A Baffling Chronic Kidney Disease in El Salvador

Scientists have come up with a gallery of rogues to explain an epidemic of kidney disease in Central America. But the culprit has stayed one step ahead. Read the full article

A mysterious, chronic kidney disease in southern Mexico and Central America appears to preferentially affect young, male agricultural workers who repeatedly become dehydrated while working in the hot, humid fields. Sugar cane workers have been particularly affected in several countries. At this sugar cane cooperative near El Paisnal, El Salvador, workers start cutting at sunup to take advantage of the cool morning hours. [CREDIT: Malcolm Linton]
Cane cutters at this cooperative about an hour out of San Salvador stop cutting before noon, dodging the brutal afternoon sun. But other cane cutters work from sunup to almost sundown, and researchers worry that they may be particularly vulnerable to what public health officials are now calling chronic kidney disease of unknown etiology, or CKDu. [CREDIT: Malcolm Linton]
When nephrologist Ramón García Trabanino began working at San Salvador's Hospital Nacional Rosales as a medical student, the huge number of chronic kidney disease (CKD) patients startled him. So in 1999, he did a study and found that two-thirds of the patients did not have diabetes, hypertension, or any other common cause of CKD. Of those, 87% were men and most worked in agriculture. Today, he runs a San Salvador center for hemodialysis—which uses a machine to remove kidney wastes from the blood—that his father, also a nephrologist, started. [CREDIT: Malcolm Linton]
In 2002, García Trabanino published the first report about what's now called CKDu. (The "u" is for "unknown" origin.) At the time, he was convinced that pesticides sprayed on the fields were likely the main cause of the disease. But subsequent data, including a study that found CKDu was no more common in pesticide sprayers, has led him to conclude that pesticides play a minor, if any, role. [CREDIT: Malcolm Linton]
Carlos Orantes, a nephrologist at the National Institute of Health in San Salvador, conducted a large study into the cause of CKDu. Published in 2009, it did not find a convincing cause of the disease, but Orantes insists that pesticides are likely an important contributor—if not the main one—to the kidney damage. At this small cemetery in Jiquilisco, 10 of the interred died of CKD. [CREDIT: Malcolm Linton]
Julio Miranda (seated), a leader of a social fund for health emergencies in Tierra Blanca de Jiquilisco, noticed the increasing number of cases of CKD in his community in the 1990s. He contacted nephrologists Ramón García Trabanino (right) after reading a newspaper article about his 2002 study of CKDu. The two began a research collaboration that continues to this day to better understand why people like Carlos Ambrosia (left) develop CKDu. Miranda says he's "grateful" that the government finally is paying attention to CKDu, but he says it still must do more. "The problem is so big that the ministry of health doesn't have the capacity to appropriately respond," he says. "It needs a separate budget for this disease." [CREDIT: Malcolm Linton]
Carlos Ambrosia, 67, who worked in corn and cotton fields most his life, has CKDu that, despite drugs, has almost progressed to the point where he needs dialysis. He is unwilling to be treated. "How many people have gone for dialysis once or twice and died?" Ambrosia asks. "It's worthless." Later, walking away, Miranda says, "For many people here, dialysis is a symbol of death." [CREDIT: Malcolm Linton]
Wilfredo Ordõnez's modest but tidy and modern home stands out in Ciudad Romero, an agricultural village in the impoverished coastal region of El Salvador called Bajo Lempa. Built with help from a daughter living in the United States, the interior includes a clean room devoted to peritoneal dialysis for Ordõnez, who 3 years ago developed end-stage kidney disease. "I had no strength and was falling over before I started the dialysis," says Ordõnez, 50, who began working in the local corn fields when he was 7. "I'd spend all day in bed." The peritoneal dialysis removes the wastes his kidneys spill into his abdomen, but it carries a high risk of infection, which is why he keeps this space immaculate and, before each draining, scrubs and masks up like a surgeon. He does this four times each day. [CREDIT: Malcolm Linton]
At 15, Osmin Sorto started harvesting cotton and planting flags for crop dusters, but at 22 he landed a government job. In his early 30s, he realized he had CKDu, which steadily progressed to the point that his kidneys failed. Unlike most people with CKDu, he had health insurance that covered the cost of a kidney transplant, which he received in 2005. He’s doing fine today. [CREDIT: Malcolm Linton]
Zulma Cruz, a nephrologist at Hospital Nacional Rosales in San Salvador, noted that on this day, 23 people checked in at the emergency room with serious kidney problems. Her wards upstairs have 85 beds with people on peritoneal dialysis, and 90 more come in each day for hemodialysis. The hospital turns away most new patients seeking dialysis. Cruz sees only one way forward: Provide more transplants. "This is the principal hospital at the level of the ministry of health for kidney disease and we don’t have transplants," says Cruz, noting that they did only 11 last year. "In the long term, it would be less expensive to do transplants than dialysis and people would have a better quality of life." [CREDIT: Malcolm Linton]
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Read the the full article in the 11 April 2013 issue of Science
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