bacterial infection (S-Y) Flashcards

1
Q

how are Salmonella serotypes be categorized?

A

-typhoidal (typhoid & paratyphoid fever) - Typhi, Paratyphi A, tartrate negative Paratyphi B, Paratyphi C

-nontyphoidal (acute diarrhea)

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

how are the Salmonella (nontyphoidal) transmitted?

A

animal reservoirs (domestic and wild)
- eating contaminated foods (dairy, eggs, meat, raw produce)
- drinking contaminated water
- contact with people who have a diarrheal illness

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

what increases the risk of nontyphoidal salmonella infection after exposure?

A

taking AB or antacid medication

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

what are the symptoms of nontyphoidal salmonella infection?

A

acute diarrhea (incubation 12-96 hours, but it can be more than 7 days)
abdominal cramps, fever, usually resolves without treatment after 1-7 days

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

what % of people develop bacteremia or focal invasive infection (osteomyelitis, meningitis, endovascular infection, septic arthritis) from nontyphoidal salmonella infection?

A

5% (higher among infants, older adults, immunocompromised)

ppl with atherosclerosis, hemoglobinopathies, or maligantn neoplasms - increased risk for extraintestinal infection

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

how to diagnose nontyph salmonella infection?

A

culture (routine stool culture, abscesses, blood, CSF, urine)

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

how to treat salmonellosis?

A
  • most just supportive care - rehydration therapy
  • AB not recommended for most with uncomplicated salmonellosis (does not shorten the duration of illness and can prolong bacterial shedding)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

who should get AB treatment for salmonellosis?

A

Consider antibiotic therapy for patients with suspected invasive disease (e.g., patients with severe diarrhea, high fever, manifestations of extraintestinal infection) and for patients at increased risk for invasive disease (e.g., infants, older adults, people who are immunocompromised, patients with known atherosclerosis). For these populations, treat infections empirically until susceptibility results are available.

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

which empiric AB drug should be used for salmonellosis?

A

fluoroquinolones in adult travelers (resistance rising globally)
ceftriaxone - children and adults with invasive disease (resistance rare)
azithromycin can be used for children and is an alternative agent for adults

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

what causes tetanus?

A

Clostridium tetani - spore-forming, anaerobic, gram positive

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

tetanus is more common in which area?

A

in rural and agricultural regions; areas where contact with soil or animal excreta is likely; warm and moist environments; and areas where immunization against tetanus is inadequate.

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

which countries have not achieved maternal and neonatal tetanus elimination?

A

Afghanistan, Angola, Central African Republic, Guinea, Mali, Nigeria, Pakistan, Papua New Guinea, Somalia, Sudan, South Sudan, Yemen

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

what is average incubation period for tetanus?

A
  • incuation on average 10 days (3-21 days)
  • duration of the incubatino period is inversely related to the severity of symptoms –> shorter incuation = riskier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do you classify tetanus symptoms?

A

generalized, localized, and cephalic

generalized: >80%, lockjaw, generalized spasms, risus sardonicus, opisthotonus

localized: muscle spasms confined to the injury site

cephalic: head or face wound and flaccid cranial nerve palsies

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

how does neonatal tetanus occur?

A

contaminated umbilical stumps and whose mothers are unimmunized or inadequately immunized

long term sequelae - behavioral, intellectual, and neurologic abnormalities

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

what is case-fatality ratios for generalized tetanus? localized tetanus?

A

25~100%
<1%

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

how to dianose tetanus?

A

clinical findings with epidemiologic support only

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

how to treat tetanus?

A
  • tetanus immune globulin (TIG)
  • aggressive wound care and debridement
  • supportive care
  • AB 7-10 days: metronidazole; alternative is IV penicillin G
  • must be hospitalized in a quiet, dim room to minimize spasms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Under 7 years, which tetanus vaccine is available? how many doses for children?

A

DTaP (diphtheria-tetanus-acellular pertussis)
DT (diphtheria-tetanus)
Infants/children - 5 doses of DTaP at 2, 4, 6, 15-18 months, 4-6 years

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

from 10 years old, which tetanus vaccine is avaialbe?

A

-Tdap (tetanus-diphtheria-acellular pertussis)
-adolescent shoudl receive 1 dose of Tdap at 11-12 years of age
-Children 7 and up can receive Tdap for catch-up vaccination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

for pregnancy what is the indication of tetanus vaccination?

A

27-36 weeks’ gestation
unvaccinated pregnant people should receive 2 doses of TTCV during their pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is contraindication & precaution of tetanus vaccination?

A
  • encephalopathy without an identifiable cause occurring within 7 days of a previous dose of DTP, DTaP or Tdap - for the pertussis component of the vaccines; can receive either DT or Td
  • progressive or neurolgic disorder due to pertussis component
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when do you get tetanus vaccination for wound management?

when do you get tetanus TIG for wound management?

A

TTCV: history of tetnus vaccine unknown or less than 3 previous doses

TIG: history of tetanus vaccine unknown or less than 3 previous doses and the wound is not clean/minor wound.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the causing agent of tuberculosis?

