Haiti is in desperate need of more doctors and nurses to help it manage a cholera crisis that refuses to loosen its grip. But finding the medical staff who can answer that call for help is no simple task.

Already, close to 60,000 Haitians have been treated for cholera and as many as 200,000 more could descend on the country's makeshift medical clinics in the next three months. Few expect the crisis to abate quickly, given the gaps in the country's sanitation and basic infrastructure that allowed the infectious disease to spread as quickly as it has.

But while finding young, eager volunteers to dig drainage ditches and build clinics is, if not altogether easy, at least straightforward, the medical workers needed to help in health emergencies such as this one are unique.

Marilyn McHarg, general director and co-founder of the Canadian section of Médecins Sans Frontières (MSF) / Doctors Without Borders says the medical staff needed for this crisis need to have flexiblity in their work schedules and flexibility in their personal lives.

They also have to be ready to transition quickly into the demands of the work, because the training and orientation in health emergencies like the one in Haiti are "really short and mostly on the job."

"When they get there, they have to function on a pretty intense level, so the more experience they have the better," McHarg said in an interview.

MSF, which now has an impressive 27 cholera treatment centres in Haiti, is recruiting all kinds of personnel: doctors, anesthetists, nurses -- anyone who can devote a few weeks or preferably, a few months to help.

The organization has been working in Haiti for 19 years and had already established a number of long-term projects and health centres before the country was hit by an earthquake in January and the cholera disaster. The staff in those long-term projects typically commit for stays of as long as a year. But McHarg says the cholera crisis is different.

"In a real emergency, you have a higher turnover because of the stress that goes with working in those circumstances," McHarg said.

That's why her group will turn first to the experienced personnel who have worked with them before, to ask them whether then can commit more time to help with the disease fight.

"After that, we then put out a call more generally, and start creating a pool of personnel who meet our qualifications and who have some flexibility in their scheduling. And then as positions open, we start to pull from our pool," she said.

Dr. Tanya Zakrison has seen the stress of post-earthquake Haiti. She says it profoundly changed her.

Zakrison, currently a trauma surgeon at St. Michael's Hospital in Toronto, says she knew pretty much nothing about Haiti before she spent two weeks there following the January earthquake.

Like many, she admits she saw Haiti as "the Africa of the Americas," a country that seemed hopeless. But after speaking with the Haitians she was treating, and after learning about the country's history, her view has shifted.

"I now feel pretty strongly about it: the earthquake was indeed a natural disaster but all it did was serve to unmask the manmade disaster that created Haiti's state of poverty," she told CTV.ca.

Zakrison was completing a trauma surgery fellowship at the University of Miami when January's earthquake toppled the Haitian capital. She quickly signed up for the university's Project Medishare program to help tend to survivors.

For her, taking time off from her surgery duties was fairly easy.

"They were very understanding. They would say, ‘Yes, you go; we'll cover your shifts. And then next week you'll cover someone else's shift'. There was a lot of support to relieve people of their clinical duties," she said.

But it isn't always that way for other personnel. It's often a challenge to find a doctor or nurse who can leave his or her practice or hospital responsibilites to help with a health crisis thousands of miles away.

"You need a very supportive practice. Your colleagues around you have to be able to cover your call, cover your clinical duties. So they have to be very understanding. And of course, you need a hospital administration that is accommodating," she said.

Zakrison encountered many medical workers who make it a point to regularly take time off from their work at home to do international relief work. Some go on their vacation time; others use up the time they've been allotted for research or academic pursuits.

"Many feel compelled to help in a catastrophe that really, shouldn't be happening anywhere," she says.

Some do it simply because it's a unique kind of medicine they may never experience at home, said Zakrison. Many of the American physicians she met, for example, told her that the work they were doing in Haiti was the first time they could actually practise medicine as physicians without concerns for whether the patient had health insurance, or without dealing with hospital bureaucracy or HMO's or case managers.

"They could just be doctors. I'm sure for many physicians, it's the most rewarding medicine they've every done," she says.