‘Flying syringes’ could detect emerging infectious diseases
Trapping and sequencing blood-sucking flies can reveal infections in wild animals before they spread to humans.
About 60% of new infectious diseases in humans come from animals. Their increasing number and rapid spread are linked to increasing levels of contact between humans and wildlife, as recently highlighted by the epidemics of Zika in Brazil or Ebola in West Africa. To anticipate and prevent similar outbreaks in the future, it would be ideal to develop new methods for the early detection and monitoring of infectious diseases in wild animals.
Currently, three methods are mainly used to screen wild animals for infectious disease, but these all have limitations. Analyses of bushmeat and game meat only investigate those animals that are eaten by humans. Testing the organs and tissues of trapped animals can be difficult and harmful for both the humans and animals involved. Collecting and examining samples of feces, urine or saliva cannot detect all diseases and can be difficult to do for some species.
Paul-Yannick Bitome-Essono and co-workers now demonstrate a new method for assessing the diseases carried by wild animals: using blood-sucking flies as ‘flying syringes’ to collect their blood. During several weeks of sampling in Gabon, Central Africa, Bitome-Essono et al. trapped thousands of these flies, about a third of which were engorged with blood. Analyses of these blood samples revealed that they had come from 20 different species, including birds, mammals and reptiles. Different malaria parasites could also be detected in the blood.
Although the study performed by Bitome-Essono et al. only focused on malaria parasites, in the future the technique could be extended to analyze a number of disease-causing microbes — including viruses, bacteria, protozoa and macroparasites — that are found in the blood of wild animals.
To find out more
Read the eLife research paper on which this eLife digest is based: “Tracking zoonotic pathogens using blood-sucking flies as ‘flying syringes’”(March 28, 2017).
