* Nurse fears for life after Ebola kills colleagues
* Deaths of scarce doctors, nurses exacerbate outbreak
* "No-one expected so many healthcare workers to get sick"
* At least 50 of them dead, including top doctors in S.Leone, Liberia
* Fatigue and lack of training add to problems
FREETOWN/DAKAR/LONDON, Aug 1 (Reuters) - Jenneh became a nurse in Sierra Leone 15 years ago with the hope of saving lives in one of the world's poorest countries. Now she fears for her own after three of her colleagues died of Ebola.
Health workers like Jenneh are on the frontline of the battle against the world's worst ever outbreak of the deadly haemorrhagic fever that has killed 729 people in Sierra Leone, neighbouring Liberia, Guinea and Nigeria so far.
With West Africa's hospitals lacking trained staff, and international aid agencies already overstretched, the rising number of deaths among healthcare staff is shaking morale and undermining efforts to control the outbreak.
More than 100 health workers have been infected by the viral disease, which has no known cure, including two American medics working for charity Samaritan's Purse. More than half of those have died, among them Sierra Leone's leading doctor in the fight against Ebola, Sheik Umar Khan, a national hero.
"We're very worried, now that our leader has died from the same disease we've been fighting," said Jenneh, who asked for her real name not to be used. "Two of my very close nursing friends have also been killed ... I feel like quitting the profession this minute."
Jenneh works at a 64-bed emergency clinic set up by the medical charity Medecins Sans Frontieres (MSF) in Kailahun town in eastern Sierra Leone, at the centre of the outbreak. She said she didn't know why so many doctors were dying from the virus, which in its most deadly strain can kill 90 percent of those it infects. In the current outbreak, the rate is running at about 60 percent.
But like other carers interviewed by Reuters, she is worried the fabric of the yellow full-body suits used to protect workers on isolation wards is too flimsy to block the virus. "Improper personal protective gear is a serious issue here," she said.
World Health Organisation (WHO) experts strongly deny there is any problem with the protective equipment. They point to a chronic lack of experienced staff that is forcing health workers to cut corners in the arduous daily task of decontaminating wards and treating patients.
The WHO launched an urgent appeal for hundreds more trained medical personnel on Thursday as part of a $100 million drive to bring the outbreak under control. It said it was seeking ways to safeguard scarce medical workers from infection.
"Protection of healthcare workers is important for two reasons," said David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine. "Number one, so they don't get infected and take it home to their families; and number two ... so healthcare workers don't just carry the infection from one patient to another."
SECOND WAVE SURPRISED DOCTORS
Doctors turned patients have been a common feature of Ebola outbreaks since the virus was discovered in Democratic Republic of Congo in 1976 near the Ebola river. However, the infection rate typically tails off as doctors and health staff get used to strict procedures for handling patients, experts say.
But a second wave of Ebola infections in West Africa from late June caught many by surprise as the disease popped up in new areas after relatives took infected patients out of clinics rather than leave them in wards they feared were death traps.
This year's outbreak was the first time the rare disease had struck in West Africa, blindsiding both the superstitious local population and unprepared healthcare systems, where even basic equipment like medical gloves was in short supply.
The scale of the disease meant that for the first time MSF - the organisation that usually spearheads Ebola reaction - was not able to cope with all the outbreaks, so local governments and other agencies had to step in.
Daniel Bausch, associate professor in the department of Tropical Medicine at Tulane University, who has worked in haemorrhagic fever outbreaks since 1996, said he was alarmed by conditions at a state-run clinic in Kenema, Sierra Leone.
"This is for sure the worst situation I've ever seen," he said, noting that doctors were examining patients in scrub suits before proper protective equipment arrived. "You don't have enough staff, and you don't have enough doctors."
When nurses walked out on strike in Kenema after their colleagues got sick, Bausch and another WHO-sponsored expert were left to cope with a ward of 55 Ebola patients, he said.
