By Wanessa Medina
Viral diseases that are transmitted by Aedes aegypti (mosquitoes), such as dengue and chikungunya, can cause a high temperature, muscle pain, intense joint pain, and hemorrhagic fever. This has been a persistent problem in Latin America for many years (more than 1.5 million cases in the last year in Brazil). Now, the situation is much worse than dengue because the Zika virus carrying Aedes has been linked with an alarming number of pregnant women delivering babies with microcephaly, a birth defect resulting in a small head and brain size. In Brazil alone there are approximately 4,000 suspected cases and 400 confirmed cases of microephaly among newborns. The World Health Organization (WHO) has declared the Zika virus a public health emergency.
The Zika virus was originally identified in Uganda in 1947 but for decades remained contained within a few African and Asian countries. Then in May 2015, it was recognized in northeastern Brazil, and since then, the number of cases has skyrocketed. Zika has exploded to over 20 countries of the world, potentially affecting four million people in the Americas in the next year. Recent outbreaks have also been recorded in Africa, the Americas, Asia, and the Pacific.
Ricardo Santaella Rosa, Ph.D., professor at the Faculty of Medicine in Faculdades Integradas Padre Albino and responsible for the ward of Infectious Diseases of the School Hospital Emílio Carlos, said that the Zika virus is diagnosed through polymerase chain reaction (PCR) and virus isolation from blood samples collected less than five days after the onset of symptoms. Diagnosis by serology can be difficult because the virus can cross-react with other flaviviruses, such as dengue, West Nile, and yellow fever. The viremic period in humans may be short, from the third to the fifth day after onset of symptoms. If genetic material is no longer present in the serum, the viruria (presence of virus in the urine) could last longer than viremia (presence of virus in the blood) and the Reverse RT-PCR detection of viral RNA in urine could be an alternative method.
The standard practices of mosquito control such as using insecticides, repellents, wearing long sleeves, and removing the standing water where mosquitoes breed, have not proved sufficient. In addition, there is a lack of population immunity, absence of rapid diagnostic test, vaccines, and treatments. The sense of urgency is heightened by the Olympics scheduled for August 2016 in Rio de Janiero. There is concern that some visitors will travel within regions of Brazil with the highest number of Zika cases (North and Northeast) thus increasing risk of exposure and contamination within other countries when visitors return home.
Considering the whole picture, the Brazilian government is in open combat with mosquitoes and promoted a “national mobilization day” (held on February, 13, 2016) where more than 200,000 military soldiers visited three million houses in order to prevent the mosquitoes spread. During visits, soldiers looked for standing water and other conditions that contribute to mosquito breeding and offered preventative techniques, such as adding detergent to water, to mitigate mosquito proliferation. Recently, WHO announced a breakthrough in cooperation between Brazil and the United States for the vaccine development against the Zika virus. Until then, significant action is needed to bring this international health crisis to an end.