TB (Quiz 2) Flashcards
1
Q
What is TB?
A
- ○scientific name: mycobacterium tuberculosis
- ○acid fast, aerobic bacteria
- ○grows rapidly - divides every 15-20 hours
2
Q
How is TB spread?
A
- ○droplets expelled when someone with active TB coughs, sneezes, speaks
- ○TB NOT spread through:
- ■shaking hands
- ■sharing drinks
- ■kissing
- ■sharing toothbrushes
- ○pulmonary TB most common
3
Q
Pathogenesis of TB
A
- •droplets with bacilli inhaled and travel to alveoli
- •macrophages in alveoli ingest bacilli
- •macrophages attract phagocytes to form a shell (granuloma) around bacilli
- •most bacilli are destroyed or controlled - latent TB
- •process can take up to 8 weeks
- •some bacilli survive and multiply intracellularly
- •they are released when macrophage dies - active TB
- •macrophages attract phagocytes to form a shell (granuloma) around bacilli
- •disseminated through lymphatic system and bloodstream
- •other immune cells, such as dendritic cells, may become involved
- •extrapulmonary TB
4
Q
Epidemiology: TB by the numbers
***
A
- •in 1989, the CDC announced a goal of eradication of TB in the US by 2010
- •Also part of the Millennium Development Goals
- •Status of TB in the US per CDC reports:
- •since 1992, incidence rates have ↓ by 3-10%/year
- •9,565 total TB cases reported in 2013
- •in 2014, total cases for ages 0-24 was 1421
- •in 2013, 555 affected persons (0.2%) died from TB
- •Worldwide, rates are quite higher:
- •9.6 million new cases in 2014
- •1.0 mil = children
- •TB is listed as a leading cause of death
- •in 2014, 1.5 million died worldwide from TB
- •140,000 = children
- •9.6 million new cases in 2014
5
Q
Mapping TB: in the US
***
A
6
Q
For the Provider: Questions to ask to assess risk for TB
A
- •where are you from?
- •if not US: when do you move here?
- •have you or someone you know ever had a positive PPD or TB test?
- •have you or someone you know ever had TB? Been treated for TB?
- •have you traveled outside of the US?
- •If so, when, how long, where?*
- •do you work/reside in a crowded place (jail or homeless shelter)?
- •is there anyone at home who is immunocompromised?
- *AAP guidelines say >1wk in high risk area puts individual at risk vs. WHO says >1mo
7
Q
For the Provider: Questions to ask to assess risk for infection
A
- •Are you (child) currently experiencing any of the following?:
- •cough
- •coughing up blood
- •fever
- •weight loss or failure to thrive
- •tiredness/lethargy
- •feeling sick
- •night sweats
- *However young children often do not show these symptoms
8
Q
For the provider: •Other potentially helpful questions:
A
- •have you (child) ever had the BCG vaccine?
- •have you (child) ever had a chest x-ray? why and results?
- •are/have you (child) taken medications?
- •which medications? why?
9
Q
High risk for TB
***
A
- •close contact with person(s) with known/suspected TB
- •foreign-born individuals from high risk countries: Africa, Asia, Latin America, Eastern Europe
- •travel abroad
- •individuals who reside or work in congregate settings: jail, homeless shelter
- •health care workers
- •immunocompromised patients
- •certain populations including medically underserved, low-income, and those who abuse drugs/alcohol
10
Q
Signs and Symptoms of Pulmonary TB (more common)
on ROS
***
A
- ○a bad cough lasting 3+ weeks (dry or productive)
- ○chest pain
- ○coughing up blood or sputum
- ○weakness/fatigue
- ○loss of appetite
- ○weight loss
- ○chills
- ○fever
- ○night sweats
11
Q
Signs and Symptoms of Pulmonary TB (more common)
on exam
***
A
- ○VS: fever
- ○LAD
- ○actelectasis
- ●*may have no symptoms!!*
12
Q
What is Extrapulmonary TB?
