A Multicentre Randomized Controlled Trial of the Efficacy and Safety of Single-Dose Praziquantel at 40 mg/kg vs. 60 mg/kg for Treating Intestinal Schistosomiasis in the Philippines, Mauritania, Tanzania and Brazil

Control of urinary and intestinal schistosomiasis is based on mass administration of praziquantel at the World Health Organization (WHO) recommended dose of 40 mg/kg, though some countries use 60 mg/kg. This multi-country randomized clinical trial compared the efficacy (cure and egg reduction rates three weeks post-treatment) and safety of these two doses for treating intestinal schistosomiasis in 856 patients in Brazil, Mauritania and Tanzania (Schistosoma mansoni), and The Philippines (S. japonicum). Transmission and infection intensities varied across the sites, but there was no bias or heterogeneity in efficacy outcomes. The two doses are equally effective in curing intestinal schistosomiasis; the higher dose may be less well tolerated, though effects are generally mild and transient. In endemic areas people can be re-infected; one year post-treatment patients on 60 mg/kg had fewer re-infections but this finding is difficult to explain. This study was conducted to respond to the demand for evidence about the dose of praziquantel when deployed in endemic countries. The results, along with those of systematic reviews, support the current WHO recommendation for using praziquantel at 40 mg/kg and should inform policy decisions in countries. The Philippines has already changed from 60 to 40 mg/kg after this study

Paediatric schistosomiasis:What we know and what we need to know

Schistosomiasis affects over 200 million people worldwide, most of whom are children. Research and control strategies directed at preschool-aged children (PSAC), i.e., ≤5 years old, have lagged behind those in older children and adults. With the recent WHO revision of the schistosomiasis treatment guidelines to include PSAC, and the recognition of gaps in our current knowledge on the disease and its treatment in this age group, there is now a concerted effort to address these shortcomings. Global and national schistosome control strategies are yet to include PSAC in treatment schedules. Maximum impact of schistosome treatment programmes will be realised through effective treatment of PSAC. In this review, we (i) discuss the current knowledge on the dynamics and consequences of paediatric schistosomiasis and (ii) identify knowledge and policy gaps relevant to these areas and to the successful control of schistosome infection and disease in this age group. Herein, we highlight risk factors, immune mechanisms, pathology, and optimal timing for screening, diagnosis, and treatment of paediatric schistosomiasis. We also discuss the tools required for treating schistosomiasis in PSAC and strategies for accessing them for treatment

Tomato treatment with chemical inducers reduces the performance of Spodoptera littoralis (Lepidoptera: Noctuidae)

The evolving understanding of plant signaling pathways has promoted the possibility of using chemical inducers as an effective tactic for crop protection. In this study, under greenhouse conditions, we conducted a growth assay of Spodoptera littoralis (Boisduval) larvae on tomato plants treated with BTH (S-methyl benzo [1, 2, 3] thiadiazole 7 carbothioate) as a salicylic acid mimic, PDJ (propyl [1RS, 2RS]-[3-oxo-2-pentylcyclopentyl] acetate) as a jasmonic acid-mimic or both chemicals as a combined treatment. The larval body weight of S. littoralis was drastically reduced with each chemical compared to control plants, and there was a significant synergistic interaction. Overall, the total weight gain of surviving larvae fed on treated plants was distinctly tenfold less than for those fed on control plants. Moreover, incorporating the chemical inducers in artificial diets had no direct or toxic impact on the larval body weight of S. littoralis under laboratory conditions. Larval survival rates were significantly lower (35–40 %) on treated plants with either combined or independent inducers’ treatments compared with control plants after 15-day feeding. In contrast, incorporating the chemical inducers in artificial diets had no direct effect on larval survival rates under laboratory conditions. The applied concentrations of BTH and PDJ had no detectable phytotoxicity to tomato plants. Our results demonstrate that BTH and PDJ can act synergistically when applied to tomato to reduce the performance of S. littoralis. These findings stress that the application of chemical inducers could provide an environment-friendly tactic to help manage insect pests and thereby play multiple roles in improving the overall plant resistance to herbivore pests