THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

Introduction: Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory. Material and methods: The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni. Results: After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni

[Performance by cytology and hybrid capture II in screening for high-grade squamous intraepithelial lesions in women with HIV].

HIV-infected women are at increased risk of developing high-grade squamous intraepithelial lesions (HSIL), the precursor lesions for cervical cancer. This study estimated and compared the performance of cytology and hybrid capture II in screening for precursor lesions of cervical cancer among HIV-infected women. The study population consisted of women from the open prospective cohort at the Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation (IPEC/Fiocruz). Colposcopy and histology were considered jointly in defining the gold standard. Cytology showed 31.8% sensitivity and 95.5% specificity, while hybrid capture II showed higher sensitivity (100%) and lower specificity (52%). The positive likelihood ratio was 7.1 for cytology and 2.1 for hybrid capture II, while the negative likelihood ratio was 0.7 for cytology and 0.0 for hybrid capture II