San Salvador, El Salvador - It's 4am and hours yet till dawn, but the streets of Apopa are full of life: stalls peddle cheap sizzling pupusas (filled corn tortillas), schoolchildren travel in giggling groups, commuters gulp down hot coffee and buses teem with passengers.
"It's the gang violence," explains Sofia Alvarenga, our translator. "Everyone wants to get all their work done before the maras [gangs] wake up."
In El Salvador, even the start of the day is dictated by the gangs. In 2015, there were more than 6,600 homicides, making this small Central American nation the murder capital of the world. It remains to be seen whether this year will be just as deadly.
The capital San Salvador, of which Apopa is a municipality, is at the epicentre of the spiralling gang violence.
As we drive through the outskirts of the city, the police escort travelling with us receives a call for assistance from a local police station and disappears to help. Now, we wait at a busy petrol station in Apopa. The team of researchers I am joining for an Al Jazeera documentary aren't, however, interested in the gang violence.
They're investigating an epidemic that has failed to catch the eye of the mass media, something insidious that has killed an estimated 20,000 people in 10 years across Central America and accounts for more deaths in El Salvador and Nicaragua than Aids, leukemia and diabetes combined. It's something called "Mesoamerican Nephropathy", also known as CKDu, a chronic form of kidney disease whose cause the medical community is still trying to determine.
Entire family surnames are disappearing - mostly those of poor labourers working in the sugarcane fields, where we are now headed.
The police escort, organised by the sugar mill we're visiting, returns. It rides on ahead of the cars and buses carrying nurses, researchers and doctors investigating the scale of the problem. After a couple of hours travelling along dirt roads, we arrive at a vast sugarcane field in Los Almendros, 35km away.
|San Salvador is at the epicentre of spiralling gang violence in El Salvador, which has become the world's murder capital [Arwa Aburawa/Al Jazeera]|
The sugarcane cutters
The faint smell of caramel, putrid and sweet, hangs in the morning air. The dawn light is quickly disappearing and the sugarcane cutters work fast to outpace the rising heat and humidity. The damp clings to their backs and drips off their faces. The sugarcane is burned before it is cut and the silence of the fields is interrupted only by the sound of chopped cane falling and the rustling of the stalks.
Ermando de Jesus Hernandez, a 39-year-old father of three, swings his sharpened machete and another row of sugarcane falls to the ground with a loud thud. Between the tall stalks, small groups of mostly male sugarcane cutters appear and after a polite "Buenos Dias" they disappear again. By the end of the day, Hernandez's white long-sleeved cotton T-shirt and jeans will be covered with black ash and sweat. The sugarcane will be weighed and Hernandez paid accordingly - usually between $3 and $4 a day.
Hernandez first picked up a machete as a 14-year-old and has worked on and off in the fields, spending 12 years in total cutting sugarcane.
In the past year, however, the volume he cuts has decreased. He rests more than his fellow workers. His hands hurt, his legs are slow. Hernandez is one of the thousands of men suffering from CKDu.
When the team of researchers arrives, he lines up for the barrage of tests which includes blood, urine, blood pressure, weight and a qualitative questionnaire. He hopes that the news won't be bad, or, more accurately, that it won't be worse and reveal that his kidney function has further deteriorated.
He knows all too well how the disease kills. He has seen it take the lives of his father and younger brother, who was only 23 when he died. Now, another brother aged only 25 has fallen seriously ill. Bed-bound, he is cared for around the clock by their mother.
Hernandez, who is not part of any gang, isn't able to visit his mother and dying brother as they live in an area controlled by one of two major gangs. When I ask our police escort about visiting them without Hernandez, they say the area is incredibly dangerous and that they wouldn't be able to go in without serious back-up.
"She's suffered a lot," Hernandez says. "First with my father and now this. But that's how mothers are, they take care of the sick people. She took care of those who died and she keeps taking care of everyone else."
|Hernandez's younger brother died of CKDu when he was only 23 years old [Arwa Aburawa/Al Jazeera]|
Heat stress and heavy labour
With CKDu, it's rare to receive a diagnosis, and when it comes, it's usually already too late.
"When the patients come to our hospital they need dialysis; we don't have anything else to offer them," says Dr Ricardo Leiva, who heads up the nephrology department at Rosales General Hospital in San Salvador.
"We cannot reverse what has been done to the kidneys. What's going on there we don't actually know but I think we have to do some prevention and early detection."
For the researchers, prevention is key and the only way to do this is to find out what is behind this silent epidemic.
Ilana Weiss, a US-based researcher with La Isla Foundation, a small research NGO with offices in Nicaragua and the United States, has been working on this epidemic in El Salvador and Nicaragua. According to the Pan American Health Organization, Nicaragua has the highest mortality rate from kidney disease - among mostly agricultural labourers - in the Americas, with about 43 deaths per 100,000.
They are burning the same calories and using the same metabolic load as soldiers on multi-day operations or adventure marathon runners. Every day, without a break.
