Rubella IgM - RUIM
Toxoplasma IgM - TIGM
2. Maternal blood specimen with a request for "TORCH screen', register as follows:-
Rubella IgM & IgG - RE
Toxoplasma IgM & IgG - TOX
CMV IgM & IgG - CMGE
Parvovirus IgM & IgG - PARV
HIV - HIV
3. Amniotic fluid with a request for 'TORCH screen' register as follows:-
CMV PCR - CVLD
Parvovirus PCR - PARP
Toxoplasma PCR - TPCR
Dr Andreas Nahmias coined the acronym 'TORCH screen" in 1971 to remind paediatricians of the then four possible congenital infections. This list has since expanded. Furthermore, molecular tests now permit these infections to be detected in amniotic fluid.
In NZ, HIV and Rubella are checked at antenatal visits. Herpes simplex rarely causes IU infection. Maternal chickenpox should be clinically apparent. Pragmatically, that leaves CMV, parvovirus and toxoplasmosis as first line possible infections which should initially be tested.
If there is clinical suspicion of other infections, please state clearly on the request form.
1) Check mother for evidence of prior infection
a) Rubella. If the mother was immune at antenatal testing, congenital rubella can be ruled out. If not known, check IgG. If negative, no further rubella testing on baby required.
b) Toxoplasmosis. Check IgG. If negative, no further toxoplasma testing on baby required.
c) CMV. Check IgG. If negative, no further CMV testing on baby required.
d) HIV - serology
Note. HSV antibody testing is not informative and should not be requested.
2) Where mother is IgG positive, check baby:-
a) Rubella IgM
b) Toxoplasma IgM
c) CMV - fresh urine or viral salivary swab for CMV PCR. Must be collected before baby is 3 weeks old.
CMV IgM - can be done but low sensitivity for congenital infection
d) HIV discuss with virologist
Note: a) Parvovirus is not associated with intrauterine teratogenicity.
b) Herpes simplex - vary rarely causes intrauterine infection. Discuss with virologist.