A YOUNG person who showed no symptoms of Covid-19 infection still went on the develop pneumonia as a result, according to a new study from South Korea.

Researchers found that, overall, a quarter (26%) of those aged 18 to 39 who had tested positive for the virus went on to develop pneumonia - an inflammation of one or both lungs, triggered by an infection, which makes it difficult to breathe.

There were seven cases of severe pneumonia, with one patient who had "no other medical history" requiring mechanical ventilation.

The findings will be presented next week at the ESCMID Conference on Coronavirus Disease, the first major international congress on the pandemic, which will be hosted online from Wednesday.

The authors said it should be a warning to young people "to be aware of the risk of pneumonia or severe pneumonia due to Covid-19".

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It comes as many countries around the world, including Scotland, are experiencing a resurgence in the virus with a majority of new cases initially emerging among younger people.

The study, led by medics from Keimyung University Dongsan Hospital and the Yeungnam University College Of Medicine, added that the "low alertness of young people" to the virus "has become a social problem around the world".

Statistics show that younger people are much less likely overall to develop serious or fatal complications.

By September 9 in Scotland, there had been just 41 hospital admissions for Covid among 20-24-year-olds out of a total of 6023, and 435 admissions among the 25-44 age group.

Intensive care data, available up to September 13, also shows that patients aged 15 to 44 accounted for just 55 (10%) of the 544 ICU admissions for Covid.

However there is evidence that a rise in infections among the young is now beginning to spread up the generations, into older populations.

In the week to September 4 - when there were 941 new cases - under-25s accounted for 45% of them (419 cases), compared to 3% (32 cases) for over-65s.

However, of the 1533 new cases reported in the past seven days, 8% (123 cases) were among over-65s, with the proportion of cases in under-25s shrinking to 28% and case numbers remaining fairly steady at 427.

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Overall, the biggest share of cases in the past week - 35% - was among 25-44-year-olds (541 out of 1533 cases), followed by 442 cases in the 45-64 age group (29%).

The South Korean research evaluated 315 patients aged 18 to 39 admitted to six hospitals in Daegu, South Korea, between February 18 and March 31.

All patients had tested positive for Covid-19 and were admitted to hospital in line with public health rules.

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In South Korea, even asymptomatic patients were quarantined in hospital after a positive test if there were beds available in a bid to stem the spread of the virus within households and communities.

Pneumonia was confirmed through chest X-rays and CT scans in a total of 83 patients - including one patient who had been asymptomatic for Covid-19.

Overall, 32 out of the 315 patients had been asymptomatic.

However, symptoms such as a fever, cough, diarrhoea and shortness of breath were significantly more frequent in patients who went on to develop pneumonia.

The ESCMID Conference on Coronavirus Disease will be held online from September 23-25.