viral infections of the bone, muscle joints II

Question 1

smallpox symptoms

Answer 1

• abrupt onset of high fever >101 F
• malaise, headache, muscle pain, nausea
• lesions- starts in mouth and then goes thru to skin- face and extremities (centrifugal distribution)
• COMMON TO HAVE PALMS OF HANDS AND SOLES OF FEET INFECTED(DIFFERENT FROM CHICKENPOX)
• SYNCHRONOUS EVOLUTION OF LESIONS -UNLIKE CHICKEN POX THAT VARY

Question 2

Evolution of small pox

Answer 2

starts as macule and then turns into a pustule and then scabs over

Question 3

what causes smallpox

Answer 3

• variola virus
• poxiviridae
• large dsDNA
• REPLICATES IN THE CYTOPLASM (like moluscum contageosum)
• USES A LOT OF ITS OWN ENZYMES FOR REPLICATION
• STRICLY HUMAN VIRUS

Question 4

transmission of smallpox

Answer 4

• fomites, contact with lesions, rarely spread aerosol

- individuals are virulent until scabs fall off

Question 5

what does variola/smallpox cause

Answer 5

• bacterial infection of the skin
• arthritis
• encephalitis
• respiratory tract infection
• fatality of 30%
• hemorrhagic and flat forms of smallpox

Question 6

small pox vaccine

Answer 6

• NOT LIVE-ATTENTUATED
• IT IS THE LIVE STRAIN OF VACCINIA VIRUS (another member of the poxiviridae family) THAT ALLOW CROSS PROTECTION FOR SMALLPOX
• Vaccine stopped in 1972

Question 7

how are smallpox and chicken pox distinguished?

Answer 7

• smallpox has centrifugal infection - infection on outter extremities- lesions on hands and feet, lesions all in same phase
• chicken- has centripetal infection- infection of core- no lesions on hands and feet, has crops of lesions meaning many lesions in different phases

Question 8

what sort of prophylaxis is available for postexposure to small pox

Answer 8

• vaccine within 3 days- prevent or significantly lessen disease outcome
• vaccination at 4-7 days- partial exposure or lessening disease

Question 9

progress of disease of measles

Answer 9

• prodrome for 2-4 that include fever and 3 C’s:
  cough, coryza (runny nose), conjunctivitis **
  -also have KOPLIKS SPOTS IN MOUTH = MEASLES
  -rash for 5-6 days that starts at the scalp and spreads down
  -anorexia, diarrhea, lymphadenopathy

Question 10

what is measles virus?

Answer 10

• ssRNA
• enveloped
• F gene important for FUSION
• HA PROTEIN IMPORTANT FOR ATTACHMENT
• one antigenic type

Question 11

measles transmission

Answer 11

• respiratory- can last up to 2 hrs in the air
• shed in nasopharynx from prodrome to 4 days out
• HIGHLY CONTAGIOUS
• Incubation is 10-12 days

Question 12

diagnosis of measles

Answer 12

• koplicks spots- rash in mouth lasting more than 3 days- white spots with red boarder
• confirm with lab

Question 13

when an adult gets measles, what is it usually a result of? a kid?

Answer 13

adult- due to measles virus

kid- usually due to bacterial superinfection

Question 14

complications of measles

Answer 14

• diarrhea, otitis media, pneumonia, encephalitis, seizures and death

Question 15

how are measles prevented?

Answer 15

• IG within 6 days following exposure

Question 16

what qualifies for resistance for measles

Answer 16

• document receipt of 2 doses of live measles vaccine
• lab evidence of immunity
• documentation from a doc verifying you had it
• born before 1957-assumed anyone got it that time

Question 17

measles vaccine

vaccine schedule

Answer 17

-live attenuated
-prepared in chick embryo fibroblasts
- combined with Mumps and rubella
-schedule: kids- at 12-15 months and adults whenever traveling or post HS or health care worker
those born after 1957- one dose

Question 18

german measles

Answer 18

• maculopapular rash that looks like measles but FAINTER
• DOES NOT COALESCE
• prodrome- fever, lymphadenopathy, URT symptoms
• sometimes associated with arthralgia or ARTHRITIS

Question 19

what are german measles caused by?

Answer 19

-caused by infection of rubella virus

Question 20

Congenital rubella syndrome

Answer 20

• obtained when mom has rubella
• baby has DEAFNESS AND CATARACTS, CHF, retinopathy
• purpura- hepatomegaly, jaundice, microcephaly, meningoencephalitis, radiolucent bone disease

Question 21

rubella virus

Answer 21

• togaviridae fam
  enveloped
• RNA genome

Question 22

how is rubella transmitted

Answer 22

• respiratory route and primary replication in nasopharynx and regional lymph nodes
• viremia 5-7 days post infection
• time for infection to rash is 2 weeks

Question 23

rubella vaccine

Answer 23

• live attenuated

- grown in tissue culture cells

Question 24

fifth disease/erythema infectiosusm

Answer 24

• slap cheeks
• fever
• characteristic rash that begins at cheeks and goes to hands
• caused by B19 parvovirus

Question 25

what is B19 parvovirus

Answer 25

-causes fifth disease
- ssDNA
-grows only in mitotic cells
utilizes host enzymes for genome transcription and replication

Question 26

at does B19- fifth disease cause in terms of symptoms

Answer 26

• fever, rash in LACELIKE PATTERN
• usually self resolves in 2 wks
• 50% of people are serotype pos
• GROWS IN HEMATOPOETIC CELLS IN BONE MARROW

Question 27

When can B-19 virus be a problem?

Answer 27

• with patients who are always anemic- sickle cell people- can cause aplastic ctisis
• it can cause arthritis
• pregnancy complications and increase of CHF and hydrops fetalis (swelling of fetus)

Question 28

roseola infantum

Answer 28

-caused by herpes virus 6- dsDNA present in almost everyone
herpes virus 6- replicates in T and B cells
-high fever that last 4 days FOLLOWED by rash that last 24-48 hrs
-*characteristic timing
-

Question 29

herpes virus 7

Answer 29

-replicates in CD4 T cells
- present in saliva of approx. 75% of adults
infection occurs after HSV6