On paper, Sewickley Heights has had one of the highest case rates of covid-19 in Allegheny County. In early January, the borough of roughly 800 residents had about 307 positive cases — a case rate of 3,700 per 10,000 residents, or 37%. Nationally, the rate was 7.5% on Jan. 25. In Pennsylvania, it was around 6.3%. “I knew that number had to be wrong,” said John Bunce, a resident of Leet. He said the Sewickley area is “very well-behaved” when it comes to following county, state and federal guidelines to curb the spread of the disease. Bunce’s daily routine includes going to Mass, a ...