The San diego county Tuberculosis Prevention and Care Program has issued a notice regarding a potential exposure to multidrug-resistant tuberculosis (MDR-TB) at California State University San Marcos (CSUSM) and on the North County Transit District Sprinter. This alert comes as health officials work to contain the spread of this serious airborne disease.
The potential exposure at CSUSM occurred between December 15, 2026 and May 14, 2026 at the main campus located at 333 S. Twin Oaks Valley Road in San Marcos. Additionally, brief exposures were reported on the Sprinter, eastbound between the Melrose Drive and Civic Center – Vista stations, at various times between 10 a.m. and 3 p.m. on May 18, 20, 26, and 27, 2026.
Understanding the Risk of TB Transmission
The county statement emphasizes that TB transmission is more likely during prolonged exposures. Short periods of contact, such as those on the Sprinter, are not considered highly likely to cause infection. However, individuals with certain health conditions may face an increased risk. The information is being shared to help anyone who may have been exposed discuss the risks with their healthcare provider.
Tuberculosis can be difficult to diagnose, and people may be sick for months before receiving a diagnosis. This situation involves MDR-TB, a type of tuberculosis that does not respond to standard medications. Dr. Sayone Thihalolipavan county public health officer, noted that MDR-TB can be more complicated and lengthier to treat since it does not respond to the usual medicines.
The Importance of Early Screening and Treatment
Despite the challenges posed by MDR-TB, health officials assure that it is treatable and curable with the right medication. Early screening and treatment are crucial to protect individual health and the community. Anyone who believes they may have been exposed is urged to contact the County Tuberculosis Department promptly.
Individuals who test positive but do not have symptoms likely have latent TB and are advised to get a chest X-ray and consult with a medical provider. Health officials stress the importance of preventive treatment to avoid the progression to active TB disease.
Rising TB Cases in San Diego County
TB cases in San Diego County have been on the rise since 2026. Health officials reported 193 cases in 2026, 201 in 2026, 208 in 2026, and 242 in 2026. In 2026, a total of 247 people were reported with active TB disease in San Diego County. Multidrug-resistant tuberculosis is less common, with three cases in 2026 and two in 2026.
An estimated 175,000 people in the county have latent TB infections. Without treatment, 5% to 10% of those people are at risk of developing active TB disease. This underscores the importance of awareness and preventive measures in the community.
For more information on this potential exposure, individuals can call the County TB Prevention and Care Program at 619-692-8621. Health officials continue to monitor the situation and provide guidance to ensure the safety and well-being of the community.
