Blood smear and polymerase chain reaction (PCR) for malaria, as well as the Plasmodium falciparum antibody test, were all negative. At D60, microscopy after enrichment for ova and parasites revealed 50 ova of S mekongi per gram of

feces (Figure 1). To confirm species identification, real-time PCR[2] and conventional PCR followed by sequence RAD001 ic50 analysis were performed on a fecal sample on D60 and D225. DNA was extracted using a QIAamp DNA stool mini kit (Qiagen). Sequencing of the real-time PCR product and of the complete Internal Transcribed Spacer (ITS) rRNA region amplified by the conventional PCR demonstrated the presence of S mekongi DNA. The 733 bp sequence amplified using the ITS4 and ITS5 primers was Angiogenesis inhibitor identical to S mekongi from GenBank (accession number U82284 and SMU22169) with the exception of a single base pair transition.[3] A real-time PCR using the Sm1-7 PCR test targeting the 121-bp tandem repeat sequence common to human schistosomes[4, 5] revealed cell-free schistosome DNA in serum at D105 but not at D60, D72, and D225 (Table 1). Instead of using 10 mL of plasma as in the original setup, DNA extraction was performed on 1.5 mL of serum on D60 and D72 and on 2 mL of serum

on D105 and D225, quantities that proved to be sufficient in S mansoni infections.[4, 6] The patient was given a single dose of praziquantel at D69, when symptoms had already subsided for 2 weeks. He declined concomitant corticosteroid treatment but was warned of a possible exacerbation of symptoms. He consulted 3 days later (D72) because of high-grade fever, severe and blood-stained diarrhea, abdominal

colics, and some cough, starting a few hours after praziquantel ingestion. By that time the eosinophil count increased to 15.350/µL and the schistosome ELISA antibody test had turned positive. The patient was treated with oral corticosteroids (methylprednisolone 32 mg o.d. gradually tapering to nil in 14 days). Symptoms disappeared promptly after the first dose and never reappeared. At a control visit at D105, the patient was asymptomatic, eosinophil count had lowered dramatically, and a stool sample PtdIns(3,4)P2 was negative for S mekongi eggs. A second treatment with praziquantel was given. No symptoms appeared thereafter. At a control visit 6 months later (D225), the eosinophil count had returned to normal, and PCR was negative both in feces and serum. His companion had bathed at the same spot in the Mekong River, but never developed symptoms. A schistosome antibody test taken elsewhere 3 months after exposure showed a positive result, and she was reportedly treated without developing symptoms. Infections with S mekongi have been reported in populations from the endemic region along the Mekong River for many years.