Table 1

Peripartum HIV test results

	Time (in weeks of gestation)
	1 T = 12 weeks (“Booking blood”)	2 T = 29 weeks	3 T = 33 weeks (“Booking blood”)	4 T = 13 weeks post partum (child presents)
^αEnzyme immunoassay (EIA) for detection of antibody to HIV-1 and 2. Biochem Immunosystems Inc, Montreal, Quebec, Canada.
^βEIA for detection of antibody to HIV-1 (Abbott Murex) Murex Biotech Ltd, Dartford, UK.
^γMicroparticle EIA for qualitative detection of antibodies to HIV-1 and 2. Abbott Laboratories, IL, USA.
^δEIA for detection of antibodies to HIV-1 and 2 (Abbott Murex) Murex Biotech Ltd, Dartford, UK.
^εPassive particle agglutination test for detection of antibodies to HIV-1 and 2 Fujirebio Inc, Tokyo, Japan.
^ζWestern blot for detection of antibodies to HIV antigens. Genelabs Diagnostics, Singapore.
^ηPolymerase chain reaction (PCR) for quantitative detection of HIV-1 RNA. Roche Diagnostics, Branchburg, NJ, USA.
^θSignal amplification nucleic acid probe assay for quantitative detection of HIV-1 RNA. Chiron Corp Emeryville, CA, USA.
Hospital where blood taken	X	Y	Y	St Mary's
	Blood was stored and retrospectively tested	Index antenatal test (serum not available for repeat retrospective testing)	Blood was stored and retrospectively tested	Postnatal test. Blood stored
HIV antibody screening tests	Clear negative	Clear negative	Weak positive	Strong positive
	i Detect-HIV^α	i Abbot Axsym HIV 1/2 gO^γ	i Murex HIV 1+2^δ	i Abbot Axsym HIV 1/2 gO^γ
	OD=−0.030, CO=0.144	S/CO=0.42	OD=0.938, CO=0.252	OD=14.86, CO=1.00
	ii Wellcozyme HIV		ii Wellcozyme HIV	ii Detect-HIV^α
	Recombinant^β		Recombinant^β
	OD=1.179, CO=0.696		OD=0.486, CO=0.839	OD=2.050, CO=0.152
			iii Serodia HIV-1/2^ε	iii Wellcozyme HIV Recombinant^β
			HIV 1:1/256, HIV 2: <1/32	OD=0.062, CO=0.532
HIV specific antibody tests (CPHL in-house EIAs)	Clear negatives, (OD/CO) HIV	—	Strong positives, (OD/CO) HIV	Strong positives for IgG and IgA; weak positive IgM (OD/CO) HIV IgG=15.41, IgM=3.14, IgA=4.18. *Note decreasing values for IgM and IgA compared to previous
	IgG=0.49, IgM=0.36, IgA=0.44		IgG=12.34, IgM=10.94, IgA=5.28
HIV western blot^ζ	—	—	—	HIV1 gag p17+, p24+++, p55+; pol p31++, p51++, p66+++; env gp41−, gp120+, gp160+++
				HIV2 gp36−
HIV RNA (copies/ml)	Not detected	—	—	41377 Quantiplex HIV-1 RNA 3.0^θ
	(< Limit of detection) Cobas Amplicor HIV-1 Monitor v1.5^η			82400 Cobas Amplicor HIV-1 Monitor v1.5^η