Pneumonia, TB, C. Diff, and Influenza Flashcards
What are important acid fast organisms
TB
Leprosy
Opportunistic wound infections
Can acid fast bacteria grow inside macrophages?
Yes
What other organisms get dyed with acid fast stain?
Norcardia
Skin and soft tissue infections associated with fish tanks
Mycobacterium marinum
Rapid grower and often a water contaminant. It is part of a group of environmental mycobacteria and is found in water, soil, and dust. It has been known to contaminate medications and products, including medical devices. It causes chronic lung disease, disseminated cutaneous disease in immunocompromised patients, and post traumatic wound infections.
Mycobacterium abcessus
Rapid grower, often found in water and sewage and will cause occasional opportunistic infections
Mycobacterium chelonae
A slow grower that is a water contaminant and may cause disease in patients with severely impaired cellular immunity
Mycobacterium kansasii
Hansen’s disease, it can affect the nerves, skin, eyes, and lining of the nose. It may take up to 20 years to develop signs of infection
Mycobacterium leprae
Rapid grower or slow grower? Mycobacterium abcessus
Rapid
Rapid grower or slow grower? Mycobacterium chelonae
Rapid
Rapid grower or slow grower? Mycobacterium kansasii
Slow
Rapid grower or slow grower? Mycobacterium chimaera
Slow
Rapid grower or slow grower? Mycobacterium fortuitum
Rapid
Rapid grower or slow grower? Mycobacterium avium complex
Slow
Rapid grower or slow grower? Mycobacterium mucogenicum
Rapid
C. Diff basics
Gram positive, spore forming rod
anaerobic
What are the main toxins of C. Diff
Toxin A
Toxin B
Binary Toxin
Describe Toxin A in C Diff
entertoxin and cytotoxin
Describe toxin B in C. Diff
cytotoxin
What isolate is binary toxin primarily found in?
B1/NAP1/027 isolate
Threat level of C. Diff
Urgent (highest level)
What antibiotics are the highest risk for CDI?
third gen cephalosporins
Description of stool related to CDI
Soft, unformed stools to watery or mucoid
How many bowel movements a day for C. Diff
3-20
How common are fever and abdominal pain with C. Diff
about 25%
What non-culture labs may be indicative of C. Diff
High WBC (ex 25k)
Positive occult fecal blood test
Predominant method of dx testing utilized for ID of C. Diff?
NAAT (nucleic acid amplification test)
Gold standard for C. Diff? Issue?
culture
takes 7 days
common complications of C. Diff
Pseudomembranous colitis
Toxic megacolon
Ileus
Perforation
Percentage of patients that exhibit pseudomembranous colitis
50%
What does pseudomembranous colitis look like?
White/ yellow plaques that show in endoscopy
what is toxic megacolon?
Extremely enlarged colon+ abdominal distention
What is ileus
painful obstruction of the ileum or other part of the intestine
Concern for perforation resulting from C. Diff
fecal matter leaks out - peritonitis
Where is BI/NAP1/027 strain widespread?
Throughout the U.S. and Europe
Concerns with B1/NAP1/027
Higher mortality (6.7%)
Can cause outbreaks in hospitals
Highly resistant to antimicrobials
General treatment options for C. Diff
Vancomycin
Fidaxomicin
Fecal microbiota transplantation
When would fecal microbiota transplantation be considered?
Multiple recurrances
What are the concerns with hypochlorite solution in cleaning for C Diff
Odor
Respiratory irritation
skin irritation
Damage to surface
has not been evaluated sufficiently for efficacy
What cleaner to use for C. Diff
Bleach
Where do the highest incidences of TB occur?
Africa (363/100,000)
Asia (180/100,000)
When did TB rates rise in the US?
1985-1992
Reason TB has decreased so much from the early 90s until 2011
- DOT
- Expanded treatment regimens
- CDC infection control recommendations
TB with resistance to INH, Rifampin, any fluoroquinolone, and at least 1 injectable second line drug
XDR-TB (extensively drug resistant TB)
Basics of M. tuberculosis
aerobic, acid fast bacillus
transmission of M. tuberculosis
Mainly via inhalation
Have caused a variety of skin diseases including pulmonary, skin, and soft tissue infections, esp in immunocompromised individuals
Nontuberculosis mycobacteria
Size of TB
1-5 um
who generates airborne TB particles
Patients with pulmonary and laryngeal TB
what is the concern for TB and ventilation
Can remain suspended in the air for a very long time and travel through ventilation system to other areas of building
What happens when the infectious droplet is breathed in?
