topnaman | Malaria blog

The mosquito vector, and by extension local ecology, drives malaria transmission. So understanding vector biology is important to malaria control. Classical studies of mosquito flight range, feeding preferences, and resting habits were crucial in the development and application of control strategies. Modern vector biology research, dominated by molecular studies, has produced new tools for monitoring insecticide resistance in mosquitoes as well as identifying Anopheles sibling species among whom the potential for transmitting malaria can broadly vary.

Recently, I browsed through a malaria journal article (open access!) whose potential I have difficulty understanding. Can someone explain to me how research on variation in chromosomal inversions and their relationship with stress responses will improve malaria control? Looking carefully through the manuscript, the sole rationale that I could find was:

Polymorphism for the 2La inversion creates heterogeneity in the stress response within A.gambiae, which could directly or indirectly reduce the efficacy of vector control measures, and influence the reaction of vector populations to environmental variation including climate change.

I find this single sentence advanced by the authors both incomplete and unsatisfying. It tells you very little. So let’s think through the rationale ourselves. Understanding the ability of a vector to exploit different habitats is certainly useful – we could predict how mosquito ranges and other characteristics may change with the climate. Understanding the molecular basis of that ability might further help – if the molecular changes had a clear association with a phenotype of interest (i.e. real world characteristics of the mosquito) and were such that they could easily be monitored. Understanding polymorphisms in those molecular mechanisms and their relationship to stress response variation however is not intuitively valuable (perhaps for modelling purposes?). To be clear, my aim is not cast the research as meaningless (though it may be). Sometimes the impact of basic science take years or decades to be realized. Rather, I’m surprised the authors, and especially the reviewers, did not seek to clearly convey the value of the work. If the purpose of public health research is to improve health, then the communication of such research should describe its relevance in explicit and detailed language.