As summer vacation nears, thousands of central Ohioans are planning a trip to an exotic locale -- perhaps to Brazil for the Summer Olympics.

As summer vacation nears, thousands of central Ohioans are planning a trip to an exotic locale -- perhaps to Brazil for the Summer Olympics.

Some doctors warn, however, there are more than sandy beaches, crystal blue waters and margaritas waiting for you: Dangerous parasites, viruses and bacteria can ruin your vacation -- or worse.

As the recent Ebola and Zika virus scares made international headlines, simple pathogens, such as dysentery and traveler's diarrhea, await some travelers.

Many communicable diseases are preventable, however, with the right medication and precautionary measures, said Dr. Ronald J. Bloomfield of the Travel & Immigration Clinic in Upper Arlington.

"Ninety percent of this is education and prevention, not shots," Bloomfield said. "The analogy we use is: Wear your seatbelt."

He breaks it down this way: A 60-year-old woman who's on several prescription medications and traveling to Delhi, India, has a different set of health risks than a 27-year-old male whose friends are planning a bachelor party in Bangkok.

Each client at the Travel & Immigration Clinic goes through a personal checklist to evaluate his or her physical condition, current list of medications and travel schedule.

Most clients should seek -- at minimum -- shots for influenza; childhood diseases such as tetanus, pertussis and diphtheria, which come in one immunization; and hepatitis A, which is transmitted through contaminated food and water.

Cipro and doxycycline, two types of antibiotics, are suggested for traveler's diarrhea, common among those who brave the local tap water when abroad.

Dr. Mary DiOrio, medical director for the state of Ohio, said travelers should plan to get their immunizations at least two weeks ahead of time because they take 10 to 14 days to be effective. Some, such as inoculations against hepatitis B, require multiple shots.

Microscopic hazards are one thing, but other dangers exist.

Jan Walker, a nurse at Bloomfield's clinic, said a group of videographers were traveling deep into the rainforest for a work project with only 24 hours advance notice.

Walker asked them what they planned to do in case they were bitten by poisonous snakes or spiders, since medical treatment could be hours away.

"I think they thought they were too cool to get bitten," she said, adding she never heard back from them.

The recommendation: Map out your medical treatment in much the same way you map out a trip. Insurers generally don't cover travel immunizations because they are considered elective. So travelers could pay $200 to $400 (sometimes more) for a full range of shots and oral medication.

They should also look into short-term traveler's insurance because some policies only cover routine treatment in other countries. Hospitals in other countries, meanwhile, require payment up front.

IMG, based in Indianapolis, is one company that offers international medical insurance.

Adam Hirschfeld, general counsel for the company, said policies vary widely based on the client's age and duration of the trip.

A typical policy for a 30- to 39-year-old traveling for a month abroad is $65 with a $250 deductible.

"You don't have to navigate the healthcare system outside of the United States of America," Hirschfeld said. "That's what we do."

The U.S. only has one required immunization -- for yellow fever -- for those traveling to countries in South America and the central belt of Africa, said Greg Stanek, co-owner of Travel Health Services in Dublin.

Otherwise, people are only required to follow their instincts, Stanek said.

That could mean a false sense of security, he said. Staying at a resort doesn't necessarily offer protection against infectious diseases; mosquitoes, for example, can live in the city as well as rural areas and the rainforest, he said.

Stanek's wife, Suzanne, a nurse practitioner who administers the immunizations, said people need to understand that not only are cultures different in other countries, so are immune systems.

In other words, people in Mexico have built up immunities to common health threats in their country, but not elsewhere.

So, when immigrants come to live in the United States, they become acclimated to the health climate in the U.S. When they go back to visit family and friends, they run the risk of getting diseases from things for which they had previously built up an immunity, so they too should seek advice before traveling.

It is nearly impossible to protect against everything, so travelers should always be cautious, Stanek says.

For example, there is no immunization or cure for Ebola; the only treatment is supportive care.

Rabies, nature's deadliest virus spread by the saliva of an infected animal, is found on all continents except Antarctica and kills tens of thousands of people a year in some countries.

Travelers, therefore, are admonished about approaching strange animals, which can transmit the disease, even if they seem to be acting ordinary.

The threat of Zika, which continues to spread across tropical climates, and other diseases spread by mosquitoes can be minimized if people follow a few simple rules: Wear long sleeves and pants, apply insect repellant and consider sleeping under a permethrin-treated bed net when not sleeping in a sealed, air-conditioned room.

Never go barefoot, even on the beach, because a small cut can provide a portal for an opportunistic microbe.

When it comes to fresh fruit, wash it with clean water, peel it or forget it.

Some people have a don't trust immunizations, which they see as causing more harm than good, although such claims are widely disputed by the medical community.

DiOrio said vaccines overall are safe, highly effective and better than the alternative -- coming down with a crippling disease that otherwise could have been prevented.

"There are some possible side effects with immunizations, but the most common one is a sore arm," she said. "But they are rare."