Variable bites and dynamic populations: new insights in Leishmania transmission

Samuel Carmichael, Ben Powell, Thomas Hoare, Pegine B Walrad, Jonathan W Pitchford

Research output: Contribution to journalArticlepeer-review


Leishmaniasis is a neglected tropical disease which kills an estimated 50,000 people each year, with its deadly impact confined mainly to lower to middle income countries. Leishmania parasites are transmitted to human hosts by sand fly vectors during blood feeding. Recent experimental work shows that transmission is modulated by the patchy landscape of infection in the host's skin, and the parasite population dynamics within the vector. Here we assimilate these new findings into a simple probabilistic model for disease transmission which replicates recent experimental results, and assesses their relative importance. The results of subsequent simulations, describing random parasite uptake and dynamics across multiple blood meals, show that skin heterogeneity is important for transmission by short-lived flies, but that for longer-lived flies with multiple bites the population dynamics within the vector dominate transmission probability. Our results indicate that efforts to reduce fly lifespan beneath a threshold of around two weeks may be especially helpful in reducing disease transmission.

Original languageEnglish
Article numbere0009033
Number of pages18
Issue number1
Early online date25 Jan 2021
Publication statusE-pub ahead of print - 25 Jan 2021

Bibliographical note

© 2021 Carmichael et al.

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