For the second time this year, the federal government has failed to stop a man infected with a dangerous strain of tuberculosis from traveling to and within the United States.

U.S. officials this spring were unable to catch a Mexican man infected with the disease because the doctor treating the man did not know his real name, according to an official who was briefed on the incident but requested anonymity because the official was not authorized to discuss it publicly.

The Mexican national traveled to the United States 76 times in the past year, even though Mexican and U.S. authorities knew he was infected with a contagious strain of tuberculosis. However, the Mexican clinic that had been treating the man, which is affiliated with the Texas Health department, unknowingly provided a fake name to U.S. authorities, the official said. The Washington Times first reported the episode in Thursday's editions.

The man crossed the U.S. border 21 times between April 16 and May 31. However, the man used his real name and real travel documents when traveling, according to Customs and Border Protection spokesman Michael Friel. The Centers for Disease Control would not provide the man's real or fake names for privacy reasons.

Customs officials sent out a nationwide alert to look for this man on April 16, but officials were not able to catch him, because the alert was for the man's fake name, Friel said.

On April 17, when Customs officials had not had any luck finding the man, they suspected they had the wrong information and alerted health officials. On May 31, the Mexican man revealed his real identity to his doctor in Mexico, according to the official.

During the same time period, U.S. officials were dealing with another man infected with tuberculosis, who also was able to travel, despite warnings.

In May an Atlanta lawyer, Andrew Speaker, was able to fly from Atlanta to Europe for his wedding and honeymoon, despite warnings from public health officials. Once he was in Europe, the CDC determined that Speaker could not be transported back to the United States because the agency did not have the equipment to safely do so for a flight longer than eight hours.

The CDC asked TSA at the time to place Speaker on its "no-fly" list so he could not re-enter the country. But there was a four-hour delay between the request and the listing. Speaker got back into the U.S. through Canada, despite instructions to Customs and Border Patrol officers not to allow him in. The 18-year veteran inspector who ignored the warning has retired.

The Mexican man had been infected with tuberculosis for five years, but was being treated under a different name, according to the official who requested anonymity. Homeland Security officials have confirmed that the man is currently living in his home in Juarez, Mexico.