How Not to Kill People With Spreadsheets

The interior of an NHS 111 Coronavirus (COVID-19) Pod, for people who believe they may have the virus, to attend and speak to doctors, seen outside University College Hospital in London on March 5. Isabel Infantes/AFP via Getty Images

Imagine that you’re working in a government subdepartment that tracks coronavirus infections and traces the patients’ contacts. You’ve just discovered that nearly 16,000 positive tests didn’t get into the system for a week. The people with the coronavirus know they have it, but their contacts don’t know. What do you do?

We don’t have to imagine it. In the United Kingdom, 15,841 people with coronavirus infections went unreported to Serco Test and Trace, the company running the U.K. government’s coronavirus tracing program, in the week from Sept. 25 to Oct. 2, with 48,000 of their possible contacts not warned—because of errors in a data import.