āāBackground
The CDPH Tuberculosis Control Branch (TBCB) has identified a substantial increase in reported TB cases in California in 2023 compared with 2022. In 2023, the number of reported TB cases increased by 271 (15%) from 1,842 in 2022 to 2,113 in 2023 (see Figure 1).
This case count is similar to the number of cases reported in 2019 when there were 2,110 cases. Since 2020, TB cases in California have been increasing each year for a total increase of 24%. āAmong the 24 local health departments that reported at least 10 cases of TB in 2023, 9 reported a single year increase of more than 20%. āTB has significant adverse consequences, as 50% of patients with TB are hospitalized. Further, TB results in death for more than 200 Californians each year, translating to a TB death every other day in California.
Figure 1: Reported cases of active tuberculosis by year, 2019-2023.
*Data for 2023 are provisional, reportāed as of February 2, 2024.
Overview
TB is an illness caused by the bacteria Mycobacterium tuberculosis. TB usually affects the lungs and spreads through the air when a person sick with TB coughs. Not everyone infected with the bacteria becomes sick. People that have been infected but are not sick have LTBI. People with LTBI can become sick with TB disease in the future if they do not take treatment for LTBI.
TB in California particularly affects people who were born outside the United States with more than 80% of cases occurring in this group. The rate of TB among people born outside the United States is many times higher than among those born in the United States.
TB also disproportionately affects other vulnerable populations such as people who are immunocompromised or experiencing homelessness. TB results in death for more than 200 Californians each year, meaning that someone in California dies with TB every other day. In 2020, 13% of people with TB died before or during treatment for TB.
Recent transmission of TB does occur in California but most TB cases (>80%) are attributable to progression from LTBI to active TB disease among people with unidentified or untreated LTBI. That means most cases of TB are preventable through testing and treating for LTBI. Among people who already have active TB disease, prompt diagnosis and treatment may prevent death and transmission of TB to others.
Recommendaātions
Recommendations for Healthcare Providers
Consider TB disease as a cause of respiraāāātory illness. ā
Providers are reminded to consider TB when TB risks, signs, symptoms, or imaging findings compatible with TB are present in a patient with a respiratory illness.
Risks for TB:
- Lived outside the United States in a country with an elevated TB rate*
*This includes most countries in Asia, Africa, Central America, Eastern Europe, Mexico, the Middle East, and South America. Elevated TB rate is defined as greater than or equal to 10 TB cases per 100,000 persons. The World Health Organization (WHO) maintains a list of country-specific annual TB incidence in its Global Tuberculosis Report.
Being immunocompromised
Close contact with someone with active TB disease
Lived in a congregate setting such as a prison/jail
Has experienced homelessness
Signs and symptoms compatible with TB:
- Persistent cough for ā„2 weeks
- Weight loss
- Hemoptysis
- Fever or night sweats
Note that symptoms of TB can be highly variable and can range from no symptoms to severe systemic symptoms.
Radiographic findings compatible with active TB:
- Infiltrates, particularly in upper lobes
- Miliary, nodular, or cavitary lesions
- Lymphadenopathy (children and immunocompromised)
- Pleural effusions
Note that radiographic findings in patients with TB can be highly variable and can include a normal chest radiograph particularly among immunocompromised patients.
To evaluate for TB:
- Order chest imaging (plain radiograph or CT scan) if not already done.
- Collect 3 sputum samples 8 hours apart for:
- AFB smear
- Mycobacterial culture
- Nucleic acid amplification testing (e.g., Xpert MTB/RIF).
Note that if an IGRA or TST is performed, a negative test does not rule out active TB disease.
Prevent TB by diagnosing anāāād treating for LTBI among people at risk for TB.
CDPH further reminds healthcare providers to test and treat for LTBI among patients at risk for TB to prevent progression to active TB disease. Primary care providers serve a critical role in identifying patients with risk factors for TB infection. Because there is no available effective vaccine (the Bacille Calmette-Guerin or BCG vaccine does not offer lifelong protection from TB disease), the most promising tool in the fight against TB is diagnosing and treating LTBI.
- Providers can use the CDPH TB Risk Assessment to identify persons for whom LTBI testing is recommended.
- Screening and treatment for LTBI is recommended by CDPH, CDC, and the U.S. Preventive Services Task Force.
- Testing with an interferon gamma release assay (IGRA, e.g., Quantiferon TB Gold+, or TSpot TB) is preferred according to CDC recommendations over tuberculin skin testing (TST, PPD) in adults and children aged >2 years especially in people born outside the United States who may have received BCG vaccination.
- Several regimens are recommended for treating LTBI. Shorter, rifamycin-based regimens of 3ā4-month duration are preferred over isoniazid monotherapy in patients able to take a rifamycin.
Report TB and consult with the local health departmeānt TB program.
Healthcare providers are required to report suspected and confirmed cases of tuberculosis to their local health department as detailed in Title 17, California Code of Regulations Reportable Diseases and Conditions (PDF). Local health department TB programs ā(PDF) can also provide input on diagnosis, treatment, and prevention of TB in their local area and can access additional consultation from CDPH if needed. TB programs may also perform contact investigations and assist with ensuring adherence to treatment for patients diagnosed with active TB.
Resources