Bugged Page 9
As with DDT, mutations in malaria-resistant mosquitoes may occur within the gene drive over time. However, I wonder if such genetically modified (GM) Anopheles could be released periodically should malaria cases rise again.
It’s not pure conjecture. One England-based company has stirred the gene pools in the Cayman Islands since 2010, reducing the population of harmful mosquitoes by 96 percent. Oxitec labs breed GM males of Walter Reed’s favorite: A. aegypti. These males produce sterile progeny. Even better, the population suppression can be reversed if needed by stopping the release of GM mosquitoes over a long period of time. Why anyone would want such a thing, after considering the facts about GM mosquitoes, is hard to say. Yet Oxitec’s proposal to release their mosquitoes in the United States has come under fire within the past decade, sparking controversy and debate—specifically in the prospective release zone of Key Haven, Florida. At the time of this writing, Oxitec awaits FDA approval to run a trial in areas prone to a dengue and Zika outbreak.
Fortunately, after a couple of e-mail exchanges with Oxitec scientists (read: persistent nagging), I was able to arrange a firsthand look at their “elegant approach” of combating A. aegypti in the city of Piracicaba in São Paulo state.3
* * *
It’s 6:30 a.m. at the São Paulo airport, and the woman at the rental car company has a mascara-smudged, hungover gaze. Bits of her leopard-print dress poke out from beneath her red Avis business suit as though she were a club-going Superwoman ready to dance in a heartbeat (or bass beat). She sits in a kiosk eating cubes of wet cheese from a container, repeatedly reminding me I didn’t buy insurance. Part of me foolishly disregards this, and I chalk it up to my nonexistent Portuguese tongue and our conversation becoming lost in translation.
Part of me is also beat from the nine-hour flight. As I was landing, a clear view of the green mountains surrounding São Paulo appeared from the clouds. A blanket of fog smothering the slopes reminded me of the chemical plumes used to kill mosquitoes here—a crude method that is gradually being replaced by the twenty-first-century innovation I’ve come to see.
I drive onto the BR-116 federal highway. Traffic in Brazil operates with the same gusto as their spoken language: full of ardent rhythm. A calvary of mopeds buzz by with quickened beeps as they cut through lanes. Tiny cars merge with zipper-teeth precision. And part of me really hopes the Avis woman was wrong as I come to an abrupt halt to avoid being pancaked by two commuter buses. What really catches my attention, though, is the Tietê River running along the highway. As Brazil’s most polluted river, it features Styrofoam cups, Carrefour grocery bags, and slums directly on the riverbanks, their detritus scattered about. All of it makes for a cozy home for Aedes aegypti. Deforestation and elimination of would-be breeding grounds exacerbates issues with dengue and Zika viruses (which causes brain abnormalities in fetuses). During the first half of 2015, 760,000 confirmed cases of dengue fever were reported by the Brazilian Ministry of Health. Over 200 people died. Reported cases tripled in São Paulo alone in the course of a year, and this was before Zika outbreaks hit hard in 2015.
“When I first came here, I was a little surprised to see dengue on the television,” says Glen Slade, Oxitec’s head of business development. He oversees the Campinas subsidiary in their Brazil office. A Brit, Slade’s visibly pleased with the 85-degree weather. “You’ll see TV adverts at night asking not to leave water in your flower pots, trays…” he goes on. Currently it’s the dry season. But in a month, the rains will come, followed by a high concentration of mosquitoes.
“We are substituting quite a large scale of chemicals in Brazil designed to kill mosquitoes,” Slade says about Oxitec. After several trial releases, aside from the ones on the Cayman Islands, the substitution of using their GM mosquitoes, aka OX513A, has proven effective. Exhibit A: the Iterberaba neighborhood of Juazerio, Brazil, home to 908 residents. Working with the University of São Paulo, OX513A helped suppress A. aegypti within 13 acres by 94 percent from May 2011 to October 2012. Exhibit B: Jacobina, Brazil. Starting in July 2013, their “organic product” reduced the dengue vector by 92 percent. And now Exhibit C: Piracicaba, a city only an hour’s drive away from their offices here in Campinas where they’ve been releasing about 800,000 GM male mosquitoes a week. Annually, that’s about 40 million.
