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Flashcards in Pre-Midterm Deck (131)
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1
Q

Until recently, _____ was the leading cause of death

A

Bacterial disease

2
Q

What types of diseases are people typically killed by?

A

Respiratory and gastrointestinal diseases

3
Q

Why is it easier to measure rates of disease in developed countries?

A

There are more accurate birth and mortality statistics

4
Q

Epidemiology stats are typically measured in what units?

A

/100 000 population/year

5
Q

The crude mortality rate in Canada is ______%

A

0.71%

6
Q

What are the top three causes of mortality in Canada? In descending order

A
  1. Major cardiovascular disease
  2. Malignant neoplasms
  3. Chronic respiratory diseases
7
Q

______ is almost as common as chronic respiratory diseases in Canada

A

accidents~

8
Q

_______ is the infectious disease causing the highest amount of deaths in Canada

A

Pneumonia

9
Q

_____ has the highest per capita TB rate in Canada

A

Manitoba

10
Q

Canada has a ______ rate of death during pregnancy, childbirth, and perinatal than most industrialized countries

A

lower

11
Q

What are the top causes of mortality in Canada due to infectious agents?

A
  1. Septicaemia
  2. Intestinal infections
  3. HIV
  4. Hepatitis
  5. Other infectious and parasitic diseases
12
Q

Why have HIV rates recently gone up?

A

Because HIV is no longer a death sentence so people are taking fewer precautions

13
Q

The most common type of hepatitis that causes death is….?

A

Hep C

14
Q

Worldwide, ______ used to be (pre-vaccination) the 4th leading cause of death due to respiratory disease

A

Measles

15
Q

Why is the overall rate of diarrhoeal diseases going down?

A

Clean drinking water

16
Q

Describe tuberculosis

A

Respiratory disease occurring in two stages. People have it for life but can go into remission where they show no symptoms.

17
Q

How was tuberculosis treated before antibiotics?

A

Often people with TB were sent to live far away so they wouldn’t spread it to anyone. There, they would either go into remission or die alone

18
Q

What is the most common form of cancer worldwide?

A

Lung cancer

19
Q

What are the most common killers in low income countries?

A
  1. Heart disease
  2. Respiratory infections
  3. Diarrhoeal diseases
  4. AIDS/HIV
  5. Tuberculosis
  6. Neonatal infections
  7. Malaria
20
Q

In low income countries, infectious disease amounts to ___% of total mortality

A

34%

21
Q

What are the most common killers in high income countries?

A
  1. Heart disease
  2. Cancer
  3. Respiratory infections
  4. COPD
  5. Alzheimer’s
  6. Diabetes
22
Q

Infectious diseases cause ____% of the total world mortality

A

20%

23
Q

Infants die primarily due to _____

A

infectious disease

24
Q

Describe how cholera broke out in a large population following the Rwandan genocide

A

Following the Rwandan genocide, 500 000 Rwandans were travelling to Zaire, stopping near the border, pooping the whole way. Cholera quickly broke out, killing about 48 000 people. Some also had dysentery and meningitis. Infant mortality rate was extremely high

25
Q

The _______ survey was conducted by the WHO in 2004 to determine how many deaths worldwide are caused by infectious disease agents

A

Global Burden of Disease

26
Q

How are disease rates different between people from high and low income situations?

A

Even within the US, low income people have much higher disease rates than high income people, likely because they are in better health

27
Q

Describe the stages of demographic transition and how they relate to mortality rates

A

Stage I - high fertility, high mortality, low or no population growth (same amount of people living and dying)
Stage II - Decreased mortality, high fertility, increase in population
Stage III - Decreased mortality, decreased fertility, low population growth

28
Q

What are the 3 groups of mortalities

A

Group I - Infectious diseases
Group II - Non-communicable diseases, cancer, heart and circulatory disease, degenerative disease
Group III - Accidents and violence

29
Q

Have cancer rates truly been going up?

A

No, rates of disease, infectious or otherwise, have been going down, so cancer comparatively looks worse

30
Q

Describe some theories for the decline in infectious disease mortality

A

There are many possible causes of the decline, including medicine, evolution, sanitation, nutrition, standard of living. Some scientists think that pathogens simply evolve to be less virulent. Others think that humans evolved to be more resistant.

