California TB Cases Surge to Highest Level in Over a Decade

California, often called America's tuberculosis capital, has hit a troubling milestone. The state recorded 2,150 new cases in 2025. This figure represents the highest number seen in over a decade. It is the first time such a high count has been reached since 2013. That means infections are up by two percent compared to the previous year.

The state currently holds the title for the most infections in the entire nation. Its infection rate is nearly double the national average. Last year, about 279 people died from the disease. That number accounts for 13 percent of all patients infected.

Nationally, the United States saw more than 10,000 cases in 2024. This was the highest total since 2011. Infections rose in 80 percent of US states during that time. Experts say distrust of doctors played a major role. This fear was forged during the pandemic. Fewer people seek treatment until the disease becomes active.

Officials recently sounded the alarm over a specific outbreak. It occurred at an exclusive private school in San Francisco. The school charges $30,000 per year for tuition. More than 241 individuals were exposed to the bacteria there.

The bacteria, mycobacterium tuberculosis, spreads easily through coughs and sneezes. It is known as the 'Victorian era' disease. Estimates suggest over 50 percent of patients die without treatment. Children under five are at the highest risk. Early symptoms include a persistent cough and blood. Later stages bring breathing difficulties and lung damage. The disease can even spread to the brain or spinal cord.

Treatment usually involves antibiotics. However, some strains are now resistant to these drugs. A vaccine exists but is not routinely offered in the US. Officials from the California Department of Public Health released the new report. Local media recently covered these findings.

The data shows all patients had active infections. This means the bacteria were causing real symptoms in their bodies. Some cases start as latent TB. The immune system suppresses the disease in these instances. If untreated, these latent cases can progress to active disease.

Officials say about 83 percent of cases came from latent infections progressing. This suggests testing and treatment could have prevented them. About seven percent involved people who arrived in the state already infected. Another ten percent resulted from recent transmission.

The state had recorded roughly 2,000 to 2,100 infections annually since 2013. These numbers dipped during the pandemic. The peak occurred in 1992 with 5,300 recorded cases. A major public health effort drove those numbers down significantly. Forty-five of the state's 61 local health authorities reported at least one case. Data on hospitalizations was not provided in the report.

Uncertainty still shrouds the exact number of tuberculosis infections recorded in California this year. Dr. Martin Willis, the former public health officer for Marin County, warned that the disease flourishes in environments where people lose access to essential healthcare. He explained that when individuals with latent disease are unable to get treatment, the condition activates and they begin spreading the bacteria to others.

Provisional national data indicates that TB cases in the United States dropped by one percent last year compared to the previous period, yet the figures remain higher than those seen in 2011, the last recorded peak in infections. The situation is particularly acute at a California school where an outbreak is currently underway. There, seven students have been diagnosed with active infection, while 241 others carry the bacteria in a latent state.

"This is a big outbreak," said Dr. Monica Gandhi, an infectious disease expert at the University of California San Francisco. She highlighted the rarity of such a high percentage of the student body being diagnosed. While latent TB is asymptomatic, seeing 20 percent of a school population affected is unusual for this country. "Kids in this country do not have latent TB like that," she noted, adding that such prevalence rates are typically found in low-income nations.

Globally, the stakes are even higher, with tuberculosis killing 1.2 million people each year. In the United States, the disease infects a few thousand Americans annually and claims around 500 lives. The risk to local communities is compounded by the lack of transparency regarding how many cases exist, leaving vulnerable populations without a clear picture of the threat they face.