COVID-19 Infected People Are Most Contagious Before They Show Serious Symptoms, Experts Warn

woman on subway with coronavirus mask
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According to new research, individuals infected with the coronavirus may be the most contagious when they show mild symptoms that many might mistake for a simple cold or general tiredness. The new findings shed light on how the virus has been able to spread so quickly — killing almost 5,000 people and infecting over 120,000 in the space of under three months.

According to Live Science, a new German study monitored nine individuals outside of Munich to better understand the life cycle of COVID-19. During the process, doctors discovered that the patients were most contagious before they were even aware that they had contracted the disease.

Samples from the noses and throats of the patients showed the highest viral load when the individuals showed symptoms such as a mild cough or fatigue.

The viral “shedding” continued, reaching a peak at around four days after the individuals began to show any symptoms.

“This is in stark contrast to SARS,” a related respiratory illness, the authors explained. In contrast to COVID-19, SARS patients peaked in viral shedding around days seven to 10, meaning that the individuals generally showed obvious signs of illness when most contagious.

Meanwhile, a majority of patients with COVID-19 showed that “peak concentrations were reached before Day 5 and were more than 1,000 times higher” than those seen in SARS patients.

The exception to this rule was for coronavirus patients who went on to develop pneumonia. Those patients exhibited viral shedding similar to SARS, peaking around day 10. However, the individuals were clearly showing symptoms of illness at that time — meaning there was likely no confusion about potentially transmitting the virus.

two people with coronavirus masks
  Pablo Blazquez Dominguez / Getty Images

The study also suggested that the immune system built up a defense against the virus shortly after exposure. Antibodies against the virus were found in all of the patients between days six and 12.

After day eight, most patients had very little chance of contagion, despite still testing positive for the virus. By day 10, patients were “likely” no longer contagious at all.

“This is a very important contribution to understanding both the natural history of COVID-19 clinical disease as well as the public health implications of viral shedding,” said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, on the findings.

It is also something that health officials will no doubt want to get to the public to ensure as little transmission of the virus as possible.

As previously reported by The Inquisitr, both the NBA and the NHL recently canceled their seasons in a bid to stop the growing crisis. In addition, President Donald Trump has halted all travel from Europe, despite the disapproval of the European Union.