Goes to the macrophages, gets phagocytised by macrophages, survive in macrophages and produce local infection. May also disseminate
If TB disseminates, where does it spread to first?
The regional lymph node
What is the initial infection of TB like?
Some have mild symptoms
usually goes unrecognized
Is the individual TB patient infectious during the initial infection?
No, not unless active disease developes
When does specific immunity develop for TB?
10-12 weeks
What happens when specific immunity developes?
Further spread of the organism is prevented
What does PPD stand for?
Purified protein derivative
What does IGRA stand for?
Interferon gamma release assay
when do the PPD/ IGRA tests become positive after infection?
2-12 weeks
What is LTBI?
Latent TB Infection - asymptomatic stage of TB
What is TB in the spine?
Potts Disease
How long after initial infection do some people develop active TB?
Within 2 years
Why do people develop active TB?
Failure of immune system to control mycobacteria
What percentage of people develop active TB?
5%
What is the annual risk for people with latent TB to develop TB if they do not develop it within the first 2 years?
5-10 percent
What is the total lifetime risk for developing active TB after initial infection?
10-15 percent
Symptoms of primary TB infection
- asymptomatic* (most) or
- fever
-cough
-erythema nodosum
Type of skin inflammation that is located in part of the fatty layer of the skin
Erythema nodosum
Where does erythema nodosum typically occur?
Front of legs below the knees
presentation for erythema nodosum
Reddish, painful, tender lumps
What is the radiological presentation of primary TB infection?
-Gohn complex
-miliary pattern in progressive cases
- Central casieous necrosis
Describe central caseous necrosis
encased mycobacteria in the lymphocytes
Unique form of cell death in which the tissue maintains a cheese-like appearance and the dead tissue appears as soft and white proteinaceous dead cell mass
Caseous necrosis
Frist symptoms of post primary TB
-Productive Cough
-Fever (37-80%)
-Night sweats
What does chest radiology show for postprimary TB?
- infiltrates on the upper lobes or superior segments of lower lobes
- cavitation on chest xrays
How to differentiate TB cough from other resp coughs
Last >2-3 weeks and produces sputum
Spitting of blood that originated in the lungs
Hemoptysis
Later symptoms of TB
-productive cough
- hemoptysis
- weight loss
- chest pain
-anorexia
-malaise
-debilitation
How does TB present (chest imagining) in patients with TB with higher CD4 T-cell counts
Typical infiltrates of postprimary TB
How do patients with HIV and low CD4 counts typically present with pulmonary TB in chest imaging?
Atypical
Miliary pattern
Lower lobe infiltrates
Sometimes normal chest xrays
_____ cell is the masterpiece of the immune response in TB, while the ______ is the effector cell
CD4 cell….
Macrophage
What are the names of the acid-fast stains?
Kinyoun or Ziehl Neelsen
What other organisms may stain acid-fast under some conditions?
Norcardia
Rhodococcus
Legionella micdadei
What is the fastest that MTB can be cultured?
With newer broths, a few days
What tests are commonly used to is TB before a sputum specimen is AFB positive
NAAT test
Why are cultures required for TB?
test for antimicrobial sensitivity
When to do susceptibility testing
initial isolate on every patient
+ if patient remains culture positive after 3 months of treatment
Injection of purified protein derived from mycobacterial cell wall
Tuberculin Skin Test (TST)
What does the TST rely on?
People who have been infected with TB will have a delayed-type hypersensitivity reaction to the PPD
Does a positive TST mean the person has active TB?
No, could have LTBI
Will a TST be positive if someone was cured of TB?
Yes
Does a positive TST rule out active TB infection?
No, people with active TB may have a negative TST
Preferred way to perform the TST
Mantoux method
How many TB units are injected in the mantoux method of the TST?
5
What happens at the site of injection in a TST?
Small wheal raises
When is the TST read?
