In a year marked by the emergence of a new coronavirus, old acquaintances of Brazilians continued to wreak havoc: dengue, chikungunya, zika and yellow fever affected the health of hundreds of thousands of people across the country.
Data from the latest epidemiological bulletin from the Ministry of Health reveal that more than 979 thousand suspected cases of dengue in Brazil throughout 2020.
Other infectious diseases transmitted by mosquito bites also had relevant numbers: there were almost 80,000 notifications of chikungunya, about 7,000 of zika and 19 of yellow fever.
Scientists classify these four diseases as endemic. This means that they happen frequently and have been repeated for years in some specific regions of our continent.
But is it possible to predict new outbreaks and prevent the numbers of cases and deaths from skyrocketing?
This is the mission of a group of scientists spread over more than ten national and international institutions.
They have just launched an ambitious project, which will monitor the behavior of these viruses for the next five years.
From there, they intend to create models that will allow to anticipate future public health crises caused by these diseases.
A ‘Big Brother’ of biology
The research will take place in four places: São José do Rio Preto (SP), Manaus (AM) and in some regions of the Pantanal and Panama.
“They are places where there is a lot of transmission of diseases by mosquitoes and where we have laboratories and trained professionals to work with”, justifies virologist Dr. Maurício Lacerda Nogueira, professor at the São José do Rio Preto School of Medicine (Famerp) and one of the coordinators initiative.
OVER THE NEXT FIVE YEARS, SCIENTISTS WILL CONTINUOUSLY MONITOR THE FOUR CHARACTERS INVOLVED IN THE PROCESS OF AN EPIDEMIC: VIRUSES, MOSQUITOES, INTERMEDIATE ANIMALS AND HUMANS.
The proposal is, among other things, to carry out the genetic sequencing of the viruses that cause these diseases and to analyze the distribution and behavior of their transmitters: mosquitoes Aedes aegypti (which spreads dengue, zika and chikungunya in urban environments), Haemagogus e Sabethes (vectors of yellow fever in wild areas).
Another activity will be to monitor animals that may also be infected by these infectious agents, especially some species of monkeys.
Although they do not transmit the disease directly to people, the increase in cases among primates may mean the beginning of a new outbreak or an increased risk of transmission in transition areas between cities and forests.
“WE WILL ALSO COLLECT AND ANALYZE SAMPLES FROM PATIENTS WITH SUSPECTED CASES AND OBSERVE WHAT HAPPENS TO THOUSANDS OF PEOPLE WHO LIVE IN CERTAIN NEIGHBORHOODS OF THE FOUR STUDY CENTERS”, DETAILS VIROLOGIST LÍVIA SACCHETTO, POSTDOCTORAL FELLOW AT FAMERP.
In 2018, Brazil faced the worst yellow fever pandemic since 1942.
Practical (and immediate) effects
From the collection of so much information, scientists intend to create models that will allow to anticipate health crises before they even start.
Nogueira recalls that, between 2018 and 2019, the region of São José do Rio Preto, in the interior of São Paulo, faced a type 2 dengue epidemic – it is known that there are four different types of the virus that causes this disease, which circulate with more or less intensity periodically.
“WE WERE ABLE TO PREDICT THAT TYPE 2 DENGUE WOULD BECOME A PROBLEM SOON AND WE WERE ABLE TO NOTIFY THE AUTHORITIES IN TIME FOR SOME PREVENTIVE MEASURES TO BE TAKEN,” HE RECALLS.
With alerts of this type, it is possible to reinforce actions to combat Aedes aegypti, such as cleaning vacant lots and reservoirs of standing water that serve as breeding grounds for the mosquito.
In the case of yellow fever, for example, the appearance of the first cases among monkeys in a region may already be enough to reinforce vaccination campaigns to protect those who are still susceptible.
A second essential point of the project is the analysis of other viruses that are also transmitted by mosquitoes and are already circulating in Brazil and the Americas.
“VIRUSES HAVE BEEN IDENTIFIED IN THE COUNTRY AS THE MAYARO IT’S THE OROPOUCHE, WHICH CAN CAUSE FUTURE EPIDEMICS AND NEED TO BE STUDIED CLOSELY “, ADDS SACCHETTO.
To start the project, those responsible recently published a scientific article in which they discuss the main factors behind the emergence of the epidemics of dengue, zika, chikungunya and yellow fever.
According to the authors, there is no longer any doubt about the role of climate change and the destruction of native forests in aggravating this process.
“WE SEE HUGE INFESTATIONS OF AEDES, WHICH TAKE ADVANTAGE OF HOT TEMPERATURES TO REPRODUCE MORE EASILY”, EXPLAINS SACCHETTO.
In addition, many viruses are “quiet” within wild areas. But deforestation and the entry of human beings in these places means that the infectious agents end up “jumping” for our species, in a process similar to what happened with the coronavirus responsible for the current pandemic.
But scientists want to go beyond that basic knowledge and establish other ingredients that trigger the increase in infections from these mosquito-borne diseases.
“We want to look closely at larger events, such as population displacement or climatic phenomena such as El Niño and La Niña, to understand how they contribute to these epidemics”, glimpses Nogueira.
The research involves about ten national and international institutions. In addition to Famerp itself, other participants come from the National Institute for Research in the Amazon, the Federal University of Mato Grosso, the Federal University of Amazonas, the State University of New Mexico (USA), the Massachusetts Institute of Technology (MIT) and the Institute Gorgas Commemorative of Health Studies (Panama), among others.
The work is financed by the National Institutes of Health of the United States and has the support of the São Paulo Research Foundation (Fapesp).