Zika virus outbreak — A Brazilian view
Diseases spread by mosquitoes aren't something quite new to warm and rainy tropical countries as Brazil. Especially those diseases witch it’s vector is a mosquito known as Aedes aegypti. Although the Aedes mosquito could be infected and spread different diseases (Yellow Fever, Dengue, Chikungunya and Zika), the main concern in Brazil was historically focuses on two of then— Yellow Fever and Dengue. Those conditions can be found in different areas in Brazil, whilst Yellow Fever is a problem related to country side and rainforest areas, Dengue is a urban problem, and both, without treatment, has moderate to high probability for complications and death.
Dengue has affected thousands of people in big cities as São Paulo and Rio de Janeiro and a several health campaigns has been made trying to control the causalities and the spread of Aedes mosquito. These efforts in the past few years have been succeeded to decrease the death toll and complications of Dengue (e.g. Hemorrhagic fever), but the mosquito have shown great capacity to adapt itself.
Yellow fever despite the possibility to be transmitted by the Aedes aegypti, the main vector of the disease is another mosquito. The greatest concern related to the Yellow Fever and Aedes is the back of urban transmission of the infection, which has been eliminated in Brazil since 1940’s. The Brazilian ministry of health has been able to control successfully the spread of Yellow Fever back into urban areas with large use of vaccine to people in (or traveling to) areas with high risk of infection.
The Brazilian seasons of high temperatures and increased volumes of rain along the great capacity to adapt have created the perfect scenario for the development and spreading of Aedes. This ends up creating a fertile territory for the rise of other infections as Chikungunya and Zika.
The initial Chikungunya infections has been detected for the first time in Brazil in 2014, causing concerns more about its complications than the acute infection itself. The acute Chikunguinya infection is less problematic than Dengue or Yellow Fever, and it’s really rare deaths or other serious complications for those acute infections. The major concern about the Chinkungunya disease is long term disabilities like chronicle joint pain.
With this scenario wasn’t a surprise when the first Zika infection has been detected in earlier 2015 in Brazil. Transmitted by the same vector as Dengue and Chikungunya, the Zika infection didn’t show at first any acute serious complication. The initial symptoms were flu-like and it’s been done in 3 to 7 days, while 80% of the infections remain asymptomatic. The surprise comes in late 2015 when an outbreak of neurological birth defects called microcephaly comes to affect newborns in the region of Brazil known as Nordeste. Blood and tissue samples taken from a deceased newborn from the state of Ceara has been capable to identify previous infections for Zika virus. Although the link isn’t total clear yet, several cases of microcephaly and Zika infection could been confirmed in pregnant women and newborns, raising great concerns to the general population and health authorities in Brazil.
Since the first report of the Zika virus in Brazil, it has spread to a number of countries in America and US, becoming a worldwide problem. The Brazilian ministry of Health started a wide campaign to fight Aedes mosquito, to get an early detection infection methods and suitable follow-up of child birth defects. The World Health Organization (WHO) released in February, 02 this year a Public Health Emergency of International Concern, recognizing the neurological syndromes associated with the Zika virus infection.
Until this day, there isn’t any treatment or vaccine available to avoid the Zika infection or prevent neurological outcomes in newborns. Our measures to control the spread of Aedes mosquito is quite inefficient, which means that even though we found a cure for Zika, Dengue or Chinkungunya infections, and successful managed their complications, we still susceptible to the rise of new infections transmitted by the Aedes mosquito.
