With scientific evidence demonstrating Zika's responsibility for the rise of microcephaly cases in hand, the Pernambuco government declared a state of public health emergency, taking the conventional actions regulated in the endemic dengue prevention program so as to wipe out the Aedes aegypti mosquito, a task the country has yet to finish despite two decades' efforts.

The government has admitted that it has been a formidable fight. Earlier this week, Brazilian Health Minister Marcelo Castro said the country was losing the battle.

Rio's authorities have been particularly alarmed by the statement, as the city, usually a hotspot for dengue, will receive hundreds of thousands of visitors during the upcoming Carnival and the Olympic Games set to open in August.

The anxiety over the spread of the Zika virus has become international after several Latin American countries reported hundreds of Zika cases.

The United States has reported its first microcephaly case related to the Zika virus. The mother of the infected baby has been to Latin America. Some countries have issued alerts warning pregnant women not to travel to Zika-affected regions.

Health authorities in several nations have launched research on the disease, hoping to find means to control the reproduction of the Aedes mosquito.