RSV...Mumps & Rubella Viruses

Question 1

mumps virus

Answer 1

acute contagious disease characterized by non-suppurative enlargement of one or both of the salivary glands

mumps virus is mild in children, but causes meningitis and orchitis in adult

1/3 of mumps inf is asymptomatic

Question 2

pathogenesis of mumps?

Answer 2

primary replication occurs in nasal or URT epithelial cell

viremia spread to the salivary gland and other organs
the incubation period is 2-4 but typically 14-18d

virus is shed in saliva 3 days b4 and 9d after the swelling of the salivary gland

it is difficult to control transmission of mumps because of the incubation period which means there is presence of

virus in saliva b4 clinical symptoms develop

mumps is a systemic virus and it replicates in visceral organs. virus frequently affect kidney and it can be detected in the urine

Question 3

clinical findings

Answer 3

most characteristic features of symptomatic people is the swelling of the salivary gland which occurs in 50% of patient
malaise and anorexia followed by
enlargement of parotid and salivary gland
CNS involvement is common (10-30%)-aspetic meningitis
meaningoencephalitis

Question 4

immunity

Answer 4

immunity is permanent after a single inf

Ab to HN glycoprotein (v antigen), f gp, internal NP nucleocapsid protein

subclinical inf also generate lifelong immunity

Question 5

lab diagnosis

Answer 5

specimen: saliva, urine, cerebrospinal fluid…few days after onset
isolation: monkey kidney cells are preferred 3-4 incubation

other test: ELISA or HI, RT-PCR

Epidemiology: occurs endemically worldwide, cases occurs in hot climate and peak in winter/srping1

Question 6

prevention and control

Answer 6

no specific therapy
attenuated live mumps virus vaccine
MMR live virus vaccine
2 doses are recommended for school entry

Question 7

Rubella (german measles) virus

Answer 7

acute febrile illness characterized by rash and lymphadenopathy that affects children and young adults

incubation period - 12 days or longer

Question 8

initial viral inf of rubella occurs?

Answer 8

respiratory tract followed by multiplication in d cervical lymph node

Question 9

viremia of rubella occurs

Answer 9

7-9 days after inf and last until the appearance of AB on art 13-15 d

Question 10

development of AB coincides with development of?

Answer 10

rash, suggesting immunological basis for the rash

Question 11

clinical findings of rubella

Answer 11

after rash appears, virus remains detectable in the nasopharynx where it persist for weeks

20-50% primary inf is subclinical

rubella begins with malaise,
low-grade fever and
rash appearing on the same day

rash starts on face-trunk-extremities and rarely last more than 3 days

Question 12

immunity of rubella

Answer 12

AB appears as the rash fades and AB titer rises over the next 1-3 weeks

initial AB is ism

one attack cover life long immunity

immune mother transfers AB to offspring and protect them for 4-6m

Question 13

lab diagnosis

Answer 13

diagnosis is unreliable

nasopharyngeal or throat swab taken 6 days b4 and after onset of rash

monkey kidney cell line

other method HI, PCR,ELISA

Question 14

prevention, treatment & control of rubella

Answer 14

peak incidence in spring

mild self limited illness with no specific treatment

immune globulin intravenous (IGIV)

Attenuated live rubella vaccines (MMR)

Question 15

congenital rubella syndrome (CRS)

Answer 15

maternal viremia associated with rubella inf during pregnancy may result in inf of the placenta or fetus

only a limited number of fetal cells become inf

growth rate of infected cells is reduced resulting in number of cells in affected organs at birth

Question 16

CRS inf may lead to

Answer 16

deranged (psychosis) and hypo plastic organ development, resulting in structural anomalies in the newborn

Question 17

the earlier in pregnancy inf occurs the greater the ?

Answer 17

damage

Question 18

fetal death and spontaneous abortion occurs in?

Answer 18

rubella inf

Question 19

clinical finding of rubella

Answer 19

3 broad categories:

1. transient effect in infants
2. permanent manifestation that shows at birth or during 1st yr
3. developmental abnormalities

Question 20

classical traid of CRS

Answer 20

cataracts, cardiac abnormalities & deafness

Question 21

transient symptoms of CRS

Answer 21

growth retardation
rash
hepatosplenomegaly
jaundice
meningoencephalitis

Question 22

most common developmental manifestation of CRS

Answer 22

moderate to profound mental retardation

Question 23

treatment of CRS

Answer 23

immunity: maternal rubella igG is transferred to infants and lost over a period of 4-6 m

no specific treatment

can be prevented by childhood immunization with rubella vaccine to ensure that women of child bearing age are immune

immune globulin intravenous (IGIV)- not helpful for fetus