Tuberculosis - PowerPoint PPT Presentation

1 / 36

  • Uploaded on
  • Presentation posted in: General

Tuberculosis. Objectives. Know current epidemiologic trends in TB Know indications for testing for TB exposure and the tests available Be familiar with treatments for latent tuberculosis infections. Background Epidemiology. 9 million Cases Annually >1/3 in India and China.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript





  • Know current epidemiologic trends in TB

  • Know indications for testing for TB exposure and the tests available

  • Be familiar with treatments for latent tuberculosis infections

Background epidemiology

Background Epidemiology

9 million cases annually 1 3 in india and china

9 million Cases Annually

>1/3 in India and China

9 million Cases Annually>1/3 in India and China

< 1 000

1 000 to 9 999

10 000 to 99 999

100 000 to 999 999

1 000 000 or more

No Estimate

Reported tb cases united states 1982 2006

Reported TB Cases* United States, 1982–2006

No. of Cases


Tb case rates united states 2006

TB Case Rates,* United States, 2006


< 3.5 (year 2000 target)


> 4.6 (national average)

*Cases per 100,000.

Tb case rates by age group and sex united states 2006

TB Case Rates by Age Group and Sex, United States, 2006

Cases per 100,000

Trends in tb cases in foreign born persons united states 1986 2006

Trends in TB Cases in Foreign-born Persons, United States, 1986–2006*

No. of Cases


*Updated as of April 6, 2007.

Drug resistant tb counted cases defined on initial dst by year 1993 2006

Drug Resistant TB Counted Cases defined on Initial DST† by Year, 1993–2006*

*Reported incident cases as of 7/18/07

†Drug Susceptibility Test

Case Count

Year of Diagnosis

Tb in children

TB in Children

  • WHO estimate of TB in children

    • 1.3 million annual cases

    • 450,000 deaths

  • 15% of TB in low-income countries children vs. 6% in United States

Making the decision to test for tb


The Initial “Test” for TB Infection is the History

Who should be tested

Who Should be Tested?

  • Those at epidemiological increased risk of having TB infection

  • Those at increased individual risk of developing TB disease if infected

  • ONLY test if you are going to treat the patient – a decision to test is a decision to treat

Questionnaire risk assessment for tb infection in children nycdoh

Questionnaire Risk Assessment for TB Infection in Children - NYCDOH

Ozuah et al. JAMA;285:451

Risk factorSens.Spec.PPVNPVOR

Contact to a case 26 99.6 38.9 99.3 92

Birth/travel to endemic area 63 89.7 5.4 99.6 15

Contact to HR adult 19 96.6 4.9 99.2 7

Age > 11 yr 67 71.0 2.1 99.6 5


Epidemiologically-Defined Groups

with HIGH Prevalence of Tuberculosis Infection

  • Immigrants from areas of world with a high incidence of TB

  • Homeless persons, and other low income groups with poor access to health care

  • Elderly persons

  • Residents and employees in congregate living facilities serving persons at high risk of TB (correctional institutions, homeless shelters, health care facilities, nursing homes, assisted living facilities, AIDS housing)

Underlying medical conditions which increase risk for progression to active tb disease

Underlying Medical Conditions Which Increase Risk for Progression to Active TB Disease

  • HIV infection

  • Chronic renal failure

  • Immunosuppressive Rx

  • Diabetes mellitus

  • Malignancy

  • TNF Alpha blocker therapy

  • Transplant recipients

  • > 15 mg Prednisone/day

  • Silicosis

Incidence of tuberculosis by selected risk factors in persons with a positive tst

Incidence of Tuberculosis by Selected Risk Factors in Persons with a Positive TST

Risk Factor

TB Cases/1000 person-years

Recent TB Infection

Infection < 1 year past

Infection 1-7 years past


Injection Drug Use


HIV-negative or unknown


Radiographic findings consistent with old TB

Weight Deviation from Standard

(5% overweight  15% underweight)









How to test


Tuberculin skin testing

Tuberculin Skin Testing

Tuberculin Skin Testing

Induration of 5mm considered a positive tst

Induration of >5mm Considered a Positive TST

  • HIV positive persons

  • Recent contacts of TB cases

  • Fibrotic Changes on CXR c/w old (not treated) TB

  • Patients with organ transplants or other immunosuppression

  • Prednisone therapy 15 mg/day > 1 month

Induration of 10mm considered a positive tst

Induration of >10mm Considered a Positive TST

  • Recent arrivals (<5 yrs) high prevalence countries

  • Intravenous Drug Users

  • Residents/employees - high-risk congregate facilities (health care, prisons, shelters, etc.)

