Tuberculosis
What aspects of control and prevention measures contributed to the decrease in tuberculosis in the United States from 1993 - 2008?
-1993-2008: Number of TB cases reported annually in U.S. steadily declined -Increased federal funds and other resources allowed TB programs to improve control efforts to: -Promptly identify persons with TB -Start appropriate initial treatment for TB cases -Ensure patients complete treatment
What differences in Alabama for TB have we seen across races/ethnicities?
-2010 (slide 41): US born (44%AA, 33% white, 19% latino...) / Foreign Born (45% Asian, 37% Latino, 13% AA)
Who (in general and specifically) should be targeted for tuberculosis testing? Why? When should people be tested? Who should not be tested for tuberculosis infection?
-At high risk for infection with M. tuberculosis -At high risk for developing TB disease once infected with M. tuberculosis •People in these groups should receive high priority for LTBI treatment if they have a positive tuberculin skin test (TST) or interferon-gamma release assay (IGRA) -People who are not at high risk generally should not be tested; only test if there is a plan for FU care
Describe the tuberculosis disease's (historical) trend in the United States over time, knowing the timeframes when the directionality of the trend changed
-Discovery of TB drugs in 1940s and 50s... -1953: More than 84,000 cases of TB -1953-1984: TB cases declined about 6% each year -1985: TB cases reached a low of 22,201 -1986: Significant increase in TB cases began
Describe the pathogenesis of tuberculosis.
-Droplet nuclei containing tubercle bacilli are inhaled, enter the lungs, and travel to small air sacs (alveoli) -Tubercle bacilli multiply in alveoli, where infection begins -A small number of tubercle bacilli enter bloodstream and spread throughout body •Within 2 to 8 weeks the immune system produces special immune cells called macrophages that surround the tubercle bacilli •These cells form a barrier shell that keeps the bacilli contained and under control (LTBI) •If the immune system CANNOT keep tubercle bacilli under control, bacilli begin to multiply rapidly and cause TB disease •This process can occur in different places in the body
Name the factors that contributed to the increase in tuberculosis morbidity from 1985 - 1992 in the United States.
-Emerging HIV/AIDS epidemic -Immigration from countries where TB was common -Transmission of TB in congregate settings -Development of multidrug-resistant (MDR) TB -Decades of funding cuts had impaired effectiveness of TB control programs
What are the general aspects of tuberculosis testing programs.
-Employees and residents are periodically given TSTs or IGRAs •Testing programs: -Identify people who have LTBI or TB disease and give them treatment -Determine whether TB is being transmitted in facility
How does the number of tuberculosis cases vary over time (i.e., 1993 - 2010) for U.S.-born vs. foreign-born persons?
-In 2013, 65% of all TB cases and 90% of multidrug-resistant TB cases in the United States occurred among people born in other countries. -2001: foreign born exceeded US born and steady decline over time in US born
Contrast tuberculosis disease and latent tuberculosis infection.
-Latent TB infection: Inactive, contained tubercle bacilli in the body TST or blood test results usually positive Chest x-ray usually normal Sputum smears and cultures negative No symptoms Not infectious Not a case of TB -TB Disease (in the lungs) Active, multiplying tubercle bacilli in the body TST or blood test results usually positive Chest x-ray usually abnormal Sputum smears and cultures may be positive Symptoms such as cough, fever, weight loss Often infectious before treatment A case of TB
Which mycobacteria cause tuberculosis?
-M. tuberculosis -M. bovis -M. africanum -M. microti -M. canetti
What are the circumstances surrounding the progression to tuberculosis disease?
-Risk of developing TB disease is highest the first 2 years after infection -people with LTBI can be given treatment to prevent them from developing TB disease -Detecting TB infection early and providing treatment helps prevent new cases of TB disease
What factors increase the likelihood of tuberculosis being transmitted?
-Susceptibility of the exposed person -Infectiousness of person with TB (i.e., number of bacilli TB patient expels into the air) -Environmental factors that affect the concentration of M. tb organisms -Proximity, frequency, and duration of exposure (e.g., close contacts) -Can be transmitted from children, though less likely
Describe the global epidemiology of tuberculosis.
-TB is one of the leading causes of death due to infectious disease in the world -One third of the world's population is infected with TB -In 1993, TB declared a global health emergency by WHO -In 2014: -9.6 million people developed TB disease (9,412 in US) -1.5 million people died of TB
What are the steps for the progression to tuberculosis disease?
1. People exposed to TB-->Not TB infected-->Not infectious-->Negative TST or QFT-G test result-->No TB infection 2. People exposed to TB-->Latent TB infection-->Not infectious-->Positive TST or QFT-G test result-->Latent TB infection
How many people in the U.S have latent TB infection?
13 million
What are the "high burden countries"?
22 "high burden countries (HBC) account for 80% of the global TB burden HBC's: Africa-11, Southeast Asia-5, South Asia-4 South America-1, Eastern Europe-1
How much of a decrease in tuberculosis disease have we seen in the United States during 1993-2004?
50%
What is the greatest amount of disease decrease in the country in recent years?
