In 33 years of practice, Rio de Janeiro obstetrician and gynecologist Isabella Tartari Proenca has helped countless expectant mothers through the anxieties of pregnancy and childbirth. But ever since an exotic virus called Zika hit Brazil a few months ago, she's run out of assurances. "I get calls and text messages all day long," Tartari told me. "My patients are terrified."
Who could blame them? Since May, when the national health ministry confirmed the first cases of Zika virus, the mosquito- borne disease has swept the country, infecting at least half a million people. While most victims escape with a low-grade fever, skin rashes and achy joints, some dire complications have ensued. Suspected to be among them is microcephaly, a condition that leads to exceptionally small infant head size, which causes lasting neurological damage and can lead to death.
Zika has since spread across Latin America. By December 22, Brazilian authorities had confirmed 2,782 cases of microcephaly this year, a fivefold increase over the yearly average since 2010; 80 babies whose mothers tested positive for Zika were stillborn or died shortly after birth.
No one knows for sure if Zika causes microcephaly, nor how the virus attacks neurological tissue. And experts can only guess at how a sleeper disease that emerged in the forests of Uganda in 1947 and was known only for scattered outbreaks in the Pacific Islands since then ended up as an urban public health emergency halfway around the globe.
Dennis Fujita and Felipe Scassi of the Institute of Tropical Medicine of Sao Paulo think the virus might have arrived with athletes or fans during the 2014 World Cup, or possibly by way of South America's Pacific coast after an outbreak on Easter Island.
What's certain is that Brazil's response to the crisis came late and may already have fallen short. True, after the surge in microcephaly cases, President Dilma Rousseff declared a "war on the virus," deploying police and even the armed forces to join public health workers in a door-to-door mission to preach prevention and root out the disease.
As encouraging as that sounds, the pathogens are faster. Zika is only the latest epidemic transmitted by an old scourge: Aedes aegypti, a stripe-legged mosquito that not only flourishes in the steamy tropics but is also at home in cities.
A century ago, the panic was over yellow fever. But when a vaccine was found in the 1930s and the crisis passed, so did mosquito control. That cleared the way for dengue fever, an affliction that made the jump from Asia to the Americas in the 1980s and quickly spread on the wings of Aedes aegypti. Dengue is now a pandemic, with four separate strains contaminating 390 million people a year worldwide. Last decade, Brazil accounted for 60 per cent of infections, and the country has logged more than 5 million cases since 2010. After years of research, the first of several dengue vaccines under development has been cleared for marketing in Brazil, Mexico and the Philippines.
There is no vaccine for Zika and no known treatment, which leaves battling mosquitoes the only recourse. That's a war best fought in September and October, when milder weather makes bug control manageable. By December, with temperatures spiking and mosquitoes swarming, there is little to be done.
Until a few months ago, however, health authorities were distracted by another exotic newcomer from Africa called chikungunya, but that virus petered out. No one was ready for Zika.
Underestimating a threat, then scrambling when the crisis hits: It's a familiar script in Latin America, and exactly the sort of blind spot that emerging diseases love. "We've been fighting a losing battle with the mosquito for 30 years," said virologist Mauricio Nogueira. By the time the authorities were paying attention, Zika had become an epidemic. Throw in underfunded hospitals and faulty primary care, and a full-blown public health crisis was born.
Though Brazil has laudable disease-control protocols, the outbreak quickly overwhelmed government-run health services. Testing for Zika is a complex and painstaking process that only 16 government-controlled labs nationwide are currently authorised to perform. Others will soon join the fight, but first they must jump some regulatory hoops -- a sensible precaution against fly-by-night labs and opportunists -- in a regimen that can take six to 12 months. That's precious time in an emergency, said Jose Mauro Peralta, an infectious-disease expert at the Federal University of Rio de Janeiro.
And yet there is just so much government can do before a wily enemy. "This mosquito is a genius," said Sylvain Aldighieri, chief of epidemic alert and response at the Pan American Health Organisation. Aedes aegypti has adapted perfectly to contemporary urban life, he said: It likes dirty water or clean. It can breed in an old truck tire, a shantytown gutter, or in the bromeliads that garland the verandas of Rio's luxury high-rises.
That makes Zika a moving target. The only way to root out such a generalised health problem is to enlist the entire country. Brazil did that early last century, when it dispatched soldiers to forcibly vaccinate citizens against smallpox, provoking a "violent revolt." Authorities have struggled ever since with how to engage the urban masses in the face of a public health threat without trampling democracy. "Eliminating the mosquito is a cultural problem," said Nogueira. "People still wait for the state to take charge."
That same inertia has led Brazil to squander vital resources. Ask Gubio Soares, a Federal University of Bahia virologist who flagged some of the country's first cases of Zika but has since had to abandon his efforts to fight it. "I have no funding for Zika," he told me. "I've never been invited by any official to develop a research project."
And so Brazilians, who are already battling dengue, must also brace for what some are calling the "Zika summer." With a vaccine likely years away and mosquitoes proliferating, there's little option but to slather on bug repellent -- one of Isabella Tartari's patients bought 150 tubes -- and appeal to a higher authority.
"We are thinking of starting a prayer group," said Isabela Maia, who is five months pregnant. It can't hurt. - Bloomberg View