31
Q

What are some examples of diseases increasing virulence?

A

Smallpox (supposedly used to be a benign disease) and 1918 influenza

32
Q

Why is milk pasteurized?

A

TB!!!! Cause it’s tasty. Seriously, have you drank unpasteurized milk? It tastes worse than semennnnnnn…that lemons.

33
Q

_______ is a diagnostic tool for diseases, developed by the WHO, used to monitor incidence and prevalence of diseases. It classifies death and vital records.

A

International Classification of Diseases

34
Q

About ____ species of bacteria cause most of the bacterial disease on earth. About ____ of those cause deadly infections

A

50, 25

35
Q

TRUE OR FALSE: Most bacteria are opportunistically pathogenic

A

TRUE

36
Q

The human body has about a ___:__ ratio of bacterial cells to human cells

A

10:1

37
Q

The first bacteria you come in contact with are found where?

A

In the birth canal

38
Q

Why is it thought that humans “choose” their bacteria?

A

All humans are remarkably similar in what grows in their bodies

39
Q

_____ occurs when live bacteria are found in the blood

A

Bacteremia

40
Q

_____ occurs when bacteria are found replicating in the blood

A

Septiceamia

41
Q

_____ occurs when viruses can be detected in the blood

A

Viremia

42
Q

The _____ and _____ pull bacteria out of your body, helping you to deal with daily infections

A

Spleen, lymph nodes

43
Q

What are the mucosal surfaces of the body? What quantity of bacteria grows in each?

A

Upper respiratory tract - good temperature and pH for bacterial growth
Gastrointestinal tract - perfect conditions, contains most bacteria in body
Urinary tract - does not contain many bacteria, usually too low in pH

44
Q

Why is it that humans have slightly different bacterial flora?

A

They all have diverse habitats, diets, clothing, and habits affecting bacteria

45
Q

Species that are not resident bacteria are referred to as _____

A

Transients

46
Q

Describe resident bacterial species

A

Usually present at all times and on all people, adapt to their environment, reproduce in their environment, hard to displace, and generally cause no health issues

47
Q

Describe transient bacterial species

A

Present only sometimes, present only in a sub population (ex. S. aureus in nose), do not show adaptations to human body, usually cannot reproduce, includes most pathogens, also called “commensals”

48
Q

What is an example of a bacteria that is both a transient and a resident bacterial species

A

Streptococcus pneumoniae lives only in humans, yet does so very rarely and often not at all in a person’s lifetime.

49
Q

Most skin bacteria are gram _____. Why is this?

A

positive. Because they are better at surviving desiccation and high salt concentrations

50
Q

Most skin bacteria grow where skin is _____

A

moist

51
Q

Describe the composition of the skin

A

Upper layer - Epidermis

Lower layer - Dermis

52
Q

The epidermis is primarily composed of _____ cells. Describe them

A

Keratinocytes. Several layers of them exist on top of the skin, dead and providing protection. They are produced in the basal layer and it takes 2-4 weeks for them to migrate to the surface. When the cells slough off it is called desquamination

53
Q

Why is skin so protective against bacteria?

A

Salt concentration (high osmotic pressure) - throws off solute balance in cell - inhibits gram negs
Waterproof/dry - inhibits gram negs
Low pH (between 4.5 and 6) - inhibits gram negs
Bacteria cannot penetrate mechanically or enzymatically (cells too fatty and dead)
Desquamination causes most bacteria to be lost daily
Free fatty acids (Long chain fatty acids) - affect gram positives
Lack of nutrients (most bacteria can’t eat keratin, molecules on skin are too large to efficiently digest)

54
Q

What important structures compose the dermis?

A

connective tissue, nerves, capillaries, hair follicles, glands, fat tissue, and immune system components

55
Q

How do bacteria compete on the skin?

A

Many gram positives secrete antibiotics to inhibit other bacteria and other strains of the same species. Also, some bacteria, when hydrolyzing lipids, release fatty acids which are toxic to other species

56
Q

What makes up the upper respiratory tract?

A

Nose, pharynx, larynx, trachea, and bronchi

57
Q

Describe the Coryneforms. List as many genera as you can

A

Non-acid fast (except TB), non branching (do not form mycelia), non-sporeforming gram positive pleomorphic rods. Include anaerobic and aerobic species.
Include genera such as Corynebacterium, Propionibacterium, Brevibacterium, Dermabacter, and Mycobacterium.

