San Diego County Public Health Services, in partnership with the San Ysidro Elementary School District, has announced a potential exposure to tuberculosis (TB) at Sunset Elementary School.
In a press release issued Wednesday, the county stated the period of potential exposure occurred between July 5, 2025, and Oct. 21, 2025. The school is located in San Ysidro, near the corner of Sunset Lane and South Vista Avenue.
Health officials are now working with the school district to notify staff and students’ families about the potential exposure. According to the county, individuals considered to be at the highest risk of having been in close contact with the infected person may have already been contacted.
To address the health concerns, the county is offering free and confidential TB screenings to any students and staff members who are identified as being at an increased risk. Concerned parents and staff can get more information about the potential exposure by calling the County TB Control Program at 619-692-8621.
What is tuberculosis?
Tuberculosis is a serious and contagious disease caused by a bacterium called Mycobacterium tuberculosis. It is an airborne illness, meaning it spreads through the air when a person with an active TB infection coughs, speaks, sings, or even breathes, expelling bacteria into the environment. It primarily affects the lungs but can also attack other parts of the body, including the kidneys, spine, and brain.
Transmission typically requires prolonged indoor exposure to someone with the active disease. It is not spread through casual contact like shaking hands, sharing food or drinks, or touching common surfaces. Health officials stress that only those who have spent extended time in the same indoor space as an infected individual are generally at risk.
Public health officials distinguish between two conditions: latent TB infection and active TB disease. Most people who are exposed to the bacteria do not become sick right away. Instead, they develop a latent infection, where the bacteria live in the body without causing symptoms. These individuals are not infectious.
Most people who become infected after exposure to tuberculosis do not get sick right away. Some who become infected with tuberculosis will become ill in the future, sometimes even years later, if their latent TB infection is not treated. For people who think they may have been exposed, blood tests and skin tests are an effective way to determine an infection.
The symptoms of an active TB infection are distinct and can include a persistent cough lasting more than two weeks, fever, unexplained weight loss, and drenching night sweats. Anyone experiencing these symptoms is advised to seek prompt medical evaluation.
A concerning trend in San Diego
The alert at Sunset Elementary is the latest in a series of TB exposure warnings in San Diego County, which has seen a marked increase in cases over the past few years. According to county data, the number of confirmed TB cases grew from 193 in 2020 to 265 in 2025, a more than 37 per cent increase. This rise puts an additional strain on public health resources, which are already stretched due to civic challenges like the city's recent budget deficit.
This incident follows a potential exposure reported in March at the Iglesia Ni Cristo church in Miramar and another at Southwestern College in April. The exposure period for the church was between September and December of last year, while the college exposure was from October to December. The succession of these events highlights that TB remains a persistent public health threat in the community. It adds to other environmental health concerns in the region, which has previously been identified as having some of the most polluted air in the United States, although smog is not related to TB transmission (San Diego region ranks 7th smoggiest in US).
While the discovery of antibiotics in the mid-20th century drastically reduced tuberculosis mortality rates in developed nations, the disease was never fully eradicated. It remains a significant cause of illness and death worldwide. In the United States, thousands of cases are still reported annually, according to the U.S. Centers for Disease Control and Prevention (CDC), requiring constant vigilance from public health departments.
Screening and treatment are key
The county's response to the Sunset Elementary exposure follows well-established public health protocols. The first step, known as contact tracing, involves identifying everyone who may have shared airspace with the infectious individual for a significant amount of time. This meticulous work is fundamental to containing outbreaks of airborne diseases and is a standard practice for health departments across North America, such as when health officials shut down 10 unpermitted Tacoma food stands to prevent foodborne illnesses.
Fortunately, effective treatments are available for both latent and active tuberculosis. For those with a latent infection, a shorter course of preventative antibiotics is usually prescribed to kill the dormant bacteria and prevent the future onset of active disease. Treatment for active TB is more intensive, requiring a combination of multiple powerful antibiotics taken for six to nine months, or sometimes longer.
Health officials say it is critically important for patients to complete their full medication regimen. Failing to do so can lead to a relapse of the illness and can contribute to the development of drug-resistant strains of TB, which are much more difficult and costly to treat. The County Public Health Services will continue to offer testing and support to the Sunset Elementary community in the coming weeks.
