Tuberculosis: Difference between revisions
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==Epidemilogy==
==Background==
[[File:MiliaryTB.png|thumb|Miliary TB neonate born to mother with active TB]]
*Over 1/3 of world's population is infected[[File:Tuberculosis-x-ray-1.jpg|thumbnail|Bilateral pulmonary tuberculosis]]


===Infection Types===
*Primary Infection
**Usually contained by body via formation of tubercles
**Hematogenous spread limited to areas with high O2 or blood flow (apical lung, vertebrae)
***PPD positive
*Reactivation Infection
**More common in immunocompromised patients (AIDS, malignancy, DM, immunosupressive medications)
*Miliary Tuberculosis
**Disseminated tuberculosis
**Looks like millet seeds
**Seen in patients with comorbid AIDS
***Check [[HIV]] in patients suspected of TB
**PPD is positive in only 50% of cases


- tb resurfaced due to poor public health systems, HIV, and immigration
===Special Populations===
*[[AIDS]]
**TB is 200-500x more common in AIDS population than general population
**CD4 count
***Increased risk when <500
***Determines the clinical and radiographic presentations of TB
*Pediatric
**More likely to progress early to active disease
***Presentation more commonly that of primary TB
**>5yr - classic symptoms
**<5yr - miliary TB, [[meningitis]], [[scrofula|cervical lymphadenitis]], [[pneumonia]] that does not respond to usual antibiotics
**Children are usually not infectious due to their weak cough


- rate of tb now declining due to better public health and decrease xmission of tb from pt with active tb
===Tuberculin Skin Test===
;Used for population screening, but not for rule-out in patients with concern for active disease
''Reaction considered positive in following situations:''
*>5 mm
**[[HIV]] positive
**Close contact with active TB patient
**Nodular or fibrotic changes on CXR
**Immunosuppressed (TNF-alpha inhibitor, chemo, organ transplant)
*>10 mm
**Children < 4 yrs old
**Healthcare/lab/prison employees and residents
**Co-morbid conditions (dialysis, DM, blood/head/neck/lung malignancy, IV drug users)
**People from high prevalence areas
*>15 mm
**Persons with no known risk factors for TB


- many people with latent tb- poses threat if turns active
==Clinical Features==
===Primary Tuberculosis===
*Usually asymptomatic (only identified by positive PPD/quantiferon gold)[[File:Screen Shot 2015-09-11 at 9.27.22 AM.png|thumbnail|Tuberculous lymphadenopathy]][[File:Screen Shot 2015-09-11 at 9.21.17 AM.png|thumbnail|Tuberculous vertebral osteomyelitis (Pott's Disease)]]
*May be rapidly progressive and fatal in immunocompromised patients
**[[Fever]], malaise, weight loss, [[chest pain]]
*Tuberculous [[pleural effusion]] may occur if subpleural node ruptures into the pleura
**Pleuritic [[chest pain]]
**Exudative fluid
***Organisms may not be visible on acid-fast staining (need pleural biopsy)


- globally, 1/3 of world pop infcted
===Reactivation Tuberculosis===
*Pulmonary: Productive [[cough]], [[hemoptysis]], [[dyspnea]], pleuritic [[chest pain]]
*Systemic: [[Fever]], night sweats, malaise, fatigue, weight loss
*Extrapulmonary
**Painless lymphadenopathy/[[scrofula]] (most common extrapulmonary manifestation)
**[[Pericarditis]]
**[[Peritonitis]]
**[[Meningitis]]
**[[Adrenal insufficiency]]
***If adrenals affected, TB typically spreads to bilateral adrenals rather than unilateral
***Think about in the patient presenting in shock with TB risk factors
**[[Arthritis]]
**[[Osteomyelitis]]
***Pott's disease, usually in thoracic spine