61% decrease from 1994 to 2014
How does the historical trend of tuberculosis in Alabama compare to that of the United States?
Alabama decrease 69% from 94-14, 61% decrease nationally.
Which areas of Alabama had tuberculosis case rates higher than the national rate?
Areas 3, 5, 7
True or False: It is not necessary to treat people with latent tuberculosis infection; they are only treated if they progress to tuberculosis disease and become infectious. (slide 70)
False
True or False: Only severe tuberculosis cases should have a specific treatment and monitoring plan developed in collaboration with the local health department.
False
True or False: Some tuberculosis cases are excluded from mandatory reporting to state or local health departments.
False
True or False: White, U.S.-born persons are most likely to be tuberculosis cases
False
Explain major points in the history of tuberculosis.
Historically known as: consumption, wasting disease, white plague TB was believed to be hereditary until mid-1800s 1865: Jean Antoine-Villemin proved TB was contagious 1882: Robert Koch discovered M. tuberculosis, the bacterium that causes TB Before TB antibiotics, many patients were sent to sanatoriums Patients followed a regimen of bed rest, open air, and sunshine TB patients who could not afford sanatoriums often died at home Drugs that could kill TB bacteria were discovered in 1940s and 1950s Streptomycin (SM) discovered in 1943 Isoniazid (INH) and p-aminosalicylic acid (PAS) discovered between 1943 and 1952 Most tb sanatoriums closed by 1970s 1989: Release of A Strategic Plan for the Elimination of Tuberculosis in the United States, MMWR 1989; 38 (Suppl. No. S-3), with goal of TB elimination in 2010 1985-1992: Resurgence of TB in the United States, fueled by several factors In response to resurgence, U.S. renewed commitment and support for TB control In 1993, upward trend was reversed; that decline has continued
What group is considered to have limited, persistent tuberculosis transmission that we should be focused on, interrupting their transmission?
Homeless
What is a source for additional tuberculosis cases in recent times?
In 2013, 65% of all TB cases and 90% of multidrug-resistant TB cases in the United States occurred among people born in other countries.
which mycobacterium do not cause TB?
M. avium complex
Which causes the most TB cases in the U.S.?
M. tuberculosis causes most TB cases in U.S.
Which gender, quantifying the amount, is more likely to have tuberculosis cases in Alabama in recent years?
Males 2-1 ratio
Which countries were the most and least prevalent birth countries for tuberculosis cases of Alabama inhabitants in 2014?
Most: mexico, india, guatemala, vietnam Least: Sudan, us pacific islander, south africa, korea
How have the tuberculosis cases in Alabama been distributed across U.S.-born and foreign-born inhabitants over time (i.e., 2001 - 2011)?
Mostly Foreign Born, 231 in 2001 then 112 in 2011. 2/3rds of cases
What is the risk of developing tuberculosis disease in a person with a normal immune system?
NORMAL: Untreated, 5% of infected persons with normal immunity develop TB in first 1-2 years post infection, another 5% later in life. Thus, about 10% of infected persons with normal immunity will develop TB at some point in life if not treated
What are the roles and responsibilities of public health sector, in terms of tuberculosis control?
Public health sector plans, coordinates, and evaluates TB control efforts Requires state and local health departments to focus on •Planning and policy development •Contact investigation •Clinical/diagnostic services for TB patients and their contacts •Training and education •Surveillance and information management •Monitoring and evaluation
How is latent tuberculosis infection diagnosed? What are the pros and cons of each test?
Skin test: •TST is administered by injection •Tuberculin is made from proteins derived from inactive tubercle bacilli •Most people who have TB infection will have a reaction at injection site •Forearm should be examined within 48 - 72 hours by HCW •Reaction is an area of induration (swelling) around injection site -Induration is measured in millimeters -Erythema (redness) is not measured •People who have been vaccinated with BCG may have a false-positive TST reaction -However, there is no reliable way to distinguish between reaction caused by TB infection or by BCG vaccine •Individuals should always be further evaluated if they have a positive TST reaction Blood Test: IGRAs: •Requires single patient visit to conduct test •Results can be available in 24 hours •Does not cause booster phenomenon •Less likely to have incorrect reading of results as compared to TST •BCG vaccination does not affect results
How much of a decrease in disease have we seen over the past 20 years here?
Steady decline over past 60 years. For the first time since 2011 AL reported an increase of 23.1% from previous years thought to be due to outbreak in prisons and jails where 14 cases were reported
how is tuberculosis transmitted?
TB is spread person to person through the air via droplet nuclei M. tuberculosis may be expelled when an infectious person: Coughs Sneezes Speaks Sings Transmission occurs when another person inhales droplet nuclei
For when or who is the TST/IGRA/both tests preferred?
TST and IGRA: -Increased risk of infection, progression to TB, poor outcome (HIV) -Clinical suspicion of and confirmation of TB desired -Additional confirmation of LTBI will help with compliance -Healthy low risk person with positive test (single test not sufficient)
What U.S. states and other places have had higher incidence rates of tuberculosis than the 2014 national average number of cases?
