Rubella

Question 1

IgG pos

IgM pos

Answer 1

Possible recent infection

repeat to confirm —> +IgM confirmed and/or rise in IgG title —>maternal rubella

Question 2

IgG +

IgM _

Answer 2

Susceptible - Imm after del
Repeat if <3/52 contact or < 7 days since onset of illness
Either seroconvert (infected) or rubella susceptible (?false + IgM)

Question 3

IgG -

IgM +

Answer 3

Possible recent infection

Question 4

IgG +

IgM -

Answer 4

past infection or immunisation

Question 5

Primary infection 1-12/40

Answer 5

Rate of fetal infection: 80%

Risk of congenital defects: 85%

Question 6

Primary infection 13-16/40

Answer 6

Rate of fetal infection 54%

Risk of congenital defects 35%

Question 7

Primary infection 17-22

Answer 7

Fetal infection 36%

Congenital defects rare

Question 8

23-30 primary infection

Answer 8

Rate of fetal infection 30%

Congenital defects rare

Question 9

Primary infection 31-36

Answer 9

Rate of fetal infection 60%

Congenital defects rar

Question 10

Primary infection >36/40

Answer 10

Fetal infection 100%

Congenital defects rare

Question 11

Management by semester in primary infection

Answer 11

Consider termination in trim 1
Amnio in second trimester
3rd trim - congenital rubella syndrome rare

Question 12

Invx for CRS at birth

Answer 12

Serology (IgM)
PCR (urine and throat swab); -ve PCR does not exclude infection
Culture urine and throat swabs, tears

Question 13

Features of CRS

Answer 13

Deafness (sensory neural hearing loss in 60-75%, CNS dysfunction (10-25%), mental retardation, developmental delay, microcephalic, CV defects,
Opthalmological abnormalities
Growth retardation
Haematological abnoramlities
GI tract abnormalities
Pneumonitis
Osteitis

Question 14

ANODE trial

Answer 14

Ivabx after op vaginal del
Reduced infection to 11% vs 19
Augmenting vs placebo