48-72 hours after placement
What should be measured in a TST test?
millimeters of induration
What results to record for TST
millimeters of induration, not just negative or positive
When is a test considered a conversion in serial testing?
If there is an increase in the amount of induration by 10mm with the previous test
-HIV positive
-Recent contact TB case
-Fibrotic changes on chest xray –consistent with old TB
-organ transplants/ immunosuppressed
TST positive mm?
5mm
Recent arrival from high prevalence country
- IV drug users
- HCP and other high-risk settings (congregate care, prisons, etc.)
- Mycobacteria lab personnel
- High risk clinical conditions (ie chronic renal failure)
- Medically underserved high risk minorities
- children under 4 or infants and children exposed to adults in high risk settings
TST positive mm?
10mm
persons with no risk factors for TB
TST positive mm?
15 mm
These tests evaluate the release of interferon gamma from the host cell when exposed to TB proteins such as the early secretory antigenic target 6 (ESAT-6) and the culture filtrate protein 10 (CFP-10)
IGRA- interferon gamma release assay
When to use IGRA
-unlikely to return for reading if TST is administered
- BCG vax
attenuated strain of M. bovis that is given as a live bacterial vax to prevent to development of active TB
Bacille Calmette-Guerin (BCG)
When BCG is used?
In countries where TB endemic, esp in children
Should you consider BCG status when reading TST in the U.S.?
No, more likely to have LTBI in the US
Who is at risk for TB infection?
- close contact with pulmonary or laryngeal TB cases
- foreign borne persons
- Residents and employees in crowded settings
- HCP
- infants exposed to high risk adults
Timeframe to be considered a close contact with a TB case
days to weeks
What can contribute to environmental transmission of TB?
- inadequate ventilation
- poor management of specimens
- inadequate cleaning of reusable medical equipment
How to prevent TB: agent
-Detection of cases
-early and complete treatment based on susceptibility testing
How to prevent TB: room
negative pressure room
How to prevent TB: PPE
airborne isolation
N95 respirator
How to prevent TB: portal of exit
Resp etiquette
How many negative sputum specimens should you have before ending isolation?
culture for AFB daily x3 in 8-24 hour intervals
How to rule out TB
Negative chest Xray and 3 negative sputum specimens at least 8 hours apart
TB that is resistant to isoniazid and rifampin
MDR-TB
TB manifestation in CSF
Lymphocytic pleocytosis
How does the TST test work?
Inject PPD, wait 48-72 hours, then measure the area of induration
Will people always have a positive TST if they have active TB?
No
Treatment for TB
INH (Isoniazid)
RIF (Rifampin)
+ 2 other drugs
After 3 months - INF+RIF
How often should active TB cases receive sputum cultures?
monthly
What baseline testing is needed for TB before treatment?
Ocular and Liver*
Treatment of latent TB
INH- 9 months or rifampin for 4 months
Monitor for active TB
Risk levels for TB
Low risk - no TB patients in the area or facility
Medium Risk - exposed to TB pts or samples
Ongoing transmission - person-person transmission within the year
Examples of TB Prevention: Administrative
- assign responsibility for TB control
- Conduct TB risk assessment
- control plan: detect, AIIR, treatment
- testing availability and reporting
- practices for managing suspected and confirmed cases
- cleaning and disinfection
-staff education and pt education - employee screening
- post signs about infection control
Prevention of TB ENV/ PPE
-Resp protection program
- Employee and family/ visitor education (resp hygiene)
- negative pressure ventilation rooms
How many air exchanges are needed per hour for an AIIR for a TB patient
6-12 air exchanges per hour
When to end AIIR for TB patient
-after 2 weeks of therapy with good clinical response and 3 negative AFB smears
Routine employee testing- how often
TST or IGRA for new hires
Medium risk - annual
ongoing transmission- every 8-10 weeks
Does non-pulmonary TB require AIIR?
No
When should you TST test an exposed employee to TB
ASAP within 2 weeks and again in 8-10 weeks (time for seroconversion)
What is the most common non-TB mycobacterium
Mycobacterium Avium Complex
What is the most common pathology of non-TB mycobacteria (NTM)?
Pulmonary
Most symptoms are the same for NTM and TB, but what is one symptom that differs?
