CNT Review Exam Flashcards
What are the 5 natural barriers to infection?
- Skin and mucous membranes of the nose, throat, urethra, and rectum
- Stomach acid
- Healthy cells of nose and lungs
- Normal mucus and saliva
- Nonspecific factors: tears, urine, acidity of vaginal secretions
What are the two types of infection?
- Autogenous infection
- Cross infection
What are autogenous infections?
Infection caused by pathogens that the patient is already carrying
What are cross infections?
Infections caused by pathogens acquired from another person
What are the two types of microorganism on the skin?
- Transient
- Resident
What are transient microorganisms that abide on the skin?
Those picked up from one patient and transferred to another patient
Soap is sufficient for cleaning
What are resident microoganisms that abide on the skin?
Life-long members of the body’s normal microbial community
Extra risk for immuno-compromised patients
Germicidal soap must be used
What are two of the most serious cross-infections?
- Hepatitis B Virus
- HIV
What are the five types of hepatitis viruses?
- A
- B
- C
- D
- E
Which types of hepatitis are transmitted via fecal-contaminated food and water?
- Hepatitis A
- Hepatitis E
Which types of hepatitis are transmitted via blood and/or sexual exposure?
- Hepatitis B
- Hepatitis C
- Hepatitis D
Hepatitis A
- Mainly due to poor sanitation and overcrowding
- Incubation period 15-30, abrupt onset with high fever to 100.4 F
- Other Sx: loss of appetite, fatigue, fever, muscle aches, nausea and vomiting
- 2 weeks later: jaundice
- Most common in children and young adults, peak in autumn
- Individual with HAV cannot be reinfected
- Symptoms are mild, no chronic carrier states, HAV vaccination available
Hepatitis B
- Bloodborne pathogen, most serious threat to health care workers
- Due to IV users and high sexual activity, most common btn 15-29 years age
- Incubation period 50-180 days
- Begins with mild flu-like symptoms such as fever, malaise, insidious onset of anorexia, abdominal pain
- Other Sx: chills, nausea, joint pains, rash, and diarrhea
- 2-6 weeks later: extreme fatigue and depression lasting months
- Of these who recover from symptoms: 70% remain infectious for 3 months or more
- 6% are lifelong carriers and may develop cirrhosis of LR and LR cancer.
- Of chronic carriers 15-25% die of LR disease
- Treatment: there is no biomedical treatment for HBV although an injection of HBIG immediately following exposure may provide protection in unvaccinated persons
- 3 injections of HBV vaccination is available and lasts for at least 20 years
Hepatitis C
- Transmitted by exposure to contaminated blood. Mostly found in adults.
- Most common in transfusion associated hepatitis
- Most prevalent in IV drug users
- No vaccine
- Incubation period 20-90 days with most occuring 5-10 weeks after exposure
- Communicability: 1 week after exposure to chronic stage
- Insidious onset with anorexia, nausea, vomiting, and jaundice
- 78-85% of those infected will develop chronic infection
- 60-70% develop chronic hepatitis and many progress to cirrhosis and cancer
- Treatment: interferon and ribavirin
Hepatitis D
- aka Delta hepatitis
- a “defective virus”-requires HBV concurrent infection
- Most cases occur in IV drug users and hemophiliacs
- Hep B vaccination will protect against this disease
Hepatitis E
- Aka epidemic non-A, non-B hepatitis. Most common in developing countries.
- Mostly due to fecal contamination of the water supply
- Incubation period is 15-60 days, average 40 days
- Communicability: unknown
- Sudden onset of fever, malaise, nausea, and anorexia. Possible jaundice.
- Varies from mild illness for 7-14 days to severely disabling disease that lasts several months
- No evidence of chronic infection. No vaccine
What are two forms of chronic carriers of hepatitis?
- Chronic persistent
- Chronic active
What is chronic persistent hepatitis?
Asymptomatic or has very minimal symptoms but can continue to infect others
What is chronic active hepatitis?
- Progressive symptomatic disease that continues to damage the liver
- S/s: malaise, weight loss, loss of appetite, and often jaundice
What are the incubation periods for the 5 types of hepatitis?
A: 15-50 days
B: 50-180 days
C: 20-90 days
D: Unknown
E: 15-60 days
Which types of hepatitis have an abrupt onset?
