SAN DIEGO — An unknown individual at San Ysidro High School has tested positive for tuberculosis, county health officials announced Tuesday.

The infected individual may have exposed students and staff members to the infection between January 11 and March 18 of this year, according to the San Diego County Health and Human Services Agency.

At this time, it is unclear if the infected person is a student or a staff member.

“Testing is recommended for people who were exposed to assure they are not infected, since initial infection usually has no symptoms,” said Wilma J. Wooten, M.D., M.P.H., County public health officer. “For any infected individuals, early diagnosis and prompt treatment can prevent the infectious form of the disease.”

HHSA officials say that they are working with San Ysidro High School to identify and notify all who were potentially exposed, and that free TB testing will be available to all students and staff. Those who were exposed and tested negative in April will be retested again in May as it can take up to 10 weeks after exposure to receive a positive result, officials say.

Mayo Clinic says tuberculosis is “a potentially serious infectious disease that mainly affects the lungs,” but “can also affect other parts of your body, including the kidneys, spine or brain.” The infection, which is spread through tiny droplets in the air when people cough and sneeze, is

According to the World Health Organization, tuberculosis is the 13th leading cause of death in the world. In 2020 alone, 1.5 million people were killed worldwide by the infection.

Tuberculosis mostly affects adults in their most productive years. However, all age groups are at risk. Over 95% of cases and deaths are in developing countries.