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Flashcards in Tuberculosis Deck (200)
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0
Q

A person is considered to be exposed if there is…
> shared breathing space with someone who has pulmonary or laryngeal TB at a time when infectious person in not wearing a mask and the other person in not wearing N95 respirator.

A

A person has to be in CLOSE CONTACT with someone with infectious TB for LONG PERIOD OF TIME to become infected.
But some people do become infected in short period of time if the contact is in a closed or poorly ventilated space.

1
Q
LTBI vs TB disease : 
>tubercle bacilli
> mantoux skin test
> chest X-ray
> sputum smear and culture
> symptoms 
> infectiousness
> case of TB
A
LTBI vs TB disease : 
>tubercle bacilli (inactive; active)
> mantoux skin test (+;+)
> chest X-ray (normal; abnormal)
> sputum smear and culture (- ;+)
> symptoms (- ; +)
> infectiousness (no; yes)
> case of TB (no; yes)
2
Q

Mode of action of isoniazid

A

Inhibits Mycolic acid synthesis in bacterial cell wall (bactericidal)

3
Q

Mode of action of pyrazinamide.

A

Exact target unclear.

Disrupts plasma membrane and energy metabolism

4
Q

TB that is resistant to one TB treatment drug

A

Mono-resistant TB

5
Q

TB class and type:
Positive result to TST
Negative smears and cultures
No clinical or X-ray evidence of active TB disease

A

Class 2 - TB infection / No TB disease

6
Q

Mode of action of rifampin

A

Inhibits beta unit of bacterial RNA polymerase thus inhibits RNA synthesis

7
Q

Is likely responsible for the resistance and a key virulence factor.

A

Mycolic acid (rich in lipids)

8
Q

The risk may be about ___ times higher (as with diabetes) to more than ____ times higher (as with HIV infection) for people who have these condition than for those who do not.

A

3x higher : diabetes

100x higher : HIV infection

9
Q

TB that is resistant to at least the drugs isoniazid and rifampin; it is more difficult to treat that drug-susceptible TB.

A

Multidrug-resistant TB (MDR TB)

10
Q

Droplet nuclei are very small droplets containing M.tuberculosis. What is its diameter?

A

1-5 um

11
Q

People with prolonged, frequent, or close contact with people with TB are at high risk of becoming infected. Infection rate?

A

22%

12
Q

Drug resistant TB can be caused by two different ways:

Caused by person to person transmission of drug-resistant organism

A

Primary resistance

13
Q

Patient with drug resistant TB must be closely monitored to see if they are responding to treatment, they should remain in isolation until it is shown that they are no longer infectious.

A

Truelala

14
Q
TB class and type:
Medical history of TB disease 
Abnormal but stable X-ray findings
Positive TST
Negative smear and culture 
No clinical or X-ray evidence
A

Class 4 - Previous TB disease (not clinically active)

15
Q

T or F: M.tuberculosis can withstand weak disinfectants and can survive in a dry state for weeks

A

True.

16
Q

Each droplet may transmit the disease, since the infectious dose of TB is very low. The inhalation of ___ bacteria may cause an infection.

A

At least 10 bacteria

17
Q

From infection to development of a positive TB skin test reaction (incubation period) is approximately…

A

2-12 weeks

18
Q

Refers to the condition when a person us infected with tubercle bacilli but has not developed TB disease

A

Latent TB infection LTBI

19
Q

Not everyone who is exposed to an infectious TB patient become infected with M.tuberculosis. The probability that TB will be transmitted depends on 4 factors:

A
  1. How Infectious or contagious
  2. Kind of environment when exposure occurs
  3. Duration of exposure
  4. Virulence of the tubercle bacilli
20
Q

Doubling time of TB

A

15-20 hrs

18-24 hrs

21
Q

Global TB has begun to fall since…

A

2004

22
Q

TB is an infectious disease that usually attacks the lungs but also attack any part of the body. TB is historically known as…

A

Consumption
White plague
Wasting disease

23
Q

Means that the tubercle bacilli are in the body, but the body’s immune system is keeping it under control and inactive.

A

LTBI

24
Q

A single sneeze can release up to…

A

40,000 droplets

25
Q

TB that is resistant to at least two TB treatment drugs (but not isoniazid and rifampin) but is not MDR TB

A

Poly-resistant TB

26
Q
TB class and type:
Signs and symptoms of TB disease but evaluation not complete.
A

Class 5 - TB suspected

27
Q

Drug resistant TB can be caused by two different ways:
Develops during TB treatment, either because the patient was not treated with appropriate treatment regimen or the patient did not follow as prescribed.