58
Q

What is size the nose good at filtering?

A

> 5 micrometers. The larger the particle the better and more efficient
anything <1 micrometer can just slide right in

59
Q

What kind of cells compose alveoli?

A

non-ciliated, simple, squamous, type 1

cuboidal epithelial, extensive microvilli. (These fuckers secrete alveolar fluid and serve as stem cells to replace the Type 1)

60
Q

How is Propionibacterium acnes potentially related to acne? Can it opportunistically cause any disease?

A

It is often the dominant species in oil gland with reduced O2 concentration. Can inflame pores by hydrolyzing triglycerides to free fatty acids.
Also can cause endocarditis, endophthalmitis, osteomyelitis, wound/catheter infecitons

61
Q

What other mucus is also produced?

A

Airway surface liquid.

62
Q

CNS stands for ____

A

Coagulase-negative staphylococcus

63
Q

Which CNS species are most important, with regard to skin

A

Staphylococcus epidermidis is most common and widespread on skin - can adhere to skin and medical devices
Other genera found on skin include: S. saprophyticus, S. sapitis, S. hominis, S. haemolyticus

64
Q

WHAT THE FUCK IS UP WITH STAPH HAEMOLYTICUS

A

Transferred the methicillin resistance gene to MRSA!!!!!!!!!!~~~~~~~~

65
Q

Why the fuck do bacteria love our RT so much?

A
host anti-microbial defenses
large populations of Gram-negatives as well as Gram-positives
larger populations
higher species diversity
frequent isolation of pathogens
ability to attach to epithelial cells
66
Q

Found on the skin, describe the yeast Malassexia

A

Oval/cylindrical, lipophilic, dimorphic. Are superficial to skin. Associated with dermatitis, dandruff, foliculities, pityriasis, versicolour.

67
Q

How are organisms often transferred to and from the skin?

A

Contact transmission to/from inanimate objects, people, other parts of the body. All bacteria and viruses can be transferred - often people touch things like their lips and nose, and that’s how they get sick
Shedding of sqaumes rids the skin of millions of bacteria every day
Hand washing helps to reduce transmission of infectious disease

68
Q

Describe how invasive hospital procedures such as catheters, IV lines, and surgery can lead to nosocomial infection. Which bacteria often cause the infections?

A

Often results in septicemiae, with a 10-15% mortality rate. 50-75% of nosocomial septicemia is caused by Staph epidermidis
Implantable devices can infect the host.
Wound and surgical site infections can be colonized by CNS, P. acnes, or Corynebacterium species.
Organisms include S. aureus, Propionibacterium acnes, Staph epidermidits and numerous gram negatives

69
Q

What are the main bacterial genus of the mouth?

A
Oral Strep
Actinomyces
Veillonella spp.
Fusobacterium
Porphyromonas
70
Q

What does the acronym EVIL stand for?

A

Every
Villain
Is
Lemons

71
Q

How do bacteria compete on the skin?

A

Many gram positives secrete antibiotics to inhibit other bacteria and other strains of the same species. Also, some bacteria, when hydrolyzing lipids, release fatty acids which are toxic to other species

72
Q

How does the human immune system protect against bacteria on the skin?

A
  • We secrete antibodies, which are thought to stop bacteria from attaching to skin
  • Antimicrobial peptides in very short chains, such as “defensins”, cationic peptides effective against gram pos and gram negs, fungi. Also includes dermicidin
  • Lysozyme: works best at low pH and high salt conc. Breaks down peptidoglycan and works better on gram positives. This is secreted onto the surface of the skin, eyes, and mouth
  • Reactive nitrogen species: H2O2 on the skin forms nitric oxide which can be lethal to cells
73
Q

Describe important pathogens in the Corynebacteria

A

Corynebacterium diptheriae - Respiratory tract pathogen

C. urealyticum - causes nosicomial UTIs

74
Q

Describe the genera Propionibacterium

A

Proteolytic (can feed corynebacteria) and liplytic. Can be microaerophilic or anaerobic.

75
Q

Describe the coagulase-negative Staphylococci (genus Staphyloccocus)

A

Includes all Staphyloccoci but S. aureus. Most inhabit mammals, and almost half of species can be found on human skin. Tolerate wide pH and temperature range, very halotolerant.

