Variable bites and dynamic populations: new insights in Leishmania transmission

TY - JOUR

T1 - Variable bites and dynamic populations

T2 - new insights in Leishmania transmission

AU - Carmichael, Samuel

AU - Powell, Ben

AU - Hoare, Thomas

AU - Walrad, Pegine B

AU - Pitchford, Jonathan W

N1 - © 2021 Carmichael et al.

PY - 2021/1/25

Y1 - 2021/1/25

N2 - 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.

AB - 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.

U2 - 10.1371/journal.pntd.0009033

DO - 10.1371/journal.pntd.0009033

M3 - Article

C2 - 33493192

SN - 1935-2727

VL - 15

JO - PLOS NEGLECTED TROPICAL DISEASES

JF - PLOS NEGLECTED TROPICAL DISEASES

IS - 1

M1 - e0009033

ER -