==Differential Diagnosis==
{{HIV associated conditions}}


==Consequences==
==Evaluation==
===[[CXR]]===
[[File:Miliary.png|thumbnail|CXR of miliary TB]]
*Primary infection
**Infiltrates in any area of the lung
**Isolated hilar or mediastinal adenopathy may be only finding
*Reactivation infection
**cavitary/noncavitary lesions in upper lobe or superior segment of lower lobe
*Latent infection
**Upper lobe or hilar nodules and fibrotic lesions
**Ghon foci, areas of scarring, calcification
*Miliary TB
**Looks like millet seeds on CXR
*Immunocompromised patients less likely to have classic lesions and may have normal CXR


===PCR Sputum Assay===
*Rapidly detects TB in sputum specimens (as well as [[rifampin]] resistance)
*Use to rule-out patients for active TB
*Need two sputum specimens (expectorated or induced) at least 8 hours apart (including at least one early morning specimen)


- xmited by air particles 1-5 microns
==Management==
===Active TB===
*[[Isoniazid]] + [[rifampin]] + [[pyrazinamide]] + [[ethambutol]] x 8wk followed by INH/rifampin x18wk
**2 drug continuation treatment x 18-31wk
===Latent TB===
*Isoniazid x 9 months
*Consider treatment for:
**Recent conversion to PPD-positive
**close contact with active TB
**immunocompromised patients (or plan to start immunosuppressive medications)


- xmission influenced by source criteria- number of bacteria excreted and nature of encounter
==Disposition==
 
===Discharge===
- infc by 1- 5 bacteria in terminal alveolus
*Otherwise healthy
 
**Contact public health services before discharge
- primary tb usually mild and self limited- often undiagnosed- bacteria seed other organs for subsequent reactivation later
***Instructions for home isolation and follow up at appropriate clinic to receive meds
 
**Do not start TB meds in ED unless specifically instructed by public health
- 5% of time, infc goes from latent to active dz in 2 yrs
 
- most active tb is from latent reactivation buy and also be from infc by second strain of tb- esp if immune compromised or heavy exposure to new bacilli
 
- classic sxs- fvr, sweats, anorexia, wt loss, weakness
 
- organ specific sxs- pulm- cough, CP, hemoptysis
 
primary tb cxr shows infc in mid to lower lungs with lymphadenopathy- reactivation is upper lobe cavitations
 
- signs and sxs more vaied if hiv
 
- lung most common site, but also lymph nodes, pleura, bone, joints. also gu, cns, abd, pericardium
 
 
==Treatment==
 
 
- reportable in all states- even if tx'd in private sector, reporting helps with compliance, tracking contacts, emerging resis patterns, education, outbreaks
 
Anti TB Drugs
 
- 5 first line drugs
 
- second line drugs are less effective or more toxic- only use if pt cannot tolerate first line or resis
 
 
==Adverse Effects==
 
 
INH- hepatitis, neuropathy, cns effects, elevated dilantin lvl, antabuse interaction, give with vit B6
 
Rif- fvr, low platelets, reduces blood levels of other drugs, caused orange urine
 
PZA- hyperuricemia
 
Ethambutol- color discrimination, visual acuity, optic neuritis
 
Strep- auditory and renal dysfnctn
 
 
==Current Recs==
 
 
- always use INH for duration of tx- effective, low cost, tolerable- if not mixed with rifampin- go 18 mo
 
- if double with INH/ rif- 9 mo for cure
 
- if triple with inh/ rif/ pza (pza for first 2 mo) shorten lenght to 6 mo
 
- try 3-4 meds initially and then 2 drugs afterwards
 
- consider local patterns of resis and schedule of administration likely to ensure adherance
 
- direct observation helps ensure compliance
 
- most common regimen- ihn/rif/pza for 8 wks, inh/rif for 16 wks with freq direct observation, and add ethambutol or streptomycin until susceptibility documented
 
- if cx ned, stop p 2 mo of inh/rif
 
- noncompliance not related to race, gender, education....cdc rec direct observation, and rewards
 