A

Mycobacterium tuberculosis complex - rod-shaped, nonmotile, slow-growing, acid-fast bacteria including M. bovis and M. tuberculosis hominis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how is the TB transmited?

A
  • coughs, through the air
  • unpasteurized dairy products from infected cattle (bovine TB - caused by M. bovis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is multidrug-resistant TB resistant to?

A

at least the 2 most effective drugs - isoniazid and rifampin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how to diagnose TB?

A

8-10 weeks after exposure, do tuberculin skin test (TST) or interferon-gamma release assay (IGRA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how much % of people who are infected with TB progress to TB disease?
If not progress to TB disease, what happens?

A

5-10%
-if not progress, it remains inactive (latent TB infection) – no symptoms, cannot spread the infection to others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how long does it take TB to progress to TB?

A

weeks to decades after initial infection

30
Q

what are the symptoms of TB?

A

70-80% cases are lung related; others bladder, bones and joints, brain and meninges, genitalia, kidneys, lymph nodes, pleura

prolonged cough, fever, hemoptysis, night sweats, decreased appetite, weight loss

31
Q

when do you do pretravel and posttravel testing for TB?

A
  • who anticipate possible prolonged exposure to TB - care for patients, work in health care facilities, prisons or jails, refugee camps, homeless shelters;
  • who plan to stay in TB-endemic countries
32
Q

which 3 methods are used for TB testing?

A
  1. culture methods - takes 2 weeks, can identify M. tuberculosis complex species
  2. microscopy - sputum smear or other body tissues or fluids - can see AFB (acid-fast bacilli) but cannot distinguish M. tuberculosis from nontuberculous mycobacteria
  3. Nucleic Acid Amplification Tests - less sensitive than culture but more sensitive than AFB smear; specific for M. tuberculosis complex - rapidly confirm diagnosis and help guide initial treatment until culture results return.
33
Q

how to treat latent TB?

A
  • 3 months once weekly isoniazid and rifapentine
  • 4 months rifampin daily
  • 3 months isoniazid and rifampin daily
  • 6-9 months isoniazid daily
34
Q

what are the interactions of rifampin with other meds?

A

interaction with oral contraceptives and certain antiretrovral medications

35
Q

how to treat TB?

A
  • isoniazid, rifampin, ethambutol and pyrazinamide for 2 months, then isoniazid and rifampin for additional 4 months
36
Q

how to treat drug-resistant TB?

A
  • older tx: 4-6 drugs for 18-24 months
  • new tx: bedaquiline, pretomanid, linezolid (all oral) for 6 months
37
Q

how to prevent TB?

A

Bacillus Calmette-Guerin (BCG) vaccine - at birth in countries with higher TB burdens
- but low and variable efficacy in preventing TB in adults

38
Q

if you had BCG vaccine, which TB test is preferred?

A

IGRA - BCG might give false-positive TST results

39
Q

how to prevent infections from Mycobacterium bovis and other foodborne pathogens?

A

avoid unpasteurized diary products

40
Q

when do you do 2nd TST for travelers?

A
  • if TST testing for the first time
  • not needed if already been tested and found to have a negative result within the previous 2 years
  • 2nd method - TST baseline negative –> retest 1-3 weeks after; if 2nd is negative then pt is not infected; if 2nd is positive, pt have skin test boosting, possibly because of previous M. tuberculosis infection
41
Q

what is the infectious agent of typhoid fever and paratyphoid fever (=enteric fever)?

A

Salmonella enterica serotypes Typhi, Paratyphi A, Paratyphi B, and Paratyphi C

42
Q

how do you differentiate Paratyphi B strains (2 distinct pathotypes)?

A

based on their ability to ferment tartrate
1. Paratyphi B - unable to ferment tartrate and is associated with paratyphoid fever
2. Paratyphi B var. L(+) tartrate(+) - ferments tartrate and is associated with gastroenteritis typical of nontyphoidal salmonellosis.

43
Q

other than water and food, what would be the rare route of transmission of enteric fever?

A

sexual contact, MSM

43
Q

how are enteric fever transmitted?

A

only humans - water or food by feces of person (a person can be acute, chronic, or asymptomatic carrier)

44
Q

each year, how many cases are there for typhoid fever and paratyphoid fever worldwide?
how many death per year?

A

typhoid - 11-21 million cases
para - 5 million cases

135,000-230,000 deaths per year

45
Q

which returning countries are most reported for enteric fever?

A

South Asia (Bangladesh, India, Pakistan), Africa, Latin America, SE Asia

lower risk regions - East Asia and the Caribbean

46
Q

what is the incubation period for enteric fever?

A

6-30 days

47
Q

what are the symptoms of enteric fever?