The virus is only transmitted via contact with body fluids - blood, urine, saliva, faeces - from someone showing symptoms of Ebola. Patients in the final stages of the disease can be bleeding from their orifices, covered in blood blisters, vomiting and suffering from diarrhoea.
For doctors attempting to clean them or deliver palliative care - like intravenous drips for hydration - while wearing protective suits, goggles clouded by tropical heat, and thick gloves, the work can be physically and mentally exhausting.
"None of us expected to have as many healthcare workers get sick as we did," said Bausch, who said 10 staff in Kenema became ill with Ebola during the three weeks he was there in July.
"There were times when nurses were getting sick and I thought, 'We have to close this ward', but that's just not an option."
Constant fatigue among overworked and poorly trained staff probably led to mistakes, Bausch said. He said he saw some staff not wearing protective suits or wearing them incorrectly, but even experienced professionals were at risk.
"Fear is not quite the right word ... but you haven't slept a lot, it's a stressful environment in a tropical country, and maybe you feel feverish. Everybody has a moment where you start to wonder," he said. "No-one who I talked to could give me a specific incident or say the moment when they got infected."
Experts say the techniques for avoiding Ebola are not complex but require rigorous training and application. But, with a crisis underway, there was not time to spend hours every day practising drills as floods of new patients arrived at centres.
Derek Gatherer, a virologist at Britain's University of Lancaster, said Ebola was not "super-infectious". Each case is expected to lead to two or three more, similar to a flu outbreak and much lower than diseases like measles, where one case could lead to 12 to 18 more.
"The reason doctors need to wear all the protective gear is because of the sheer consequences of getting it," he said.
Sierra Leone's Chief Medical Officer, Brima Kargbo, admitted that many local health workers were not following standard precautions, leading to their infection.
Mohamed Sheriff, spokesman for nursing staff in Kenema, said workers had only been offered workshops in how to wear the protective clothing once the crisis was well under way: "We don't have the technical know-how ... Some of our colleagues are new nurses dealing with a new disease."
Just taking the suits on and off under controlled conditions required up to 45 minutes and must be done with the assistance of another person, experts say. After removing goggles, mask, suit and gloves and throwing them in a plastic bag, workers are sprayed down with chlorinated water.
Samaritan's Purse, which ran the case management centres in Foya and Monrovia, said that with its workers only able to wear the suits for four hours, it was using 75 Personal Protective Equipment suits per centre per day.
"The risk of getting infected when taking the suit off if proper procedures are not followed is high," said Ken Kauffeldt, Liberia country director for the U.S.-based charity.
It has said its two American staff - Kent Brantly and Nancy Writebol - probably contracted the virus in the scrub-down area from a local worker who caught it at home.
HARD TO TRACK
As well as the medical challenges, health workers in West Africa also face social stigma for working with Ebola, including the risk of physical attack by a sometimes hostile population.
MSF has said some of its staff in Guinea prefer to conceal where they are working for fear of being ostracised. Gangs of youths have blocked access to affected villages and mobbed health workers.
Tracking the infected and isolating them is a key element in tackling Ebola. If a case were to be detected in the West, it would likely be relatively easy to contain, experts say, but not so in West Africa.
With a highly mobile population, sufferers have often reappeared in an entirely new community - exposing the lack of equipment and training in rural healthcare.
"In rural health clinics and centres, they don't have the ability to protect themselves," said Kauffeldt. "They don't even have simple supplies such as examination gloves."
Early symptoms of the disease are like malaria or flu, with headaches and joint pains, so doctors can be unaware they are coming into contact with the disease for the first time.
One of Liberia's top doctors, Samuel Brisbane, became the first healthcare worker to die from the disease after examining a patient in a Monrovia hospital for symptoms of peptic ulcer disease. Since then, more than 17 doctors in Liberia have died.
"A lot of health workers are getting infected, and they're afraid," said Assistant Health Minister Tolbert Nyenswah. "Every patient who goes to a facility during this outbreak should be an Ebola suspect until it is proven otherwise." (Additional reporting by Clair MacDougall in Monrovia and Adam Bailes in Freetown; Editing by Will Waterman)