'What else do I remember? Nothing. I slept for two days and two nights'. Picture: time.kz

Scientists are puzzled by the mysterious condition which causes people suddenly fall asleep from between two to six days in the areas around Kalachi village and the almost abandoned Soviet town of Krasnogorsk. The condition is typically accompanied by a startling memory loss.

Marina Felk, 50, a milkmaid in Kalachi, said: 'I was milking cows, as usual, early in the morning, and fell asleep. I remember nothing at all, only that when I came round I was in a hospital ward, and the nurses smiled and me, and said: 'Welcome back sleeping princess, you've finally woken up'.

'What else do I remember? Nothing. I slept for two days and two nights.

'The women tin my ward said that I tried to wake up several times, saying urgently needed to milk my cows'.

Alexey Gom, 30, came to visit his mother-in-law in Kalachi, some 400 kilometres north west of capital Astana, 230 km from the Russian border, and was also hit by the sleep plague.

'I came with my wife to visit my mother-in-law,' he explained. 'In the morning, I wanted to finish my work. I switched on my laptop, opened the pages that I needed to finish reading - and that was it.It felt like somebody pressed a button to switch me off.

'I woke up in the hospital, with my wife and mother-in-law by my bedside. The doctor found nothing wrong with me after a series of tests he performed. I slept for more than 30 hours. But it never happened to me before, never in my life, or to anyone from my family.'

Entrance to the village of Krasnogorsk, and below Alexey Gom and Marina Felk at hospital. Pictures: Zamzagul Adrakhmanova, K31 TV

Yet such stories are all too familiar in these sleeping communities. Some residents even keep bags packed, in case they are rushed to hospital. Strangle, some families seem ultra-prone while the sleep attacks pass others by.

One woman called Lyubov Belkova was selling clothes as usual at her local market stall, and suddenly keeled over.

Other women rushed to her asking what was going on, and then rapidly called an ambulance. The doctor thought she had suffered a stroke, and yet - two months later, a woman working alongside Lubov at the market fell asleep in identical fashion. Then Lyubov Belkova dozed off again. Sooner or later, all five women who were selling things at the small market on the road from Krasnogorsk to Kalachi fell asleep in the same way.

So did their security guard. By the end of it, as journalist Uliana Skoibeda recounted in Komsomolskaya Pravda, pensioner Lyubov Belkova slept in this way seven times, her daughter Natalia Mikhel twice and her 15 year old granddaughter Diana once.

Diana Mikhel was at a school concert rehearsal and felt so weak she had to sit down, put her head on her crossed arms, and slept. Doctors initially thought the condition might be linked to bad quality vodka, but of those struck down in March 2013, none of the six people had taken any alcohol.

Some residents even keep bags packed, in case they are rushed to hospital. Pictures: K31 TV

The sleeping epidemic has appeared in definite waves among locals who are mainly ethnic Russians and Germans.

The second came in May 2013, around Easter time. Since then there were three move waves of this sleeping epidemic - around New Year 2014, after the winter school holiday and this month, in May 2014.

Locals say in all that 40 to 60 people suffered from this long sleep, and they speculate that the problem arises after a sudden rise in temperature. One theory is water from the disused uranium mine seeping into the local rivers and then into domestic supplies.

A large number of scientists have come to this remote backwater to seek to explain the phenomenon. In all, they have conducted 7,000 experiments on soil, water, air, patients' blood, hair, nails, without pinpointing the problem, it is claimed.

They have discounted underground gas and the local mobile phone mast. They tested homes for radon gas. Tests on high radiation levels, heavy metal salts, bacteriological and viral tests have proved negative.

In the USSR era, Krasnogorsk was a secret and 'closed' town run directly from Moscow. Around 6,500 citizens lived here, their work linked to the uranium mine, and life was unusually prosperous because the work was seen as of high state importance.

Today a mere 130 remain here at a town that lost its purpose in 1991 with the Soviet breakup. Kalachi now has 680 residents.

In the USSR era, Krasnogorsk was a secret and 'closed' town run directly from Moscow. Around 6,500 citizens lived here, their work linked to the uranium mine, and life was unusually prosperous because the work was seen as of high state importance. Pictures: Zamzagul Adrakhmanova

Local community council head Alexander Rats said of Krasnogorsk: 'You could find everything in our shops: meat, condensed milk, boots made in Yugoslavia - a miner could buy three new cars every year. We had two children's nurseries, both with swimming pools.'

