TB EPIDEMIOLOGY TB Clinical Intensive Course Curry International Tuberculosis Center September 30, 2015 Varsha Nimbal, MPH Tuberculosis Control Branch California Department of Public Health 1 Outline TB epidemiology Global burden United States California Summary of surveillance data Demographic characteristics Clinical characteristics Summary 2 Estimated Global TB Burden, 2013 9 million incident cases; 1.1 million HIV positive 126 cases per 100,000 population 1.5 million deaths 360,000 HIV Positive 480,000 developed MDR WHO, Global Tuberculosis Control 2014 3 1
4 TB Epidemiology United States 5 30,000 Reported TB Cases United States, 1982 2013 25,000 No. of Cases 20,000 15,000 10,000 5,000 0 6 2
TB Morbidity United States, 2008 2013 Year No. Rate 2008 12,893 4.2 2009 11,519 3.8 2010 11,164 3.6 2011 10,509 3.4 2012 9,940 3.2 2013 9,582 3.0 2014* 9, 412 3.0 *Provisional Results from CDC MMWR 2015; 64(10); 265 269 7 8 Reported TB Cases by Age Group, United States, 2013 65 yrs (23%) <15 yrs (5%) 15-24 yrs (10%) 45-64 yrs (31%) 25-44 yrs (31%) 9 3
TB Case Rates by Age Group and Sex, United States, 2013 10 Reported TB Cases by Race/Ethnicity,* United States, 2013 *All races are non Hispanic. Persons reporting two or more races accounted for less than 1% of all cases. 11 TB Case Rates by Race/Ethnicity, United States, 2003 2013 40.0 30.0 Cases per 100,000 20.0 10.0 0.0 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 American Indian or Alaska Native Black or African American White Asian Native Hawaiian or Other Pacific Islander Hispanic or Latino 12 4
Number of TB Cases in U.S. born vs. Foreign born Persons, United States, 1993 2013 13 TB Case Rates in U.S. born vs. Foreign born Persons, United States,1993 2013 Cases per 100,000 14 Countries of Birth of Foreign born Persons Reported with TB, United States, 2013 15 5
Primary Anti TB Drug Resistance, United States, 1993 2013 % Resistant Note: Based on initial isolates from persons with no prior history of TB. Multidrug resistant TB (MDR TB) is defined as resistance to at least isoniazid and rifampin. 16 % Resistant 14 12 10 8 6 4 2 0 Primary Isoniazid Resistance in U.S. born vs. Foreign born Persons, United States, 1993 2013 U.S. born Foreign born Note: Based on initial isolates from persons with no prior history of TB. 17 Primary MDR TB in U.S. born vs. Foreign born Persons United States, 1993 2013 % Resistant Note: Based on initial isolates from persons with no prior history of TB. MDR TB defined as resistance to at least isoniazid and rifampin. 18 6
TB Epidemiology California 19 6,000 5,000 4,000 3,000 2,000 1,000 0 Number of Tuberculosis Cases: California, 1988 2014 Year Number of Tuberculosis Cases and Case Rates: California, 2005 2014 Case Rate per 100,000 Number of Cases Case Rate per 100,000 Population National Case Rate (3.0 per 100,000) * 7
Tuberculosis in California, 2014 Tuberculosis Case Rates per 100,000 Population: California, 2014 >= 5.6 (state average) 3.0-5.6 < 3.0 (national average) < 5 cases Note: The map illustrates TB case rates by reporting jurisdiction in 2014. Thirteen jurisdictions (including Long Beach, not represented) had TB case rates equal to or above the state average of 5.6 cases per 100,000 population. Eight jurisdictions had tuberculosis case rates below the 2014 national rate of 3.0 per 100,000 population. Eleven jurisdictions (including Pasadena and Berkeley, not represented) had case rates greater than the national rate or less than the state rate (3.0 to 5.6 cases per 100,000 population). Case rates were not calculated for 29 jurisdictions because there were fewer than five cases in these areas. CA Epidemiology Reflects Global Epidemiology 23 Tuberculosis Cases by Country of Origin: California, 2014 Unknown 14 ( 0.7%) U.S.-born 463 (21.6%) Foreign-born 1,670 (77.8%) All Others 404 (24.2%) Mexico 450 (26.9%) India 96 (5.7%) China 160 (9.6%) Vietnam 205 (12.3%) Philippines 355 (21.3%) 8
Tuberculosis Cases in Foreign born and U.S. born Persons: California, 2005 2014 Tuberculosis Cases by Race/Ethnicity: California, 2014 Black 118 (5.5%) White Non-Hispanic 165 (7.7%) American Indian/ Alaska Native 4 (0.2%) 79 Asian/Pacific Islander 1,081 (50.3%) Hispanic 776 (36.1%) How do TB Cases Occur in California? Importation TB within 1 year of US arrival 835 of 11,149 cases 2010 2014 occurred within 1 year of arrival in US 7.5% Reactivation of remote infection Cases not from importation or recent transmission: 75.5% ~2,000 TB Cases Per Year Recent Transmission 26% genotype clustering within county (3 year window) 8% with indication of transmission within 2 years on RVCT Midpoint = 17% Thanks to Pennan Barry 9
