17.2

Question 1

rubella and parvovirus

Answer 1

usually mild, rash causing infections of early childhood
both may cause polyarthritis in older children and adults
both are associated with serious effectson the fetus if infection durng pregnancy occurs

Question 2

rubella virus

Answer 2

enveloped RNA virus
togavirus of the genus rubivirus
it is similar to some arboviruses but doesn not require a vector for transmission

Question 3

rubella is transmitted by

Answer 3

person to persoon by respratory secretions

Question 4

incubation period of rubella

Answer 4

14-21 days

Question 5

clinical features of rubella

Answer 5

50% of infections are asymptomatic
causes transient, generalised maculopapular rash
associated featuures include post articular and sub occipital adenopathy, arthralgia and arthritis

Question 6

maternal infection of rubella

Answer 6

rubella infection during pregnancy may causse congenital rubella syndrome
up to 90% of infants born to mothers infected during first trimester have CRS

Question 7

features of congenital rubella syndrome

Answer 7

intellectual disabilities 
cataracts 
deafness
cardiac defects 
intrauterine growth retardation 
infants may be born wth a heamorrhagic rash

Question 8

prevention of rubella

Answer 8

vaccine preventable

children have 2 doses of MMR or MMRV vaccine

Question 9

paravirus B19

Answer 9

the only important uman virus of the parvovrus family, genus erythrvirus
small DNA virus
highly contagious
long lasting immunity results from infection
>50% of adults are seropositive

Question 10

transmission of parvovirus B19

Answer 10

transmission via respiratory droplets

Question 11

clinical features of parvovrus

Answer 11

cause of ‘slapped cheek syndrome’
‘fifth disease’
or ‘erythema infectiosum’

following fever, a characteristic erthymatous rash of the cheeks appears
rash of trunk and arthritis may occur

Question 12

parvovirus incubation period

Answer 12

4-14 days

Question 13

other consequences of parvovirus infection

Answer 13

prolongued arthritis
aplastic crisis
infection during pregnancy may be assciated with hydrops fatalis

Question 14

prologed arthritis in parvovirus

Answer 14

more commn in adult females

Question 15

aplastic crisis in parvovirus infection

Answer 15

infection reduces erythropoiesis

in patients with sickle cell anaemia, this can lead to a sever anaemia

Question 16

hydrops fetalis in parvovirus infection

Answer 16

this is foetal heart failure and subcutenous oedema
due to reduced foetal loss or miscarriage may results
intra-uterine transfusion may be required

Question 17

prevention of parvovirus

Answer 17

no vaccine or treatment available
pregnant contacts of infections require blood tests for serological and molecular testing
if blood tests suggest infection, referral to a specialise obstetrician is required