- get cxs- helps with resis
 
- baseline lfts, creatinine,cbc
 
- if use pza- check uric acid
 
- if use ethambutol- check vision and red/green color perception
 
- baseline cxr
 
- if cx neg, go by sxs and cxr at 3 mo
 
- sputum cx going from pos to neg - objective tx success- should change in 2 mo
 
- if longer than 3 mo, consider nonadherence, malabsorption, resis
 
- can also test urine for color in rif, urate in pza
 
- cx sputum at end of tx to document cure
 
 
==HIV Pts==
 
 
- hiv pt who adhere to standard tx do not have increased tx failure
 
- tx 6 mo- longer if slow response
 
- protease inhibitors and NNRT inhibitors mixed with rif cause rif toxicity and low levels of PI and NNRTI- avoid by using rifabutin
 
- do not use PI ritonivir or NNRTI delavirdine with rifabutin
 
 
==Extrapulm TB==
 
 
- since fewer bacilli in extrapulm site and good tissue penetration of drugs, tx should be no more difficult
 
- use regular 6 mo regimen
 
- 12 mo for meningitis in kids, bone/ joint or miliary tb
 
 
==Drug Resis==
 
 
- inh resis tx with rif, pza, ethambutol for 6 mo
 
- rif resis- inh, ethm for 18 mo or inh, pza, strep for 9 mo
 
- mulitidrug resis- resis to inh and rif- curable even in poor countries
 
 
==Management of Latent TB==
 
 
- test for tb only in high risk pt and those who will benefit from tx.
 
- if test low risk population- will get too many false postives
 
- test hiv pt, immigrants, homeless, long term care residents, health workers
 
- those at risk for progression from latent to active dz are immune suppressed ore recently exposed to infectious tb- highest rate of progression is from pt with both hiv and tb- also dm, crf, CA, organ xplant, ivda,
 
- silicosis, abnormal cxr, too thin person also indication for testing
 
 
==TB Skin Test==
 
 
- PPD is gold standard for latent tb testing- intradermal not multipronged
 
- measure induration not redness 48- 72 hrs
 
- 5 mm- positve if pt with weak immune response- hiv, steroid use, recent exposure and body hasn't had time to mount immune response, abnormal cxr
 
- 15 mm- positive if low risk pt
 
- 10 mm- all other pts
 
- if long standing infc, may actually have neg test initially- if give second skin test will be positve since first test reinvigorated immune sys- so if pt needs serial testing- do second test in 2 wks- called 2 Step Testing- if second postive represents long standing infc not recent infection
 
- ppd will not cause 10 mm induration in uninfected pt ever
 
 
==BCG==
 
 
- not recommended in US but used elsewhere
 
- size and persistence of tb reaction p bcg vary with bcg dose and manufacturer
 
- CDC rec ignoring hx of bcg when giving and interpreting ppd test since bcg only givien in high risk populations in first place
 
- anergy testing not recommended in tb testing of hiv pt since results highly variable and not reproducible.
 
 
==Latent Tx/ PPD + Tx==
- 9 mo inh if no hiv and neg cxr. 12 mo better but less compliance and more cost
 
- 9 mo ihn if hiv + or pos cxr or age <18yr
 
- can also do 2 mo of rif and pza or 4 mo of rif alone
 
- baseline labs if hiv +, preg, etoh, liver dz
 
- if duration of tx interrupted, add on additional 3 mo of inh. If lapse is greater than 3 mo, restart whole tx
 
- if previously tx pt reexposed to tb, repeat tx not recommended


===Admit===
*Ill-appearing
*Diagnosis is uncertain
*Patient is treatment non-adherent


==References==
<references/>
[[Category:ID]]
[[Category:ID]]
[[Category:Pulm]]
[[Category:Pulmonary]]

Revision as of 21:50, 13 October 2019

Background

Miliary TB neonate born to mother with active TB
  • Over 1/3 of world's population is infected
    Bilateral pulmonary tuberculosis

