Rather, they tested people on the street in small ways.
About 50 people have been tested so far, including students and members of the public.
"There is a significant amount of work that goes on in the first three to six months when people are being tested."
It was only when the doctors came to test people for the survey that they found out the truth.
Through these research facilities, over 120,000 people have been tested.
No one knows precisely how many people have been tested.
US immigration doesn't test people for disease, but officials at the point of entry may question anyone about his or her health.
"It would be much better to test people first, and if employees come up positive, then to treat them," he said.
Health officials would have time to test people in the local population and treat those who were infected before it was too late.
More than 85 million people, or shields, have been tested there.