Zika, Mosquitos Outwit Brazil’s Rio as Carnival, Olympics Loom

The Brazilian government has shuttered hospitals and research laboratories because of lack of funds.

A health worker sprays insecticide to combat the Aedes aegypti mosquitoes that transmits the Zika virus in Rio de Janeiro, Brazil. (Photo: AP) 

As Rio de Janeiro prepares to welcome hundreds of thousands of visitors for upcoming Carnival festivities and the Olympic Games in August, the city is scrambling to expel one unwelcome new arrival: the Zika virus.

It will be an uphill battle.

Zika is causing a widening health scare across tropical and subtropical regions of the Americas, where it has spread to over 20 countries.

In Brazil, where the virus is believed to have arrived in the hemisphere before spreading via mosquitoes, it has been linked to a brain defect in nearly 4,000 newborns.

But even as authorities knock on doors to warn people about the virus and spray tourist sites and mosquito hotbeds with insecticide, public health officials see no easy solution because the area is rife with the insects that transmit Zika and there is no vaccine.

<p>We are losing the battle in a big way.&nbsp;</p>

<b>Marcelo Castro, Brazil’s health minister</b>

Castro announced plans to deploy 220,000 troops in February to distribute educational pamphlets and help scour cities for mosquito breeding grounds.

The illness is minor for most people except pregnant women and others affected by complications that scientists still struggle to understand.

Zika has become more widespread as the Aedes aegypti mosquito that transmits the virus by biting an infected person has migrated around the globe.

Governments and health agencies, including the World Health Organization and the U.S. Centers for Disease Control and Prevention, have cautioned pregnant women to consult physicians before they travel to affected countries.

U.S. health officials are stepping up efforts to study the link between Zika infections and birth defects in infants amid predictions for widespread circulation of the virus within the United States during warmer months.

The Zika virus is spread through mosquito bites from Aedes aegypti and the CDC is investigating whether it is also spread by Aedes albopictus. (Photo: AP)

The virus is expected to continue spreading apace because the Aedes aegypti mosquito is notoriously adaptive.

The insect thrives in puddles, nooks and crannies common in Rio and other tropical cities peppered with chaotic and unplanned neighborhoods, where rainwater, open sewers and litter offer ample habitat.

<p>It is the perfect set-up for proliferation. It can keep spreading until we find a way to contain the virus or keep the mosquitoes from transmitting it.</p>

<b>Isaac Bogoch, tropical infectious disease specialist at Toronto General Hospital</b>

Engaging Residents

Zika was first identified in Uganda in 1947 and has caused limited outbreaks ever since, most recently on Pacific islands in the last decade.

Officials believe it may have arrived in Brazil with a traveler when the country hosted the 2014 World Cup.

So little is known about Zika that the believed association with microcephaly, the brain defect in babies born to women thought to have carried the virus, was not hypothesized until the Pacific outbreak.

The link was only empirically tested when scientists began collecting amniotic samples from mothers of affected children in northeast Brazil last year.

A health worker pours insecticide into his tank sprayer. (Photo: AP)

Now, laboratories are rushing to produce a test that can identify the virus quickly in suspected patients and, more significantly, develop a vaccine, a process that scientists say will take years.

Meanwhile, doctors and public health administrators say the challenge is to get citizens engaged in the struggle against the mosquito.

Although authorities have sought to educate locals about the dangers of stagnant water, dengue has worsened in recent years. Last year, Rio registered 10 times as many cases as in 2014, including at least 22 deaths.

The outbreaks come at a time when Rio’s state government, strapped for cash because of plummeting royalties from offshore oil fields, has been forced to shutter hospitals and research laboratories.