But, while affirming children's vulnerability, the study also noted that cases of COVID-19 in young patients were usually not as severe as in adults.
Chinese experts warned about the newly discovered symptoms of COVID-19, including diarrhea, loss of appetite and nausea.
Medical researchers in Shanghai examined the symptoms and transmission patterns of COVID-19 among almost 2,200 pediatric patients between the ages of 2 and 13. The effect is called the "gut-lung axis", which may further explain why patients with Covid-19 pneumonia often have digestive symptoms.
Researchers found that nearly half - 48.5% - of the 204 patients in the study said their "chief complaint" was digestive issues, such as diarrhea, vomiting and abdominal pain.
In this study, COVID-19 patients with digestive symptoms have a worse clinical outcome and higher risk of mortality compared to those without digestive symptoms, emphasizing the importance of including symptoms like diarrhea to suspect COVID-19 early in the disease course before respiratory symptoms develop. That in itself could lead to an earlier diagnosis of COVID-19, "which can lead to earlier treatment and more expeditious quarantine to minimize transmission", he said.
Ninety-nine had digestive symptoms and 92 of these also suffered with respiratory problems as a result of the infection.
Researchers however found that majority of these patients did not have underlying digestive diseases.
"Many people won't have developed symptoms yet", Lloyd-Smith said.
Some of these cases - 7% - did not even report any respiratory problems, which was one of the most common symptoms associated with the contagious virus, according to the researchers.
For the general study population, Pan and colleagues found that the average time from symptom onset to hospital admission was 8.1 days.
According to the researchers, the figure is based on prior studies of children with coronaviruses detectable in the respiratory tract. "There is so much we do not know about this virus, and while we are moving as fast as possible, it is up to the community to stay home to control the spread", he says.
Out of more than 246,000 confirmed cases, the death toll now exceeds 10,000, and over 86,000 have recovered, according to data compiled by the USA -based Johns Hopkins University.