Review 3: "Changing Species Dynamics and Species-specific Associations Observed between Anopheles and Plasmodium Genera in Diebougou Health District, Southwest Burkina Faso"

RR\ID Evidence Scale rating by reviewer:

• Strong. The main study claims are very well-justified by the data and analytic methods used. There is little room for doubt that the study produced has very similar results and conclusions as compared with the hypothetical ideal study. The study’s main claims should be considered conclusive and actionable without reservation.

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Review: The paper provides a detailed examination of the evolving relationship between Anopheles mosquitoes and Plasmodium parasites, with a focus on how these dynamics are influenced by changing socio-economic factors around Burkina Faso. The study provides thorough ground on species specific interactions, molecular mechanisms and clear malaria control using ivermectin. This study is particularly significant regarding its implications for malaria transmission and control strategies especially using an already applied mass drug administration with ivermectin. The authors explore various themes related to the complexities of vector-parasite interactions, highlighting how shifts in species dynamics and specific associations between Anopheles species and Plasmodium strains are reshaping malaria epidemiology over the five-year period using two trials of Repeat Ivermectin Mass Drug Administrations for control of Malaria over a five-year period. 

One of the key points emphasized in the article is the changing species dynamics between Anopheles mosquitoes and Plasmodium parasites in Burkina Faso. Socioeconomic factors such as high rates of poverty, limited community uptake and/or compliance with parasite and vector control tools, political upheaval with high migrant flows, and extensive artisanal gold mining across the country and habitat modifications, have contributed to shifts in the distribution of both mosquito vectors and parasite strains. As a result, regions that once had a relatively stable malaria transmission pattern are now experiencing new dynamics, with previously dominant Anopheles species being replaced by others that may have different susceptibilities to Plasmodium. Increasing prevalence of different malaria prevalence with their varying cycles have been highlighted. There is also a reported occurrence of multiple plasmodium infections rather than single infections.

A particularly valuable contribution of the article is its exploration of the species-specific relationships between Anopheles mosquitoes and Plasmodium species. The paper discusses how certain Anopheles species have developed unique associations with specific Plasmodium species, which affects the efficiency of transmission. By examining the molecular and ecological factors that drive these associations, the article underscores the complexity of malaria transmission and the need for precise targeting in vector control efforts. Additionally, the paper’s emphasis on species-specific associations is particularly valuable, as it moves beyond the general understanding of Anopheles as a vector of Plasmodium, and delves into how specific species of mosquitoes interact with specific Plasmodium species.

While the article provides an extensive analysis of current knowledge, it also points out gaps in research, particularly in terms of understanding the genetic mechanisms that drive species-specific associations. The authors highlight that future studies should use fresh blood samples and be done over a larger area to allow generalizability. Additionally, there is a call for more research on the potential for change in prevalence from Plasmodium falciparum to more non-falciparum species and if non-falciparum infections. More so, is there any correlation of the presence of Anopheles funestus or increased rainfall during the wet season in other areas? Furthermore, the mosquito feeding assays with the blood from infectious participants should be validated. Other environmental and ecological interventions that target these dynamics at community level, rather than just focusing on individual species or pathogens should be explored.