THE symptoms were slow to appear, at first. Keith Newbould had been feeling unwell the day before he left Kenya, where he had been working for a charity, helping with maintenance work on a hospital and orphanage.

He put it down to over-indulgence after spending his last night in the African country celebrating at an all-inclusive hotel with his co-workers.

Squeezed between his fiancee Donna and friend Lucy on the plane back home from Nairobi, the 6ft 2in teenager thought the dull ache in his back, which had started to develop, was probably not unusual for an eight-hour flight.

By the time he returned to his home near Gosforth, Newcastle, on Monday morning, he felt shattered. The nagging ache in his back was still there, but again, he put it down to the travelling.

A few hours later, the 18-year-old was catching up with his friends at a nightclub in Newcastle. They were eager to hear all about his travels, but as the night wore on, the pounding music and flashing lights became a distant blur as searing pains shot through his head and the persistent backache intensified.

The next morning he woke with blurred vision and was violently sick. His body was drenched in sweat one minute, frozen cold the next. He finally realised he wasn't coming down with flu.

"I had aches and pains everywhere," he says. "I phoned the doctors and when I told them I'd just got back from Kenya they told me to come round in one hour. They took a blood test and I went home, but by the time my mum came round, I was talking nonsense, not making any sense. I didn't really know where I was and I kept staring into space."

Recalling his doctor's advice, he made his way straight to the tropical diseases unit at Newcastle General Hospital, where staff quickly suspected malaria.

"I could just about walk by myself, I was zig-zagging down the corridor," he says. "I was extremely dehydrated. They had to get fluids into me straight away because I couldn't even keep water down when I came in. My temperature was up and down. At its highest, it was 39.9C.

"The doctors said I was lucky I came into the tropical diseases unit instead of accident and emergency - I would have been sitting there for hours."

Doctors found Keith had the most severe malignant strain of malaria - falciparum - which can lead to a coma and death if left untreated. The other three strains - vivax, ovale, and malariae - are benign, but equally virulent.

Lying back on his hospital bed, looking pale-faced and weak, Keith recalls taking precautions for sunburn, lost luggage, yellow fever, typhoid, polio and hepatitis A and taking proguanil and chloroquine for malaria. But the drugs to protect him from malaria weren't strong enough; he should have taken larium.

"Chloroquine made me really ill last year for a week before I went away, so I wondered what on earth larium was going to do," says Keith, who is hoping to take English Language and Literature A levels at Newcastle College in September.

He admits he didn't cover up as well as he should have, sometimes wearing T-shirts in the evening instead of long-sleeved tops. Nor did he always remember to take the tablets. He can remember being bitten a few times on his hand and he fully admits it was his "ignorance" that landed him in hospital for a week.

According to a new survey by vaccine makers Aventis Pasteur, he is not alone. One in five people don't even both getting vaccinated and almost half are ignoring basic health precautions.

Dr Mike Snow, consultant in infectious diseases at Newcastle General Hospital, says staff have investigated 50-60 cases of suspected malaria over the past year, with 25 being confirmed. Every year, about 2,000 people return to Britain with the disease and about ten die.

Malaria is caused by a small parasite which is transmitted from one person to another by mosquito bites. Symptoms are flu-like and it can take weeks for the disease to show. It is usually diagnosed by a blood test.

But contrary to popular belief of repeated attacks for life, Dr Snow says the parasites can be cleared from the blood stream and liver for good. It is the benign strains which can cause repeat attacks if specific treatment is not given to ensure the parasite has been cleared from the liver.

"With proper treatment, we can eradicate malaria," he says. "It's important people get the right advice before they go because the malarial prophylaxis (preventative treatment) varies according to where they go. They should also avoid the risk of being bitten by wearing long sleeves and using the appropriate repellents."

But some travellers fear injections or the nasty side-effects of drugs such as larium, where people have complained of nightmares, hallucinations, anxiety and dizziness.

Heather Skee, 44, of High Heaton, near Newcastle, took a range of homeopathic medicines for a recent trip to Kenya. She spent three weeks in the East African country where she carried out voluntary work with the Kenya Acorn Project at a hospital.

Her remedies, for Hepatitis A, Malaria etc, were made up for her by Annie Gray, director of the New Life Trust which runs the Natural Healthcare Centre in North Shields.

Even the first aid kit she took with her, containing remedies for puncture wounds, high fevers, headaches and stomach upsets, came in useful. She developed gripping pains one day and took a remedy containing arsenicum album (raw white arsenic) used for food poisoning, which she says helped her body fight the symptoms.

"It's not the injections themselves I don't like, it's what's in them and the side-effects," says Heather, who works in cardiography at Newcastle's Freeman Hospital. "People ask me all the time why I use them and they think I'm mad. But I think it really just helps your immune system and it gives it a boost to cope with what's happening. I have utter faith in it."

She plans to go back to Kenya on holiday with her husband Bill, and children Sharon, 23, and Mark, 16. But they will probably opt for conventional medicine.

Homeopathy has been around for a couple of hundred years. It is based on the idea that things that can make you ill can also make you better. Minute doses of plants, animals or chemicals, such as raw white arsenic for food poisoning, are used.

Says Annie Gray: "What these minute doses do is really help your body to help itself and bring it back in to balance. No-one really knows how it works. But it has to be the remedy which is right for the person. A homeopath should train for four to five years and the skill is in finding the whole picture of a person and matching it with the right remedies."

Annie says more and more people are seeking alternatives to conventional anti-malaria drugs and injections for diseases such as yellow fever.

"It is a very contentious issue," she admits. "There's a lot of doubt between homeopathic and conventional medicine, but there are a lot of books written about the dangers of vaccinations. Our job is to support people, for them to make the decisions which are right for them. We would never push anyone into having an alternative against vaccination. But there is an awful lot of evidence to prove that homeopathy does work."

Dr Snow says. "There is no scientific evidence that homeopathic remedies provide protection against infectious diseases like malaria or yellow fever. "I don't believe that homeopathy works and I think it is frankly dangerous for people to use this sort of alternative remedy rather than conventional medicine. People who get really ill from malaria are those who don't take effective prophylaxis."

Recovering from his bout of malaria, Keith Newbould is thinking about his next trip to Kenya in a year and has already made his decision. He says. "I'll be taking larium next time.