The research is called “Study of the presence of Flavivirus and Dirofilaria by molecular tools in mosquitoes (Diptera: Culicidae) in a desert area of Chile” and constitutes an unprecedented study in continental Chile.
Millaray Mariqueo, Science in Chile.- María Beatriz Cancino is a scientist and researcher with a Master’s in Biomedical Sciences with a mention in Microbiology and a PhD in Biotechnology from the University of Barcelona, whose line of research focuses on neglected, emerging and re-emerging diseases transmitted by vectors. Along these lines, Beatriz discovered her concern about mosquitoes, an animal known to be the one that causes numerous deaths worldwide, mainly because it transmits malaria.
Based on this, the researcher developed the question: Do mosquitoes in Chile have viruses or parasites that could infect us?, a question that led to the initiation of a research in 2019 funded by ANID.
Methodology and results
The research involved the collection of samples in the regions of Arica and Parinacota, Tarapacá and Antofagasta, managing to gather more than 3 thousand samples, 3,085 to be more exact.
The objective was to look for viruses of the family of Flavivirus, which have medical importance such as Zika, Dengue, Yellow Fever, among many others. The researcher mentioned that a parallel objective was also the study of a parasite that is also transmitted by mosquitoes, however, this was made difficult because the logistics of transporting traps and their batteries to the north, to collect adult females, was very complex, making it impossible to obtain the number of females sufficient for the study, for which reason female mosquitoes were collected and analyzed in the Maule region, finding genetic material of nematode parasites (worms) of animals such as Acanthocheilonema reconditum, which are not transmitted to people.
However, in the search for Flavivirus, mainly watercourses and stagnant waters were studied, where the aquatic phases of mosquitoes (larvae and pupae) breed, since flaviviruses are transmitted from the female to their eggs (vertical transmission) and This allowed us to analyze not only the adults but all the evolutionary stages of the mosquito, eggs, larvae and pupae. “Due to the complex logistics of taking traps and their batteries or dry ice more than 2,000 kilometers to collect adults, it was more feasible than collecting the larvae and pupae that were in the water, since in the north they breed all year round for the temperature” indicated the researcher.
After that, the identification of the species was carried out by the entomologist Christian González and they were grouped according to the species and geographical location. The mosquitoes were placed in tubes with a preservative of genetic material (DNA and RNA), and then they were taken to the laboratory more than 2,000 km away. There they were studied by two techniques: RT-PCR and RT-qPCR, with different primers, both methods to study the presence of virus RNA. The mosquito species studied were mostly of the Culex genus, which are the most abundant species in our country.
Although, the results showed that all the mosquitoes were negative for Flavivirus, this agrees with what happens in Chile, “we do not have cases of Dengue, nor Yellow Fever or endemic Zika in Chile, all the cases that come are from abroad, people who were to places where these diseases are present. So so far we are free of Flavivirus, however, a new threat emerges.
Aedes aegypti
Global warming, the migration of people to and from endemic places and the activities of commercial exchange with our neighboring countries favor the entry of mosquitoes that are more aggressive as is Aedes aegypti. “At the moment there is a health alert because they found this species in the Fifth Region, which could change this Flavivirus-free scenario,” the researcher mentions.
This mosquito was present in Chile until 1961, when, after the eradication campaign in the north, the product of existing Malaria (produced by another species of mosquito) led to its elimination. However, in 2002 it was detected on Easter Island and later in 2016 in the north of our country, “this mosquito is one of the most important vectors of serious diseases such as Dengue or yellow fever, mainly because it is anthropophilic, prefers to feed on human beings than on animals and because it is by nature more aggressive than the others”.
Currently, the Ministry of Health through the Zoonosis Unit maintains active surveillance of mosquitoes, however, it is unknown whether or not they have viruses inside, a matter of investigation that is still pending, mentions the Doctor in Biotechnology. Since, on Easter Island it is the only place where Flavivirus has been studied in Aedes aegypti, due to the outbreaks of Dengue and Zika. “I think it is important to have a flat and to know that at this moment we are free of Flavivirus, but we do not know what will happen tomorrow and for that there should be a public policy to implement mosquito surveillance through the molecular study of these vectors either through the Institute of Public Health or another body” Cancino emphasized.
The project will also be part of the Dissemination Book of 25 projects Fondecyt 2023. “I found it super interesting that you could see what is being done right now in this country about science, and that the book concentrates a lot of scientific research, that motivated me to participate. And of course, the need to disseminate the study and put these problems on the table, since outbreaks of this nature are complex for the population and for countries due to their rapid spread, something that neighboring countries like Argentina, That is why the situation of progress that Aedes aegypti has had in our country is so complex”, concluded the researcher.
You can review the research at: https://doi.org/10.1016/j.actatropica.2023.10692