For almost two decades, everything from fertilisers, bacterial infection contracted by rats in the fields to the workers' unhealthy lifestyles and even their genes were suspected causes. But now, for the first time, there is a growing medical consensus that the harsh working conditions - the heavy labour and heat stress - are a major cause of this mysterious kidney disease.
Long hours of extremely physically challenging work in temperatures over 40C with little access to water cause acute kidney damage. Over time, this can develop into chronic kidney disease, which is fatal.
"They are burning the same calories and using the same metabolic load as soldiers on multi-day operations or adventure marathon runners. Every day, without a break," Weiss explains.
To test the heat stress and heavy labour theory, La Isla has been working closely with El Angel sugar mill in El Salvador to improve the working conditions of 300 sugarcane cutters.
El Angel was the only mill willing to cooperate with the researchers. Many other mill owners deny that there is a problem among their workers or deny that it has anything to do with the labour conditions.
Sugarcane cutters are not directly hired by the mill but are employed by subcontractors, which means that they aren't protected by the usual labour laws and mills don't see them as their responsibility.
|Sugarcane, which is burned before it is cut, lies at a field in Los Almendros [Arwa Aburawa/Al Jazeera]|
La Isla has introduced simple interventions, such as regular breaks, shaded tents for the workers to rest and water to help keep them hydrated. It's nothing ground-breaking. In fact, these are the basic labour conditions the US Federal Institute for Occupational Health and Safety advises for labourers working outdoors in heat.
If Weiss and the team, however, see a significant stabilisation in the workers' kidney function following the interventions, it means they have finally begun to crack the mystery of CKDu.
There are some researchers, including La Isla, who suspect that CKDu is in fact multifactorial, with pesticides and toxins affecting rehydration, but the research is ongoing and results are pending. For now, they are focused on strengthening the hypothesis that dehydration is the principal driver of the disease.
"I've had some preliminary results from last year which indicate that giving people water and rest and shade breaks during the work day could stabilise their kidney function," Weiss says. "But it's a small sample group so we're expanding this year from 45 to about 300 to see if we can see that effect in a larger group."
The results from the larger group, which includes Hernandez, have yet to come in, but the hope is that with real scientific proof of the cause and also simple steps to resolve it, the crisis will finally be taken seriously - not just by the mill owners and the medical community but also by civil rights groups.
And this could have implications for more than just the sugarcane workers of El Salvador. The researchers have observed a similar disease among rice farming communities in Sri Lanka and India, where labourers work in extreme heat. There have also been anecdotal reports of CKDu affecting workers in Egypt, Thailand, Ecuador, the US and even other sugarcane workers in Brazil.
It's predominantly affecting very poor, vulnerable populations so it may just be that nobody was asking the right questions and the right populations to determine whether or not this is a more widespread disease than previously thought," Weiss says.
"We don't know enough about it yet to know if it's the same disease for sure," Weiss adds. "But everywhere we look, we find something that resembles this kind of chronic kidney disease."
But these vulnerable communities are difficult for researchers to access and not everyone is willing to go looking for them. La Isla's team need to travel with a police escort and although they haven't had to deal with the gang violence directly, Weiss has seen dead bodies on the side of the road with bullets in their heads and admits that she anxiously checks every ravine they pass as that's where gangs usually dump their victims.
"We are isolated from the worst but these folks [sugarcane workers], they work in these brutal conditions and they go home to some of the worst gang violence," she explains.
"The police will also come to their neighbourhood and assume that all these young guys are in gangs and rough them up .... It's a tough place for these guys."
|Hernandez at his Los Almendros home with his wife Marie Elise and their oldest son Gustavo [Arwa Aburawa/Al Jazeera]|
No way out
It's around 3pm and Hernandez is back at his Los Almendros home with his two sons and wife after a tough day cutting sugarcane. His wife Marie Elise is shy and softly spoken and Hernandez listens closely as she explains how she copes when he is out of work because of his illness.
"I go out and sell water and make rice biscuits to sell. So I am able to give my kids food," she says. When asked how he feels listening to her talk about her struggle, Hernandez's voice breaks and he pauses for a moment.
"It makes me sad to hear what she feels when I get sick. I know that it's not easy for her. She's suffering with me, isn't she? Those nights that I feel pain and I keep her up because when my feet swell, they hurt me so much it feels like they're exploding."
"A lot of doctors have told me that I shouldn't work in the fields, but the problem is that if I stop working who's going to feed our children?" Hernandez asks.
For El Salvador's sugarcane workers, caught between the gang violence and chronic disease, life is hard and many see no way out.
Maria Elise and Hernandez are resigned to their situation but want their children to succeed through their studies so that they don't have to work in the fields. And researchers at La Isla Foundation hope to provide some answers to the men and women affected by CKDu, who are forced to pay the ultimate price to feed their families.
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Source: Al Jazeera