A

Secondary resistance

28
Q

TB of the lungs may also occur via infection from the blood stream

A

Simon focus

Hematogenous transmission

29
Q

Flow chart of TB suspect

A

Do it!!!

30
Q

Type of blood test that measures a person’s immune reactivity to M.tuberculosis.

A

Interferon gamma release assay (IGRA)

31
Q

The best way to stop transmission is to…

A

Isolate infectious persons and give standard TB treatment ASAP.

32
Q

TB class and type:
No history of TB exposure
Negative result to TST or to QFT-G

A

Class 0 - No exposure / Not infected

33
Q

Refers to ability of an organism to produce a disease

A

Virulence.

It is associated with the severity of the disease.

34
Q

The risk for developing active disease is the highest in the _____ after infection and development of positive TB skin test reaction.

A

The first two years

35
Q

Blood test used to determine TB infection. It measures the response to TB proteins when they are mixed with a small amt of blood.

A

Quantiferon TB-gold test (QFT-G)

36
Q

Develops during TB treatment. Also referred to As acquired drug-resistant TB

A

Secondary drug-resistant TB

37
Q

T caused by organism that are able to grow in the presence of particular drug; TB that is resistant to at least one 1st line anti-TB drug.

A

Drug resistant TB

38
Q

Tuberculous mycobacteria

A
M.tuberculosis
M.bovis
M.africanum
M.canetti
M.microti
39
Q

The granuloma prevents dissemination of the mycobacteria and provides a local environment for interaction of cells of the immune system

A

Another feature if granuloma is the development of abnormal cell death (necrosis) in the center of tubercles.

40
Q

TB disease that occurs in the lungs typically causing cough and an abnormal chest X-ray

A

Pulmonary TB

Infectious

41
Q

Simon focus can spread infection to more distant sites such as peripheral lymph nodes, kidneys, brain and bones.

A

All parts of the body can be affected by the disease, though for unknown reasons it RARELY AFFECTS the heart, skeletal muscles, pancreas and thyroid.

42
Q

TB disease develops when the immune system can’t keep the tubercle bacilli under control and the bacilli begin to multiply rapidly.

A

About 10% of all people with normal immune systems who have LTBI will develop TB disease at some point of their lives.
The remaining 90% will stay infected but free of disease for the rest of their lives.

43
Q

Environmental actors that increase risk for transmission

A
  1. Exposure to small, enclosed spaces
  2. Inadequate ventilation
  3. Recirculating air containing infectious droplets
  4. Inadequate cleaning and disinfection of equipment
  5. Improper specimen-handling procedures
44
Q

Factors to be considered in the management of persons exposed to TB

A
  1. Likelihood that contact is newly infected
  2. Likelihood that strain is multidrug resistant
  3. Estimated likelihood that contact, if infected, will develop active TB
45
Q

Mode of action of ethambutol

A

Inhibits Mycolic acid synthesis in bacterial cell wall (bacteriostatic)

46
Q

TB patient characteristic that increase risk for infectiousness

A
  1. Coughing
  2. Undergoing cough-inducing or aerosol-generating procedure
  3. Failing to cover cough
  4. Having cavitation on chest radiograph
47
Q

Staining for M.tuberculosis

A

Ziehl-Neelsen staining

Acid fast staining

48
Q

A person with active but untreated TB may infect ___ other people per year.

A

10-15 people/yr

49
Q

TB class and type:
Positive culture
Positive TST
Clinical, Bacteriological and X-ray evidence of TB disease

A

Class 3 - TB disease (active)

50
Q

Occurs when an antibiotic has lost its ability to effectively control or kill bacterial growth.

A

Antibiotic resistance

Bacteria are resistant and continue to multiply in the presence of therapeutic levels of an antibiotic.

51
Q

The main route of TB transmission in children

A

From adult ps who have infectious cavitation or pulmonary TB

52
Q

M.tuberculosis may be expelled when an infectious person…

A

Coughs
Sneezes
Speaks
Sings

53
Q

T or f: BCG protects against miliary, meningitic and pulmonary TB in children.

A

Only protective against miliary and meningitic TB but pulmonary disease is inconsistent.

54
Q

T or F: no tuberculous mycobacteria are NOT usually spread from person to person.

A

True.

