After months of anticipation, the Zika virus has finally arrived to the continental U.S., with 15 non-travel cases being reported in Florida as of August 2. The virus is carried primarily by a species of mosquito called Aedes aegypti.
The Centers for Disease Control (CDC) issued its first-ever warning for within the U.S., urging pregnant women to avoid travel to a Miami neighborhood where the Zika investigation is centered.
CDC and the Florida Health Department recommended an aerial spraying program to cover a 10-square-mile area just north of downtown Miami. The state is spraying a chemical called Naled, which is an organophospate pesticide that causes severe skin and eye irritation; it also contains an inert ingredient called napthaline which is classified by the EPA as a “possible human carcinogen.”
When this chemical was recommended to be sprayed in Puerto Rico, protests erupted from residents concerned about their health and the environmental impacts. Organophosphate pesticides also devastate bee populations and other beneficial insects, which affects agriculture as well as ecosystem health.
Governments are often quick to pour chemicals into the environment as a first reaction, as it gives the appearance of “doing something” and enriches chemical companies who contribute to political campaigns. So, with 15 cases of Zika and sustained media fear-mongering, the first government-sponsored spraying program has begun in Florida.
According to the CDC, for most people the Zika virus causes mild symptoms of fever, rash, joint pain, red eyes, muscle pain and headache that last up to a week. Many patients don’t even know they have it, as it is like symptoms of other common sicknesses. Hospital visits are rare, and death very rare.
The bigger fear is the purported link between Zika virus in pregnant women and microcephaly in the baby. However, as we reported on July 2, the only country experiencing an abnormally high rate of microcephaly is Brazil, where doctors insist that a larvacide called pyriproxyfen could be a factor in microcephaly.
Colombia is also experiencing a Zika virus outbreak, but there is no connection between Zika virus and microcephaly in that country.
Of the nearly 12,000 pregnant women with clinical symptoms of Zika infections until March 28, no cases of microcephaly were reported as of May 2.
Five new cases of microcephaly with Zika infections were found prior to June 18 in Colombia; however, this is still consistent with the random co-occurrence of each of the separate conditions.
Back in Brazil, the expected “explosion” of cases where brain defects are linked to Zika virus has not occurred. Defying predictions, most of the cases have remained clustered in the northeast region, which has caused Brazil to open a probe into the possibility of co-factors such as other viruses or environmental factors.
The story of Zika-carrying mosquitoes gets even more interesting when we delve into history. And, perhaps unsurprisingly, the U.S. military is involved.
An investigation by Sarah Laskow at Atlas Obscura found that in the 1950s, the U.S. was seeking to weaponize the Aedes aegypti mosquito while Brazil and other Latin American countries were trying to eradicate it.
At Fort Detrick, the military’s biological weapons base in Maryland, in great secret, Army scientists were considering how fleas, grasshoppers, and mosquitoes might be deployed against the Communist threat. These insects were harder to protect against than gas— masks wouldn’t help. The threat they posed would last, as long as a population of insects remained alive. Plus, it would be very difficult to pin an insect-borne attack on the U.S.
Among these possible insect soldiers, A. aegypti was “the golden child,” writes Jeffrey A. Lockwood, in Six-Legged Soldiers, because the disease it carried, yellow fever was so terrible. The Army Chemical Corps, in a 1959 report, notes that yellow fever is “highly dangerous” and that “since 1900, one-third of patients have died.” There were parts of the Soviet Union that had never been exposed to the disease, which made them vulnerable, but which had the right climate to support mosquitoes. The Chemical Corps started to experiment with how a brigade of A. aegypti might be deployed and what sort of damage they might do.
Concerted efforts began around 1900 to tackle the deadly problem of yellow fever, which was afflicting American troops carrying out imperialistic adventures in the Caribbean. After discovering that the mosquito caused yellow fever, Americans led a successful eradication program in Cuba.
American scientists took their methods to Brazil, where Fred Soper – with the help of the authoritarian Brazilian regime – implemented a strict A. aegypti eradication program that succeeded in eight cities in northern Brazil.
In 1947, the year Zika was discovered, he had convinced enough people that eradication was possible that a consortium of American countries endorsed a plan to rid the entire hemisphere of the mosquito.
Most of the countries succeeded. By 1962, there were no A. aegypti to be found in 18 continental countries and a number of Caribbean islands. Only a few hold outs had failed to start programs to destroy these mosquitos. The one that made Soper the most frustrated was his own.
When the U.S. Public Health Service finally began A. aegypti eradication efforts in the Southeast to combat yellow fever, the military was simultaneously studying their use as biological weapons against Communist countries.
As part of this research, Army scientists had to see how quickly A. aegypti populations spread through populations, so they released hordes of mosquitoes (uninfected by yellow fever) in American cities like Savannah, Georgia and Avon Park, Florida.
They would load hundreds of thousands of mosquitos into planes and, later, helicopters, then drop them over the field and see how far they could spread.
The mosquitoes apparently performed well enough: By 1960, the Chemical Corps was producing 500,000 A. aegypti every month, rearing them on sugar water and blood and letting them lay their eggs on paper towels. Scientists had found they could infect a new generation of mosquitoes with yellow fever by mixing the virus in the solution in which the mosquito eggs grew. Hundreds of thousands of mosquitoes were not enough to start a real epidemic, though. The corps proposed constructing a facility in Arkansas that could produce 100 million A. aegypti mosquitoes each week.
Yellow fever was not so much of a problem in the U.S. as it was in tropical regions, and the same authoritarian methods employed in places like Brazil could not be applied in the United States. Funding and enthusiasm was also a problem, and it was becoming realized that true eradication was a pipe dream.
After being beaten back for a few decades, A. aegypti has now invaded more territory than it ever inhabited before. And scientists now say the species may be “more sophisticated, individually complex, and formidable than anyone imagined.”
Of course, we can’t blame the American military for the spread of the mosquito species largely responsible for the Zika virus and yellow fever, but the secret history tells us much about how these sorts of things are viewed by government.
Even as the world was battling against infectious disease, the military saw an opportunity to find more effective ways at killing people. And it used its own citizens as unknowing subjects for research.