First it’s the asphalt and then the dirt roads, the weeds. From the top of the Canaán district you can get one of the best panoramic views of Tegucigalpa. The largest buildings are far away, but they are few; Closer: the tin roofs, the lush vegetation, the extravagant tree that colors the ground with its large orange flowers. Up to this point, information posters about the Wolbachia method, Doctors Without Borders’ new pilot project to curb dengue fever, have arrived at a post in one of the most complicated neighborhoods in the Honduran capital. EL PAÍS accompanied the organization in the release of thousands of mosquitoes in an important test to combat an epidemic that is breaking records in the region.
Dengue fever is bleeding America dry. In these months of 2023, the continent has already recorded the highest number of infections in the last five decades: more than 3.35 million. According to the Pan American Health Organization (PAHO), there are 1,567 deaths. More cases than ever have been recorded in Mexico, Bolivia, Peru and Brazil. In Argentina, the number of patients has increased 160-fold compared to all of 2022, already marking the deadliest outbreak in its history. Behind this health emergency is the Aedes aegypti, a mosquito that is extremely adaptable to humans.
It lives in stagnant water, but prefers clean water: it stays in pots, containers or garbage bags that form small pools when it rains, and breeds in wells. He is more attracted to the dark color and it is the female that bites. It has recognizable black and white legs and breeds outside but always returns indoors. It affects older adults and especially children, almost 50% of those who suffer from its bites are under 18 years of age, and many of its deaths also occur. With climate change and rising temperatures, it is adapting more and more and emerging in new places.
Volunteers catch mosquitoes in Sector 4 of the Canaán district. Monica González Islas
Aedes transmits the so-called arboviruses Dengue, Zika and Chikungunya, for which there is still no effective vaccine for the entire population. Therefore, given the uncontrolled spread of the disease, health engagement focused on preventing the bite of the mosquitoes that transmit the disease. This is where the release of these insects with Wolbachia comes into play. Honduras will be the first country in Central America and the second on the continent to deploy it, after Colombia. Although the method is not a magic wand and is more useful in combination with larvicides and household insecticides, it has opened a new front of hope.
The hatchery
There are hundreds of them and they become angry when the light is brought near them. They were locked in a boat with water, liver powder (typical fish food) and activated charcoal for ten days. They have evolved from tiny eggs and pupae into giant adult mosquitoes. Their Médecins Sans Frontières caregivers, Jocelyn, Fer and Alejandra, have been monitoring their growth since their arrival in refrigerators sent to them from their mother colony: the World Mosquito Program (WMP) biofactory in Medellín, Colombia.
In the insectarium that the medical organization built in Tegucigalpa, it smells like an aquarium and the temperature is 29 degrees, which suits them best. The workers put cotton candy on the top of the boats where they are trapped so they can feed, but the females want blood, they need it to reproduce. That’s why the girls sometimes stick their arm into the container to get dozens of small stitches. All for the success of the ambitious project that Doctors Without Borders is carrying out together with the National University of Honduras, the Ministry of Health and the WMP against one of the most resistant endemic diseases in the region.
Volunteers prepare some of the cans full of mosquitoes to distribute. Monica González Islas
Wolbachia is a bacterium that approximately 60% of all insects, from dragonflies to bees to butterflies, naturally possess. But not this mosquito. For more than 15 years, the WMP has been extracting Wolbachia from fruit flies and injecting it into the eggs of Aedes aegypti. The bacteria prevents the spread of dengue fever. The mosquito may have the disease, but it does not transmit it. The first modified mosquitoes were released in northern Australia more than 10 years ago and the area has already been declared “dengue-free”. It also worked in Indonesia, where the incidence fell by 77%. Doctors Without Borders call them “safe mosquitoes”: There are bites, but no fever, no muscle pain, no hospitals.