55
Q

Mantoux tuberculin skin test us a method of testing for TB infection. A needle and syringe are used to inject ___ ml of ___ tuberculin units of liquid tuberculin between the layers of skin (intradermally), usually on the forearm.

A

1 ml of 5 tuberculin units of liquid tuberculin

56
Q

TB disease that occurs in the places other than the lungs.

A

Extrapulmonary TB

Most of it are not infectious.

57
Q

The bacteria evade macrophage killing by neutralizing the reactive nitrogen intermediate.

A

Yes.

58
Q

T or F: the length if TB incubation arises depending on the individual risk factors

A

True. Within 6 wks of being exposed, an infected person develops a primary infection in the lungs which may have no symptoms. The disease then enters a dormant state that can last for weeks to years.

59
Q

Mantoux skin test is measured ___ hrs after injection.

A

48-72 hrs

60
Q

Flow chart for the exposure of individual to droplet nuclei from source case of open TB.

A
  1. Duration and intensity of exposure (infected/not infected) [not infected: no infection]
  2. Protective immune response (weak/ strong) [weak: primary progressive TB]
  3. Strong immune response: limited initial bacterial growth
  4. Bacterial growth arrest (some persist/ eliminated) [eliminated: sterilizing immunity]
  5. Immune response (compromised/ persists)
    [compromised: reactivation TB] [persists: clearance of latent infection]
61
Q

The length of time required for TB patient to be non infectious after starting TB therapy varies.

A

However, once the standard TB therapy is started, and as long as the patient followed the prescribed TB regimen, the infectiousness can rapidly decline.

62
Q

M.tuberculosis also carry _____ which prevents acidification of the phagosome.

A

UreC gene

63
Q

Rare type of MDR TB that is resistant to isoniazid and rifampin, plus resistant to any fluoroquinolone and at least of three injectable 2nd line drugs (amikacin, kanamycin, capreomycin)

A

Extensively drug resistant TB (XDR TB)

64
Q

Symptoms of TB

A
(Pulmonary TB)
Productive cough
Night sweats 
(Afternoon) Fever 
Poor appetite
Weight loss
Weakness
65
Q

Cells that aggregate to form granuloma

A

Macrophages, T or B lymphocytes and fibroblasts.

Lympho surr the infected macro

66
Q

Mycobacterium the do not cause TB often called non tuberculous mycobacteria. Example?

A

M.avium complex

67
Q

When in lungs, M.tuberculosis is taken up by ____, but they are unable to digest the bacterium.
Its cell wall prevents _______.
Specifically, it blocks the bridging molecule ______. However this blockade does not prevent fusion of vesicles filled with nutrients.

A

When in lungs, M.tuberculosis is taken up by ALVEOLAR MACROPHAGE, but they are unable to digest the bacterium.
Its cell wall prevents PHAGOSOME-LYSOSOME FUSION.
Specifically, it blocks the bridging molecule EARLY ENDOSOMAL AUTOANTIGEN 1 (EEA1). However this blockade does not prevent fusion of vesicles filled with nutrients.

68
Q

Persons with LTBI carry the organisms that cause TB but their are asymptomatic and can not spread germs to others

A

Persons with LTBI usually have positive mantoux tuberculin skin test or quantiferon TB-gold test

69
Q

Conditions that increase risk

A

Infection with HIV
Chest X-ray suggestive of previous TB
Substance abuse (esp illegal injection drug use)
Recent TB infection (within past 2 yrs)
Prolonged therapy with corticosteroids and other immunosuppressive therapy

70
Q

TB class and type:
History of exposure
Negative result to TST

A

Class 1 - TB exposure / No evidence of infection

71
Q

WHO recommends that BCG should not be given to HIV infected infants

A

Yeah!

72
Q

Persons at higher risk for Exposure to infection with M.tuberculosis

A
  1. Close contact
  2. Foreign born persons from or areas with high TB incidence
  3. Residents and staff if high-risk congregate settings
  4. Health care workers who serve high risk clients
  5. HCWs unknowingly exposed to TB patient
  6. Low-income, medically underserved groups
  7. Locally define high risk groups
  8. Young persons exposed to high risk adults
73
Q

Pre clinical state of TB

A

Class 2

74
Q

Anti TB drugs that blocks B unit of bacterial RNA polymerase. Stops bacterial RNA synthesis. Bactericidal.

