RELATED: For more up-to-date information, sign up for our daily newsletter. An April report out of China, published in the journal Nature Medicine, found that “44 percent of secondary cases were infected during the index cases’ pre-symptomatic stage.” Translation? Nearly half of coronavirus cases stem from those who are sick before their symptoms even appear. Based on these findings, the authors suggest that “disease control measures should be adjusted to account for probable substantial pre-symptomatic transmission.” This report mirrors what has been found in other studies that seek to gauge the most contagious points in the virus’s infection cycle. According to another recently published study in the journal Eurosurveillance, data collected showed that 48 percent of cases in Singapore and 62 percent in Tianjin, China, were caused by pre-symptomatic individuals. Another study, also published in the journal Nature Medicine and conducted by researchers out of WHO’s Collaborating Centre for Infectious Disease Epidemiology and Control in China, found that patients are most likely to spread COVID-19 up to 72 hours before they show signs of having contracted the virus.ae0fcc31ae342fd3a1346ebb1f342fcb That’s part of the reason why coronavirus is so difficult to track and control. The authors of these studies urge the medical community and public officials to use effective preventative measures, such as contact tracing, to prevent new outbreaks from developing. And for more on how COVID-19 spreads, check out The Surprising Thing Making Coronavirus Up to 10 Times More Infectious.