***
A
- ●less common than pulmonary TB but is common in pts with both HIV and TB
- ●often disseminated through blood
- ●if CNS involvement, can cause meningitis
13
Q
Sx of extrapulmonary TB on ROS and exam
***
A
- ○LAD (chronic or generalized)/lymphadenitis
- ○malaise
- ○headache
- ○fever
- ○personality changes
- ○back pain
- ○abdominal pain
- ○vomiting or diarrhea
- ○melena or blood in urine…
14
Q
Active vs. Latent TB
A
- •so far what we have discussed is active… recap:
- •active infection with s/s present
- •can spread disease
- •Latent:
- •TB is present but the immune system has fought off active infection
- •no s/s to indicate its presence
- •might only be picked up incidentally or if asked the right questions
- •person is not infectious and cannot spread TB to others
- •when the immune system can no longer fight off TB, latent stage → active infection
15
Q
What is Reactivation TB?
Who is at risk?
A
- •AKA chronic, secondary, or post-primary tuberculosis
- •occurs in previously infected individual who had not fully healed
- •can go undiagnosed for a long time (years)
- •presents with similar symptoms but may have additional complications from long-term disease
- •are at risk for reactivation if:
- •immunocompromised or comorbid condition
- •recent TB infection (within the past 2 years)
- •was not treated properly for TB in the past
16
Q
Image summary: TB
A
17
Q
Differentials for TB
A
- •Depending on the presentation consider…:
- •cancer
- •GERD
- •FUO
- •Lymphadenopathy/lymphadenitis
- •fibrotic lung disease
- •anorexia nervosa
- •other infections (pneumonia, CMV, histoplasmosis)
- •other chronic conditions (diabetes, HIV, lupus)
18
Q
Screening Tests for Tuberculosis
A
19
Q
Tuberculin Skin Test (TST): describe how it’s done and read
A
- Standard method for children of all ages (birth and up):
- •TB antigens = purified protein derivative (PPD)
- •0.1mL intradermal injection
- •6-10mm elevation of skin (a wheal)
- •Read 48-72 hours after administration
- •Measured in millimeters of INDURATION
- •palpable, raised, hardened area/swelling,
- •not erythema
20
Q
Skin Test Interpretation in children
A
- Positive results:
-
Induration of 5mm
- •close contact with known or suspected people with TB disease
- •suspected to have TB disease
- •with immunosuppressive conditions/receiving immunosuppressive therapy
-
Induration of 10mm or more
- •less than 4 years old
- •with other medical conditions (ex. Hodgkin disease, lymphoma, DM)
- •Recent immigrants, born from or travel to high-incidence countries
- •Resident of/exposed to high risk congregate settings
-
Induration of 15mm or more
- •age 4 and older with no known risk factors
21
Q
TST: when might you see false positives or negatives
A
- False positive may seen with:
- •infection with nontuberculous mycobacteria
- •improper administration
- prior BCG vaccinations ONLY if child was vaccinated in the last 2-3 months. rare after a couple months.
- False negative may be observed:
- •In setting of recent TB exposure (within 8-10 weeks)= test 8012w after exposure
- •Infants < 6 months old
22
Q
What is Interferon-Gamma Release assay (IGRA)
types, advantages
A
- •Blood test that measures immune system reactivity to Mycobacterium tuberculosis
- •Types:
- •QuantiFERON-TB Gold In-Tube test (QFT-GIT)
- •T-SPOT - TB test
- •Advantages:
- •Single patient visit
- •Result within 24 hours
- •Recent BCG vaccination does not cause false positive results
- •Preferred use for children > 5 yo
- •Evidence for IGRA use in children is limited
23
Q
What to do with positive results of TB tests?
Is it recommended to do >1 test?