A

Rifampin

75
Q

Ocular TB

A

Phlyotenular keratoconjunctivitis

76
Q

M, tuberculosis infects human only, while m. Bovis infects…

A

Cattle and human

77
Q

(+/-) history of exposure
(-) s&s
(+) mantoux tuberculin tesT
(-) chest radiograph

A

Class 2 : TB infection

78
Q

(+) exposure to an adult with TB
(-) s&s
(-) mantoux tuberculin tesT
(-) chest radiograph

A

Class 1: TB exposure

79
Q

Cd8 T cells are

A

Cytotoxic T cells

80
Q

A BCG resistance gene linked with the molecule Nramp (natural resistance asso macrophage protein) has been characterized in mice. Likewise, a human homologous has been found on chromosome___.

A

Chromosome 2

81
Q

One cough = _____ droplets nuclei

A

3000

82
Q

Side effects of ethambutol

A

Reversible retrobulbar (behind eyeballs) neuritis
Loss of central vision
(Patients must have baseline ophthalmogic exam prior to treatment)

83
Q

Therapeutic use of ethambutol

A

15mg/kg/d

10-15mg/kg/d - children >5yrs/old

84
Q

High risk groups

A

Children less than 4 yrs of age
Person with HIV coinfection
Persons with close contact to person with TB
Person whose tuberculin skin test converted to positive in the past 1-2yrs
Persons who have chest radiographs suggestive of old TB
Persons with certain medical conditions: DM, silicosis, prolonged therapy with corticosteroid, immunosuppressive therapy, leukemia, Hodgkin disease, head and neck cancers, severe kidney disease, certain intestinal conditions, malnutrition

85
Q

Introduction of BCG vaccination program with assistance from UNICEF

A

1951

86
Q

All of the anti TB drugs is administered parenterally and orally, except one.

A

Streptomycin is administered intramuscularly.

87
Q

Contraindicated to children less than 5 years old

A

Ethambutol

88
Q

Side effects of isoniazid

A

Peripheral neuropathy
Hepatitis
Hepatotoxicity

89
Q

RIFATER

A

50mg isoniazid
120mg rifampin
300mg pyrazinamide

90
Q

Stage of pulmonary TB where bacilli undergo unrestrained replication. With time, more and more macrophages and more and more bacilli accumulates in the developing lesion called tubercle or granuloma.

A

2nd stage - symbiosis

91
Q

Stage of pulmonary TB where the logarithmic increase in number of bacilli is inhibited by CMI and DTH. Infected macrophages presented tuberculous antigen set to t lymph.

A

3rd stage

92
Q

Stage of pulmonary TB where liquefaction occurs. Liquefaction of the caseous center provides am excellent growth medium for the bacilli.

A

4th stage

93
Q

Lesions involving bones and joints are seen in ___% of infected children and appear ___yr after infection.

A

Occurs in 5-10% of children after 1yr of initial infection

94
Q

Anti TB drugs with hepatic excretion

A

Rifampin

95
Q

Strain of m.tuberculosis
Aka Oshkosh strain
Isolated from a male children’s clothing factory worker which is highly virulent in mice but not caused widespread epidemics in man

A

CDC-1551

96
Q

Primary defenses against TB

A

Macrophage and T lympho

97
Q

Decreased Th1

A

Pulmonary TB.

98
Q

In class 1, the development of DTH to tuberculin may take up ___ months after the infectious droplets has been deposited in the lung, and before the clinical s&s develop.

A

3 months

99
Q

Single tuberculin test is considered positive in an immunocompetent patient if the induration a tithe skin test site measures…

A

1cm

100
Q

DTH acts on the large ag load resulting in cavity formation and destruction of bronchial wall.

A

The bacillus and liquefied caseous material are discharged into the airways and spread to other parts of the lungs and the outside environment

101
Q

T to F: the relative contribution of other cell types to the total pattern of cytokines production in TB is also not known.

A

True

102
Q

Combination of calcified peripheral lung lesions and calcified hilar nodes.

A

Ghon complex

103
Q

Lesions of the ghon complex heal by..

A

Shrinkage, fibrous scarring and calcification

104
Q

TB is prevalent in economically underdeveloped countries. Other contributing factors aside from poverty are..

A

Parasitic disease, malnutrition, ignorance, superstition, and over-crowding.