Texas, Arkansas, Alaska, Georgia, Florida, California, New York, DC, Maryland, New Jersey, Hawaii (CA, TX, FL and NY- 4 states responsible for most ***) Africa, Southeast Asia, South America, South Asia, Eastern Europe
True or False: Tuberculosis is preventable and curable.
True
True or False: Without a tuberculosis vaccine available, treatment of tuberculosis infection is secondary prevention for individuals and a primary prevention measure for communities.(slide 82)
True
What is the risk of developing tuberculosis disease in a person with a weak immune system?
WEAK: Persons with weak immunity at increased risk of progressing to TB disease: -Untreated HIV infection highest risk factor: risk of developing TB disease is 7%-10% each year; -Children <5 years of age also at increased risk
What are the high-risk groups for tuberculosis?
a) High risk for BECOMING INFECTED with M. tuberculosis and b) High risk for DEVELOPING TB DISEASE after infection with M. tuberculosis BOTH FROM CAPS
Describe the progress toward tuberculosis elimination, according to the latest CDC report.
•After 2 decades of annual decline, TB incidence leveled at ~3.0 new cases/ 100,000 •Total of 9,563 TB cases were reported in U.S. •~6,335 TB cases occurred among persons born outside the U.S. (two-thirds of total) •Twenty-nine states and the District of Columbia each reported an increase in TB cases in 2015.
Who are at high risk for tuberculosis infection?
•Close contacts •Foreign-born persons •Low-income groups and homeless persons •Individuals who live and/or work in special settings •Health care workers who serve high-risk groups •Racial and ethnic minorities •Infants, children, and adolescents •People who inject drugs
What are the major goals of tuberculosis treatment?
•Cure patient, minimize risk of death/disability, prevent transmission to others •Provide safest, most effective therapy in shortest time •Prescribe multiple drugs to which the organisms are susceptible •Never treat with a single drug or add single drug to failing regimen •Ensure adherence and completion of therapy
How should persons with positive tuberculosis tests be evaluated?
•Facilities should consult with local health department before starting testing program to ensure evaluation and treatment resources are available •Persons with positive TST or IGRA should be evaluated for disease •If disease is ruled out, consider for LTBI treatment •If patient not willing or able to take treatment, educate on TB signs and symptoms
How does the tuberculosis risk for HIV-infected persons compare to others?
•HIV is the strongest known risk factor for developing TB disease •TB is the leading cause of death for people with HIV/AIDS •Risk of developing TB disease is 7% - 10% each year for people who are infected with both TB and HIV
Define directly observed therapy. Who should receive this type of treatment? Why?
•Health-care worker watches patient swallow each dose •DOT is preferred management strategy for all patients •Can reduce acquired drug resistance, treatment failure, and relapse •Nearly all regimens can be intermittent if given as DOT •DOT reduces total number of doses and encounters •For drug-resistant TB, use daily regimen and DOT
Name some of the approaches for eventually eliminating tuberculosis.
•Increase case detection and cure rates globally •Reduce TB transmission in institutional settings •Increase detection and treatment of preexisting latent TB infection •More emphasis on interrupting ongoing transmission among homeless •Continue research on better means to diagnose, treat and prevent TB infection and disease
What is the importance of tuberculosis treatment adherence? How do you ensure adherence?
•Nonadherence results in inadequate treatment •Can lead to treatment failure, relapse, ongoing transmission, and drug resistance •Clinician responsible for completion of therapy •To ensure adherence, provide education, case management, DOT, incentives and enablers, and combination pills •If these fail, take more restrictive action
What are the high-risk groups for tuberculosis disease?
•People living with HIV •People with medical conditions known to increase the risk for TB •People infected with M. tuberculosis within past 2 years •Infants and children younger than 4 years old •People who inject drugs
Which medical conditions make people high-risk for tuberculosis disease?
•Prolonged therapy with corticosteroids, and other immunosuppressive therapy, such as tumor necrosis factor-alpha [TNF-α] antagonists •Silicosis •Diabetes •Severe kidney disease •Certain types of cancer •Certain intestinal conditions
What is the role of public health workers when it comes to tuberculosis?
•Provide DOT •Help monitor patients' response to treatment •Educate patients and families about TB •Locate patients who have missed DOT visits or clinic appointments •Act as interpreters, arrange and provide transportation for patients, and refer patients to other social services •Work with private physicians to make sure TB patients complete an adequate regimen
What is the minimum amount of time recommended for tuberculosis treatment?
•TB disease must be treated for at least 6 months; in some cases, treatment lasts longer -e.g., patients with cavities on chest x-ray and positive sputum cultures at 2 months should have treatment extended to 9 months
When does drug-resistant tuberculosis occur?
•Treatment must contain multiple drugs to which organisms are susceptible •Treatment with a single drug can lead to the development of drug-resistant TB
What is the prevalence of latent tuberculosis infection in the U.S.? Approximately how many of them will develop tuberculosis?
•~13 million persons in U.S. estimated to have LTBI •5%-10% will develop TB disease if untreated