People infected with coronavirus are most likely to pass on the virus in the first five days after showing symptoms, new peer-reviewed research suggests. The authors of the extensive new study published by medical journal The Lancet Microbe said the findings underlined the need to identify and isolate cases of COVID-19 early.
Understanding when patients are most likely to be infectious has become of critical importance for informing effective public health measures to control the global spread of COVID-19.
The review, one of the most comprehensive to date with 98 studies included, analyzed three human coronaviruses — SARS-CoV, SARS-CoV-2, and MERS-CoV — and their viral loads. Of the three, COVID-19 was found to be the most likely to be highly infectious in the first five days of showing symptoms.
While genetic material of COVID-19 was still detected in respiratory and stool samples for several weeks, researchers found that no live virus was found in any samples taken from patients beyond nine days of infection, the review noted.
The current guidance in many countries is to self-isolate for 10 days after symptoms first manifest themselves, which the authors of the research say is in line with their findings.