Open AccessVariable bites and dynamic populations; new insights in Leishmania transmission
Author(s) -
Samuel Carmichael,
Ben Powell,
Tony Hoare,
Pegine Walrad,
Jonathan W. Pitchford
Publication year - 2021
Publication title -
plos neglected tropical diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.99
H-Index - 135
eISSN - 1935-2735
pISSN - 1935-2727
DOI - 10.1371/journal.pntd.0009033
Subject(s) - transmission (telecommunications) , vector (molecular biology) , biology , leishmania , leishmaniasis , cutaneous leishmaniasis , disease transmission , tropical disease , parasite hosting , population , disease , phlebotomus , ecology , zoology , immunology , virology , medicine , environmental health , computer science , pathology , biochemistry , world wide web , gene , recombinant dna , telecommunications
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.