Evaluating human landing catches as a measure of mosquito biting and the importance of considering additional modes of action
- PMID: 38769342
- PMCID: PMC11106315
- DOI: 10.1038/s41598-024-61116-0
Evaluating human landing catches as a measure of mosquito biting and the importance of considering additional modes of action
Abstract
Entomological evaluations of vector control tools often use human landing catches (HLCs) as a standard measure of a direct human-vector contact. However, some tools have additional characteristics, such as mortality, and HLCS are not sensitive for measuring other effects beyond landing inhibition. Therefore, additional measures may need to be considered when evaluating these tools for public health use. This study has two main aims (1) the evaluate the accuracy of HLCs as a proxy for feeding and (2) to compare the predicted reduction in vectorial capacity when we do and do not consider these additional characteristics. To achieve this, we analyse previously published semi-field data from an experiment which used HLCs and another where mosquitoes were allowed to feed in the presence of different dosages of the volatile pyrethroid spatial repellent, transfluthrin. We compare results for two mathematical models: one which only considers the reduction in feeding effect and one which also considers mortality before and after feeding (using data gathered by the aspiration of mosquitoes after the semi-field feeding/landing period and 24 h survival monitoring). These Bayesian hierarchical models are parameterised using Bayesian inference. We observe that, for susceptible mosquitoes, reduction in landing is underestimated by HLCs. For knockdown resistant mosquitoes the relationship is less clear; with HLCs sometimes appearing to overestimate this characteristic. We find HLCs tend to under-predict the relative reduction in vectorial capacity in susceptible mosquitoes while over-predicting this impact in knockdown-resistant mosquitoes. Models without secondary effects have lower predicted relative reductions in vectorial capacities. Overall, this study highlights the importance of considering additional characteristics to reduction in biting of volatile pyrethroid spatial repellents. We recommend that these are considered when evaluating novel vector control tools.
Keywords: Anopheles; Entomological trials; Malaria; Spatial repellent; Vector control; Volatile pyrethroid.
© 2024. The Author(s).
Conflict of interest statement
The authors declare no competing interests.
Figures
Similar articles
-
Transfluthrin eave-positioned targeted insecticide (EPTI) reduces human landing rate (HLR) of pyrethroid resistant and susceptible malaria vectors in a semi-field simulated peridomestic space.Malar J. 2021 Aug 30;20(1):357. doi: 10.1186/s12936-021-03880-2. Malar J. 2021. PMID: 34461911 Free PMC article.
-
Inference for entomological semi-field experiments: Fitting a mathematical model assessing personal and community protection of vector-control interventions.Comput Biol Med. 2024 Jan;168:107716. doi: 10.1016/j.compbiomed.2023.107716. Epub 2023 Nov 17. Comput Biol Med. 2024. PMID: 38039890
-
Predicting the impact of outdoor vector control interventions on malaria transmission intensity from semi-field studies.Parasit Vectors. 2021 Jan 20;14(1):64. doi: 10.1186/s13071-020-04560-x. Parasit Vectors. 2021. PMID: 33472661 Free PMC article.
-
Entomological monitoring data driving decision-making for appropriate and sustainable malaria vector control in Côte d'Ivoire.Malar J. 2023 Jan 12;22(1):14. doi: 10.1186/s12936-023-04439-z. Malar J. 2023. PMID: 36635720 Free PMC article. Review.
-
The biological activity of a novel pyrethroid: metofluthrin.Top Curr Chem. 2012;314:203-20. doi: 10.1007/128_2011_259. Top Curr Chem. 2012. PMID: 22025064 Review.
References
-
- World Health Organization and others. Guidelines for efficacy testing of mosquito repellents for human skin. Technical report, World Health Organization (2009a). https://iris.who.int/bitstream/handle/10665/70072/WHO_HTM_NTD_WHOPES_200....
-
- Namango IH, Marshall C, Saddler A, Ross A, Kaftan D, Tenywa F, Makungwa N, Odufuwa OG, Ligema G, Ngonyani H, Matanila I, Bharmal J, Moore J, Moore SJ, Hetzel MW. The Centres for Disease Control light trap (CDC-LT) and the human decoy trap (HDT) compared to the human landing catch (HLC) for measuring Anopheles biting in rural Tanzania. Malar. J. 2022;21(1):181. doi: 10.1186/s12936-022-04192-9. - DOI - PMC - PubMed
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Medical