A
- •TST or IGRA are used to screen for both TB disease or latent TB infection
- •Positive results can mean latent or active TB infection
- •Not recommended to do both tests
- •Other evaluation/clinical evidence must follow to distinguish diagnosis
24
Q
Chest Radiography – F/U Screening
What type of CXR to order
A
- •Frontal and lateral chest radiography
- •Confirms or rules out pulmonary/intrathoracic TB, if positive skin/blood test and/or asymptomatic
25
Q
Chest Radiography: most commonfindings in children / adolescents with TB
A
- •Most common positive finding in children with TB:
- •Primary complex consisting of opacification with hilar or subcarinal lymphadenopathy, in the absence of notable parenchymal involvement
- •Most are asymptomatic
- •Adolescents with TB
- •Typical adult disease findings
- •Upper lobe infiltrates, pleural effusions, cavitation
26
Q
Negative vs Positive Film Findings - Child
A
HILAR LAD in pic #2
27
Q
Negative vs Positive Film Findings -Adolescent
A
2 is upper lobe infiltrates
28
Q
Two main ways to obtain smear and culture for diagnosis:
A
-
•Sputum sample
- •Suggested for adolescents
- •Difficult to obtain in young children = insufficient tussive force
- •Sputum induction may be used
- •Admin. aerosolized heated saline + salbuterol → suction
- •Suggested safer than gastric aspiration
- •Suggested for adolescents
- •Gastric aspiration
- •Primary method for young children
- •Early morning gastric contents collected from fasting child
- •3 samples on different days
- •Lumbar puncture for Children <12 months old suspected of having pulmonary or extrapulmonary TB
29
Q
Algorithm: what to do if suspicion for active pulmonary TB
A
- If children < 4yo or high suspicion of active TB >>TREAT before getting back culture results
- -Younger children have risk for rapid disease progression
- -Example = abnormal chest x-ray, positive TST, positive smear
- If low suspicion is low >> wait for cultures before treating
- -Example = abnormal chest x-ray, negative TST, negative smear
- Graph source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068897/figure/F1/
30
Q
Diagnosis of Latent Tuberculosis Infection
A
- Asymptomatic/no physical findings
- Positive TST or IGRA
- Normal Chest radiography
→ Consider treatment for prevention
31
Q
Treatment for Latent TB Infection: 1st line
A
- •1st line: Isoniazid (INH)
- •Daily for 6-9 months, well tolerated
- •Monitor every 4-6 weeks for 3 months → every 2-3 months
- •Assess for possible drug toxicity
- •Side Effects: GI intolerance (n/v, abd pain), dark urine(color of coke), rash, fatigue, risk of hepatotoxicity
- •Baseline or routine LFTs not recommended
- The preferred regimen for children aged 2 to 11 years is 9 months of daily INH.*
- Isoniazid on an empty stomach, liquid option available*
32
Q
Treatment for Latent TB Infection: 2nd line
A
- •2nd line: Isoniazid+Rifapentine (INH-RPT) OR Rifampin
- •INH-RPT = Directly observed treatment for 2-17 yo, another regimen option for healthy patients > 12yo with risk for developing TB
- •Rifampin = daily for 4 months, for INH intolerance/resistant
- •Side Effects: Nausea, anorexia, pruritis, orange discoloration of body fluids, hyperbilirubinemia
- •Watch for drug interactions (ex. phenytoin >> increase levels; oral contraceptives à decrease blood levels)
- INH-RPT = use if recent exposure to contagious TB, conversion from negative to positive on TST or IGRA, chest x-ray findings of healed pulmonary TB,*
- -Do not give under 2 yo*
- OCP drug interaction applies to both RPT and Rifampin à advices alternative contraceptive method*
33
Q
Diagnosis of Active TB Disease
A
- •Clinical symptom(s) or asymptomatic
- •History of contact or at high risk
- •Positive TST or IGRA
- •Abnormal Chest X-ray findings usually
- •Positive sputum, possibly
- → Needs treatment
- Symptoms may include one or more of the following: fever, cough, chest pain, weight loss, night sweats, hemoptysis, fatigue, and decreased appetite.*
- Chest radiograph is usually abnormal. However, may be normal in persons with advanced immunosuppression or extrapulmonary disease.*
- The laboratory tests used to find TB in sputum are less likely to have a positive result in children because children are more likely to have TB disease caused by a smaller number of bacteria (paucibacillary disease). Also, difficult to collect sputum in younger children.*
- Smear positive in about 50% of patients*
34
Q
Treatment for Active TB Disease
A
- → Most likely to refer to a specialist!
- •For first 2 months (Initial phase):
- •INH + Rifampin (RIF) + Ethambutol + Pyrazinamide daily
- •4 or 7 month continuation phase
- •INH + RIF daily
- •Monitor monthly
- •Disease progression, adherence, drug toxicity
- •Sputum cultures monthly after initial phase until 2 consecutive negative cultures
- •Follow up chest x-ray not necessary
- •For first 2 months (Initial phase):
35
Q
Drug-Resistant Tuberculosis
what is it / when to suspect
A
- •Resistant to Isoniazid and Rifampin
- •Suspect if…
- •TB treatment failure à positive sputum smear/culture after 4 months of treatment OR drug susceptibility test
- •TB in a region with known high drug-resistance rates
- •Contact with drug-resistant TB
36
Q
Drug-Resistant Tuberculosis
Dx and Tx
A
- •Optimal tx for children is uncertain, but recommend Fluoroquinolone for tx
- •Nucleic acid tests/assay for diagnosis:
- •GeneXpert MTB/RIF, MTBDRplus, MTBDR
- •Management difficult → Expert consultation important!
