Nearly 40,000 people learned this week that a trip to the doctor may have made them sick. In a type of scandal more often associated with Third World countries, a Las Vegas clinic was found to be reusing syringes and vials of medication for nearly four years. The shoddy practices may have led to an outbreak of the potentially fatal hepatitis C virus and exposed patients to HIV, too.

The discovery led to the biggest public health notification operation in U.S. history, brought demands for investigations and caused scores of lawyers to seek out patients at risk for infections.

Thousands of patients are being urged to be tested for the viruses. Six acute cases of hepatitis C have been confirmed. The surgical center and five affiliated clinics have been closed.

“I find it baffling, frankly, that in this day and age anyone would think it was safe to reuse a syringe,” said Michael Bell, associate director for infection control at the national Centers for Disease Control and Prevention.

One of the infected patients is retired airplane mechanic Michael Washington, 67, who was the first to report his infection. On the advice of his doctor, he received a routine colon exam in July at the Endoscopy Center of Southern Nevada.

In September, he started to get sick. He was losing weight fast. His urine turned dark. His stomach hurt. By January, it was clear what had happened.

Washington describes his virus as a “creeping death sentence” and worries that others will hear his story and think twice before getting preventive care they need.

In letters that began arriving this week, patients who received injected anesthesia at the endoscopy center from March 2004 to mid-January were urged to get tested for hepatitis B and C, and HIV.

Because all three viruses are transmitted by blood, they could have been passed…