76
Q

CNS stands for ____

A

Coagulase-negative staphylococcus

77
Q

Which CNS species are most important, with regard to skin

A

Staphylococcus epidermidis is most common and widespread on skin - can adhere to skin and medical devices
Other genera found on skin include: S. saprophyticus, S. sapitis, S. hominis, S. haemolyticus

78
Q

Is S. aureus commonly found on the skin?

A

Nope, usually found in the nose.

79
Q

Found on the skin, describe the yeast Malassezia

A

Oval/cylindrical, lipophilic, dimorphic. Are superficial to skin. Associated with dermatitis, dandruff, foliculities, pityriasis, versicolour.

80
Q

How are organisms often transferred to and from the skin?

A

Contact transmission to/from inanimate objects, people, other parts of the body. All bacteria and viruses can be transferred - often people touch things like their lips and nose, and that’s how they get sick

81
Q

Describe how invasive hospital procedures such as catheters, IV lines, and surgery can lead to nosocomial infection. Which bacteria often cause the infections?

A

Often results in septicemiae, with a 10-15% mortality rate. 50-75% of nosocomial septicemia is caused by Staph epidermidis
Implantable devices can infect the host.
Organisms include S. aureus, Propionibacterium acnes, Staph epidermidits and numerous gram negatives

82
Q

What is the only bacteria in the stomach?

A

Helicobacter pylori

83
Q

Describe “amensalism”, give an example within bacteria

A

One organism adversely affects another. Ex. antibiotic production to inhibit competitors

84
Q

Describe “parasitism”, give an example within bacteria

A

One (the parasite) benefits while the host suffers

Ex. most bacterial/all viral infections

85
Q

How are bacteria subject to predation?

A

Bacteria can kill each other - ex. Bdellovibrio and Vampirococcus
Protists often kill bacteria in their natural environments. However, some bacteria just live inside their captors. Stockholm-syndrome like.

86
Q

Describe “commensalism”, give an example within bacteria

A

One symbiont benefits while the other is neither benefited or harmed.
Ex. Facultative anaerobes consuming most O2, the nstricter anaerobes can survive

87
Q

How can H. pylori survive in the stomach?

A

It has a flagella that allows it to penetrate the mucuosal membrane of the stomach and catalyzes urease into ammonia which increase the pH of the stomach to a point where it can survive.

88
Q

Describe “mutualism”, give an example within bacteria

A

Obligate symbiosis with benefit to both parties. Good example is Buchnera aphidicola and aphids. Bacteria ferment the sugars in plant sap and release amino acids for aphid. Bacteria cannot live outside of aphids and aphids treated with antibiotics die

89
Q

There is a low amount of bacteria duodenem, what are the genuses that inhabit it?

A
Lactobacillus and Strep (Both have to be acid tolerant)
Bacteroides
Clostridium
Entrococcus
Enterobacteria
90
Q

Describe the Enterobacteriaceae of the large intestine (include genera)

A

Facultatively anaerobic, mostly motile, gram negative (small) rods. Most common are Escherichia, Proteus, Enterobacter, Citrobacter

91
Q

What can be used as a representative image of the body?

A

Poop, its poop.

It contains 10 to the 8 cells/gram for facultative anaerobes and 10 to the 11 cells/gram of obligate anaerobes.

92
Q

What is the main source of carbon in the large intestine?

A

Complex carbohydrates from plants

cellulose/hemicellulose
pectins
xylans
mucoproteins, glycoproteins, and glycolipids

93
Q

Describe “cooperation”, give an example within bacteria

A

Both symbionts benefits but the relationship is not obligatory. Ex. I don’t want to explain it, it’s that long thing about SCFA fermentors and H2 consuming methanogens

94
Q

How do bacteria gain nutrients and essential things in the large intestine?

A

Bacteroids consume the complex carbohydrates and break them down. Then Eubacteriums consume these simple sugars and change them into SCFA (short chain fatty acids). Clostridium and Enterococcus also ferment the sugars, but they instead ferment them into acids.

95
Q

What is “symbiosis” between organisms? What are the types of symbiosis?