Cast ye fears aside, GMO watchdogs. Not only has the National Biosafety Committee in Brazil approved the use of OX513A, but the UK’s House of Lords has reported GM mosquitoes could “save countless lives worldwide.” What’s unique about the trial is that Oxitec is working directly with the Piracicaba municipality rather than third parties. This makes fine-tuning processes in treating the tiny Piracicaban neighborhood of 5,000 residents more concise. (The residents all receive door-to-door counseling on the mosquito do bem. In Portuguese, that translates to “the good mosquito.”) Later Oxitec will expand to producing hundreds of millions of OX513A to combat dengue fever, which endangers 40 percent of the world, as well as the explosive outbreak of Zika virus.
OX513A is the brainchild of chief scientist Luke Alphey. What sets it apart are two altered genes in A. aegypti males. Remember, they don’t bite. Rather than hitting these delicate, mustachioed bugs with radiation via the decades-old sterilized-insect technique, Alphey needed to keep their physical endurance intact enough to compete with wild males while breeding. So he developed a “lethal system” specific to males. One autocidal gene ensures the progeny have a decreased life span. To keep the lab-bred males alive long enough to mate with females, this gene is subdued by an antibiotic.
“When we add tetracycline, it turns the gene off,” Karla Tepedino tells me. As Oxitec’s Brazil production and field trial supervisor, she oversees the factory line here from egg to promiscuous adulthood. She’s in her mid-twenties and wears stylish earlobe plugs, and the job has fortified her patience. “Someone always brings up Jurassic Park,” she says, hands in the air, dumbfounded. Campfire theorists argue that Oxitec mosquitoes—despite being largely unchanged for millions of years—could rapidly evolve to carry the most potent strain of the dengue virus. “Why do you think we’re going to be capable of such a thing?” Karla asks. This is frustratingly accompanied by GMO jabs and people accusing her and Oxitec of “playing god.”
Genetic clock ticking, Alphey needed a marker to enable Oxitec to track their success from OX513A eggs collected in the wild. Hence the fluorescent dotted pattern, detectable under a microscope, in their larval progeny. “It’s a shame they don’t fluoresce naturally,” says Karla, who has a plushy mosquito doll on her desk. “It would be so nice to have fluorescent mosquitoes flying around.” Although these two genes are altered in their chromosomes back in the UK, OX513A must be bred locally in a controlled setting here in Campinas.
A biohazard sign on the containment room’s glass door reads: Proibida a entrada de pesos não autorizadas. Karla Tepedino keys me in. She asks that I run my shoes through the bootie dispenser—a fun little machine you drag your foot through to wrap in blue sterile fabric (and one I’d like to cleverly reengineer back home for my socks). Like the Rearing Room back in Colorado, this sample-sized “mosquito factory” has that familiar buggy scent tied to such places. Karla pins the smell to the fish food used to feed mosquito larvae.4
My guide takes me through rows of white cages with screen-door meshes. This is where the process begins. Close inspection of cage C28 reveals a 3:1 female to male ratio of 16,000 mosquitoes. Lamb blood, served in these penetrable thin discs no larger than a Big Gulp lid, is slid into the cages to quench the females’ thirst, while a sugar-saturated rod feeds the males. Eggs are laid in the bottom of the cage on thin strips of paper. Karla shows me a clear container labeled Ovos OX513A with approximately 3.3 million black eggs that have been collected from the paper strips. Dried, they resemble gunpowder and feel as potentially dangerous when ignited by water—were they not GM. In this dried condition, eggs can survive for up to a year. Next, about 10,000 of them go into water trays and hatch into floating
larvae, basically two squint eyes with a tail. Each white tray is diluted with tetracycline to ensure survival and is slid into a baker’s sheet pan rack to incubate at 81 degrees. In oddly sentimental ways, the process of manufacturing mosquitoes felt comparable to my early days as a pizza boy: leavening larvae in trays, prepping orders for delivery.
