SARS-CoV-2 Infection Diagnosed by Cell Culture in 7-Week-Old Italian Baby

By Will Boggs MD

May 22, 2020

NEW YORK (Reuters Health) - A 7-week-old Italian baby boy was diagnosed with SARS-CoV-2 infection before the local outbreak by cell-culture isolation, according to a new case report.

"All febrile babies, even if transiently febrile, should be investigated for all respiratory viruses, including SARS-CoV-2," Dr. Adriana Calderaro of the University of Parma told Reuters Health by email. "This could help to reduce the viral spread."

Dr. Calderaro and colleagues report that the baby had no clinical suspicion and/or risk factors of SARS-CoV-2 infection and was proven to be SARS-CoV-2-positive only by a cell-culture method.

The baby presented after having developed a fever to 38 C and vomiting at home, they write in the International Journal of Infectious Diseases. At hospital admission, his temperature was 37.5 C and he had mild leukopenia, pharyngeal hyperemia, and upper respiratory tract inflammation, but no signs or symptoms of pneumonia.

There was no suspicion of SARS-CoV-2 infection, as he had no specific risk factors and the virus had not been reported yet in Parma province.

The baby was discharged three days later in good condition and remained healthy in the following weeks.

A nasopharyngeal aspirate, a nasal swab, and a pharyngeal swab were sent to the microbiology and virology labs, where cytopathic effects were detected in cell cultures at day 10. Electron microscopy detected viral particles belonging to the Coronaviridae family, and a subsequent real-time RT-PCR assay confirmed the presence of SARS-CoV-2 RNA.

Subsequently, SARS-CoV-2 RNA was also identified in the stored nasopharyngeal aspirate.

Pharyngeal swabs conducted two weeks after discharge were negative for SARS-CoV-2 RNA.

"It was quite strange that the parents did not appear to become infected, as they were healthy, but their throat swabs were not done and this is missing information," Dr. Calderaro said.

"The natural history of the infection is still unknown, and this should stimulate (us) to collect biological samples from all cases of respiratory infections in babies and adults in order to allow the virologists to apply all the diagnostic tools to detect and then study the virus, (rather than) to stop at the first step of the laboratory diagnosis (usually only RNA detection)," she said.

Dr. Calderaro added, "This viral strain we have isolated could be considered the 'wild type' of our area, because it was isolated before the epidemic and in a small baby not receiving therapy (symptomatic or antiviral) and it should be useful to study it in comparative analysis with other isolates to assess differences, if any."

SOURCE: International Journal of Infectious Diseases, online May 14, 2020.