105
Q

Suggested media for cultivation of mycobacteria

A
Solid media 
    A. Agar-based 
    B. egg-based
Liquid media 
    A. Bactec TB medium
    B. middlebrook 7H9 broth
    C. Septi-check AFB
    D. BBL mycobacteria growth indicator tube (MGIT)
106
Q

High prevalence groups

A

Persons born in countries with high prevalence of TB
Groups with poor access to health care
Persons who live or spend time on certain facilities (eg. Nursing homes, homeless shelters, drug treatment centers)
Persons who inject drugs

107
Q

Strain of m.mycobacteria which w first isolated in 1905 bit which has retained it’s virulence over the years in animal models, is drug susceptible and can be genetically manipulated

A

H37Rv

108
Q

Lung lesion of primary TB

A

Ghon focus

109
Q

Conventional culture of mycobacteria

A
Solid media 
(For sputum that is contaminated with normal bacterial flora, mitchison's selective 7H11 agar should be inoculated)
110
Q

Anti tb drugs that is Never used alone due to rapid resistance

A

Pyrazinamide

111
Q

It is added to promote dispersed growth of mycobacteria

A

Tween (nonionic detergent)

112
Q

Mycobacteria retain carbolfuchsin dye when decolorized with acid-ethanol by the _____ method.

A

Zehl-neelson method

113
Q

Lesions involving renal appear ___yr after infection.

A

5-25 years

114
Q

Relatively poor immune response leads to …

A

Advances, progressive pulmonary disease

115
Q

Virulence factor of mycobacteria that inhibits fusion of secondary lysosomes with bacilli-containing phagosome within macrophage

A

Sulfatides

116
Q

Anergy indicated by neg tuberculin test reflects suppression of DTH from processes which interfere with Th1 response.. Such as..

A

Malnutrition, HIV infection, Steroid therapy and severe TB itself

117
Q

A miracle drug streptomycin was first used for TB treatment

A

1949

118
Q

Creation of tuberculosis commission by virtue of Act 3743 under Philippine health service (now DOH)

A

1930

119
Q

The interval between initial infection and disease in adolescents is (longer, shorter).

A

Shorter interval

120
Q

Elevated Th1 means

A

Pleural effusion

121
Q

Risk of acquiring infection is determined mainly by

A

Exogenous/extrinsic factors

122
Q

Side effects of pyrazinamide

A

Hepatitis

Hyperuricemia with Gouty arthritis

123
Q

CD4 T cell subset which is pro inflammatory cytokines

A

Th1

124
Q

Therapeutic use of rifampin

A

600mg/d 1hr before or 2hrs after meal

10-20mg/kg - children

125
Q

Immunological reaction that causes caseous necrosis

A

DTH

126
Q

Anti-TB drugs that inhibits mycolic acid synthesis in wall of m.tuberculosis. Bactericidal.

A

Isoniazid

127
Q

The pathologic events in the initial TB infection seem to defend on the balance among the mycobacterial ag load, CMI and tissue hypersensitivity. When does the vigorous granulomas produced?

A

Small ag load

128
Q

Cd8 T cells can also be against m.bovis-infected macrophage

A

True

129
Q

High oxygen tension areas

A
Apical posterior areas of Lung
Lymph node
Kidney 
Epiphysis of long bone
Vertebral bodies
130
Q

A less common alternative course is _____ which occurs in situation where the immune response fails to control multiplication. The ghon focus, hilar and mediastinal lymph nodes are enlarged = compression of bronchi = atelectasis of distal lung = “middle lobe syndrome”

A

Primary Progressive TB

131
Q

Anti TB drugs that inhibits my colic acid synthesis in bacterial cell wall. Bacteriostatic.

A

Ethambutol

132
Q

MOTT includes what species

A

M. Avium-intracellulare

M. Kansasii

133
Q

MTBC includes what species

A

M. Tuberculosis

M. Bovis

134
Q

The ghon focus with an infected lymph nodes and associated lymphangitis forms..,

A

Ghon complex

135
Q

The CDC recommends that the culture system used should detect growth within 14 days. In this case, what is the most widely used culture media?

A

Bactec TB medium

136
Q

Entry into the body occurs largely by inhalation of Aerosolized particles containing ____tuberclenbacilli that are deposited in alveoli.