Karla leads me through the dough racks pillared across the room to a larvae siphon. Here the litter pass through what looks like a closed folding gate allowing males—who pupate after eight days—to rise to the surface. The main function of this factory line is to separate the females. “The first part of the process is to pass them through an LPS.” This stands for larvae-pupae separator.5 “Ta-da!” she says, demoing the device. “Just like a sieve. Once we are happy with that, we take them here.” She presents a white bin labeled “LOT 193.” The mosquitoes have graduated from grains of sand to BB shots with kicking tails, kind of like plump bass clefs. “They’re sensitive to light,” she says as she waves her hand over them. Her shadow scatters pupae from the surface. I give this a try. Their tiny, scurrying splashes feel like soda fizz on my palm.
She illustrates their size difference with two hand-sized trays. Though it’s minute, the females are arguably larger because of the eggs they store. She asks me to guess which are males. “Is there a difference or not?” she asks, testing as a college professor would.
“I’d say these guys are smaller.” I point to the wimpy lads.
“Yes. For me, it’s evident.”
But the possibility remains that smaller females sneak by. That’s where the individual checkers come in. After sieving out pupae once more, a line of eight people sitting at a metal bench use a light microscope to count the pupae with a fine paintbrush in one hand and a tally counter in the other. Clck-clck-clck … One lady goes through them rapidly. The room is full of this sound with intermittent zaps from electric flyswatters. Sample sizes of each batch are checked here. If they have over 2 females per every 1,000 males, they toss the batch and recalibrate their instruments. Finally, the pupae go into pots. Once the pupae grow into adults, workers drain the water and hundreds of thousands of male mosquitoes are stored for two to three days prior to release. We visit the holding room. OX513A float in the clear plastic containers, weightless as black dandelion seeds. “The nicest part,” Karla says, smiling, “is the sound.” It’s a faint, ninja-like buzz. As steady, calm, and resolute as a stove hissing natural gas.
* * *
The next day, Guilherme Trivellato, Oxitec supervisor and mosquito delivery man, wakes up at 4:30 a.m. to feed his chickens. It’s less about quirk than his biologist virtuosity—and fresh eggs. Like Karla, he’s also young and personable with a lambent wit. By the time his helpers load 500 buckets of mosquitoes into a high-roof cargo van at Oxitec, it’s 6:00 a.m., and he’s brewing a pot of jolting coffee for him and me—“ugh, too strong”—that we both dilute with water. We’re in the building’s second story. The empty offices are gray in what light comes from the dingy fluorescent tubes overhead. I sit with Guilherme, sipping my coffee at a round table. From a nearby window I can see the van running idle in the driveway.
“We used to release in a pickup truck for a smaller project,” says Guilherme. But scaling up Oxitec to treat a city for dengue and Zika will require a fleet of sturdy vans. So the cargo van has undergone a bit of MacGyver-ing. Vacuum hoses rigged to the dashboard’s A/C vents run along the roof to the van’s back to build air pressure. Aimed through the side window, like a miniature cannon, is a plastic tube. Attached to it with packing tape is an O-mouthed Dyson fan. When Guilherme does his thrice-weekly releases, an assistant sits in the back emptying the mosquitoes through the tube to execute swift mosquito drive-bys.
Jerry-rigged as the process may sound, Guilherme has refined it over time. Oxitec employees in the UK are developing an automatic release system. “But I like the feeling of doing it by hand,” he tells me. He began working in Campinas in the fall of 2013 when their warehouse “workforce” comprised himself, “a plastic table, and a cell phone.” Located within the business center, called Technopark, is a branch of Monsanto.
“It’s complicated for us because what we do is completely opposed to what Monsanto does,” Guilherme says. “It’s genetic modification, but the aim and goal and the technique is completely different.”
The van is already on its way to the village; otherwise, the mosquitoes will suffer in their buckets, as Piracicaba gets particularly hot. Daylight begins to break as Guilherme and I catch up to the other Oxitec employees. On the highway, looking out his car window, I take in the saturated green of Brazil. Along the roadsides are termite colony mounds as well as mountainous heaps of rust-colored junk and tires. It reminds me of my view of the river when I first arrived in São Paulo. “That has to be a perfect spot for mosquitoes,” I tell Guilherme.
