1. Tuberculosis Infection & Disease: Fundamentals for the General Public
Division of Tuberculosis Control
Virginia Department of Health
Richmond, Virginia
Picture of tuberculosis bacteria under the microscope

2. Table of Contents Introduction
Role of the Public Health Department and the Virginia Tuberculosis Control Laws
Tuberculosis Transmission and Pathogenesis
Epidemiology of Tuberculosis in Virginia
Screening for Tuberculosis Infection
Evaluating for LTBI and TB Disease
Treatment of LTBI and TB Disease
Infection Control Guidelines

3. 1. Introduction

4. Tuberculosis (TB): A Disease of Public Health Significance
Potentially fatal disease transmitted by droplet nuclei after close contact with a person who has infectious, TB disease
Long, multidrug treatment regimens increase potential risk of nonadherence
Serious impact on community if TB treatment is improper and/or inadequate
Disproportionate impact on persons with inadequate access to health care

5. Current TB Challenges in Virginia
Increasing proportion of TB patients born outside the US
48 different countries of origin in 2003
At least 20 primary languages, other than English, spoken in 2003
High incidence of drug-resistant TB cases
21 deaths from TB in 2003
TB is a curable disease

6. Role of the Health Department

7. The Public Health Department
Is a recognized expert in TB control for the local community
Is a resource for the latest on testing and treatment standards
Has access to medical experts at CDC for consultation on complicated TB cases

8. Health Department’s Role in Community TB Control
Provides follow-up care to persons diagnosed with TB
Has ultimate responsibility for TB control in Virginia
Has authority to legally enforce the VA Health Code
Requires compliance to TB treatment
See Guidebook for the 2001 TB Control Laws
Assists in interjurisdictional referrals for patients who move residences

9. VA Division of TB Control (DTC) Role of the Central Office in Richmond
Mission of the DTC
Provide leadership in overcoming barriers to protect the people of Virginia from tuberculosis
Objectives of the DTC
Detect all cases of TB disease
Treat all cases of active TB disease
Complete treatment of all cases of active TB disease and their infected contacts

10. Virginia TB Control Laws: Key Points
Require reporting of TB disease
Require treatment and adherence to TB treatment
Allow isolation of infectious TB disease patients who refuse TB treatment and/or put the public at risk for TB infection

11. 3. Transmission and Pathogenesis of TB

12. How TB is Transmitted
TB is caused by a bacteria, Mycobacterium tuberculosis (tubercle bacillus)
TB transmission occurs when a person with active, infectious TB disease coughs, sneezes, laughs, sings, etc.
TB spreads through the air by inhaled droplet nuclei
TB needs prolonged contact for transmission

13. Factors That Determine TB Transmission
Infectiousness of the person with TB disease
The more infectious a person, the more likely the TB will be transmitted to others who are in close contact with this individual
Environment in which exposure to TB occurs
Room size and ventilation -- Transmission of TB is likely to occur in rooms that are small and with poor ventilation
Length of time spent with the infectious TB patient
The longer the time spent with an infectious TB patient, the more likely TB transmission will occur
Virulence (strength) of the TB bacteria
The stronger the TB bacteria, the more likely the transmission of TB infection will occur

14. Pathogenesis of TB
TB occurs most commonly in lungs (85% of the time), but can occur in other parts of the body
A person with TB infection and a normal immune system has a 10% chance of developing active TB disease in his/her lifetime
This risk is greatest within the first 2 years after acquiring TB infection

15. Common Sites in the Body Where TB Disease May Occur
Pulmonary (Lungs) -- (85% of the time)
Extrapulmonary (outside the lungs)
Pleura (lining of the lungs)
Central nervous system
Lymphatic system
Genitourinary systems
Bones and joints
Multiple sites in the body
Pleura (sac that surrounds the lungs)

16. TB Infection or Latent TB Infection (LTBI)
Occurs when TB bacteria are in the body, but are inactive
Does not have any clinical symptoms of active TB disease
Is not infectious to others
Produces a “positive” reaction to the TB Skin Test
Presents a normal chest X-ray

17. Active TB Disease
Occurs when the inactive TB bacteria in the body (LTBI) become active
May be infectious
Has clinical symptoms (see next slide)

18. Symptoms of Active TB Disease
Prolonged cough (may produce sputum)*
Chest pain*
Hemoptysis*
Fever
Chills
Night sweats
Fatigue
Loss of appetite
Weight loss or failure to gain weight
*Symptoms commonly seen in cases of pulmonary (lung) TB

19. TB Infection (LTBI) vs. Active TB Disease
Pulmonary (Lung) TB Disease
Tubercle bacilli in body
Tuberculin skin test reaction usually positive
Chest X-ray usually normal
Chest X-ray usually abnormal
Sputum smear & culture negative
Sputum smear & culture positive
Asymptomatic
Often infectious before treatment
Not a case of TB (Reportable only in children < 4 years of age)
A case of TB (Reportable)
Treated with 1 drug
Treated with multiple drugs

