Chapter 16

Question 1

Methicillin-resistant Staphylococcus aureus (MRSA) - soft tissue infection

Answer 1

strain of G+ S aureus that is resistant to multiple antibiotics
- normal flora for many
-various virulence factors

Question 2

Signs and symptoms MRSA

Answer 2

-localized inflammation with pus
- occur in breaks in skin/around hair follicle
-fever

Question 3

transmission and epidemiology MRSA

Answer 3

-surfaces/objects
-active MRSA lesions should be covered

Question 4

Pathogenesis/virulence factors MRSA

Answer 4

coagulase and other enzymes

Question 5

culture and diagnosis MRSA

Answer 5

-PCR
Culture
Blood agar/mannitol salt agar
Catalase/coagulase test

Question 6

prevention and treatment MRSA

Answer 6

-hygiene
-drainage
-antibiotics

Question 7

Measles (rubeola) - Maculopapular rash diseases
Signs and symptoms

Answer 7

-soar throat
-dry cough
-fever
-koplik’s spots
- rash on head/progresses to trunk and extremities

Question 8

complications of Measles

Answer 8

Secondary bacterial infections - ear, sinus infections/ pneumonia

encephalitis/subacute sclerosing panencephalitis- resulting in CNS changes, coma/death

diminished immunity

Question 9

pathogenesis/virulence factors

Answer 9

virus infects respiratory tract
- travels to the skin via lymph/blood
-results in syncytia
-disables aspects of immune system - diminishes immunologic memory

Question 10

transmission and epidemiology of measles

Answer 10

• R0 of 13-18
  -transmitted by respiratory droplets
• humans are the only reservoir

Question 11

culture and diagnosis of measles

Answer 11

• clinical presentation/PCR/ELISA

Question 12

prevention of measles

Answer 12

MMR vaccine - live, attenuates measles virus
- protection up to 20 yrs
- healthy children aged 12-15months

Question 13

treatment of measles

Answer 13

-supportive care
-vitamin A

Question 14

Chickenpox (varicella) - vesicular/pustular rash diseases

Answer 14

Human herpesvirus 3 (Varicella-zoster virus_
-enveloped DNA virus

Question 15

Signs and symptoms chickenpox

Answer 15

-fever/abundant rash appear after ~ 10 to 20 days incubation
-rash begins on scalp, face, and trunk–> radiates to extremities
- skin lesions progress to itchy vesicles filled with clear fluid

Question 16

Shingles (herpes zoster)

Answer 16

caused by same virus that causes chicken pox
-virus enter spinal nerves and remains dormant
-may reemerge as shingles
-stress, immunosuppressive/ other drug therapy, surgery or malignancy

Question 17

signs and symptoms if shingles

Answer 17

Characteristics of asymmetrical distribution on the skin of the trunk/head
- virus migrates down nerve ganglion to skin
- multiplication of virus resumes

tender, persistent vesicles
-actively shedding viable virus in fluid

Question 18

Pathogenesis and virulence factors: chickenpox&shingles

Answer 18

HHV-3 enter respiratory tract
- eventually enter bloodstream traveling to skin
- cells fuse and lyse, causing characteristics lesions
- virus then enter sensory nerves/dorsal root ganglia

Question 19

transmission and epidemiology: chickenpox&shingles

Answer 19

-humans are the only host
-communicable from respiratory droplets/fluid from active chickenpox/shingles lesions
-infected persons are infection prior to rash appearance

Question 20

prevention of chickenpox&shingles

Answer 20

Live, attenuated vaccine for chickenpox
- greatly reduces chance of developing shingles

zostavax shingrix approved to prevent shingles
- >60 yr old

Question 21

treatment of chickenpox&shingles

Answer 21

usually self-limiting/supportive care

Question 22

Smallpox - Vesicular/pustular rash disease

Answer 22

variola virus
- Enveloped DNA virus : Variola major/ minor
- Diagnosis of a single case must be treated as health/law enforcement emergency - eradicated in 1980!

Question 23

signs and symptoms of smallpox

Answer 23

fever,malaise, and rash
- begins in pharynx, spreads to face/extremities

Question 24

transmission and epidemiology of small pox

Answer 24

-respiratory droplets
-fomites