- hypersensitivity to hot H2O
Who is most likely to get disseminated disease from MAC?
AIDS patients
These organisms, MAC, M. Kansasii, M. Abcessus, and M. fortuitum cause ______ disease
pulmonary
M. fortuitum, M. marinum, M. chelonae, M. abcesses, and M. ulcer can cause _________ disease
skin and soft tissue disease
Think- damaged skin from fresh H2O
How does MAC manifest in young children?
Lymphadenitis
What are the rapid growing NTMs?
M. Chelonae, M. Abcesses, and M. fortuitum
What NTM is a concern for SSI, Dialysis, and cath ass infections related to tap water
M. chelonae
What are the precautions for NTM?
Standard, not spread person to person
Who is at the highest risk for influenza?
65+
Under 2
Pregnant
Chronic conditions
How long does influenza virus shed?
7-10 days, but most contagious 5 days after
How long is someone contagious with flu?
24 hours before onset- 5 days after
How long is the incubation period for flu?
2 days
How is flu transmitted?
Droplet
What are the symptoms of flu?
- Fever
-Cough
-Headache
-Sore throat
-muscle aches
OR Asymptomatic
What is one characteristic about the onset of flu
Rapid onset
What is the season for the flu in the U.S.
October- March
What are common secondary bacterial infections after flu?
1) strep pneump
2) H. influenzae
3) staph aureus
How long after the flu do secondary infections typically happen?
4-14 days after improvement
Dx for flu
PCR
Rapid
Viral culture
Treatment for flu
Supportive
Antivirals within 48 hours
Viral treatment for flu
Ostelamivir
Naming convention for influenza strains
Virus type (A,B,C), Place, Strain #, year, virus serotype
Two pairs of influenza serotype
Hemaglutinin
neuraminidase
What types of flu cause human disease
A and B
Small changes to the flu virus
Antigenic drift
Major changes to flu strains
Antigenic shift
What are nonhuman reservoirs of flu?
Avian, Swine
Pandemic Phase: No flu in animals that can infect humans
Phase 1
Pandemic Phase: Virus circulating in animals, known to infect humans
Phase 2
Pandemic phase: animal to human transmission, small clusters, but no human to human transmission
Phase 3
Pandemic phase: Human to human transmission
Phase 4
Pandemic phase: Human to human and outbreaks in 2 or more countries in a single region
Phase 5
Pandemic phase: outbreaks in >1 region
Phase 6
Pandemic phase: Flu levels decrease from peak levels
Post-peak
Pandemic phase: returned to seasonal rates
Post pandemic
Pandemic planning phases 1-3 (animal- human, no human - human)
education: flu symptoms and iso
- vax
- facility plans for surge
- exp mgmt plans
- plan just in time training
- comms plan
Pandemic planning phase 4 (human to human)
- Est # HCP needed
- Start to increase iso
- review exp mgmt plans
- plan to sustain ops
- visitor screening plan
- staffing guidance for cases
Phase 5 pandemic planning for flu OB in 2+ countries in same region
- enhanced screening and surveillance
- just in time training (NOW)
- sched staff comms
-Incident command
Phase 6 pandemic planning (outbreaks in multiple regions)
- surge strategy: staff, supplies, space
- cxl elective procedures
- implement employee exp management plan
When to get routine flu vaccine
6 months and older
annually
What is the contraindication to the flu vax?
GBS within 6 weeks of prev flu vax
egg based vax
What should the IPC have plans in place for flu?
- early ID nad iso of pts
- annual education
- vax to pts and HCP
= Restrict ill pts and hcp
ICP influenza- how to prevent transmission
- flu vax
-resp hygiene and cough ett
-manage ill HCP
What precautions should be used for flu
Standard precautions
Droplet precautions
How long should the influenza patient be on droplet precautions?
7 days + fever free for 24 hours
What are the droplet precaution recommendations for flu?
- private room
- surgical mask if leaving room
- surgical mask to enter room
-N95 for aerosol generating procedures
How long should a mom with flu be separated from her baby post-partum
until afebrile for 24 hours and resp symptoms under control
Who should feed the baby when the mother has influenza?
Health caregiver
Can the mom’s breast milk be used when she has influenza?