Infection Types

  • Primary Infection
    • Usually contained by body via formation of tubercles
    • Hematogenous spread limited to areas with high O2 or blood flow (apical lung, vertebrae)
      • PPD positive
  • Reactivation Infection
    • More common in immunocompromised patients (AIDS, malignancy, DM, immunosupressive medications)
  • Miliary Tuberculosis
    • Disseminated tuberculosis
    • Looks like millet seeds
    • Seen in patients with comorbid AIDS
      • Check HIV in patients suspected of TB
    • PPD is positive in only 50% of cases

Special Populations

  • AIDS
    • TB is 200-500x more common in AIDS population than general population
    • CD4 count
      • Increased risk when <500
      • Determines the clinical and radiographic presentations of TB
  • Pediatric
    • More likely to progress early to active disease
      • Presentation more commonly that of primary TB
    • >5yr - classic symptoms
    • <5yr - miliary TB, meningitis, cervical lymphadenitis, pneumonia that does not respond to usual antibiotics
    • Children are usually not infectious due to their weak cough

Tuberculin Skin Test

Used for population screening, but not for rule-out in patients with concern for active disease

Reaction considered positive in following situations:

  • >5 mm
    • HIV positive
    • Close contact with active TB patient
    • Nodular or fibrotic changes on CXR
    • Immunosuppressed (TNF-alpha inhibitor, chemo, organ transplant)
  • >10 mm
    • Children < 4 yrs old
    • Healthcare/lab/prison employees and residents
    • Co-morbid conditions (dialysis, DM, blood/head/neck/lung malignancy, IV drug users)
    • People from high prevalence areas
  • >15 mm
    • Persons with no known risk factors for TB

Clinical Features

Primary Tuberculosis

  • Usually asymptomatic (only identified by positive PPD/quantiferon gold)
    Tuberculous lymphadenopathy
    Tuberculous vertebral osteomyelitis (Pott's Disease)
  • May be rapidly progressive and fatal in immunocompromised patients
  • Tuberculous pleural effusion may occur if subpleural node ruptures into the pleura
    • Pleuritic chest pain
    • Exudative fluid
      • Organisms may not be visible on acid-fast staining (need pleural biopsy)

Reactivation Tuberculosis

Differential Diagnosis

HIV associated conditions

Evaluation

CXR

CXR of miliary TB
  • Primary infection
    • Infiltrates in any area of the lung
    • Isolated hilar or mediastinal adenopathy may be only finding
  • Reactivation infection
    • cavitary/noncavitary lesions in upper lobe or superior segment of lower lobe
  • Latent infection
    • Upper lobe or hilar nodules and fibrotic lesions
    • Ghon foci, areas of scarring, calcification
  • Miliary TB
    • Looks like millet seeds on CXR
  • Immunocompromised patients less likely to have classic lesions and may have normal CXR

PCR Sputum Assay

  • Rapidly detects TB in sputum specimens (as well as rifampin resistance)
  • Use to rule-out patients for active TB
  • Need two sputum specimens (expectorated or induced) at least 8 hours apart (including at least one early morning specimen)

Management

Active TB

Latent TB

  • Isoniazid x 9 months
  • Consider treatment for:
    • Recent conversion to PPD-positive
    • close contact with active TB
    • immunocompromised patients (or plan to start immunosuppressive medications)

Disposition

Discharge

  • Otherwise healthy
    • Contact public health services before discharge
      • Instructions for home isolation and follow up at appropriate clinic to receive meds
    • Do not start TB meds in ED unless specifically instructed by public health

Admit

  • Ill-appearing
  • Diagnosis is uncertain
  • Patient is treatment non-adherent

References

  1. ↑ Gutteridge, David L MD, MPH, Egan, Daniel J. MD. The HIV-Infected Adult Patient in The Emergency Department: The Changing Landscape of the Disease. Emergency Medicine Practice: An Evidence-Based Approach to Emergency Medicine. Vol 18, Num 2. Feb 2016.
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