Induration of 15mm considered a positive tst

Induration of >15mm Considered a Positive TST

  • TB lab personnel

  • Persons with “high-risk” medical conditions

  • Children <4 yrs or exposed to adults at risk

Interferon gamma release assays

Interferon Gamma Release Assays

  • Quantiferon – measure of interferon gamma in supernatant, currently at third generation test – Quantiferon Gold In-tube

  • Elispot – measure of individual T-cells that produce interferon gamma.

Positive skin test

Positive Skin Test

Now what?

Before treatment of ltbi exclude active tuberculosis

Before Treatment of LTBI: Exclude Active Tuberculosis

  • Absence of symptoms

  • Negative CXR

  • Negative medical evaluation

  • Order and wait for sputum culture if

    any question

Hilar adenopathy with infiltrate and collapse

Hilar adenopathy with infiltrate and collapse

Miliary tb in a child

Miliary TB in a child

Chest radiograph pearls

Chest Radiograph “Pearls”

  • Hilar nodes, pleural disease – extrapulmonary, few bacteria

  • Cavitary disease – many bacteria

  • Parenchymal scars – NOT active, only needs preventive therapy (LTBI) IF scar is > 2.5 cm

  • Calcified node is functionally like a normal chest radiograph (very very few live AFB)


Childhood TB diagnosed by:

  • Combination of :

    • Contact with infectious adult case

    • Symptoms and signs

    • Positive tuberculin skin test

    • Suspicious CXR or CT/MRI

    • Bacteriological confirmation

    • Serology?



Treatment of ltbi

Treatment of LTBI

  • Treatment regimens:

    • INH x 9 months

    • Alternative: Rifampin 600mg daily x 4 months for adults, 6 months for children and HIV+

    • Possible:

      • INH & Rifampin x 3 to 4 months

      • INH, Rifampin, EMB & PZA x 2 months

    • No longer used: Rifampin/PZA x 2 months

    • New? Rifapentine & INH weekly x 12 weeks

Isoniazid preventive therapy worldwide trials 1955 1965

19 controlled trials in 11 countries:

United States







Over 100,000 participants

Household contacts (6), Entire communities (3), Inactive

pulmonary lesions (5), Children with primary TB (2), School

children (1) Railway workers (1), Mentally ill patients (1)

25-92% protection






How much isoniazid is needed for the prevention of tuberculosis

How Much Isoniazid Is Needed for the Prevention of Tuberculosis?

  • Longer durations of therapy corresponded to lower TB rates among those who took 0-9 mo

  • No extra increase in protection among those who took >9 months

Community based study, Bethel Alaska

Comstock GW, 1999.

Int J Tuberc. Lung Dis 3:847-850

Iuatld study of inh therapy for ltbi

IUATLD Study of INH Therapy for LTBI

  • Reduction in culture positive TB at 5 years all participants

    • 6 months therapy 65%

    • 12 months therapy 75%

  • Reduction in culture positive TB at 5 years in the group of completer-compliers (took > 80% of doses):

    • 6 months therapy69%

    • 12 months therapy 93%


Contacts Of INH Resistant TB

  • Four month regimen daily Rifampin for adults

  • Six month regimen daily Rifampin for HIV infected

  • Six month regimen daily Rifampin for children

Treatment of latent tb infection in special situations

Treatment of Latent TB Infection in Special Situations

  • For children and adolescents (<18 years old):

    • Isoniazid for 9 months

  • For pregnant women:

    • Isoniazid for 9 or 6 months - may defer except for HIV- infected women and those recently infected with Mycobacterium tuberculosis

  • For persons exposed to isoniazid resistant TB:

    • Rifampin for 4 months

  • For persons likely infected with multidrug-resistant TB:

    • Pyrazinamide and ethambutol, or pyrazinamide and

    • quinolone for 6-12 months (i.e., at least 2 drugs to which the organism is susceptible)

Tb and bcg vaccination

TB and BCG Vaccination

  • Efficacy for adult pulmonary TB 0-80% in randomized clinical trials

  • Best efficacy against serious childhood disease

    • 64% protection against TB meningitis

    • 78% protection effect against disseminated TB

  • BCG important for young children, inadequate as single strategy

Colditz GA et al. JAMA 1994; 271: 698-702.

  • Login