ON his way out the door, Dr. Eliseo Vargas, former executive president of Costa Rica’s Social Security System (Caja), announced the possibility of a looming health scare.Amid the controversy that precipitated his resignation last month – the low rent he pays for a luxury home owned by the financial manager of one of the Caja’s main suppliers (TT, April 23) – Vargas brought to light a study on one danger of pet feces.It involves a parasitic worm (Toxocara canis) that infects pets and propagates itself through its larvae in their feces. After a person ingests infected feces, the worm migrates toward the eyes and can provoke swelling and detachment of the retina – a condition doctors say is, in some cases, irreversible.CHILDREN are much more susceptible to the parasite than adults.According to Dr. Joaquín Martínez, director of the study, since 1996 there have been 40 cases of children in Costa Rican who contracted the disease. Of those, 80% have been left with poor vision, and in rare cases blindness, in one eye. It is not clear why the illness affects only one eye.Though perhaps difficult to believe, there are numerous ways for people to unwittingly ingest infected feces.For example, if an infected pet should defecate in a vegetable garden and the larvae mix with the soil, people could ingest them if they do not wash their vegetables well. Another example given by doctors is if dog feces in a park dry up and bits of it are caught in the wind, it could coat playgrounds and benches and areas where childrenmight put their hands.BEFORE resigning, Caja director Vargas made an urgent call for people to rid their pets of parasites by taking them to a veterinarian for shots and de-worming, and for parents and others to encourage children to wash their hands well before eating.Still, the problem may not be as drastic as it may seem. Dr. Martínez said although there are more cases of infection this year than other years in the study, it is not an epidemic and should not scare anyone.Dr. Gerardo Vicente, a veterinarian with the Ministry of Health’s Department of Human Environment Protection, pointed out there is a higher risk of dying after eating bad seafood than there is of contracting this parasite.“THE only way to get this disease is to eat poop,” Vicente said. “I’m not saying there’s no risk, just that there is a very low probability.”He added that dogs, because of their companionship, are much more beneficial than harmful to human beings.“You add the numbers of deaths and infections from any disease over a long time and you will get surprising results,” he said.Like Dr. Martínez, he stressed the disease is not an epidemic and should not scare anybody, since basic sanitation precautions are enough to avoid the problem.