Important to get smear/culture after 2 months of TB treatment (active) to assess if treatment is working/ risk of drug resistance à result should be negative by 2 months, if not get drug susceptivility
37
Q
Bacille Calmette-Guerin (BCG) Vaccine
what is it, what does it protect against?
A
- •Vaccine to prevent TB and other mycobacterial infections
- •Meningitis and disseminated TB (Military)
- •Protects against extrapulmonary, but not latent pulmonary
38
Q
Bacille Calmette-Guerin (BCG) Vaccine
when is it recommended in US, efficacy, implications for TB screening
A
- •U.S.A. = recommended only for immune-competent children with high risk of exposure
- •Efficacy depends on extent of prior exposure & age
- •No exposure = more benefit
- •Less effective with age
- •May cause false positive TST 2-3 months after vaccination
- •At risk children should still get screened/tested even if vaccinated by BCG
39
Q
Other Vaccines to be aware of in screening for TB
A
- •Vaccination with live viruses (ex. Measles) can interfere with TST reactions >> suppress (+) results
- •Skin testing must be given…
- •Same day as the live-virus vaccination (OR)
- •4-6 weeks after vaccine administration (OR)
- •One month after smallpox vaccination
- •Effect of live-virus vaccination on IGRA has not been studied
- •Skin testing must be given…
40
Q
Recommendations for screening and tx in adolescent mothers: nursing or pregnant
A
- Adolescent mothers - nursing or pregnant
- •Pregnancy: Screen and treat if at high risk for latent to active
- •Tx choice: Isoniazid + pyridoxine supplement
- Should have pretreatment LFT test, first 2 months
- •No BCG vaccination with pregnancy
- •Breastfeeding: not contraindicated if treated w/ first line agents
- •Do not breastfeed if treating for drug-resistant TB
- •Pregnancy: Screen and treat if at high risk for latent to active
41
Q
Recommendations for screening and tx in HIV infected or immunosuppressed
A
- •Important test: Sputum samples, lymph node aspiration if needed, Xpert MTB/RIF assay for rapid diagnosis
- •Positive if TST is >5mm, more likely to be negative w/ low CD4
42
Q
Recommendations for screening in international adoptees
A
- •Initial screening 2 weeks after arrival – screening, TST and HIV testing performed
- >>If negative TST = recommend repeat TST/IGRA 3 months after initial TST
- •Follow up visit 6 months after initial visit, unless earlier visit warranted
- •If child has symptoms, sputum tests required (even if TST/IGRA and chest x-ray negative)
- •If known HIV infection, chest x-ray AND sputum tests required
- •If treated, DOT = Directly Observed Therapy >> provider watches child swallow or take each dose of medication, 6 months to complete
- ? of overestimation of latent tb in international adoptees. More w/TST than IGRS - recommend getting IGRA if TST +
43
Q
Monitoring and future surveillance if + TST
A
- •Patients with documented positive TST should not repeat the skin test
- •Repeat testing has no clinical utility for assessing effectiveness of treatment
- •Ongoing potential TB exposure + positive TBT history → should get baseline chest x-ray
- •Recommend screening for HIV if positive latent or active TB
44
Q
When to report…
A
- •Must contact and report to local or state TB control program if…
- •In contact with a positive TB disease
- •Child had contact with someone with TB disease
- •Do not need to report latent TB infection
45
Q
Community resource for kids w/TB
A
- The Winchester Chest Clinic - YNHH
- •Only specialized pediatric tuberculosis outpatient clinic in Connecticut
- •Dr. Robert Baltimore
- •Located at 789 Howard Avenue, New Haven
46
Q
Key points for exam
A
- Key points for Tuberculosis
- World wide risks and high risk populations in US.
- Epidemiology and pathophysiology
- Unique factors about TB in children
- Risks
- Transmission
- Presentation
- Screening recommendations for children
- Risk levels
- Types of screening TST, IGRA
- Timing of screening
- From possible exposure (2-10 weeks)
- Relationship to immunizations especially MMR
- Facts about BCG
- Interpretation of screening
- Latent and active disease
- Definitions
- Approaches to distinguishing
- Risk assessment
- CXR findings
- Risks of LTBI and active
- Management
- Public health ramifications
