delayed tb diagnosis thomas r. navin md chief, surveillance, epidemiology, and outbreak...

Delayed TB Diagnosis

Thomas R. Navin MDChief, Surveillance, Epidemiology, and Outbreak Investigations BranchDivision of Tuberculosis EliminationCDC

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?

Patients Evaluated for TB at CDC-funded Public Health Laboratories,

2008-2009

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

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., CDCRachel Royce, Ph.D., M.P.H., RTI InternationalCharles Wallace, Ph.D., Texas Department of Health

4

Measuring TB Diagnostic Delay

Months from Symptom Onset to Diagnosis

(N=346)

5

 Race Mean (SD) Median

African-American 4.4 (6.1) 2White 19.7 (48.4) 4p=0.04      

Months from Symptom Onset to First Medical Care: Patient Delay

(N=346)

6

 Race Mean (SD) Median

African-American 2.4 (5.2) 1White 9.2 (29.5) 1p=0.8      

Months from First Medical Care to Diagnosis: Provider Delay

(N=346)

7

 Race Mean (SD) MedianAfrican-American 2.2 (3.5) 1White 4.5 (4.5) 1p=0.4      

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

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

National TB Surveillance System:

Trends in culture-positive, smear-negative pulmonary TB

Data from Recent TB OutbreakCases by sputum smear status

Mar Apr May Jun Jul Aug Sep Oct0

1

2

3

4

5

6

Smear-negativeSmear-positive

TB

Cases

Treatment Start Date

Culture-confirmed Pulmonary TB bySputum Smear Status, United States

2000-2009

TB

Cases

0

1000

2000

3000

4000

5000

Smear positive

Smear negative

Smear status unknown/not done

Proportion of Pulmonary TB Cases* That Are Sputum Smear-Negative,

United States, 2000-2009

•Culture-positive TB cases

20002001200220032004200520062007200820090%

20%

40%

60%

80%

100%

Proportion of Pulmonary TB Cases* That Are Sputum Smear-Negative,

by Race/EthnicityUnited States, 2000-2009

TB Case Count Date* Culture-positive TB cases

20002001200220032004200520062007200820090%

20%

40%

60%

80%

100%

WhiteBlackHispanic

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?

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

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

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

haystack

Community-acquired pneumonia

Lung CA TB (0.3%)

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

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

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

0

5

10

15

20

25

Outbreak Associated TB Cases, 2002-2010 (N=109)

No.

of

cases

a As of August 2010