Los Angeles study suggests virus much more widespread

LOS ANGELES (AP) — An estimated 320,000 adults in Los Angeles County may have been infected with coronavirus, according to preliminary results of a study that suggests the illness is far more widespread than current testing shows and the death rate is much lower.

The study conducted April 10-11 by the county and the University of Southern California estimated that approximately 4.1% of the county’s adult population of 8 million has antibodies to the virus. When adjusted for margin of error, the infection rate ranged from 2.8% to 5.6%, or about 220,000 to 440,000 adults.

The study, which was criticized by some outside experts, follows other research that has suggested more people have had coronavirus than previously determined through testing — many without symptoms or without feeling ill enough to seek a test. But it also means that more people have been silent carriers of the virus that has killed more than 1,200 people in California.

Public health officials emphasized that the results do not mean people should stop practicing social distancing and should assume that most people are still susceptible to the virus.

“Given the high rate of people that may have been infected at some point with COVID-19, we need to assume that at any point in time that we could be infected and that all the other people that we come in contact with could also be infected,” Public Health Director Barbara Ferrer said.

The study was similar to one conducted among 3,300 Santa Clara County residents in early April that estimated 48,000 and 81,000 of the county’s 1.9 million people — a range of 2.5% to 4.2% — had been infected.

The Santa Clara study that used some of the same researchers as USC was heavily criticized for its methodology, which recruited volunteers on social media. The test it used — the same one used by USC...