New research suggests that far more people have had the Corona Virus without any symptoms, fueling hope that it will turn out to be much less lethal than initially feared. Based on known cases, health officials have said the virus usually causes a mild or moderate flu-like illness. In the last week, reports of silent infections have come from a homeless shelter in Boston, a U.S. Navy aircraft carrier, pregnant women at a New York hospital, several European countries and California.
None of these numbers can be fully trusted because based on flawed and inadequate testing, said Dr Michael Mina of Harvard’s School of Public Health. The head of the U.S. Centers for Disease Control and Prevention says 25% of infected people might not have symptoms. The vice-chairman of the Joint Chiefs of Staff, Gen. John Hyten, thinks it may be as high as 60% to 70% among military personnel.
Now evidence is growing that a substantial number of people may have no symptoms at all. Scientists in Iceland screened 6% of its population to see how many had previously undetected infections and found that about 0.7% tested positive. So did 13% of a group at higher risk because of recent travel or exposure to someone sick.
Aboard the aircraft carrier USS Theodore Roosevelt, where one crew member died from the virus, “the rough numbers are that 40 per cent are symptomatic,” said Vice Adm. Phillip Sawyer, deputy commander of naval operations. The ratio may change if more develop symptoms later, he warned.
One Japanese study found more than half of those who had no signs when they tested positive then felt sick. Better answers may come from newer tests that check blood for antibodies, substances the immune system makes to fight the virus. But the accuracy of these, too, is still to be determined. For more health news click here.