Despite the scientific progress that the world is witnessing in all fields, researchers are still unable to predict exactly where, when and how human epidemics will arise.
A new study found that bloodsucking flies can be used as a “jet drawing injection” to detect infectious diseases in animals before they spread to humans.
The researchers analyzed the blood meals of flies that absorbed the blood of animals to find out the types of animals that carry certain diseases, according to the British newspaper “Daily Mail”.
The research could help fight future disease outbreaks, such as Ebola and Zika, which are contagious diseases in animals that can be transmitted to humans.
7 new pathogens
According to the researchers, 7 new pathogens are identified around the world each year, and they are expected to reach between 15 and 20 each year by the year 2020, due to increased human contact with wildlife species that are likely to carry the disease.
“This is a huge public health issue that urgently requires new tools to actively monitor outbreaks of the diseases concerned and quickly diagnose their causes,” said the study’s lead author and evolutionary genetics scientist, Dr. Franck Brugnoll of the National Center for Scientific Research in Montpellier, France.
“We wanted to study whether insects feeding on blood could be used as a sampling tool in the wild environment, which would allow us to monitor the presence and emergence of infectious diseases,” he added.
An alternative to hunt animals
Usually, to study the pathogens that are circulating in wild habitats, researchers analyze animals that humans have hunted in order to obtain food. However, these animals typically offer little of the realities of the wildlife in the area.
Another method is to set traps for animals to study the presence of infection in their organs and tissues, but this is not easy to do, and it is also dangerous for endangered species.
Previous research has shown that animal DNA, and from diseases like malaria, is preserved in the blood meals of flies.
This was what inspired Dr. Brunoll and his research team the idea to see if blood meals could be used as a non-invasive way to study pathogens circulating in wildlife.
So the researchers conducted a study over a period of 16 weeks in 4 national parks in the forests of Gabon, in Central Africa. They set up traps for 3 species of flies (“tsetse”, “stomexids” and “tapanides”) and then analyzed insect blood meals to determine the source of the blood and the types of malaria parasites present.
More than 4000 flies were caught, 30% of which were the tsetse flies that were saturated with blood. The tsetse fly bite transmits so-called sleeping sickness, which causes symptoms such as fever, headache, joint pain and disturbed sleep cycles.
The lead author of the study, Dr. Paul Yannick Bitum-Esono, of the National Center for Scientific Research in Montpellier, France, explains, “We thought that the tsetse fly might be a good candidate in our study, as both sexes feed on blood. It is large and easy They are also found in large numbers in central Africa, and they are opportunistic feeders, with no strong preference for specific host animals, so they may feed on a wide range of wildlife. “
18 new malaria species
The researchers used a new technique to study the DNA of a blood meal, and found the origin of the host animal for three-quarters of the samples. The results showed that the flies may have fed more than 20 different species, ranging from elephants and hippos to reptiles and birds. They found malaria parasites in about 9% of blood meals, including 18 cases of malaria that had not previously been documented. They also identified host animals for some types of malaria whose preferred host was not known before.
“These results show that blood meals from flies saturated with blood can be used successfully to analyze the diversity of known malaria parasites,” said Dr. Brunolle, noting that the next step is to look at ways to improve the method using new techniques for DNA sequencing and disease detection methods.
He added: “This approach of” non-host monitoring “can detect pathogens before they spread to humans, as well as the emergence of new diseases in wild animals that may threaten their long-term survival.