Twenty new viruses can enter Brazil during the Olympics, researchers say

About 20 new viruses transmitted by the Aedes aegypti can enter Brazil during the Olympics in August. Information came from the researchers Pedro Vasconcelos, director of the Evandro Chagas Institute, and Rodrigo Brindeiro, from the Department of Genetics and the Laboratory of Molecular Virology of the Federal University of Rio de Janeiro (UFRJ). They attended a session on the virus zika at Brazilian Academy of Sciences's Magna Meeting, which celebrated the centenary of the institution and was held at the Museum of Tomorrow, Rio de Janeiro, from 4 to 6 May.

Rodrigo Brindeiro; the Academic Helena Nader, who led the session on zika; and Pedro Vasconcelos

According to the researchers, the risk is that these new viruses enter the country through the tourists from around the world who come to Rio de Janeiro in the Olympics. "These are viruses that are circulating in Africa, Asia and Oceania," said Pedro Vasconcelos, explaining that probably was in this way that the virus zika arrived in Brazil during the Confederations Cup, held in 2013. At the time, there was a large outbreak of zika in French Polynesia, and one of the teams that participated in the competition was Tahiti - which was hosted in Recife, Pernambuco, just where the prevalence of the virus was one of the highest.

The zika is a type of arboviruses, those that are primarily transmitted by arthropods, such as mosquitoes. Some of them cause epidemics such as zika, dengue and chikungunya, and symptoms can range from a febrile syndrome and haemorrhagic fever to encephalitis and neurological problems such as microcephaly. However, often infections are asymptomatic. This is the case of zika: in about 80% of the cases, the infected have no symptoms.

This has influence on virus spread. Since many people are infected and do not know, the spread of the virus is facilitated. Therefore, the zika virus was detected in Brazil only in April 2015 and spread so rapidly across the country - in December, it was already present in 19 states and today it is in all of Brazil. The transmitter is the Aedes Aegypti mosquito, responsible for also transmitting dengue, chikungunya and yellow fever - which, after 30 years without epidemic, returned to spread through Angola and is spreading in the Democratic Republic of Congo, Kenya, Uganda and other African countries.

It was in February 2016 that, because of its relationship with microcephaly, the zika started to be considered an emergency issue. "An obscure virus has become global, causing many public health problems," said Vasconcelos. Furthermore, arbovirus has always been associated with the transmission vector, but in the case of zika it was observed unusual various transmission mechanisms, such as through semen, urine and saliva. "I believe it is happening much sexual transmission that we are not aware because the cases are asymptomatic." Vasconcelos added that the transmission of the virus has been detected even in cases of blood donation and organ transplantation.
"In the Americas, dengue took 20 years to spread, chikungunya took three years, and zika took only a year," pointed Vasconcelos. "And today, there are already reporting in more than 60 countries." The researcher also informed that it was made a few surveys that showed a greater likelihood that people with diabetes, lupus and other immune disorders develop more severe forms of zika. "That does not mean they will necessarily die, but that the occurrence of these forms is facilitated." Another worrying factor is that zika can cause very serious damage to the eyes, even leading to partial or total blindness.


Insecticide spraying, popularly known as "fumacê" [fogging] and normally used to combat the Aedes Aegypti, proved ineffective, said Vasconcelos. The individual use repellent also does not work. According to the researcher, the only effective solution to combat the spread of the virus is to destroy the breeding, which is very difficult. "We have to create measures to combat the breeding until the end of the Olympics, but we have problems with the entry of other viruses."

There is no vaccine against zika, but there are some experiments being made. One of the challenges is to produce vaccines and medicines that can be used by pregnant women. "We are developing two approaches vaccines. One is making mitigations in the sample of the virus inducing mutations, for general use in women of childbearing age. The other would have therapeutic function even for pregnant women after infection." 

Vasconcelos looked for the fact that you need to investigate what the zika can cause in the medium to long term. "We have seen deafness problems, blindness and heart problems. In the case of rubella, for example, it is known that in the long run, it causes type 1 diabetes."

Rodrigo Brindeiro, UFRJ, stressed that it is also necessary to investigate why this virus causes different conditions in each individual - it is asymptomatic in some people, causes skin fevers in other and severe neurological problems in some others, such as Guillain-Barré syndrome, a rare condition in which the immune system attacks cells of the peripheral nerves, and neonatal microcephaly.

In the case of microcephaly in newborns, Brindeiro reported that cases increased violently from 2015 until today, especially in the Northeast, and the frame should be the same in Rio de Janeiro shortly. "In metropolitan region of Rio de Janeiro, we already have a high number of people affected. The microcephaly has a number of possible causes: genetic disorders, chemical poisoning and drugs, maternal malnutrition and infection by viruses and bacteria."

The socio-demographic profile of mothers of infants with microcephaly shows that they are generally young age - 25 years old in average - and have a very low income. They are generally housewives. "Microcephaly is just the tip of the iceberg. Why, for example, it was not detected in Africa, Asia, Oceania?"

Brindeiro also informed that it has also been detected several cases of double infection. "It's a classic case: people who have had an apparent cure, and one or two months later, they returned with the same or aggravated frame. So, the reactivation of zika is possible? There is also a mess of syndromic diagnosis - often, we confuse zika with chikungunya." 

One possible medicine

Brindeiro said the researchers from his team are progressing in the production of medicines, especially for pregnant women. They managed to isolate the virus zika using chloroquine, a drug already used against malaria. Studies in the laboratory have shown that chloroquine was able to protect neurospheres, cellular structures that reproduce the brain in formation, up to 95%. "There is no contraindication for pregnant women," he celebrated.

The researcher recognized the urgency to develop drugs that can deal with the epidemic and stressed the country's potential in this sense: "Brazil has shown that even with little investment in research it was possible to progresse. Imagine, then, if there was investment, which we would be able to do?"

(Clarice Cudischevitch for NABC)

webTexto é um sistema online da Calepino