A <i>Schistosoma haematobium</i>-Specific Real-Time PCR for Diagnosis of Urogenital Schistosomiasis in Serum Samples of International Travelers and Migrants

<div><p>Background</p><p>Diagnosis of urogenital schistosomiasis by microscopy and serological tests may be elusive in travelers due to low egg load and the absence of seroconversion upon arrival. There is need for a more sensitive diagnostic test. Therefore, we developed a real-time PCR targeting the <i>Schistosoma haematobium</i>-specific <i>Dra1</i> sequence.</p><p>Methodology/Principal Findings</p><p>The PCR was evaluated on urine (n = 111), stool (n = 84) and serum samples (n = 135), and one biopsy from travelers and migrants with confirmed or suspected schistosomiasis. PCR revealed a positive result in 7/7 urine samples, 11/11 stool samples and 1/1 biopsy containing <i>S. haematobium</i> eggs as demonstrated by microscopy and in 22/23 serum samples from patients with a parasitological confirmed <i>S. haematobium</i> infection. <i>S. haematobium</i> DNA was additionally detected by PCR in 7 urine, 3 stool and 5 serum samples of patients suspected of having schistosomiasis without egg excretion in urine and feces. None of these suspected patients demonstrated other parasitic infections except one with <i>Blastocystis hominis</i> and <i>Entamoeba</i> cyst in a fecal sample. The PCR was negative in all stool samples containing <i>S. mansoni</i> eggs (n = 21) and in all serum samples of patients with a microscopically confirmed <i>S. mansoni</i> (n = 22), <i>Ascaris lumbricoides</i> (n = 1), <i>Ancylostomidae</i> (n = 1), <i>Strongyloides stercoralis</i> (n = 1) or <i>Trichuris trichuria</i> infection (n = 1). The PCR demonstrated a high specificity, reproducibility and analytical sensitivity (0.5 eggs per gram of feces).</p><p>Conclusion/Significance</p><p>The real-time PCR targeting the <i>Dra1</i> sequence for <i>S. haematobium</i>-specific detection in urine, feces, and particularly serum, is a promising tool to confirm the diagnosis, also during the acute phase of urogenital schistosomiasis.</p>