When we heard that the federal Centers for Disease Control and Prevention had created a potentially lethal safety risk by improperly sending deadly pathogens — like anthrax — to other laboratories around the country, our first reaction was disbelief.

As one of the most esteemed disease-sleuthing agencies in the world, the CDC for several generations has helped set the standards that protect humans from the ravages of epidemics — not just in America but around the world.

Yet there was Dr. Thomas Frieden, the CDC’s director, telling a worried congressional committee earlier this month that the safety lapses were part of an institutional pattern in the agency that administrators had simply missed.

It was an astonishing confession.

It tells us that for all of the CDC’s skill over the years at identifying and controlling complex killers like the AIDS virus, this organization of scientists, doctors, researchers and epidemiologists is just as vulnerable as other human efforts to the disasters that can come with overconfidence.

Among its most recent incidents:

As many as 84 scientists were potentially exposed to live anthrax bacteria in June when researchers at a CDC lab in Atlanta that was equipped to handle live bacteria failed to render the material harmless before they shipped it out to several unequipped labs.

And the CDC isn’t alone.

In Maryland this month, a scientist stumbled on at least two forgotten vials of live smallpox virus while cleaning out an unused storage room on the campus of the National Institutes of Health. The results could have been horrific. Once a scourge among humans, smallpox was officially eradicated in 1980, after killing 300 million people in the 20th century alone. A few samples of the virus remain in labs. But a full return of the disease might be catastrophic.

So now as the inquiries lurch on, a sensitive but crucial question lingers: How did some of the sharpest public health agencies around end up committing such howlingly boneheaded, but potentially ghastly, errors?

Time for a full report on the pathology of complacency.