Impact of species hybridization on the clinical management of schistosomiasis: A prospective study.

BACKGROUND: Species hybridization represents a real concern in terms of parasite transmission, epidemiology and morbidity of schistosomiasis. It is greatly important to better understand the impact of species hybridization for the clinical management. METHODS: A prospective observational study was carried out in sub-Saharan migrants who were diagnosed with confirmed genitourinary schistosomiasis. A tailored protocol was applied, including Schistosoma serology, a specific urine LAMP tests for schistosomiasis and an ultrasound examination before treatment with praziquantel. A scheduled follow-up was performed at 3, 6 and 12 months to monitor treatment response, comparing patients carriers of Schistosoma hybrids with carriers of only genetically pure forms. RESULTS: A total of 31 male patients from West Africa were included in the study with a mean age of 26.5 years. Twelve (38.7 %) of the patients were carriers of Schistosoma hybrids. As compared with patients infected with S. haematobium alone, hybrid carriers had lower haemoglobin levels (13.8 g/dL [SD 1.8] vs 14.8 g/dL [SD 1.4], p = 0.04), a greater frequency of hematuria (100 % vs 52.6 %, p = 0.005), a higher ultrasound score (2.64, SD 2.20 vs 0.89, SD 0.99; p = 0.02). However, the presence of hybrids did not result in differences in clinical and analytical responses after treatment. CONCLUSIONS: The presence of Schistosoma hybrids seems to cause increased morbidity in infected individuals. However, it does not appear to result in differences in diagnostic tests or in clinical and analytical responses after treatment.

Usefulness of ultrasound in sub-Saharan patients with a serological diagnosis of schistosomiasis.

OBJECTIVE: To evaluate the usefulness of ultrasound examination in patients with just a serological diagnosis of schistosomiasis but no other evidence of active infection. METHODS: 346 sub-Saharan patients with possible schistosomiasis that presented at a Tropical Medicine Unit between 2008 and 2019 were retrospectively selected. Possible schistosomiasis was considered in those patients with a positive serology for schistosomasis in the absence of direct microbiological isolates, hematuria and/or eosinophilia. Data from ultrasound examinations before and after treatment with praziquantel were collected and categorized following the World Health Organization-Niamey score to standardize the use of ultrasonography for the assessment of schistosomiasis-related morbidity. RESULTS: Ultrasound examinations were abnormal in only ten patients (2.89%). Main findings were focal thickening of the bladder wall (n = 6), ureteral dilatation (n = 3) and grade I hydronephrosis (n = 1). No malignant lesions, hepatic lesions nor hepatobiliary related disorders were found. After treatment, the S. haematobium global score (5 vs 3.4, p = 0.06) and the urinary bladder score (2 vs 1, p = 0.059) showed a trend towards improvement after treatment. In three patients the score after treatment dropped to 0, and in another three it remained the same although with signs of improvement. No worsening of the score was observed in any case. CONCLUSION: For those patients with a diagnosis of schistosomiasis based solely in a positive serology, the ultrasound examination could safely be spared due to the low prevalence of pathological findings and its response to treatment anyway.