Environmental risk from existing and emerging parasites

Mathematical models

Measure the impact of infectious diseases on the populations (human and wildlife)

Invasive species

Exogenous intrusive species

• Develop in autochthonous ecosystems

• Cause biodiversity disturbance

Autochthonous species

Native to a given region or ecosystem

Intentional introduction of invasive species

Pets, plants for food, medicinal, or esthetic reasons

• Domestication of goats → disappearance of many indigenous plant species

• House, muskox, pigs

• Donkey proliferation (Australia) → vegetation destruction → danger for indigenous herbivores

• Wild dromedaries proliferation → danger for plants and animals

Non-intentional introduction of invasive species

Transport of merchandises

• Rhipicephalus sanguineus (ticks): illegally imported dog → responsible of canine hepatozoonosis → incurable disease

• Dirofilaria immitis (worms): dog transports → responsible of canine dirofilariasis → canine heart failure

Rabbits’ proliferation in Australia

• Intentional introduction

• No natural predator → 60% of the territory colonized

• Causes desertification through vegetation removal → ecological and agricultural crisis

• Means developed:

  • Hunting, traps → failure

  • Introduction of fox as a predator - more affinity for marsupials

  • Lethal myxomatosis → efficient during the first years → poorly adapted vectors → virus-resistant rabbits

  • Spanish flea → more infectious, less stable → risk of mutations

  • Hemorrhagic fever virus → in wet areas, competition with another virus which annihilates its virulene

Asiatic hornet

• Unintentional introduction

• Yellow-legged hornet

• Arrived in France in pieces of pottery imported from chinaChina

• Continuous expansion

• Feed on bee larvae → co-responsible for the reduction of the bee population

Mosquitoes and viral vectors

• Unintentional introductions

• Tiger: spread to 80 countries, aggressive

• Aedes: dengue virus, air traffic

• A. albopictus: chikungunya virus → massive epidemic

Leishmaniases

• Infectious diseases caused by protozoan parasites from the genus Leishmania sp.

• Transmitted by sandflies

• Depending on the species of leishmaniasis, the clinical manifestation

  • L. donovani → anthroponotic disease

  • L. infantum → zoonotic disease

Leishmaniases vector control

• insecticides for dogs: permethrin, fipronil, afoxolaner, deltamethrin

• Sanitation efforts: filling wall cracks and removing vegetation near habitats

Global changes and leishmaniasis spreading

• Climate change: temperature, rainfall distribution → change in seasonality of vector distribution

• Globalization: trade, economics → change in human migratory flux

• Human pressure: deforestation, urbanization → increase of human contact with vectors and parasites

Consequences of invasive species

• Devastation of native ecosystems

• Rise of autochthonous human health crises

• Mutations and increased virulence of new vectors

• Threats to animal welfare

• Unpredictable and uncontrollable chain reactions