The Costa Rican government is launching the region’s first in-depth study into the mysterious epidemic of kidney failure which has claimed the lives of thousands of sugar cane workers in Central America.
Since it was first identified that high rates of kidney failure exist in the young, male, working populations along the Pacific coast of Central America, many theories have surfaced as to the root of the problem. Although prolonged dehydration is agreed upon in the scientific community as a likely candidate, many others have been proposed.
Some of the others include: exposure to pesticides, from the sugar cane work many of the afflicted participate in, consumption of a homemade liquor that is popular in the rural regions where the problem is most prevalent and chronic consumption of pain medications possibly linked to the aches and pains of a manual labor workforce. Genetics could also play a part, but researchers seem to agree that environmental factors are most likely to blame.
What the Costa Rican study hopes to draw is a more concrete link between one of the possible culprits, or a combination of several, and the affected population. Ray Wong, a health expert based in Liberia, which is directing the study, said other descriptive studies have been done in the region but no associative ones.
He said if everything goes as planned, the pilot study could begin as soon as late March, after it is approved by an ethics committee. It will be conducted through eight clinics in the Guanacaste region, where researchers have determined the biggest problem exists. Guanacaste in northwest Costa Rica is mostly a rural region where many participate in hard labor, especially harvesting of sugar cane.
According to Caja Costarricense de Seguro Social statistics, over the last several years the Guanacaste region has accounted for about 12 percent of the nation’s documented kidney failures while it only represents 6 percent of the countries population.
In other words, Wong said, that province is very high-risk in terms of a resident developing a chronic kidney disease.
Wong, himself a Caja physician, said the study will be conducted by doctors in each of the participating clinics who will survey patients with chronic kidney problems with a host
of labor and lifestyle related questions. For every person surveyed with a chronic kidney illness, two healthy patients
will also be surveyed. The healthy patients will be similar in age, sex, nationality and location, he said.
More than 800 people will be surveyed in total over about 10 months in total, Wong said, adding that he hopes the results will either determine a common thread among the sick or point researchers in the right direction for another study.
Roberto Castro, who works with the Ministerio de Salud and specializes in occupational health, said if conclusive evidence is found, the results could have a direct affect on workplace practices. Castro, also a physician, said he believes the problem
is most likely linked to chronic dehydration. He said the disease has been identified in laborers outside of the sugar cane industry such as construction, possibly ruling out the link to pesticides. Homemade alcohol consumption more commonly causes neurological effects, he added.
Castro described the kidney as a filter that needs to be purged frequently with an intake of water to remove the toxins. He said a laborer working in the sun can expel two kilograms or 4.4 pounds of water in a day, all which needs to be replaced promptly. Often it is not. He said sugar cane workers also frequently burn the fields before harvest, doubly exposing them to high temperatures inducing dehydration.
Weeks and years of this type of work can have a cumulative affect, he said.
Castro said concrete evidence may result in widespread mandatory changes in labor practices. In the example of chronic dehydration, he said it may mean outdoor work schedules will have to be altered with a mandatory break between 11 a.m. and 2 p.m. when the sun is the hottest. Fluids may be more readily available to employees and specific clothing to keep cool may be required, he said.
An analysis of global health data showed that from 2005 to 2009, kidney failure has killed more than 2,800 men a year in the region, according to the Center for Public Integrity, which first reported on the issue in December.
In Costa Rica, death from the disease is up 16 percent from 2005. In El Salvador and Nicaragua over the last two decades, the number of men dying from kidney disease has risen fivefold, according to the report. Now more men are dying from the ailment than from HIV/AIDS, diabetes and leukemia combined, the U.S.-based center added.