Barely more than a week ago, South Korea’s coronavirus outbreak appeared to be contained as the number of confirmed infections stabilized at 30. Sensing a turning tide, many Seoul residents took off their surgical masks and resumed riding the subways and shopping at malls. Then, on Feb. 17, a 31st case surfaced at a health clinic in Daegu, a city about 150 miles south of the capital where the vast majority of known infections were located. An unidentified 61-year-old woman, who lived there and occasionally commuted to Seoul, tested positive for the novel coronavirus. It seemed like a standard case until public health authorities started tracing the patient’s tracks. What they learned shocked them: the woman had, during the previous 10 days, attended two worship services with at least 1,000 other members of her secretive religious sect whose leader says the end of days is coming. Within 24 hours, the nation’s number of confirmed cases started multiplying exponentially. The tally rose by 20 during that period, doubled the following day and then doubled again on the third day. By Wednesday, the count skyrocketed past 1,000 — a more than 30-fold increase in a week that prompted the government to raise its health alert to the highest level. At least half of the new cases are linked to the sect called the Shincheonji — which translates to “new heaven and land” and whose members worship side-by-side in cramped spaces. “What made this case so much worse was that this person spent [More]