Tuberculosis Cases by HIV/AIDS Diagnosis*: California, 2004-2013 Number of Tuberculosis Cases with HIV/AIDS Percent of Tuberculosis Cases with HIV/AIDS Number of Cases with HIV/AIDS * Match found in HIV/AIDS Registry, California Office of AIDS Figure 12. HIV/AIDS-associated Tuberculosis* by Race/Ethnicity: California, 2004-2013 Number of Cases with HIV/AIDS 150 125 100 75 50 25 0 Asian/Pacific Islander Black Hispanic White American Indian/Alaska Native 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Year * Match found in HIV/AIDS Registry, California Office of AIDS Figure 13. Tuberculosis Cases with Multidrug Resistance (MDR) on Initial or Final Drug Susceptibility Testing*: California, 2003 2012 Number of MDR Tuberculosis Cases Initial Susceptibility Test 41 36 37 34 28 Final Susceptibility Test 36 32 33 25 16 *Cases with resistance to at least isoniazid and rifampin reported on the Initial Drug Susceptibility Report (Follow-up 1) or on the Case Completion Report (Follow-up 2) 10
Deaths in Persons with Tuberculosis: California, 2003 2012 Number of Deaths Percent of Cases Died During Treatment Died Before Starting Treatment Dead at Diagnosis Percent Dying with Tuberculosis What are the implications for public health practice? Continued vigilance, surveillance, and active prevention measures are needed to reach the TB elimination. To continue making strides toward elimination, alignment of domestic TB control activities with international TB control initiatives is needed to address increasing disparities between U.S. born and foreign born persons. Treatment of persons at high risk with latent Mycobacterium tuberculosis infection is also needed to address this disparity. CDC MMWR 2015; 64(10); 265 269 32 The Challenges of Latent TB Infection Preventing TB disease by detecting and treating those with latent TB infection (LTBI) is a cornerstone of the U.S. strategy for TB elimination. LTBI is not reportable It is estimated that more than 11 million people in the U. S. (including 2.5 million in California*) have LTBI If not treated, about 5 to 10 percent of people with LTBI will develop TB disease. (~550,000 to 1.1 million people in the U.S.) Source: CDC TB Epidemiologic Studies Consortium, http://www.cdc.gov/tb/topic/research/tbesc/default.htm * California estimate derived from Census population data in 2013 and native born and foreignborn LTBI prevalence estimates in Bennett et al., Am J Respir Crit Care Med 2008;177:348 55. 33 11
Common Risk Factors for Progression from TB infection to active disease Risk factor Relative Risk (95% CI) Advanced, untreated HIV 9.9 (8.7-11) infection Close contact to infectious TB 6.1 (5.5 6.8) Radiographic evidence of old, healed, untreated TB 5.2 (3.4 8.0) Prednisone treatment 2.8 (1.7 4.6) Chronic renal failure 2.4 (2.1 2.8) TNF-α antagonist treatment 2.0 (1.1 3.5) Diabetes (poorly controlled) 1.7 (1.5 2.2) Underweight 1.6 (1.1 2.2) Smoking 1.5 (1.1 2.2) 34 Source: Horsburgh et al. New Engl J Med 2011; 364(15):1441 8. CI=confidence interval Medical risk factors for progression to TB disease, TB cases in CA, 2013 N % Diabetes 540 24.9 Non HIV immunosuppressive condition 112 5.2 End stage renal disease 77 3.6 TNF α antagonist treatment 20 0.9 Post organ transplantation 15 0.7 At least one medical risk factor 35% 35 Summary Case count ~ 9,500 new cases of TB per year in the U.S. ~ ¼ of cases in the U.S. occur in California Disease incident rate Declining, but the pace of decline has slowed since ~2000 The decline from 2013 to 2014 was the smallest in over a decade California s rate nearly twice that of the U.S. (5.6 vs. 3.0 in 2014) Certain groups disproportionately affected Men (e.g., among 45+ years) Foreign born Race/ethnicity disparities TB Deaths ~9% of TB case patients die 36 12
Summary HIV 7% of TB cases in the U.S. and 3.5% of cases in CA are HIV positive Other Medical Risk Factors More than 1/3 of TB cases in CA have at least one medical condition known to increase risk of progression from TB infection to disease Diabetes most common (1/4 of TB cases) Drug Resistance Isoniazid and multidrug resistance are higher among foreign born than among U.S. born LTBI An estimated 11 million people in the U.S. (2.5 million in CA) have LTBI Majority of cases of TB disease that occur in foreign born patients result from reactivation of LTBI Prioritizing TB screening for groups with elevated LTBI prevalence and medical risk of progression from LTBI to TB may help prevent future TB cases 37 References CDC. Reported Tuberculosis in the United States, 2013. Atlanta, GA: U.S. Department of Health and Human Services, CDC Tuberculosis Control Branch. Report on Tuberculosis in California,2014. Richmond, CA: California Department of Public Health 38 Acknowledgements Peter Oh Lisa Pascopella Saul Kanowitz Janice Westenhouse Pennan Barry 39 13