Yes, but healthy caregiver should feed
If the mom with flu and the baby need to colocate, what controls should be in place?
- engineering controls (curtain or room sep)
- 6 ft distance
- healthy caregiver
- mom dons mask
How long should a post-partum mom with influenza be on droplet precautions?
7 days
Best practice- HCP with ILI
Don’t report to work, don’t return until 24 hours no fever
What is PEP for influenza
vax unvaccinated people + dose of antivirals
Outbreak control of flu
1 case- enhanced surveillance
Test symptomatic cases
Droplet precautions suspected/ confirmed
cohort pts and residents with vax
consider PEP
stop non-urgent medical procedures
Leading cause of death from infection in a hospitalized patient
Pneumonia
Pneumonia in patient admitted to the hospital from the community
community acquired pneumonia
Pneumonia in a patient:
1)in an acute care hospital for 2+ days within 90 days of infection
2) resided in a nursing home
3) received IV antibiotics, chemo, or wound care within 30 days
- attended hosp or hemodialysis clinic
Healthcare associated pneumonia (HCAP)
Pneumonia that develops within >=48 hours after admission to a hospital
Healthcare acquired pneumo
Pneumonia in someone intubated with mechanical ventilation for at least 48 hours
ventilator associated pneumo
Most common organisms to cause CAP
S. pneumo
H. influenza
S. aureus
Moracella catarhallis
Organisms that most often cause atypical pneumo
Legionella
Chlamydia
Mycoplasma
Enterobacter
What puts someone at higher risk for pneumo from P. aeuruginosa?
- Structural lung disease
- chronic steroid use
- prior antibiotics
What puts someone at a higher risk for s. aureus pneumo?
-endstage renal disease
- IV drugs
- Prior flu
- Prior antibiotic (fluroquinolones)
What are the clinical signs of MRSA pneumo?
Severe
neutropenia
Abnormal chest Xray
hemoptysis
risks for HAP/ HCAP
- antimicrobials in the last 90 days
- hospitalized for 5+ days
- high freq MDROs in community
- immunosuppressive state
Risks for VAP
-Emergency intubation
- nasotracheal intubation
- etomediate use
- head not elevated
- subpar oral care
CAP quality measures: when blood culture should be collected
within 24 hours and before antibiotics
CAP quality measures: antibiotics
antibiotic timing
antibiotic selection
CAP quality measures: vaccination
- pneumo vax when appropriate
- influenza vax
-smoking cessation
Preventing CAP
Vax with flu and pneumo
Smoking cesation
Prevention of HAP, HCAP, and VAP: vax
- Flu and pneumo vax
Prevention of HAP, HCAP, and VAP: precautions
HH
gloves
isolate pts with resistant organisms
Prevention of HAP, HCAP, and VAP: resp equipment
Proper resp equip maintenance
Prevention of HAP, HCAP, and VAP: intubation and tubes
Avoid endo-tracheal intubation when possible
-reduce nasogastric tubes
Prevention of HAP, HCAP, and VAP: maintaining oral and oropharyngeal hygiene
Oral decontamination
Subglottic secretion drainage
How long should you wait for enteral feeding after intubation?
24-48 hours
How to prevent aspiration
- avoid endotracheal tube when possible
- use orotracheal intubation (not naso)
- Raise head 30-35 degrees
- oral cleaning with aseptic
What is the ventilator bundle?
- Elevate the head
- move the body
- Peptic ulcer PEP
- DVT PEP
- Daily oral care
If there is a case of VAE, what does the IP need to do?
Assess why- fishbone
Correct
What complication of C. Diff has a high mortality rate?
Ileus
Is C. Diff part of the normal intestinal flora?
Yes, can be colonized with non-toxigenic C. Diff which is protective
First action when Dx’d with C. Diff
Discontinue current antibiotics
How often does C. Diff reoccur?
15-25%
How to interrupt transmission of C. diff
Hand washing
gloves
isolation
cohorting
environmental cleaning and disinfection
How long should isolation last for C. Diff?
unknown- debated if a few days after diarrhea stops or entire hospital stay
Environmental cleaning and disinfection for C. diff
1:10 dilution sodium hypochlorite solution where CDI rates are high
Consider UV-C device- need to terminally clean room
