Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DTM&H 2024 > TB > Flashcards

TB Flashcards

1
Q

TB Susceptible treatment

A

2HRZE4HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

TB Shorter treatment

A

Consider in milder disease - no cavitation and smear <2+ BUT stratifying treatment is difficult in a high burden setting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

TB Natural history

A

Most infection does not lead to disease, infection is a dynamic continuum not a binary state, self-cure is probably common but we cannot test for it, active pulmonary TB is a chronic cavitatory pneumonia. TB further impoverishes the poor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

TB Key clinical features of PTB

A

Cough, fever, weight loss, night sweats are cardinal features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

TB Diagnostic approach PTB

A

Sputum is key sample, microscopy widely used and detects the most infectious cases but misses half. Auramine improves performance over ZN. Xpert MTB/RIF detects MTB DNA. Sputum culture is usedd less and less, mainly if concerned about drug resistance. CXR useful and automated (CAD) reading of digital imaging increases access

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

TB Therapeutic principles

A

Multidrug therapy for 6m remains standard (2HRZE4HR), shorter 4m regimens endorsed but not implemented, TRUNCATE-TB shows we can go shorter if we can find the right regimen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

TB Access

A

TB diagnostic and treatment services are free of charge in the public sector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

TB Vaccines

A

TB vaccine enthusiasts believe no attempt at TB control will work without a new, effective vaccine, BCG is most widely used but efficacy is limited, objective of vaccine design (and thus study population in vaccine trials) vary, particular focus on prevention of infection (POI) and prevention of disease (POD) in those already infected, major hurdle is correlate of protection - there is no Ab level or other biomarker identified that can predict a vaccine will work, so large and long trials are needed. Therapeutic vaccines aim to improve outcome of treatment of active disease (add to standard treatment) tough as standard treatment already works well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

TB LTBI Diagnosis

A

TST and IGRA are tests of immunoreactivity (not viable latent infection). Indeterminate IGRA means no assessment of TB risk can be made - the test is not valid, the PPV ~5% (fewer than 5% with positive result will go on to develop active TB disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

TB LTBI Treatment

A

6H or 3HP (weekly) or 1HP (daily) - (P=rifapentine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

TB Epidemiology

A

Global TB report tracks national and global data on TB diagnosis, treatment, prevention, screening, financing, social determinants and research - also tracks progress against END-TB targets - progress has been glacial, and short on intermediate milestones, 70% TB burden in 8 countries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

TB WHO 2030 END-TB Targets

A

90% reduction in TB patients, 95% reduction in TB deaths, reduce costs that increase poverty

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

TB HIV and Diabetes

A

Predispose to active TB, relative importance of each varies in different parts of the world, HIV is major driver in sub-Saharan Africa but not in Sth America

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

TB 8 top countries

A

India 27%, Indonesia 10%, China 7%, Phillippines 7%, Pakistan 6%, Nigeria 5%, Bangladesh 4%, DRC 3%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

TB Diabetes

A

Risk of TB is 3x higher in diabetes than non-diabetes in same population, holds true in both low and high TB burden settings. T2DM is rapidly increasing and accounts for vast majority of this effect, risk in T1DM is probably higher but much less common. People diagnosed with TB should be tested for DM as the TB might be the first manifestation of DM (as for HIV). Screening people with DM for TB is low yield and not cost effective. TB in people with DM is not substantially different to TB in people without DM, treatment is the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

TB Natural history

A

Some clear infection, most control infection and develop latent TB, of those with LTBI 10% will go on to develop active TB in their lifetime (90% don’t), some develop active TB (develops over weekls to months)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

TB HIV coinfection

A

Different natural history, phenotype and diagnosis, HIV increases probability of early progression, and probability of TB reactivation to 10% per year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

TB Paediatric TB

A

Different natural history, phenotype and diagnosis, larger number go on to active disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

TB TB control

A

Stop transmission, treat adults with pulmonary TB who are the infectious source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

TB Empiric antibiotics

A

Stop giving empiric antibiotics as it does not discriminate between those with TB and those without - broad spectrum Abx are NOT a discriminator

21
Q

TB Definition PTB

A

Involves lung parenchyma, includes miliary disease and any PTB with EP manifestations

22
Q

TB Definition EPTB

A

Involves any other system than lung parenchyma, includes hilar lymphadenopathy and pleural disease, for EPTB think HIV

23
Q

TB Median time to culture conversion

A

37d in fully susceptible disease

24
Q

TB WHO Vaccine priorities

A

1 safe effective & affordable TB vaccine for adolescents and adults, 2 affordable TB vaccine for neonates and infants with improved safety & efficacy, 3 therapeutic vaccine to improve TB Rx outcomes

25
Q

TB Vaccine challenges

A

Efficacy seems to be different, including how far people are from the equator, gender, important to consider when looking at vaccines

26
Q

TB BCG

A

Only licenced TB vaccine, protects children from TB meningitis and miliary disease, non-specific effects, protection from pulmonary TB lowest near the equator

