Table 1.

Tests used to diagnose congenital T. cruzi infection at the time of birth or within 30 days of age, Hospital Regional Ushuaia, Ushuaia, 2001–2002

Technique	Case 1 (age: 10 days)	Mother 1	Case 2 (age: 10 hours)	Mother 2	Case 3 (age: 2 hours)	Mother 3
Direct parasitemia (microhematocrit)	5 parasites	NA	2 parasites	NA	4 parasites	NA
IHA reactive ≥ 1/16	1/512 (reactive)	1/256 (reactive)	1/512 (reactive)	1/256 (reactive)	1/128 (reactive)	1/64 (reactive)
EIA (IP) reactive ≥ 1	5.3 (reactive)	6.9 (reactive)	6.6 (reactive)	5.9 (reactive)	4.7 (reactive)	5.0 (reactive)
EIA-SAPA cut-off = 0.300	OD = 1.885 (reactive)	OD = 0.201 (not reactive)	OD = 1.118 (reactive)	OD = 0.102 (not reactive)	OD = 2.607 (reactive)	OD = 0.179 (not reactive)

NA = not applicable; IP = index of positivity (OD/cut-off); IHA = indirect hemagglutination; EIA = enzyme-linked immunosorbent assay.