The next step in the plan is for mosquitoes with Wolbachia to breed with native mosquitoes. There are two options, explains the logistics manager of Doctors Without Borders, Stavros Dimopoulos: If the female has Wolbachia and the male doesn’t, the next generation also inherits the bacteria and cannot transmit dengue fever, if the male has Wolbachia and the female doesn’t: ” The eggs do not hatch or are too weak to become adult mosquitoes.” The population is not suppressed in order not to create an imbalance in the ecosystem, but rather it is replaced. “In locations with high breeding densities, up to 98% of mosquitoes can be reached with Wolbachia. But it takes a while: probably about three years to reach that percentage, but it can be sustained for a very long time,” explains Dimopoulos. Mathematical studies speak of 60 to 80 years with mosquitoes without dengue fever.
Larvae of the Aedes aegypti mosquito. Monica González Islas
Delivery of mosquitoes
It’s the first day and Héctor Espinosa is excited. He is 38 years old and has always traveled on his motorcycle, running errands in Tegucigalpa and transporting tourists or packages. On this Tuesday in August, at five in the morning, as the sun rises, the Honduran puts on his shin pads and crosses his backpack full of mosquito canisters. Each container has between 150 and 200 Aedes. He previously worked for Hugo or Pedidos Ya, the home food ordering applications in Honduras: “It’s like mosquito delivery,” he jokes, “but it will benefit my country.”
A supervisor and 10 motorcyclists will travel 250 routes over six months to rid the mosquitoes of Wolbachia. In total, they will release more than eight million, or 40,000, new mosquitoes every day. The distribution is taking place in El Manchen, an area north of Tegucigalpa that experienced one of the worst dengue outbreaks last year and usually records almost half of the cases in the entire capital. It covers 39 neighborhoods, from the border to the imposing US Embassy to the gang-controlled high districts. That same day, the delivery drivers encounter former Honduran President Carlos Flores walking his Yorkshire dog in the wealthy Lara district, and they set off early for La Fraternidad, one of the areas monitored by the gangs, “before “wake them up.” “get the boys up to speed” and make their work more difficult.
Around 90,000 people live in El Manchen. If all goes well, dengue cases in this region are expected to have declined by 85% to 95% by 2025; It is also likely to impact the Aedes population across the Central District, where MSF calculations indicate a 30 to 40 percent drop in cases. A revolution for an area where dengue fever has become another companion.
Isaac Martínez releases mosquitoes that carry the Wolbachia bacteria. Monica González Islas
All the residents of these colonies that América Futura interviewed have a severe case of dengue fever, either themselves or their families have suffered from it. A gang member’s mother was hospitalized a few weeks ago, she was rescued and is now watering her flowers again; Several family members of Wendy Espinal, a neighbor from Canaan, fell ill with the pimples at the same time a few days ago, and the girlfriend of Isaac Martínez, one of the delivery drivers for Doctors Without Borders, cannot get up because of the illness while driving the Suzuki and the Modified mosquitoes drive through the streets of Some: “I don’t see it as work, but as help for my community. And if it ends well for the country, because it would be something we have been fighting against our whole lives.”
“But they’re crazy, how are they supposed to release more mosquitoes?”
Sandra Espinal’s breath is unsteady as she winds her way up the hill in the fourth sector of the Canaán district. At 45 years old and with two long black braids, Sandra is the key element in the second part of the plan drawn up by humanitarian organizations, the government and the university to combat dengue. Without it, the chain falls apart.
In Tegucigalpa, like most Latin American capitals, there are many areas where cars do not pass. Eroded land where the path was created with machetes and clearing: nothing with wheels fits in there. So, in addition to distributing mosquitoes by motorcycle, MSF has come up with something they call “community liberation.” By January, they will place boats in the homes of residents of Manche so they can raise and release the Wolbachia mosquitoes themselves. This is easy to write and requires six months of work.
