1. Delayed TB Diagnosis Thomas R. Navin MD
Chief, Surveillance, Epidemiology, and
Outbreak Investigations Branch
Division of Tuberculosis Elimination
CDC

2. Test of Baseline Knowledge
How many patients are evaluated for TB each year in the United States?
Are the number of persons evaluated going down or staying stable?
Are delays in TB diagnosis getting worse?
Are delays worse for racial/ethnic minorities?

3. Patients Evaluated for TB at CDC-funded Public Health Laboratories, 2008-2009
% change
Patients evaluated for TB
103,708
97,568
-5.9%
Patients with cultures positive for M. tuberculosis
4,972
4,217
-15.2%
Ratio of patients evaluated to patients diagnosed with TB
21 : 1
23 : 1

4. Measuring TB Diagnostic Delay
Preliminary Results from TBESC Task Order 23: National Study of Early Diagnosis of TB in the African-American Community
Co-Principal Investigators: Dolly Katz, Ph.D., CDC Rachel Royce, Ph.D., M.P.H., RTI International Charles Wallace, Ph.D., Texas Department of Health

5. Months from Symptom Onset to Diagnosis (N=346)
 Race
Mean
(SD)
Median
African-American
4.4
(6.1) 2
White
19.7
(48.4) 4
p=0.04

6. Months from Symptom Onset to First Medical Care: Patient Delay (N=346)
 Race
Mean
(SD)
Median
African-American
2.4
(5.2) 1
White
9.2
(29.5)
p=0.8

7. Months from First Medical Care to Diagnosis: Provider Delay (N=346)
 Race
Mean
(SD)
Median
African-American
2.2
(3.5) 1
White
4.5
(4.5)
p=0.4

8. Summary of Findings from Task Order 23: Study of Patient and Provider Delay
Snap shot in time (rather than trend over time)
Both patient and provider delay observed
Delay not worse for African Americans compared with whites

9. Number of Outbreaks where item was considered a contributing factor
Contribution of Provider Diagnostic Delay to 27 TB Outbreaks Investigated by CDC*
Contributing factors
Number of Outbreaks where item was considered a contributing factor
Prolonged infectious period 24
Provider-related diagnostic delay 12
Patient-related delay in access to care 6
* From: Mitruka et al., EID 2011;17(3):425

10. National TB Surveillance System: Trends in culture-positive, smear-negative pulmonary TB

11. Data from Recent TB Outbreak Cases by sputum smear status
TB Cases
Treatment Start Date

12. Culture-confirmed Pulmonary TB by Sputum Smear Status, United States 2000-2009
Smear negative
TB Cases
Smear status unknown/not done

13. Proportion of Pulmonary TB Cases
Proportion of Pulmonary TB Cases* That Are Sputum Smear-Negative, United States,
Culture-positive TB cases

14. Proportion of Pulmonary TB Cases
Proportion of Pulmonary TB Cases* That Are Sputum Smear-Negative, by Race/Ethnicity United States,
TB Case Count Date
* Culture-positive TB cases

15. Test of What You Have Learned
How many patients are evaluated for TB each year in the United States?
Are the number of persons evaluated going down or staying stable?
Are delays in TB diagnosis getting worse?
Are delays worse for racial/ethnic minorities?

16. Test of What You Have Learned
How many patients are evaluated for TB each year in the United States?
100,000 persons evaluated each year at public health labs alone
Ratio of evaluated-to-diagnosed: 20+
Are the number of persons evaluated going down or staying stable?
Number is going down, but ratio of evaluated-to-diagnosed may be going up

17. Test of What You Have Learned
Are delays in TB diagnosis getting worse?
Data are not good, but no evidence of worsening
Are delays worse for racial/ethnic minorities?
Data are not good, but no evidence of a difference

18. Getting Physicians to “Think TB” is asking them to look for a needle in a haystack

19. Can Physicians be Educated to “Think TB”?
As TB rates decline, general medical expertise and education targeted at TB will decline
Untargeted campaigns may not be successful
“Think TB” campaigns may have impact in targeted situations:
In high-risk communities
During outbreaks

20. Can Physicians be Educated to “Think TB”
Can Physicians be Educated to “Think TB”? Challenges During TB Outbreaks
Most media stories about TB “outbreaks” describe contact investigations at schools
Most contact investigations at schools do not detect additional TB cases
Health Departments often work hard to keep information on large TB outbreaks out of media

21. Outbreak-associated TB cases can make up a significant portion of TB cases in a community and can continue for years

22. Outbreak Associated TB Cases, 2002-2010 (N=109)
No. of cases
a As of August 2010