Week 13 - Microbiology II Flashcards
Fever
An increase in hypothalamic setpoints:
- pyrogeniccytokines → increased prostaglandin e2 → signals Hypothalamic set range increase → leads to fever
Fever symptoms
1 decreased cutaneous blood flow = perception of chills
2. Shivering to generate heat to match rapid rise in setpoint.
3. Thermogenesis from brown fat
Fever range.
Practical →
38 C
monitor closely 37.7 -39.9
suggested –>
AM temperature > 37.2 C
PM temperature >37.8 C
Febrile Neutropenia
Fever and Neutropenia
- Fever – >38.3 C x1 orally or > 38 C for over 1 hr
- Neutropenia - low neutrophil count
- ANC <500 cells/mm3
- ANC <1000 cells/mm3 with predicted decr to <500 cells/mm3
- typically occurs in patients undergoing chemotherapy (suppressed WBC) . neutrophils fall low –> patient cant fight infection
Fever of unknown origin
- > 38.3C
- no cause after initial standard investigations
- not applicable to:
- immunocompromised patients
- nosocomial acquisition
- returned travelers
- children
(groups with other potential differentials and sets of causes than a healthy person in community)
3 Parameters of risk for BBV transmission
Healthcare setting
- Risk in type of percutaneous injury
- Risk of the contaminated instrument or HCW /patient’s blood contacting the other person’s blood
- Susceptibility of individual exposed
the 3s
Risk of BBV transmission
HIV, HCV, HBV - patient to healtcare worker
- HIV - 1in 300
- HCV - 1 in 30
- HBV - 1 in 3
Risk of BBV transmission
HIV, HCV HBV - HC worker to patient
- HIV - 1 in 42000
- HCV - 1 in 1750
- HBV - 1 in 420
Reflects the amount of circulating virus in the blood
Risk of injury
- long complicated surgery - greater risk of sustaining injury while operating on the patient
- expertise is a factor
- compliance with Infection Prevention and Control practices
- Experience or training level (students more likely)
Risk of Transmission
- nature of injury (deep vs superficial)
- Frequency of injury ( those performing exposure prone procedures)
- Volume of blood (volume of virus in the blood) present during exposure
- viral load (amount of Virus ciruclating in the person)
- fitness of the virus (virus infectivity)
- suceptibility of exposed individual (no vaccine for HIV or HCV)
Risk of Percutaneous Exposure to BBV
- Deep intramuscular injury
- visible blood on sharp device
- meedle used to enter blood vesel
- HCW or source patient with terminal AIDS or HEP with high viral load
- Lack of PEP
Managing exposure to BBV
- Assess type of exposure/injury
- Assess status of source patient and HCW (are they carrying the virus and how much in the blood)
- Assess Vaccination and Immume status of HCW and patient
- Assess Overall Health status (underlying health concern, medication, allergy)
HBV Exposure Management
- someone exposed and not immune -> give HBV immuge globulin (HBIG) gives instant antibodies as protection
- get HBV vaccine for long term protection
- timeline is 72 hours post incident
HCV Exposure Management
- no vaccine for prophylaxis
- regualr followup and monitoring, especially if symptoms develop
- early treatment increases chances of clearing virus
HIV Exposure Management
Risk of infection after:
a. percutaneous exposure - 0.3 %
b. mucus membrane exposure - 0.1%
c. skin exposure - <0.1%
- antiviral therapy is used in combination for prophylaxis post exposure - reduses risk by 80%
- prophylaxis should be taken ideally within 2 hours, up to 72 hours.
- combination theraphy for 4 weeks
- expensive
- side effects - nausea, fatigue, headache, vomiting
- apply first aid to injury site (make sure immunizations are up to date and given.)
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