Table 2.
Course of Parasitemia in Infected Infants Based on Detection Polymerase Chain Reaction (PCR) Targeting Trypanosoma cruzi Kinetoplast DNA (kDNA) and Quantitative PCR (qPCR) and Comparison with Micromethod (ie, Microscopy of Concentrated Heparinized Blood in Microhematocrit Tubes)
| Infant, technique | Cord blood specimen | Sample time | Age at treatment, days | |||||
|---|---|---|---|---|---|---|---|---|
| 7 days | 21 days | 30 days | 90 days | 180 days | 270 days | |||
| Infant 19 | ||||||||
| kDNA | − | ND | ND | + | + | + | + | 275 |
| qPCR, copies/mL | ND | ND | ND | <1a | 48,883 | 3127 | 8 | … |
| Micromethod | − | ND | ND | − | − | − | − | … |
| Infant 19 | ||||||||
| kDNA | + | − | + | + | ND | ND | − | 48 |
| qPCR, copies/mL | <1 | <1 | 825 | 10,539 | ND | ND | <1 | … |
| Micromethod | − | − | − | + | ND | ND | − | … |
| Infant 120 | ||||||||
| kDNA | + | + | ND | ND | ND | ND | ND | Not treatedb |
| qPCR, copies/mL | 42 | 44 | ND | ND | ND | ND | ND | … |
| Micromethod | − | − | ND | ND | ND | ND | ND | … |
| Infant 179 | ||||||||
| kDNA | ND | + | + | ND | ND | + | + | 27c |
| qPCR, copies/mL | ND | 1470 | 8251 | ND | ND | 5188 | 29 | … |
| Micromethod | ND | + | + | ND | ND | + | − | … |
| Infant 203 | ||||||||
| kDNA | + | + | + | ND | ND | − | − | 51 |
| qPCR, copies/mL | 9770 | 45,320 | 207,943 | ND | ND | <1 | <1 | … |
| Micromethod | − | + | + | ND | ND | − | − | … |
| Infant 218 | ||||||||
| kDNA | + | + | − | + | + | + | + | Not treatedd |
| qPCR, copies/mL | 1 | <1 | <1 | 3 | 61,146 | 4377 | 70 | … |
| Micromethod | − | − | − | − | − | − | − | … |
| Infant 270 | ||||||||
| kDNA | + | + | + | + | + | + | − | 230 |
| qPCR, copies/mL | 43 | 10 | 86 | 599 | 5412 | 875 | <1 | … |
| Micromethod | − | − | − | − | − | + | − | … |
| Infant 342 | ||||||||
| kDNA | − | − | − | − | + | ND | − | 122 |
| qPCR, copies/mL | <1 | <1 | <1 | <1 | 19,504 | ND | <1 | … |
| Micromethod | − | − | − | − | + | ND | − | … |
| Infant 471 | ||||||||
| kDNA | + | + | +e | ND | ND | − | − | 15 |
| qPCR, copies/mL | 174 | 12,274 | 12,508 | ND | ND | <1 | <1 | … |
| Micromethod | − | + | − | ND | ND | − | − | … |
| Infant 478 | ||||||||
| kDNA | − | − | − | − | + | + | + | 314 |
| qPCR, copies/mL | <1 | <1 | <1 | <1 | 8 | 1032 | 127 | … |
| Micromethod | − | − | − | − | − | − | + | … |
NOTE. ND, not done; +, positive; −, negative.
a
qPCR result less than the threshold of detection of 1 parasite copy/mL.
b
Family refused follow-up.
c
Infant diagnosed with treatment failure at 270 days on the basis of increasing positive serological test values.
d
Family moved to an area without access to treatment before serological results were available.
e
Specimen collected at 15 days.