A

Two different organisms living together, usually in close proximity, may be permanent
If there is a large difference in size the larger one is often called the “host”
Endosymbiosis = one inside the host, often intracellular
Ectosymbiosis = outside the host

96
Q

Describe Peptostreptococcus

A

Obligately anaerobic, gram positive cocci in pairs, tetrads, and clusters. Very strictly anaerobic, which makes one wonder how they even got there. Performs amino acid fermentation

97
Q

What’s an antibiotic?

A

Substance produced by a living organism that kills or inhibits bacterial growth

98
Q

What does it mean to be bacteriostatic?

A

Inhibits growth of bacteria until removed from your system, then the bacteria can grow again

99
Q

What does it mean to be bacteriocidal?

A

Bacteria are killed

100
Q

Is it necessary for antibiotics to be bacteriocidal to be effective?

A

No, bacteriostatic ones can inhibit growth enough to give your immune system a chance to strike

101
Q

how are antibiotics tested for effectiveness?

A

Vials are produced containing the same amounts of bacteria but different amounts of antibiotics (half of the previous vial and so on). The vial with no growth that had the smallest amount of antibiotic added gives us the Minimum inhibitory concentration (MIC). Then, the organisms from each of the “no growth” vials are plated, and if something grows, the antibiotic is only bacteriostatic

102
Q

Differentiate between wide and narrow spectrum antibiotics

A

Wide spectrum - work against many types of bacteria

Narrow spectrum - effective against only one type of bacteria

103
Q

Differentiate between MIC and MLC

A

MIC - minimum inhibitory concentration - lowest concentration of antibiotic needed to stop growth of that species
MLC - minimum lethal concentration - lowest concentration of an antibiotic that kills all bacteria of a given species

104
Q

What are the 4 main targets of antibiotics

A
  1. Antimetabolites
  2. Cell wall (peptidoglycan) Biosynthesis
  3. DNA-RNA Biosynthesis
  4. Protein Biosynthesis
105
Q

Describe how antimetabolites work. What form do these antibiotics come in? What spurred their development?

A

interfere with cellular metabolism (usually small molecule metabolism. Antibiotics are all synthetic, called sulfonamides (sulfa drugs).
In the early 1900s a mostly toxic antibiotic called Salvarsan was used to treat syphilis, and people thought they wanted something much less toxic

106
Q

Describe the antibiotic “sulphanilamide”. How does it work and what does it inhibit?

A

Sulphalimide inhibits –aminobenzoic acid, an essential component in the development of folic acid. Folic acid is necessary for biosynthesis of purines, pyrimidines, methionine.
Inhibits Group A strep, Strep. pneumoniae, Staphylococci, Neisseria spp, Haemophilus influenzae, Bordetella pertussis, Yersinia pestis, Chlamydia
Most suphonamides are not used because of toxicity and resistance but some are still used in treating UTIs as they concentrate in the urine

107
Q

What type of antibiotic is Penicillin?

A

Peptidoglycan synthesis inhibitor

108
Q

Who “discovered” (in a lab) penicillin?

A

Fleming

109
Q

What is penicillin most useful against?

A

Staphylococci, pneumococci (ex. Streptococcus pneumoniae), Meingococci (ex. Neisseria meningitidis), Gonococci (ex. Neisseria gonorrhoeae)
NOT gram negs

110
Q

Describe the structure of penicillin

A

beta-lactam ring is what attacks peptidoglycan. Whatever is attached to it just affects the properties of the antibiotic, but the beta-lactam ring is the most important part

111
Q

What are the six major classes of penicillin used today?

A
  1. Penicillin G
  2. Penicillin V (oral)
  3. Penicillins resistant to Staph Beta-lactamase
  4. Broad spectrum (amino) penicillins
  5. Penicillins active against P. aeruginosa
  6. Beta-Lactamase resistant Penicllin
112
Q

Describe the Benzyl Pencillins (Penicillin G)

A

The original, which was a crystallized penicillin. Acid labile, effective against most gram positives. Still the antibiotic of choice against S. pneumoniae, N. gonorrhoeae, Staphylococci that are not resistant, and Beta haemolytic Streptococci.
It is cheap and nearly non toxic

113
Q

Describe oral penicillins (Penicillin V)