A

1-3 tubercle bacilli

137
Q

Anti TB drugs that penetrate cns

A

Rifampin

50% ethambutol

138
Q

TB enteritis

A

Tabes mesenterica

139
Q

A relatively good immune response is seen in patient with…

A

TB pleuritis

140
Q

Primary mode of transmission

A

Inhalation of droplet nuclei

141
Q

Virulence factor of mycobacteria that differs on the ability to stimulate cytokines release from mononuclear cells

A

Lipoarabinomanam

142
Q

The pathologic events in the initial TB infection seem to defend on the balance among the mycobacterial ag load, CMI and tissue hypersensitivity. When does the caseous necrosis occurs?

A

High ag load

143
Q

Th1 produces what cytokines

A

IFN-gamma
TNF-alpha
IL-2

144
Q

Factors contributing to the rise in TB

A
HIV infection
Poorly managed TB programs
Increase international travel
Poverty
Increase in number of refugees and displaced people
Multidrug resistant TB
145
Q

T or f: in solid caseous material, the tubercle bacilli can survive even for years, and can multiply.

A

False. It cannot multiply due to the anoxic condition, reduced pH and presence of inhibitory FA

146
Q

Side effects of rifampin

A

Secretions turn red
Hepatitis (esp.alcoholics)
Flu symptoms
Induces cyp450 thus increases metabolism of oral contraceptives and other drugs

147
Q

RIFAMATE

A

150mg isoniazid

300mg rifampin

148
Q

Side effects of streptomycin

A

Vestibular toxicity

Nephrotoxicity

149
Q

Lesions involving hematogenous spread is seen in ___% of infected children and appear ___mos/yr after infection.

A

Occurs in only 0.5-3% of infected children and occurs after 3-6months of initial infection.

150
Q

Risk of developing disease after being infected depends largely on…

A

Endogenous/intrinsic factors

151
Q

When does the WHO declared tuberculosis as a global emergency

A

1993

152
Q

TB bacilli can also induce macrophages to produce variety of cytokines. What are those?

A

TGF
IL-6 (suppress T cell response)
IL-12 (enhance T-helper responses)

153
Q

Advantage and disadvantage of conventional culture (solid media)

A

Advantage: allows visualization of colony morphology and pigmentation
Disadvantage: prolonged time of growth ( 3-4wks) and low sensitivity

154
Q

Virulence factors of mycobacteria

A

1) trehalose dimycolate
2) sulfatides
3) lipoarabinomanam (LAM)

155
Q

TB bacilli has a slow doubling time of…

A

18-24hrs

156
Q

Refers to the period from the time the tubercle bacillus enter the body until tissue hypersensitivity develops.
Time interval between the initial infection with tubercle bacilli and the development of an altered tissue reaction to the bacilli and their metabolic products.

A

Incubation period

157
Q

Gold standard Laboratory diagnosis for TB

A

PCR (culture)

158
Q

Depression of CMI may lead to ..

A

Re activation of TB

159
Q

Anti TB drugs excreted renally

A

Isoniazid
Pyrazinamide
Streptomycin

160
Q

In mice, protective immunity against TB can be induced by live, but NOT dead mycobacteria while ______ can be induced by either dead or live organisms or by cell wall components

A

Delayed-type hypersensitivity (DTH)

161
Q

Anti TB drug that is the first aminoglycoside (inhibits protein synthesis) by binding 30/50s ribosome site. Bactericidal.

A

Streptomycin

162
Q

T or f: depletion of CD4 T cell results in severe TB

A

True

163
Q

Cells mediating the tuberculin skin test are CD4-positive producing mostly Th1 cytokines. DTH response is asso with but not identical to CMI. The reasons may be (3)

A
  1. DTH responses are function of Cd4 T cells whereas protective immunity involves CD8 T cells.
  2. PPD does not contain all the ag derived from m.tuberculosis
  3. In TB with granuloma formation who have neg tuberculin test, T cells may be trapped in granuloma s reflecting their accumulation at the site of defense
164
Q

Mycobacteria are (anaerobe, aerobe); (motile, nonmotile)

A

Obligate aerobe and nonmotile

165
Q

Founding of Philippine tuberculosis society (PTS), a private agency with government subsidy.

A

1910

166
Q

Bacille Calmette-Guerin (BCG) used for vaccination is presumed to be derived from what species of mycobacteria?

A

M. Bovis

167
Q

Anti TB drug that is a nicotinamide analog with unknown mechanism.

A

Pyrazinamide

168
Q

Other rare mode of transmission

A

By ingestion of contaminated milk causing infection with M.bovis
Skin inoculation from contamination of an abrasion

169
Q

Demonstration of bacilli in children is limited because primary TB is often paucibacillary and young children can’t raise up sputum. What specimen is of greater importance for children?

