Intestinal parasites are my companion in Costa Rica. Every six months or so I make a trip to the pharmacy and ask for pastillas antiparasiticos. The most common over-the-counter pill is the anti-protozoal agent Nitazoxanide: two pills a day for three days to treat an array of intestinal parasites. The pills scour your digestive system, wiping out nematodes, cestodes, and helminths, as well as various protozoa with exotic names such as Cryptosporidium parvum, Giardia lamblia, and Entamoeba histolytica.
My body always lets me know when it is time for a treatment. The first sign is a growling stomach within a half hour of finishing a meal. Next comes fatigue, dull headaches, and irregular sleep patterns. My auto-diagnosis is made official the first time I sprint to the bathroom for a total diarrheic bowel evacuation soon after eating. Finally comes an errand to town to buy the magic pills that bring relief. Right now I am halfway through the dosage and my digestive system is settling back to normal.

Over thirty years ago, I had emergency surgery in the Pérez Zeledón hospital to remove an ulcerating parasite from my intestines. I had been sick off and on for the previous month, but it was not until the pain in my gut rendered me almost immobile that I went to the hospital. Had I waited another day I might have died. Within a few hours of admission, doctors sliced me open and extracted the offending two-inch by five-inch parasite.
The explanation was a complicated cycle that included rats, slugs, feces, flies, and bad luck. The flies deposited microscopic larvae on unrefrigerated and unwashed fruits or vegetables, which then passed into my digestive system when eaten. It lodged in my intestines, gradually growing until it had to be surgically removed. Since then, I have religiously washed fruits and vegetables before consuming them as part of an overall program of monitoring my gut health.
These maladies seem common only to people not originally from Costa Rica. My three adult kids, all born and raised here, have never had this issue. Nor has my Tica wife, nor any of her family, nor anyone else I know, save a few other gringos. For me it is like clockwork. Every half year, just when the thought of intestinal parasites has vanished from my mind, they return. And every half year, I return to the pharmacist and give thanks to science and medicine for providing the cure.





