Affiliation:
1. Department of Clinical Sciences, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
2. Department of Biology, Royal Museum for Central Africa, Tervuren, Belgium
Abstract
Abstract
Background
Diagnosis of schistosomiasis remains elusive soon after infection. We evaluated several diagnostic methods in a cluster of travelers with simultaneous freshwater exposure in South Africa.
Methods
Eosinophil count, schistosome antibody tests, stool and urine microscopy, and serum Dra1 PCR assays were performed at weeks 4–5 (early symptomatic phase), 7–8 (praziquantel treatment), and 13–14 (after treatment). Sequencing was done on serum samples from 3 patients to identify the species.
Results
Of the 34 travelers (16 adults and 18 children), 32 developed symptoms 2–6 weeks after exposure. A raised eosinophil count (>750/µL) was seen in 12 of 33 at weeks 4–5, and in 22 of 34 at weeks 7–8. Schistosoma antibodies were detected in 3 of 33 at weeks 4–5 and in 12 of 34 at weeks 7–8 and weeks 13–14. The Dra1 PCR result was positive in 24 of 33 travelers at weeks 4–5, in 31 of 34 at weeks 7–8, in 25 of 34 at weeks 13–14, and at least once in all. Ova were absent in all urine and stool samples obtained. Sequencing identified Schistosoma mattheei nuclear and Schistosoma haematobium mitochondrial DNA, indicative of a hybrid species.
Conclusions
The Dra1 PCR confirmed the diagnosis in all exposed travelers at a much earlier stage than conventional tests. The causative species is probably an S. mattheei × S. haematobium hybrid.
Publisher
Oxford University Press (OUP)
Subject
Infectious Diseases,Microbiology (medical)