A

gradual onset - increase fatigue and a fever that increases daily from low-grade to 38-40 degress in 3-4 days.
fever lowest in AM, peaking late afternoon or evening.

all experience anorexia, headache, malaise.

abdominal pain, constipation, diarrhea are common. (more in children)

dry cough, fatigue, myalgias, sore throat

hepatospenomegaly often can be detected.

a transient, maculopapular rash of rose-colored spots can occasionally be seen on the trunk.

clinical presentation is often confused with malaria.

untreated, case-fatality ratios are 10-30%; treated <1%

serious complications of typhoid fever occur in 10-15% of hospitalized patients - GI hemorrhage, intestinal performation, encephalopathy

48
Q

how to diagnose enteric fever?

A

blood culture (bacteremia) - a single culture is positive in only 50% of cases - multiple blood cultures might be required; cultures might need to be held and observed for up to 7 days before reporting a negative result

bone marrow culture - more invasive but increases the sensitivity to 80%, and is relatively unaffected by previous or concurrent AB use.

stool culture - usually not positive during the first week of illness and has less diagnostic sensitivity than blood culture.

rapid diagnostic tests are not very reliable.

49
Q

what are the regional estimates for multidrug-resistant (MDR) Typhi in South Asia and Africa?

A

9%
35-59%

50
Q

what is the treatment of choice for enteric fever?

A

fluoroquinolones (eg. cipro)- but resistance >90% returning from South Asia

Azithromycin and ceftriaxone are increasingly being used as empiric

51
Q

patients with suspected typhoid fever who traveled to Iraq or Pakistan, or who did not travel internationally before their illness began, what is the empiric tx for uncomplicated & complicated illness?

A

uncomplicated: azithromycin

complicated: carbapenem

52
Q

what is the empiric treatment of typhoid fever for travelers returning from most other countries then Iraq or Pakistan?

A

ceftriaxone

53
Q

when do you consider treatment with alternative ABs for enteric fever or begin looking for a persistent focus of infection (e.g. an abscess, or an infection in a bone, joint, or other extraintestinal site)?

A

if fever do not subside within 5 days

54
Q

how many % of relapse occurs after clinical recovery of enteric fever?

A

10%

55
Q

what is the efficacy of typhoid vaccines?

A

50-80%

56
Q

what are the new type of typhoic vaccines?

A

protein conjugated Vi vaccines (80% effective)

57
Q

what is the age indication of oral Vivotif?

how often is the booster dose?

A

6 years and up
every 5 years

58
Q

how to take vivotif?

A
  • 1 caps every other day, with cool liquid no warmer than 37 degrees, 1 hour before a meal, 2 hours after meal
  • no alcohol 1 hour before and 2 hours after
  • complete at least 1 week before
59
Q

contraindication of vivotif (Ty21a)?

A

pregnant, or immunocompromised people

60
Q

how long do you need to wait to get oral typhoid (Ty21a) vaccine after antimicrobial agents? or vice versa?

A

72 hours

61
Q

are there any interactions between oral typhoid and other live virus vaccines?

A

no

62
Q

when should you take oral typhoid vaccine after oral cholera vaccine?

A

8 hours after

63
Q

are there any interactions between oral Ty21a and immune globulin?

A

no

64
Q

what causes yersiniosis?

A

yersinia species - facultative anaerobic gram - coccobacili

Yersinia enterocolitica (serogroups O:3, O:5, 27, O:8, and O:9)
Yersinia pseudotuberculosis
Yersinia pestis is not included (this causes plague)

65
Q

how are Yersinia spp transmitted?

A

consuming or handling food - raw or undercooked pork ;
unpasteurized milk ;
drink untreated water ;
direct or indirect contact with animals through the fecal-oral route.

66
Q

which animals are involved with Yersinia?

A

Pigs - major
domestic (dogs), farm (cattle), wild (deer) can also transmit

67
Q

who is at greater risk for yersiniosis infection and severe disease?

A

ppl with high iron levels (e.g. hemochromatosis, thalassemia), including those on iron chelation treatment

68
Q

which countries have cases reported for yersiniosis?

A

norther Europe - Scandinavia; Canada, Japan

69
Q

what are the symptoms of yersiniosis?

A

incubation 4-6 days - gradual symptoms;
enterocolitis is the most common symptoms (abdominal pain, diarrhea- can be bloody and persist for several weeks), fever

sore throat can occur, particularly in children.
Mesenteric adenitis (pain mimicking appendicitis).
Necrotizing enterocolitis in young infants.
reactive arthritis affecting the wrists, knees, and ankles can occur, usually 1 month after the initial diarrhea episode, resolving after 1-6 months.

erythema nodosum, manifesting as painful, raised red or purple lesions along the trunk and legs, can occur, and usually resolves spontaneously within 1 month.

70
Q

how to diagnose Yersoniosis?

A

isolate the organism from bile, blood, CSF, mesenteric lymph nodes, peritoneal fluid, stool, a throat swab, or wounds.

Culture-independent diagnostic tests (CIDTs) now available.

culture needed for antimicrobial susceptibility testing.

71
Q

how to treat yersiniosis?

A

self-limited
moderate to severe - AB; aminoglycosides, third-generation cephalosporins, fluoroquinolones, tetracyclines, trimethoprim-sulfamethoxazole

  • typically resistant to 1st gen cephalo and most penicillins.