20. (Continued on next slide)
Persons at Higher Risk for Becoming Infected with TB
Close contacts of persons known or suspected to have active, infectious TB disease
Foreign-born persons from areas in the world where TB is common
Residents and employees of high-risk congregate settings
Health care workers (HCWs) who serve high-risk clients
(Continued on next slide)

21. Persons at Higher Risk for Becoming Infected with TB (continued)
Medically underserved, low-income populations
High-risk racial or ethnic minority populations
Children exposed to adults in high-risk categories
Persons who inject illicit drugs

22. Once Infected with TB, Factors That Would Increase the Risk for Developing TB Disease
HIV infection
Substance abuse
Recent TB infection
Low body weight (10% or more below the ideal)
Diabetes mellitus
Silicosis
Prolonged corticosteroid therapy
Other immunosuppressive therapy
End-stage renal disease
Cancer of the head or neck
These high-risk persons should be tested for TB infection, and if positive, treated.

23. TB and HIV Coinfection: A Concern
For persons infected with TB, HIV positive status is the strongest risk factor for developing active TB disease
In persons who are HIV positive and have TB infection, the chances of developing TB disease increases from 10% in a lifetime to 7% to 10% each year!

24. 4. Epidemiology of TB in Virginia

25. What is Epidemiology?
Epidemiology is the study of the distribution and determinants of disease in human populations
Epidemiological data tell us:
who in the population is most at risk for developing TB disease
what risk factors these individuals possess
where TB disease is most prevalent
how to best protect the public from the spread of TB disease

26. Epidemiology & Surveillance
Epidemiology guides the efforts of the Virginia Division of TB Control and health departments
Epidemiology helps determine which persons to screen for TB
Surveillance is an epidemiological method where there is an on-going systematic collection of disease data to obtain a thorough understanding and analysis of disease patterns

27. TB Cases Reported in Virginia, 1992-2003
Overall, in the last 10 years, Virginia saw a steady decrease in TB cases reported.
However, in 2000, there was an increase, albeit very slight (2.9%), in the TB cases. In 2001, 306 TB cases were reported. In 2002, 315 TB cases were reported. Division of TB Control needs to continue monitoring the cases of TB.
See Notes pages for an explanation of this graph. [In the menu bar, click “View,” then “Notes Pages.”]

28. Percent of TB Cases by Age and Sex in Virginia, 2003
See Notes Pages for an explanation of the graph.
Unlike the past, TB is becoming less a disease of the elderly, and more a disease of the economically productive members of the population
TB is becoming more a disease of a younger population
15-24 year olds
25-44 year olds
The change in the age groups affected by TB in Virginia also reflects a global trend. The Virginia TB cases reflect demographic characteristics similar to TB cases in nations where TB is a leading cause of death.
Another concern with TB in this younger population is that this group is the same age group affected by HIV infection; so, TB/HIV co-infection may be more likely in this group.

29. Percent of TB Cases in Virginia, by Region 2002 and 2003
In the last 10 years, the prevalence of TB cases has shifted. In 1992, the Eastern, Northern and Central regions shared the majority of the TB cases occurring in Virginia. The geographic distribution of TB cases shifted in Currently, the Northern Virginia region contains half of the state’s total TB cases.
2002
2003

30. 5. Screening for TB Infection (LTBI)

31. Goal of Screening for LTBI
Find persons with LTBI who would benefit from treatment to prevent the development of TB disease
Find persons with TB disease who would benefit from treatment [Persons at no risk for TB infection should not be tested for TB]

32. Mantoux Tuberculin Skin Test (TST)
A test for TB infection only
Preferred test for TB infection
Clinician performs procedure
An injection
Interpretation of TST result (positive, negative) based on:
Size of the induration (swelling) and
Person’s risk factors for TB
Mantoux Tuberculin skin test also known as Purified Protein Derivative (PPD)
TST should only be done on people who have risk factors for TB infection or positive TB risk assessment
Most people who have a TB infection will have an induration (swelling) of some length near the injection site

33. Persons Who Have Had the BCG Vaccine
Persons born outside the US, and in a country where TB is common may have received the Bacille Calmette-Guerin (BCG) vaccine one or more times
These persons can still receive the TB skin test
Persons who had the BCG vaccine and have a positive TB skin test should be treated for TB infection

34. 6. Evaluating for LTBI and TB Disease

35. Steps in Evaluating for LTBI and TB Disease
Health care worker will perform the following when evaluating persons for LTBI or TB disease:
Assess risk for TB infection, and if necessary…
Administer TB Skin Test
Refer persons for Chest x-ray
Collect sputum and/or other specimen to determine presence of TB

