COVID-19 long-haulers, even those with mild infections of the virus, experience significant decline in kidney function, according to a deep dive into federal health data. The findings add to concerns that many people who have had COVID-19 go on to suffer a range of adverse conditions months after their initial infections. The data show that those infected with SARS-CoV-2 are at an increased likelihood of developing kidney damage as well as chronic and end-stage kidney diseases. “The kidney function decline we’ve observed in these patients is not graceful aging. It is not normal anything. It is definitely a disease state.” Known as the silent killer, kidney dysfunction and disease tend to be free of pain and other symptoms—so much so that the National Kidney Foundation estimates that 90% of people with ailing kidneys don’t know it. Kidney disease affects 37 million people in the US and is one of the nation’s leading …