Development of a natural molluscicide prototype kit (MoluSchall) for the control of schistosomiasis mansoni transmission

Abstract

Introduction: In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are intermediate hosts of Schistosoma mansoni, the etiological agent of schistosomiasis mansoni. Molluscicide use is recommended by the WHO for controlling the transmission of this parasite. Euphorbia milii latex has shown promising results as an alternative molluscicide. Thus, a natural molluscicide prototype kit based on freeze-dried E. milii latex was developed and evaluated against Biomphalaria spp. Methods: E. milii latex was collected, processed, and lyophilized. Two diluents were defined for freeze-dried latex rehydration, and a prototype kit, called MoluSchall, was produced. A stability test was conducted using prototype kits stored at different temperatures, and a toxicity assay was performed using Danio rerio. Additionally, MoluSchall was tested against B. glabrata under semi-natural conditions according to defined conditions in the laboratory. Results: MoluSchall was lethal to three Brazilian snail species while exhibiting low toxicity to D. rerio. Regardless of storage temperature, MoluSchall was stable for 24 months and was effective against B. glabrata under semi-natural conditions, with the same LD 100 as observed under laboratory conditions. Conclusions: MoluSchall is a natural, effective, and inexpensive molluscicide with lower environmental toxicity than existing molluscicides. Its production offers a possible alternative strategy for controlling S. mansoni transmission.

Molluscicides against the snail-intermediate host of Schistosoma: a review

“…Recently, some achievements on the discovery of novel chemical and natural molluscicides have been accomplished to control snails (Chen et al 2019 ; de Paula-Andrade et al 2019 ). For the development of new molluscicides, exploration of the mechanism is important for the enhancement of molluscicidal activity and the reduction in non-target toxicity (Huang 2019a , b ).…”

“…For example, chemical treatment using molluscicides was performed in an area of 78,308.26 hectare in China, and environmental improvements were only carried out in an area of 4738.37 hectare in 2018 (Zhang et al 2019 ). Great efforts have been made to explore all kinds of molluscicidal substances including chemical and plant molluscicides (Perrett and Whitfield 1996 ; de Paula-Andrade et al 2019 ). Herein, we undertake a systematic review of molluscicides, and their detailed molluscicidal activity, structure–activity relationship, and possible mechanism of some molluscicides are also highlighted.…”

Larval trematodes hosted by Biomphalaria straminea in the Brazilian semiarid region: implications for schistosomiasis control

“…Despite being less susceptible to S. mansoni infection than B. glabrata (Bezerra et al, 2018), B. straminea has a wide distribution and is responsible for maintaining human infection rates above 50% in some locations in northeastern Brazil (Quinino et al, 2010;Neto et al 2012;Costa et al, 2017). B. straminea has previously been identified in 24 Brazilian states and usually inhabits temporary and permanent water collections, being more adjusted to the dry climate of the Northeast (Paula-Andrade et al, 2019;Ohlweiler et al, 2020).…”