[Fury]

Press release “USC-LA County Study: Early Results of Antibody Testing Suggest Number of COVID-19 Infections Far Exceeds Number of Confirmed Cases in Los Angeles County
“
- see http://publichealth.lacounty.gov/phcommon/public/media/mediapubhpdetail.cfm?prid=2328

“LAC DPH Health Advisory: SARS-CoV-2 Serology”
- see http://publichealth.lacounty.gov/eprp/lahan/alerts/LAHANCOVID041620.pdf

[Fury]

From the Press Release: "Based on results of the first round of testing, the research team estimates that approximately 4.1% of the county's adult population has antibody to the virus. Adjusting this estimate for statistical margin of error implies about 2.8% to 5.6% of the county's adult population has antibody to the virus- which translates to approximately 221,000 to 442,000 (emphasis added) adults in the county who have had the infection"

[PA Engineer]

I would like to see the actual study and doubt it was random by their own admission.

About the study With help from medical students from the Keck School of Medicine of USC, USC researchers and Public Health officials conducted drive-through antibody testing April 10th and 11th at six sites. Participants were recruited via a proprietary database that is representative of the county population. The database is maintained by LRW Group, a market research firm.