In Cambodia almost anyone who sees a doctor or goes to hospital, is given an injection or put on an intravenous drip. This is what patients want, and what medical staff give them - it has become part of the healthcare routine. But it has serious, sometimes tragic, effects.

Mom Hing is chewing as he talks. The abbot of a Buddhist temple, he is sitting on the floor in his orange robes. He's been receiving gifts of food, drink and some money from worshippers in the village of Roka. In exchange, he gives them a blessing.

But this 82-year-old monk is HIV-positive, and he's certain how that came about. "Since I came to this village in 1994, I've been having injections from a medical doctor who was trained in a refugee camp. And I got HIV-Aids from him - I only got injections from him."

The man he's talking about was the village "doctor" for two-and-a-half decades - an unqualified, unlicensed doctor. Earlier this month he was given a 25-year prison sentence for manslaughter, accused of reusing needles and syringes.

Yet Mom Hing bears no malice. "Let it be - life and death are normal things," he says. "I'm not worried about myself at all. I'm getting older. What I'm concerned about is the young."

Tragically, more than 270 people in and around Roka - a population that numbers in the hundreds rather than thousands - have tested positive for HIV. Ten are reported to have already died from Aids.

Lap Hoy, a 51-year-old grandmother, says she went to the village doctor when she had a cold and a fever. She is now HIV-positive and so are four other members of her family, who were also given injections by the doctor.

"My grandchild got infected, her mother got infected and I, her grandmother, also got infected," she says.

Lap Hoy says she doesn't want the doctor to ever to return. Her son-in-law, lying in a hammock, is more forthright. "If he ever came back, he wouldn't have any chance of survival," he says.

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The mass outbreak shocked a country which, with substantial help from foreign donors and NGOs, has made good progress over the last decade in reducing HIV levels. It also prompted the Cambodian government to announce a clampdown on unlicensed health workers.

But are the unlicensed doctors, midwives and pharmacies really the problem?

A Westerner, who has worked in Cambodia's health sector for many years says there is a general lack of knowledge about infection control throughout the country's healthcare system.

"I would say there are many more Rokas in Cambodia," she says.

The practices are so poor that it's inevitable. I don't think there's a difference between licensed and unlicensed doctors. I think what we saw in this case was a breach of infection control practices [and] doctors working in the government sector get very little training - if any - in infection control."

Part of the problem is the fascination many Cambodians have with injections and intravenous drips. Driving from the capital Phnom Penh, towards Roka, in the west of the country, I regularly saw people on IV drips - and not just on IV drips but also on motorbikes. These were mobile IV drips.

I stopped one motorbike, which had three people on it. The passenger at the back was holding up a stick, at the end of which, covered in a black plastic bag, was a bottle of IV fluid.

The plastic tube leading from the bottle was injected into the right arm of the man sitting in the middle. He said he'd been diagnosed with malaria by a private doctor and that he had liver disease and intestinal problems. He also felt weak.

The IV drip, he said, was "cooling" his body down and giving him more energy.

"There are a lot of people who have IV drips on motorbikes," he said. "I'm poor, I'm not rich, I don't have a car to drive, so I have a drip on a motorbike."

The Western doctor, who prefers to remain anonymous for fear of repercussions, says demand for IV drips in Cambodia is immense.

"It's not just in the village. Everybody who goes to hospital gets an IV because they think it's important and the doctors and nurses think it's important.

"I think IVs and injections are given for spurious reasons. And they can be harmful. If you walk into a hospital, pretty close to every patient will have an IV. They'll just get them, you know, ad infinitum, until they leave the hospital."

In theory, hospitals are the only institutions allowed to give injections. Local health clinics are forbidden from doing so. But this helps to push patients into the hands of the unlicensed doctors.

"A mother brings her child to the clinic and says, 'OK physician, just give my child an injection,'" says Vong Tu, who trained as a nurse and is director of the Tuol Ampil health centre in Kompong Speu Province, south-west of Phnom Penh.

"And I say, 'No, I can't give that to you, it's impossible.' Then the mother goes to the unlicensed doctor and simply says, 'Just one injection, one IV drip.' And the unlicensed doctor gives her what she wants."

He says people take their children to private, unlicensed doctors to get IV drips or injections even when they only have a "normal fever".

Ten minutes' drive from the health centre, lives "Dr Chin", an unlicensed doctor, who says he learned his skills from Vietnamese doctors after being recruited by the Khmer Rouge 40 years ago. War was raging and he dealt with malaria and dengue fever, while also patching up wounded soldiers.

"My training was in the forest. It was all based on experience and reality," he says.

As he goes on his medical rounds, weaving through the rice fields on his motorbike, it's clear that Chin is both popular and busy despite the government's intention to stop unlicensed doctors from practising. He's cheaper than the official hospitals and clinics, he lets his patients pay in instalments, and he's available day or night.

He also gives his patients plenty of injections and IV drips.

One woman says her husband had an operation in hospital to remove a tumour, and doctors gave him just five days to live. She credits Chin with keeping him alive for the last eight months.

When I visited, the husband was attached to an IV drip, with yellow liquid in the bottle, which Chin said included painkillers and antibiotics.

I spent about half a day with Chin. Despite his assurances that he never reuses needles, I wasn't wholly convinced by his infection control practices. He didn't wash his hands, or wear surgical gloves. I had my suspicions about a loose needle he kept in a silver metal box, which he used to fill the syringe with medicine from a bottle, before returning it to the box. And I had doubts about how sterile his cotton swabs were.

I took my concerns to the Western doctor who quickly pointed out that no needle should ever be reused, whether it's to inject directly into a patient or to draw up the medicine.

"Of course, things are only problems if you recognise them as problems," the doctor warned.

"Many Khmer do not see these problems - for example antibiotic resistance [and] infection control breaches.

"People blame this HIV outbreak [in Roka] on an unlicensed practitioner. But it could be many practitioners, licensed or unlicensed, working for the government or not, who have bad practices which can end up with Hepatitis B, or Hep C, or HIV. If you aren't aware of the problems then it's harder to fix them."

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