27
Q

TB Vaccine strategy

A

Efficacy signals obtained by POI candidates would require a much lower sample size and a shorter duration of follow-up compared to those candidates tested in Prevention of disease (POD) trials. POI vaccine with partial efficacy would likely have an important public health impact

28
Q

TB Vaccine for PLHIV

A

Live mycobacterial vaccines like BCG, VPM1002, and MTBVAC might present a safety risk for PLHIV. This risk needs to be evaluated in the context of ART, viral suppression, CD4 recovery, and completion of TPT. Inactivated mycobacterial, viral-vectored and protein-subunit candidate vaccines, including M72/AS01E, might be safer for vaccination of individuals with HIV and other immune-suppressive conditions

29
Q

TB Paed prevention gap

A

In 2020 2/3 of 1.1mil eligible contacts <5y did not access TB preventive treatment (TPT) and less than 5% of eligible HIV-uninfected older child/adolescent contacts accessed TPT

30
Q

TB RF for paed TB

A

Infectiousness of the index case, age of child, proximity to and duration of contact with index case, immune status of child, children of families living with HIV, other illnesses (HIV, pertussis, malnutrition, post-measles

31
Q

TB Paed TB clinical features

A

Persistent unremitting cough >2-3 weeks, intermittent fever, weight loss/failure to gain weight - other common sx loss of appetite, cough, night sweats, reduced energy/playfulness, recent measles, pertussis and not returning to normal health

32
Q

TB Tuberculin Skin Testing (TST)

A

Based on delayed-type hypersensitivity reaction to PPD, positive result suggests infection or sensitisation, do not indicate or rule out TB disease, false positive with previous BCG vaccine, NTM and HIV - positive >=10mm regardless of BCG, >=5mm in children with HIV/malnutrition

33
Q

TB Interferon gamma release assay (IGRA)

A

Rely on measurement of IFNg released by memory CD4 T cells stimulated with TB antigens ESAT-6 CFP-10 Pro: one visit Con: expensive, sophisticated lab technology, not available in most resource-poor settings, suboptimal sens in children

34
Q

TB TST/IGRA limitation

A

Most people will be sensitised from a very early age, so both TST and IGRA have a low positive predictive value – limits use, as knowledge of epidemiology is just as useful. IGRA NNT (no needed to test) ~80 to make one additional diagnosis

35
Q

TB Xpert MTB/Rif

A

SEN ~66% (Ultra ~72%); SPE >98%, does not differentiate between viable and non-viable MTB, SEN lower in routine testing compared to research findings

36
Q

TB Paed TB diagnosis

A

Confirmed Mycobacterial confirmation (smear, Xpert or culture) with or without CXR changes, positive TST/IGRA, improvement on antiTB Rx and no confirmed alternative diagnosis - unconfirmed is same minus micro

37
Q

TB Paed TB diagnostic challenges

A

Smear sens <10% Xpert sens lower than adults, Culture pos <30%, CXR changes non-specific, TST/IGRA of limited value in TB-endemic settings

38
Q

TB Paed TB treatment pulmonary, lymphadenitis

A

2HRZE4HR - daily in intensive phase, intermittent 3x/wk in continuation phase - shorter treatment for children and adolescents with non-severe/smear neg TB are an option

39
Q

TB Paed TB treatment meningitis, miliary, bone

A

2HRZE10HR

40
Q

TB Paed TB treatment

A

Fixed dose combinations widely available - ensures accurate dosing, simplifies treatment, improves compliance

41
Q

TB BCG culture process

A

M bovis in media with ox bile, gradually lost virulence over 18y

42
Q

TB BCG first administered

A

1921 infant of mother who died of TB

43
Q

TB BCG Lubeck disaster

A

1929 MTB administered to 250 infants instead of BCG, 72 died

44
Q

TB BCG explanation for variable efficacy

A

Differences in methods, genetics, geography (works better away from equator), epidemiology (differences in annual risk of infection), nutrition, BCG strains over time, environmental mycobacterial exposure - cellular immunity may be formed due to NTM exposure which blocks/masks BCG effect

45
Q

TB BCG NTM exposure

A

BCG more effective in those who are immunologically naïve than in those with prior mycobacterial sensitivity

46
Q

TB BCG effects

A

BCG has very good protection against TB meningitis, whereas it is a mess for pulmonary - BCG is a better vaccine against leprosy than it is against TB – major factor behind the worldwide decline in leprosy

47
Q

TB BCG WHO policy

A

Single dose at birth, to protect (primarily ?) against childhood TB disease eg: one case of TB meningitis prevented for each 3,500 doses (c.$200 per year of life saved). This policy has relatively little impact on adult pulmonary tuberculosis, or on transmission of M tuberculosis nb: WHO does not advocate repeat vaccination

48
Q

TB TB vaccine future

A

Much interest, several candidates, world is ‘saturated’ with BCG - cannot get BCG-free individuals in high endemic TB regions, major problem is no ‘correlate’ of protection - no Ab level etc - very difficult to design immunologic and/or epidemiologic study

DTM&H 2024 (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions