the disease because their respiratory and immune systems are still immature, and they no longer rely on maternal antibodies for humoral immune defence.[1]

As in adults, detection of SARS-CoV-2 nucleic acid through RT-PCR is a highly specific tool for diagnosis.[2]

Clinical Perspective:

This patient presented with fever and upper respiratory symptoms but rapidly progressed to a severe clinical state, with dyspnoea and persistent oxygen saturation under 90%. In cases of worsening respiratory status like this, CT scan is indicated to get detailed information about the lung involvement extension and to exclude complications as bacterial coinfection, common in children.[3]

Imaging Perspective:

Since most of the pediatric patients are mild cases, CXR often fails to show alterations.[2] In severe cases, it may reveal parenchymal involvement expressed as multifocal ground-glass opacities or consolidations.[4]

CT scans may exhibit subpleural ground‐glass opacities, consolidations with surrounding halo sign and bronchial wall thickening. Bilateral, multifocal and peripheral distribution with lower-lobe predominance is usual.[5]

In severe cases, chest CT shows an expansion of the lesions, involving multiple lobes of both lungs, as seen in this patient scan. Ground‐glass opacities and consolidation may be accompanied by interlobular septal thickening and fibrosis.[2]

The mentioned findings are nonspecific, so the diagnosis depends on the correlation between clinical manifestations, imaging findings and viral detection.[2]

Outcome:

Beyond symptomatic treatment, antiviral drugs have been experimentally used to minimize respiratory complications of COVID-19. Appropriate antibiotics are indicated if bacterial coinfection is suspected.[2]

This patient was treated with ceftriaxone since the presentation, plus lopinavir and ritonavir since confirmation of COVID-19. On day 6 of symptoms, he had a noticeable clinical worsening, with chest CT showing extensive lung parenchyma involvement. Symptoms disappeared after 7 days of continued treatment. The infant was discharged after two consecutive negative RT-PCR results.

This brief course of the disease is common in pediatric patients and they tend to have a good prognosis, with an average hospital stay of 13 days.[2] However, the long-term consequences of lung injuries are yet to know.

Teaching points:

Clinical manifestations of COVID-19 in children are generally mild, with a small percentage of severe respiratory affection.

Chest CT scan is indicated in case of worsening respiratory status.

Pediatric patients tend to have an overall good prognosis.