Ultimately, your health is dependent on the choices you make, and chief among these is what you put in your mouth. One longtime resident says staying healthy in the tropics is more than just possible—it is an “art form.”
As you master the art, expect your digestive system to take some time getting accustomed to the new food and microorganisms in the Nicaraguan diet. During this time (and after), use common sense: wash or sanitize your hands often. Eat food that is well cooked and still hot when served. Avoid dairy products if you’re not sure whether they are pasteurized. Be wary of uncooked foods, including ceviche and salads. Use the finger wag to turn down food from street vendors and be aware that pork carries the extra danger of trichinosis, not to mention a diet of garbage (and worse) on which most country pigs are raised.
Also, be aware of flies as transmitters of food-borne illness. Prevent flies from landing on your food, glass, or table setting. You’ll notice Nicaraguans are meticulous about this, and you should be too. If you have to leave the table, cover your food with a napkin or have someone else wave their hand over it slowly. You can fold your drinking straw over and put the mouth end into the neck of the bottle to prevent flies from landing on it, and put napkins on top of the bottle neck and your glass, too.
Have the waiter clear the table when you’ve finished with a dish—and beware the waiter who, in response to your complaints about the flies, comes back and douses you and your dinner in an aerosol cloud of pesticide.
Nicaragua  is located a scant 12 degrees of latitude north of the equator, so the sun’s rays strike the Earth’s surface at a more direct angle than in northern countries. The result is that you will burn faster and sweat up to twice as much as you are used to. Did we mention that you should drink lots of water?
Ideally, do like the majority of the locals do, and stay out of the sun between 10 a.m. and 2 p.m. It’s a great time to take a nap anyway. Use sunscreen of at least SPF 30, and wear a hat and pants. Should you overdo it in the sun, make sure to drink lots of fluids—that means water, not beer. Treat sunburns with aloe gel, or better yet—find a fresh sábila (aloe) plant to break open and rub over your skin.
While most Nicaraguan municipal water systems are well treated and safe (sometimes over-cholorinated), there is not much reason to take the chance, especially when purified, bottled water is widely available. But rather than contribute to the growing solid waste problem in Nicaragua, why not bring a single reusable plastic water bottle and refill it in your hotel lobby’s five-gallon purified water dispensers? If you are diligent about refilling, it is entirely possible to spend a week or more in Nicaragua drinking purified water without using a single plastic throwaway bottle.
If you’ll be spending time in rural Nicaragua, consider a small water filter or, alternately, use six drops of iodine (or three of bleach) in a liter of water; this will kill every organism that needs to be killed, good if you’re in a pinch, but not something you’ll find yourself practicing on a daily basis. Bringing water to a boil is also an effective means of purification.
Standard precautions include avoiding ice cubes unless you’re confident they were made with boiled or purified water (which they are in many restaurants). Canned and bottled drinks without ice, including beer, are safe, but should never be used as a substitute for water when trying to stay hydrated.
Probably the single most effective item you can carry in your medical kit are the packets of powdered salt and sugar known in Spanish as suero orál. One packet of suero mixed with a liter of water, drunk in small sips, is the best immediate treatment for all of the following: diarrhea, sun exposure, fever, infection, or hangovers. Rehydration salts are essential to your recovery as they replace the salts and minerals your body loses from sweating, vomiting, or urinating, thus aiding your body’s most basic cellular transfer functions.
Whether or not you like the taste (odds are you won’t), consuming enough suero and water is very often the difference between being just a little sick and feeling really, really awful (we know at least one expat who swears by the stuff for hangovers, too).
Sport drinks like Gatorade are super-concentrated suero mixtures and should be diluted at a ratio of three to one with water to make the most of the active ingredients. If you don’t, you’ll urinate out the majority of the electrolytes. Gatorade is common in most gas stations and supermarkets but suero packets are more widely available and much cheaper, available at any drugstore or health clinic for about $0.50 a packet.
It can be improvised even more cheaply, according to the following recipe: Mix one-half teaspoon of salt, one-half teaspoon baking soda, and four tablespoons of sugar in one quart of boiled or carbonated water. Drink a full glass of the stuff after each time you use the bathroom. Add a few drops of lemon to make it more palatable.