“I would love to work in a place like that,” he says, excited by the thought. “How can you spray pesticide if the mosquitoes are a few meters underneath the pile of tires?” He sighs. “It’s complicated. The public administration say it’s the fault of the people who dump garbage everywhere, and it’s true. And the population said that the city hall doesn’t take care of a proper place to put the garbage. Well, that’s also true. So, it’s throwing the fault to each other, and that doesn’t solve anything.”
There’s personal investment at play in Piracicaba. This is, I learn, the city Guilherme lived in for 10 years while studying at the university. He contracted dengue fever in 2011. “You feel nauseous when you try to drink anything,” he recalls. “Pain in your joints … And there’s nothing you can do. It’s quite frustrating.” Everyone I spoke to, including my Couchsurfing host’s brother, either fell ill with dengue fever or was one degree away from someone who did. When we drive into the city’s Cecap barrio and visit its health center, I ask the head nurse how frequently she sees cases during the peak season. Guilherme translates for us, but even with my rubbish Portuguese I do pick up: “Seis pessoas por dia.” That is: “Six people per day.”
As we drive, a pair of barking, grungy street dogs follows us. An older man leans on a lamppost, his rounded gut jutting from a tucked-in shirt. Guilherme lightly honks twice at him and waves. “I know everybody here in the neighborhood,” he laughs. “He’s the most boring guy.” Someone dumps gray water from their balcony onto the sidewalk. “The city is growing a lot. And it’s good to have options.” He points toward the drug deal we see under way in broad daylight. “If you want to have some crack stones,” he jests, “feel free. Have a cachaça6 at seven a.m.? Go ahead.” We follow the trail of the Oxitec van that arrived ahead of us, zigzagging through Cecap. My host parks the car. His timing is perfect as we see the van of Oxitec employees driving down the quiet street. Just as they pass, the on-flying things launch from the van and encircle me in cloud formation before dispersing. The release ratio is ten OX513A for every wild A. aegypti. To monitor their success, Oxitec employees place ovitraps—water buckets with fibrous wood paddles—throughout the trial zones; this is where eggs are laid. Guilherme points to an ovitrap shaded by a recessed wall. Later a biologist will collect it and stick the eggs under a fluorescence microscope to verify that their altered genes are passed to their now-sterile progeny.
Guilherme and I hop in the van. After watching mosquito emancipator Augustus’s technique, I’m mentally prepared to take the helm. An AlpineQuest app, opened on a tablet before me, has a GPS map outlining their release points with little dots as if we’re playing PAC-MAN. Area F was rather dense with delivery blips, so Guilherme’s having me take over for Area E as he drives 6 mph through the quiet village street.
“Fasten your seat belt,” I’m told, to which I lift a brow, but comply. “Pay attention…” Guilherme’s voice trails. “We are beginning … now.”
A single beep on the map signifies we’ve entered a release spot. I quickly grab one of the stacked to-go soup containers filled with buzzing males. I rap it on the table, open the lid, and
a black-and-white polka-dotted fleet of engineered mutants launch from the tubular airstrip. “Don’t worry about tapping hard to get them all out,” Guilherme advises about emptying the containers. I give one the ol’ “Shave and a Haircut” knock in the tube and OX513A pour out. We continue through Area E for a few minutes, releasing more buckets. Looking through the Dyson fan’s porthole, I can briefly make out a billowy squadron of bugs on a mission to save humanity.
Months after my visit, just before outbreak season, Oxitec and Piracicaba officials reported an 82 percent reduction of A. aegypti. Dengue cases dropped by 91 percent. And officials planned to expand Oxitec to a factory compound and hire an additional 100 hands. With a new facility and greater manpower, the company can target larger areas. Next up is a city with a population density of 300,000. What’s more, the National Health Surveillance Agency of Brazil has now temporarily permitted the company to release OX513A throughout the entire country to combat the burgeoning outbreak of Zika virus.