A

Acid stable, just like Penicillin G but can be taken orally

114
Q

Describe Penicillins resistant to Staph Beta-lactamase

A

Used to treat penicillin-resistant Staph infections. Basically, the extra part of penicillin is cleaved off and the beta lactam ring is left over (makes it semi synthetic).
Includes Methicillin (as in MRSA), oxacillin (form used in North America), cloxacillin, flucloxacillin.
MIC is higher in this than Penicillin G and V, basically just used for resistant species

115
Q

Describe the Broad spectrum Penicillins

A

Better against gram negs, still active against gram positives, not resistant to Beta-lactamase.
ex. amoxicillin (ideal because it is cheap and safe)

116
Q

Describe penicillins that are active against P. aeruginosa

A

P. aeruginosa doesn’t do much to the body unless you have a condition like cystic fibrosis, then it can be fatal. In those situations penicillins like ticarcillin and carbenicillin are used

117
Q

What is the only beta-lactamase resistant penicillin

A

temocillin

118
Q

What are the Cephalosporin antibiotics?

A

Related to penicillin, still have beta lactam. Basically the same as penicillin but has a slightly wider spectrum of activity. Resistant to Staph beta-lactamase. This was the basis for semi-synthetic antibiotics and we currently use over 25 of them

119
Q

Describe the first generation cephalosporins

A

Cephaloridine was the first in use, effective against penicillin-resistant S. aureus, streptococci, E. coli, K. pneumoniae and Proteus mirabilis

120
Q

Describe the second generation cephalosporins

A

Cefoxitin. Resistant to gram negative beta lactamases. Can attack the same as first gen plus Haemophilus and Enterobacter

121
Q

Describe the third generation cephalosporins

A

Effective against P. aeruginosa, almost all enterobacteriaceae, Neisseria gonorrhoeae

122
Q

Vancomycin was the antibiotic of choice when treating MRSA for a while, why was it an issue?

A

SUPER toxic, lots of side effects

123
Q

Describe the Carbapenams

A

acid labile, last resort antibiotic. similar to beta-lactams, highly resistant to beta-lactamases and cephalosporinases. Wide spectrum against gram pos, neg, include P. aeruginosa and MRSA. Last resort because we do not want things to develop resistance

124
Q

Describe protein synthesis inhibitors

A

most diverse antibiotics, rely on differences between eukaryotic and prokaryotic ribosomes (low therapeutic index), often can be toxic or have side effects

125
Q

What is the therapeutic index?

A

toxic dose/therapeutic dose

126
Q

What is used to treat herpes?

A

Cidofovir

127
Q

What are the three kinds of antivirals that target HIV?

A

Nucleotide analog reverse transcriptase inhibitors
Non-nucleotide RT inhibitors
HIV protease inhibitors

128
Q

Describe tetracycline

A

Introduced in the late fourties, bacteriostatic, blocks binding of amino-acyl tRNAs to ribosomes
Effects Staph, Strep (not Enterococci), many gram negatives (not P. aeruginosa), Mycoplasmas, Chlamydia and Richettsia, Spirochetes.
this antibiotic is limited by resistance and minor toxicity. Used to treat intracellular bacteria, STIs, respiratory infections, UTIs.

129
Q

Describe the Macrolides

A

Have a very large lactone ring. Bacteriostatic, wide spectrum of activity, end in “thromycin”. Are protein synthesis inhibitors. good against gram negs but not gram pos. Used as an alternative to penicillin when patients are sensitive (basically a shittier penicillin). Antibiotic of choice for Corynebacterium diphtheriae, whooping cough (Bordetella petsusis) and Legionnaire’s Disease (Legionella pneumophilia).
Also used to treat CAP (community acquired pneumonia), mycoplasma infections, and non-TB mycobacterium

130
Q

What is the primary DNA Synthesis Inhibiting antibiotic> Describe them

A

Fluoroquinolones. used to treat UTIs and effective against gram negs (incld. P. aeruginosa - with a good MIC), and some gram pos (staph, strep, enterococcus).
over generations they got less toxic and more expensive
Often used to treat respiratory tract infections, UTIs, nosocomial gram-neg infections

131
Q

Describe RNA synthesis inhibitor antibiotics

A

inhibit DNA dependent RNA polymerase, bacteriocidal, very narrow spectrum of activity (gram pos, neisseria, mycrobacterium.
Used in meningitis outbreaks, as part of multi-step TB treatment