Under immunocompromised conditions, the ______________may open up and cause reactivation of the disease
What body system(s) may be attacked by TB?
- the Lung is the most commonly affected body system.
- Any part of the body can be a site of infection (including GI tract, lymph nodes, bones/joints, the brain, etc
Children and those who are immune compromised are more subject to what type of TB?
Primary progressive pneumonia or disseminated (Miliary) TB with extra-pulmonary disease
Can lead to rapid death
How do we differentiate between LTBI & active TB disease?
1) LTBI – constitutes an INFECTION with TB, but one that is being controlled by the body’s immune systems; These people are NOT symptomatic and CANNOT spread TB
2) Active TB disease – The infection has become active and is no longer being kept under control by the body’s immune system; Patient typically feels sick; usually has specific symptoms and can spread tuberculin bacteria with pulmonary disease.
May be much more difficult to diagnose with atypical disease or sites of infection (atypical disease is more likely in children and immune compromised patients).
What are the Risk Factors for LTBI TB?
Immigrant/Refugee status within the last 5 years from high risk regions
Poor standard of living (residence or travel)
Minority Race/Ethnicity (related to poverty)
Low socio-economic status (crowded conditions & lack of medical care)
Co-infection with HIV
Frequent or continuous exposure to high risk individuals/groups – Esp infants and children
Chemical dependency: Tobacco, Alcohol, Drugs
Visiting endemic areas
What are the risk factors for Active TB disease?
Age (< 5 and > 65)
Time since infection (increased within 2 yrs post acquiring infection for developing active TB)
Immune deficiency or people on immune suppressive therapies
Drugs and alcohol
< 90% of ideal body weight
Gastrectomy or a Jejuno-ileal bypass surgery (for weight loss)
Various chronic diseases, including diabetes, chronic renal failure, leukemia, lymphoma, CA of head/neck/lungs, silicosis
About what % of people will develop ACTIVE TB disease at some time during their life after becoming infected (after developing LTBI)?
- About 5-10% of infected people with normal immune systems
- LTBI prophylaxis reduces the risk of active disease to about 1% (up to a 90% drop in risk)
- Risk increased in immune compromised, and other high risk groups
Why are health care professionals generally tested with an annual TB skin test? (Consider the risk factors for active TB disease to answer this.)
- Because the risk of progression from LTBI to active TB disease is greatest within the first 2 years after initial infection, a change to Positive status on an annual PPD is of key concern for HCWs.
What are general and organ specific symptoms of active TB disease?