RICHMOND, Texas (AP) — Health officials say tuberculosis testing conducted after four active cases were found at a Houston-area school at the end of the school year revealed 20 infections, but no more active cases.

Fort Bend County Health and Human Services said Wednesday that mass screenings of students and faculty at George Bush High School in Richmond were conducted in June and August.

Tuberculosis is spread by those who become actively ill. Health officials say a person who only tests positive for infection might not develop the disease and can't spread it. Preventive medication is being o...