36. What is the Purpose of a Chest X-Ray?
Chest x-rays…
Are needed if the TB skin test is positive, or if a patient has symptoms of TB disease
Help determine if LTBI has progressed to TB disease in persons who have a positive TB skin test
Check for lung abnormalities in persons with symptoms of TB disease

37. What is the Bacteriology Process?
Patients provide specimen (sputum or other)
Laboratories:
Prepare a smear of the specimen to assess the presence of the tubercle bacilli
Guides in making a presumptive diagnosis of TB
Culture (grow) the specimen for presence of TB bacteria
Positive culture confirms diagnosis of TB disease
If culture is positive, further tests are done to determine the susceptibility/resistance to TB drugs
Helps clinicians choose correct drugs for patient

38. 7. Treatment of LTBI and TB Disease

39. Basic Principles of TB Treatment
Goals of treatment for TB disease are:
Provide the safest, most effective therapy in the shortest possible time
Give multiple drugs to which the TB bacteria are susceptible
Ensure patient adherence to therapy

40. Treatment of LTBI
Treating LTBI prevents the development of TB disease, especially for persons at high risk for developing TB disease if infected with TB
Usual medication regimen for treating TB infection
Isoniazid (INH) for 9 months is optimal
6 months of INH is acceptable
Rifampin for 4 months is alternative in certain circumstances

41. Medications for TB Disease
Usual medication regimen
Minimum of 6 months of therapy, sometimes longer
Initial 4 drug therapy standard, and they are:
Isoniazid (INH)
Rifampin
Pyrazinamide (PZA)
Ethambutol
Medications may need to be changed if the TB is drug resistant to any medication listed above

42. Treatment of Extrapulmonary TB Disease
In most cases, extrapulmonary TB is treated with same regimens as those used for pulmonary (lung) TB
A minimum of 12 months of treatment is recommended for bone and joint TB, miliary TB, or TB meningitis in children

43. Treatment of Multidrug-Resistant (MDR) TB Disease
MDR presents difficult treatment problems
Treatment must be tailored to each patient and the strain of the patient’s TB bacteria
Use of directly observed therapy (DOT) is mandatory in treating persons with MDR-TB

44. Causes of Drug Resistance
Physician prescribes an inappropriate drug regimen
Patients do not take their TB medications exactly as instructed
Infection with a TB bacteria that is already drug-resistant

45. Monitoring of Treatment
Patients will be monitored for adverse reactions to the TB therapy
Clinicians will conduct baseline tests to assess a patient’s health at the start of therapy
Patients will be seen at least monthly to:
Assess the response to medications
Assess the adverse reactions to medicines

46. Directly Observed Therapy (DOT)
A health care worker watches a TB patient swallow each dose of the prescribed drugs
DOT is recommended for all persons who have TB disease
The health care worker will conduct DOT at a time and place convenient for each patient who has TB disease

47. Benefits of DOT
DOT allows for the rapid identification of problems patients may experience with the TB medicines
Health care workers can intervene earlier to resolve any reactions to medication
[Health care workers are routinely checking on patients’ progress]

48. 8. Infection Control and TB

49. Infectiousness of TB Patients
Persons with active TB disease of the lungs and throat are considered infectious if they:
Are coughing
Are undergoing cough-inducing or aerosol-generating procedures
Have sputum smears positive for acid-fast bacilli and are not receiving therapy
Have just started TB therapy
Have poor clinical response to therapy

50. Infectiousness of TB Patients (continued)
The infectiousness is directly related to the:
number of tubercle bacilli the TB patient releases into the air
clinical characteristics of the patient’s TB disease
patient’s response to therapy
Infectiousness declines rapidly after adequate treatment is started

51. When are Persons with TB Disease Considered Non-Infectious?
Patients with TB disease are considered non-infectious if they meet all of the following criteria:
They are on adequate therapy for at least 2 weeks
They have had a significant positive clinical response to therapy
They have had 3 consecutive negative specimen smear results

52. How to Protect Yourself From TB Infection
When in close contact with a person with infectious TB disease:
Wear a mask
Open windows in rooms
Get screened for TB at your local health department
Learn more about TB infection and disease from your local health department

53. How to Protect Others From TB If You Have Infectious TB Disease
Eliminate contact with others if you are infectious
If close contact with others is inevitable, make sure that you always:
Wear a mask
Open windows in rooms
Cover your mouth and nose with hands when sneezing, speaking, coughing, singing, etc.
Encourage persons who spend a great deal of time with you to be screened for TB infection

54. For More Information…
Virginia Department of Health Division of TB Control 1500 East Main St, Room 119, Richmond, VA (Telephone); (Fax)
Local Health Departments
Centers for Disease Control and Prevention Division of TB Elimination