A woman and a girl walk through the Canaán district. Monica González Islas
“We went from house to house asking and explaining,” said Espinal, a leader in the La Estanzuela community. She enjoys the trust of her neighbors and is able to gain access to an area completely controlled by the gangs. Alicia Salazar’s first reaction to the project illustrates the sentiment: “Oh no, but these guys are crazy, how are they supposed to release more mosquitoes so they don’t come?” Sandra says she was shocked at first too: “People are scared and think that they will have a big cloud of mosquitoes that they can’t even see.” But we have already trained and understood the method.” To support the project, Doctors Without Borders conducted a population survey before the publications began : It achieved 93% approval.
Carmen Mendoza didn’t even go to the supermarket this morning to get a soda. He is waiting for the doctors and Lilian Carbajal, the organization’s health promoter, who told him about Wolbachia. Carmen assures that she was not afraid of the liberations, on the contrary: “I was always happy because it is like a herd, we can’t even sleep at night because of the mosquitoes.” His 15-year-old son was diagnosed with dengue fever Hospitalized for two weeks, he survived, but the fear has not gone away.
He has his place covered well because he knows it is a breeding ground for Aedes. In these neighborhoods, water only arrives for two hours on Mondays and Thursdays. For the rest of the week it must be kept in fountains, buckets or containers for washing and bathing. This is one reason why cases are increasing throughout the Manche area. Poverty, the high concentration of people, the proximity to the mountains and the normalization of symptoms are some others. Sandra Espinal’s granddaughter had dengue hemorrhagic fever. It took a while to get them to the hospital because they thought it was just a fever. “The doctors scolded us and said, ‘How is it possible that we waited until it came to this point?’ that the girl could die of dengue fever. I was six years old. Sometimes we don’t consider the risk involved. Because we looked at it as something that we have in our communities every day and we don’t try to fight it.” Until now.
Sandra Espinal with a boat full of “Aedes Aegypti”. Monica González Islas
Six health emergencies in a decade
Before publication, technicians at the National University of Honduras (UNAH) calculated that six out of 10 mosquitoes in the Manchen region were Aedes. Now the same drivers who release Wolbachia are responsible for the new catches so that this university’s Microbiology Institute can monitor how the bacteria are multiplying in populations. To do this, explains researcher Dennis Escobar, you have to do a PCR test on the mosquito. When they get to the lab, they liquefy it and use reagents to separate the DNA and analyze it to check if it contains Wolbachia. They will spend 18 months collecting samples. This monitoring is essential to verify the effectiveness of the project.
“It’s not about generating information that looks pretty on paper, but about making it very useful for authorities’ decision-making and thinking about being able to scale it up in the future and transfer this methodology to other places,” says Escobar, who points out that the government’s “operational capacity” to combat the disease has so far been limited. The aim, says the researcher, is that it can be part of the Ministry of Health’s package of options to combat dengue.
The coordinator of the Doctors Without Borders project, Edgard Boquín, explains that, in addition to the vulnerability of the medical infrastructure and the susceptibility to natural disasters, the organization chose Honduras from the entire region because there have been six health emergencies there since 2010 due to dengue fever. , the last one last year. One of the 2019 outbreaks left more than 100,000 cases and 180 deaths, in addition to collapsing hospitals.
“It was the moment when we said we had to do something different and sustainable,” explains the coordinator. Initiatives like these are neither immediate nor intended to control an outbreak, as the first results will be visible in a few months and they are also expensive. The organization has budgeted $1 million for the entire project (WMP’s modified mosquitoes alone cost $500,000). But they serve to relieve the burden on health systems that are overwhelmed with every emergency.
The organization and the experts defend the possibilities of repeating what they have just started, not only in other areas of Honduras, but also in other Latin American countries that are also gaining ground in the fight against dengue fever . The heavens open and the Supaya Basilica watches over the traffic of Tegucigalpa. Between the cars, 10 motorcyclists with red backpacks on their backs carry the bet against mosquitoes in the region.
The modified mosquitoes of the WMP. Monica González Islas