Tuberculosis in California: 2025 Snapshot

1. Core Framework: "Getting to Zero" (Barry et al., 2016)

The primary thesis established by Barry et al. in Current Epidemiology Reports (2016) is that standard TB control measures (prompt case finding and treatment of active disease) are insufficient for elimination.

• The Latent TB Infection (LTBI) Reservoir: The vast majority of active TB cases in California (>80%) stem from the reactivation of longstanding, untreated latent TB infections rather than recent transmission within the state.

• Targeted Testing and Treatment: To achieve true elimination (defined as less than 1 case per 1,000,000 population), public health strategy must shift upstream toward identifying and treating high-risk populations with LTBI before reactivation occurs.

• Focus Populations: Priority groups include non-US-born individuals from areas with high endemic TB rates, immunocompromised individuals (e.g., HIV, immunosuppressive therapies), and close contacts of active cases.

2. Updated Data Highlights: Tuberculosis in California (CDPH 2024–2025 Data)

Recent surveillance metrics from the CDPH show both progress and ongoing challenges in reaching elimination goals.

Key Statistical Trends

• Case Counts & Incidence: California continues to report the highest total number of active TB cases of any US state. Following a temporary decline during the early pandemic, active TB incidence has trended back upward, reflecting both improved diagnostic catch-up and persistent reactivation dynamics.

• Disproportionate Impact: Over 80% to 85% of active TB cases occur among non-US-born residents.

• Underlying Risk Factors: Diabetes, end-stage renal disease, and other chronic health conditions continue to represent significant risk factors for LTBI reactivation among adults.

Metric / Dimension	Strategic Focus (2016 Foundation)	Surveillance Snapshot Findings (2025 Update)
Primary Driver	Reactivation of Latent TB (LTBI)	~85% of active cases originate from LTBI reactivation
High-Risk Demographics	Non-US-born individuals, immunocompromised	Non-US-born individuals represent over four-fifths of total cases
Diagnostic Preference	Shift away from TST toward IGRAs	Increased reliance on Interferon-Gamma Release Assays (IGRAs)
Elimination Barrier	Low LTBI screening rates in primary care	Persistent gap in primary care routine LTBI testing and treatment completion

3. Key Policy & Clinical Practice Implications

1. Integrating Screening into Primary Care: Because public health clinics alone cannot reach millions of individuals with LTBI, screen-and-treat efforts must be integrated into routine adult primary care visits.

2. Shorter Treatment Regimens: Broad adoption of shorter, safer regimens for LTBI treatment—such as 3HP (3 months of weekly isoniazid and rifapentine) or 4R (4 months of daily rifampin)—improves treatment completion rates compared to traditional 9-month isoniazid courses.

3. Addressing Health Disparities: Targeted community outreach and culturally responsive care are critical to overcome barriers in high-burden demographic groups.

   
   

   Barry PM, Kay AW, Flood JM, Watt J. “Getting to Zero: Tuberculosis Elimination in California.” Current Epidemiology Reports. 2016;3:136–144.

   
   

   Full text — PubMed Central

   
   

   PubMed record

   
   

   DOI: 10.1007/s40471-016-0076-6

   California Department of Public Health. “Tuberculosis in California: 2025 Snapshot.” This is the source for the updated 2,150 cases, 83% attributable to LTBI progression, >2 million Californians with LTBI, and nearly 40% of cases occurring in adults ≥65.

   
   

   CDPH — Tuberculosis in California: 2025 Snapshot