Real-time PCR was used for the identification of hookworm
species. A total of 56 of 76 (73.7%) hookworm real-time PCR positive
samples were positive for N. americanus specific real-time PCR only.
In particular five of 76 (6.6%) were positive for A. duodenale specific
real-time PCR only and 15 of 76 (19.7%) samples yielded positive
results for both N. americanus and A. duodenale specific real-time
PCR.
Among the 56 N. americanus DNA positive samples half (28,
50.0%) were concomitantly positive by microscopy. Only 1 of 5
A. duodenale DNA positive sample (20.0%) was also positive by
microscopy.
Twelve of 15 (80.0%) samples with positive results for N. americanus
and A. duodenale-specific real-time PCR were also positive by
Kato-Katz.
3.3. Samples with multiple detections
Strongyloides spp. and hookworm co-infections were detected
in 26 of 218 (11.9%) samples by classical parasitological methods.
Twenty-three of these positive samples (88.5%) yielded a real-time
PCR positive result. In detail, 13 (50.0%) yielded positive results by
both real-time PCR for S. stercoralis and hookworms; 2 (7.7%) were
positive by S. stercoralis real-time PCR only; 8 (30.8%) samples were
positive by hookworm real-time PCR only; 3 (11.5%) were negative
by both real-time PCR.
Interestingly, 11 of 15 (73.3%) Koga Agar positive samples for
S. stercoralis, which tested negative by Strongyloides real-time PCR
yielded a hookworm positive result in the Kato-Katz method. In
addition, 4 of 11 (36.4%) hookworm positive samples Strongyloides
larvae were found in Koga Agar method.