A + E
Which hepatitis types have an insidious onset?
B + C
Which type hepatitis has an unkown onset?
D
Which types of hepatitis have vaccines?
A + B
Which types of hepatitis can become chronic?
B: depends on age group- 6% are lifelong carriers
C: 60-70% develop chronic hepatitis
What are the S/S of hepatitis A?
Fever, nausea/vomiting, fatigue, no appetite, muscle ache
What are the S/S of hepatitis B?
Flu-like, joints pain, fatigue, depression (2-6 weeks later)
Asymptomatic in 30% of cases and in children
What are the S/S of hepatitis C?
After chronic carrier goes to cirrhosis, LR cancer may result in adult
What are the S/S of hepatitis D?
Need hepatitis B replicated fulminating
What are the S/S of hepatitis E?
Sudden onset of fever, malaise, nausea and anorexia
What is HIV?
Human immunodeficiency virus
- HIV targets CD4 (T4) lymphocytes as its host.
- play an important role in immune system
- HIV destroys T4 lymphocytes producing immune deficits
What are the two types of HIV?
- HIV-1: most infectious & most common
- HIV-2: less infectious
What is the infection process for HIV?
- initially infection is usually followed within 2-4 weeks by a febrile illness resembling mononucleosis or influenza which resolves spontaneously
- As immune damage progresses, symptoms of malaise, body aches, fever, skin rash, lymphadenopathy develop
- Other s/s: weight loss, chronic diarrhea, persistent cough, persistent fever and night sweats, flat or raised pigmented lesion on the skin ranging from faint pink to red, brown or blue
- Late stage development of infection diseases: candidiasis, cytomegalovirus, Kaposi’s sarcoma & Pneumocystis carinii
- Pneumonia: the most common opportunistic infection and cause of death in AIDS
Who is at risk for HIV?
- The population distribution of HIV: initially found primarily among men who had sex w/ men, injection dug users, sex workers, and transfusion recipients. Today HIV is no longer limited to these initial populations. Recently, more cases are associated with unprotected sex between mixed gender couples. Due to successful protocols for perinatal cases, newborns are acquiring HIV from their mothers much less frequently.
- Incubation: due to its long incubation period (2-15 years to AIDS) most infected individuals are unaware
- HIV may NOT be transmitted via: shaking hands, touching, hugging, holding hands, or casual kissing, use of objects handled or touched by an HIV-infected person (i.e. toilet seat or phone)
- Risk of infection: 0-3%
What is the clinical presentation of AIDS patients?
- “Wasting disease”, severe involuntary weight loss, chronic diarrhea, constant or intermittent weakness
- If HIV enters the CSF: encephalopathy, myelopathy, peripheral neuropathy, dementia, death
-
Rate of disease progression may vary:
- Contributing factors: stress, nutrition, alcohol, drugs, STD’s
- Secondary infections pose additional risks to practitioners: tuberculosis, staphylococcus, herpes, hepatitis
Protection for patients, practitioners, and staff (yearly physical)
- PPD (tuberculosis test)–> once/year
- Practitioners who work in an inner city clinic w/ AIDS patients or drug addicts –> every 6 month
What are the 3 HIV tests?
- ELISA (Enzyme-Linked ImmunoSorbent Assay)
- IFA (Immuno Fluorescence Assay)
- Western Blot (Protein Immunoblot)
What is MRSA?
Methicillin-resistant staphylococcus aureus
- Recently, MRSA has become a significant source of antibiotic resistant infections
- The bacterium Staphylococcus aureus is a gram positive, coagulase positive aerobic coccus associated with wound infections and other medically significant infections
- Between 25-30% of the population may be carriers of MRSA
- Majority of MRSA infections appear to be acquired from the health care setting (nosocomial)
- 12% of the MRSA are community-acquired
How to prevent MRSA?
- Appropriate handwashing and the use of hand disinfectants
- The use of barrier protection such as gloves, lab coats or gowns and face masks as necessary
- Proper handling of potentially contaminated materials such as sharps, disposable supplies such as cotton and gauze, and soiled or blood-stained linen
- Avoid contact with draining wounds or skin lesions that may be a site of infection
- Scrupulous use of disinfectants