A

Gastric aspirate specimen

170
Q
3 or more of the ff:
(+) history of exposure 
(+) s&s
(+) mantoux tuberculin tesT
(+) chest radiograph
(+) lab findings suggestive of TB
A

Class 3 : TB disease

171
Q

While intracellular killing follows phagocytosis, m.tuberculosis can evade such killing mechanism by (3)

A
  1. Prevention of acidification of phagosomes
  2. Neutralization of effects of reactive oxygen intermediates by mycobacterial cell wall components (more likely?)
  3. Probable inhibition of phagosome-lysosomal fusion
172
Q

Cytotoxic T cells kills cells harboring intracellular pathogens such as m.tuberculosis. These cells either exhibit..

A
  1. Granzyme/perforin mediated killing of target cells

2. Or induce apoptosis

173
Q

Specimens for culture

A
Pulmonary secretion
Urine 
Genital discharge
CSF
Blood 
Pleural fluid
174
Q

Excellent results for patients with nondrug resistant TB can be obtained with ___ month course

A

6 months
1st 2 months: PIRE
Last 4 months: IR

175
Q

Therapeutic use of pyrazinamide

A

15-30mg/kg/d

Not to exceed 2g/d

176
Q

Poor inflammatory and DTH responses may develop

A

Military TB

177
Q

Ghon focus is usually located in..

A

Sub pleural area of upper segment of lower lobe or lower segment of upper lobe

178
Q

T or F: a positive culture with or without a positive smear of m.tuberculosis is the gold standard for dx of TB and must be ought for whenever possible.

A

True

179
Q

T or f: both DTH and CMI inhibit multiplication of bacilli equally

A

True

180
Q

Therapeutic use of isoniazid

A

5mg/kg/d (300mg max)
10-20mg/kg/d (600mg max) - severely ill patients
10-20mg/kg/d (300mg max) - children

181
Q

Cd4 T cells are

A

T helper cells

182
Q

TB of cervical lymph nodes

A

Scrofula

183
Q

The interval between initial infection and disease in infants is (longer, shorter).

A

Longer interval.

184
Q

The stage of pulmonary TB where there’s is scavenging non activated alveolar macrophages ingests the tubercle bacilli which gets destroyed or inhibited depending on virulence of org and the innate microbicidal ability of macrophage.

A

First stage

185
Q

Virulence factor of mycobacteria responsible for its morphologic appearance - serpentine cords if bacilli in close parallel arrangements.

A

Trehalose dimycolate

186
Q

Incubation period of TB

A

19-56 days (3-8wks)

187
Q

M.bovis is intrinsically resistant to …

A

Pyrazinamide

188
Q

Advantage and disadvantages of bactec TB medium

A

Advantage:
Rapid detection of growth (5-12days)
Increased sensitivity
Ability to distinguish MTBC from other mycobacterial species
Rapid susceptibility testing of isolates of m.tuberculosis

Disadvantage: its radioactivity in which its disposal is expensive and may be problematic for some institutions.

189
Q

First line TB drugs

A
RESPI
rifampin
Ethambutol
Streptomycin
Pyrazinamide
Isoniazid
190
Q

Refers to infection at disseminated sites where the multiple small yellow nodular lesions are produced in several organs like lungs, lymph nodes, kidney, adrenal, bm, spleen and liver.

A

Miliary TB

191
Q

Cutaneous TB

A

Scrofuloderma

192
Q

Classification of TB

A
M. Tuberculosis complex (MTBC)
Nontuberculous mycobacteria (MOTT or mycobacteria other than TB)
193
Q

CD4 T cell subset that produces cytokines important for humoral immunity

A

Th2

194
Q

TB of the spine

A

Pott’s disease

195
Q

2 ends spectrum of TB

A

Healthy tuberculin reactor
Severe miliary TB
(Reflecting extremely effective and poor immune response to m.tuberculosis respectively)

196
Q

Single tuberculin test is considered positive in an immunocompromised patient if the induration a tithe skin test site measures…

A

0.5 cm

197
Q

It is inhibited by higher tension of oxygen

A

M.bovis

198
Q

Therapeutic use of streptomycin

A

15mg/kg/ 12hr
20-40mg/kg/12 hrs - children

Not to exceed 1g/d

199
Q

T or F: transmission does not occur from large droplets.

A

True, since these fall to the ground, or if inhaled, are removed by mucociliary action and coughing.