But now the place lies in ruins after the fall of the Red flag saw the cash stream cut off. Today even the heating doesn't work properly in winter.

Doctor Kabdrashit Almagambetov in the district capital Esil was treating another local Alexander Pavlyuchenko, who fell into a long slumber while on a visit to the local cemetery. He awoke insisting he had been on a fishing expedition.

The doctor said: 'When the patient wakes up, he will remember nothing. The story is one and the same each time - weakness, slow reactions, then fast asleep.

'Sadly, the nature of this condition is still not known. We have excluded infections, we checked blood and spine liquid, nothing is there. We categorised it as toxic encephalopathy, but 'toxic' is just a guess here, and encephalopathy is just the title of the set of brain diseases.'

While higher levels of radon gas were found, he is suspicious that this is the true cause.

'I am an anaesthesiologist myself and we use similar gases for anaesthesia but the patients wake up a maximum in one hour after surgery. These people sleep for two to six days, what is the concentration of this gas then? And why one person falls asleep and somebody who lives with him does not?'

Today a mere 130 remain in Krasnogorsk, with 680 residents living in Kalachi. Pictures: Zamzagul Adrakhmanova

One fear locally is that they buried an elderly man who seemed to be dead - but this was before the sleeping condition was known about.

Two children who have suffered the sleep epidemic were struck by hallucinations.

Misha Plyukhin told how he saw light bulbs and horses flying around him, and then saw his mother with eight eyes and a trunk. Then he recalled snakes and worms in his beds, eating his arms.

Rudolf Boyarinos saw something too, but he does not remember. His relatives say four of them had to calm him when he shouted 'monsters!'.

The boys are back at school but seem to struggle to cope with their studies while adults report headaches and memory loss.

Weakness, drowsiness and dizziness were all reported.

As for the experts, somnologist Mikhail Poluektov, who is a tutor of neurotic illnesses at the First Medical Institute, in Moscow, said: 'What is going on in Kazakhstan has nothing in common with any of 85 known sleeping disorders. But it does not look like toxic encephalopathy either. People with encephalopathy do not walk and talk, they lie there and going deeper and deeper asleep.

'We also do not know what is the toxic agent, so the doctors cannot offer any particular treatment.

'At the same time we see that patients are getting better even with general therapy. It supports the idea of psychogenic nature.'

This would indicate that it stems from psychological or mental stresses. He suggests the the sleep disorder is could be a case of massive psychosis, something like 'Bin Laden itch' in the USA when people found rashes on their skin because they were scared of possible bacteriological attack.

'Something like this often happens in closed communities', he said.

'What is going on in Kazakhstan has nothing in common with any of 85 known sleeping disorders'. Pictures: Zamzagul Adrakhmanova

Scientists in Tomsk say they are convinced it is from a very different cause.

Leonid Rikhvanov, professor of geo-ecology and geo-chemistry of Tomsk Polytechnical University, said: 'We know about this problem and are happy to take part in solving it. We have even obtained some results. We have studied the samples of uranium ore which Kalachi citizens sent us.

'We tested the samples and came to the conclusion that radon gas is the reason, but it is not because of radioactive radon. It comes from chemical effect of the gas. In other words, the disease is caused by evaporation from the mine.

But Tomsk scientists must prove it, and to do so they would need to visit and establish why some families are hit, and not others.

'Unfortunately, the agreement for our help in this matter is not yet signed,' he said. One thought is more tests on heating vapours.

In March this year the deputy head of the regional health department said Yesenbai Akadilov said: 'We have ruled out a viral infection, one of the versions was that radon which can give away vapours might be a cause for the disease.

'For the time being there are doubts on this matter and so the research will continue. The commission is leaving, but will come back with more experts.'

Kazakhstan's Environmental Protection and Water Resources Minister Nurlan Kapparov pledged three months ago to discover what caused the encephalitis outbreak in residents. So far, it remains unsolved, with the Tomsk scientists so far unable to travel to Kazakhstan.