Table 3.
Review of studies comparing the performances of PCR and microscopy for helminth detection.
| Targets | Micro + |
Micro + |
Proportion of false-negative from PCR | Reference |
|---|---|---|---|---|
| PCR + | PCR − | |||
| Ascaris spp. | 7 | 1 | 13% | This study |
| 154 | 7 | 4% | [17] | |
| 34a | 2a | 6%a | [13] | |
| 23 | 5 | 18% | [20] | |
| 8 | 0 | 0% | This study (+bb) | |
| 35a | 1a | 3%a | [13] (+bb) | |
| 192 | 27 | 12% | [15] (+bb) | |
| E. vermicularisb | 7 | 4 | 36% | This study |
| 8 | 3 | 27% | This study (+bb) | |
| Hookworms | 6 | 7 | 54% | This study |
| 89 | 9 | 9% | [17] | |
| 48 | 1 | 2% | [10] | |
| 136 | 15 | 10% | [15] (+bb) | |
| Hymenolepis spp.b | 20 | 1 | 5% | This study |
| 21 | 0 | 0% | This study (+bb) | |
| Strongyloides spp.c | 28 | 7 | 20% | This study |
| 30 | 5 | 14% | This study (+bb) | |
| 33 | 21 | 39% | [25] | |
| 88 | 12 | 12% | [17] | |
| 14 | 14 | 50% | [5] | |
| Taenia spp. | 5 | 0 | 0% | This study |
| 7 | 0 | 0% | [18] | |
| T. trichiura | 1 | 10 | 91% | This study |
| 18a | 9a | 33%a | [13] | |
| 10 | 1 | 9% | This study (+bb) | |
| 26a | 1a | 4%a | [13] (+bb) | |
| 297 | 23 | 7% | [3] (+bb) |
Micro: Microscopy; (+bb): with bead-beating pretreatment.
a
In this study, different conditions were evaluated for sample preservation and pretreatment. In order to be in conditions similar to our study, the results shown in this table correspond to frozen samples without preservative.
b
No published evaluation compared PCR and microscopy for E. vermicularis and Hymenolepis spp.
c
As many evaluations of S. stercoralis have been published, sometimes with substantial bias, we focused on studies comparing real-time PCR targeting the 18S rRNA gene to a combination of parasitological methods as the reference, and without age restriction of the population.