FOR three weeks, seven-month-old Mohammed Abu Amra has been lying in Gaza's main paediatric hospital, suffering from immune deficiency and suspected cystic fibrosis.

His doctors do not have the drug they need to relieve his symptoms, which include fever and distressed breathing, racking his thin ribs at almost twice the healthy rate of breaths per minute.

Nor does any hospital in the sealed-off Gaza Strip have the equipment or expertise needed to clinically diagnose Mohammed's condition. For eight days his doctors have been waiting for a reply to their request to transfer the baby to a hospital in Israel. If it is not granted, they say, he will probably die.

"Because of the Israeli siege the number of patients who can travel is very limited," says paediatrician Dr Ahmed Shakat, standing over the child's bed in Gaza's al-Nasser hospital.

"In the past it took one day to transfer an urgent patient to Israel. Now I need maybe five, maybe 10, if it happens at all. The Israelis say it's because of security, but it means urgent cases can die. In the past we could have transferred him also to Egypt, but now that border is closed because of the siege."

Baby Amra is not expected to die quickly if denied proper treatment. Nor would any single factor or player be directly responsible for his death. If he dies it will be partly because he was sick, partly because he was weak, partly because he could not escape from Gaza, partly because the things he needed to survive were not provided to him quickly enough or in sufficient quantity; a variety of reasons that the Israeli government, the rival Palestinian factions and international humanitarian bodies all seek to blame on each other.

In this the child resembles the Gaza Strip itself, a real-life dystopia cut off from the outside world where, under the pressure of half a dozen or so slowly tightening screws, life is coming apart at every seam. Mahmoud Daher, Gaza director of the UN-affiliated World Health Organisation (WHO), says that the health service is where the effects of Palestinian infighting and Israel's blockade are showing most dramatically.

Last week WHO reported that out of the 782 Gaza patients to have sought specialist treatment outside the Strip since the siege was tightened in June, 100 have been granted permits by Israel to leave.

Of those, 27 were turned back to Gaza after being interrogated by Israeli security agents at the Erez crossing. Four died after their passage was delayed or refused; another seven died while waiting for permits in Gaza hospitals.

In October, an Israeli newspaper and two human rights groups charged that agents of the Israeli security organisation Shin Bet who are based at Erez were attempting to recruit patients or their parents as informers by threatening to prevent them gaining treatment.

Several who declined said they were turned back or subsequently refused passage for follow-up treatment on the grounds they were "security risks".

The Israeli government denied the allegation, claiming it was the Hamas government in Gaza which was somehow closing the crossings after it took control of the Strip from its Fatah rival in June. A spokesman also suggested that the rights groups did not have access to Shin Bet's secret information on the patients.

According to the WHO report, one-fifth of essential drugs and 31% of medical supplies were no longer available in Gaza by October and 11 out of 18 psychiatric drugs had run out in August, a time when health workers were observing a "growing proportion of the population experiencing psychological symptoms".

The neonatal death rate in Gaza's paediatric hospitals has increased from 5.6% in January-October 2006 to 6.9% in the same period this year.

But while local doctors and politicians blame the crisis on Israel's blockade, alleging that vital drug shipments are being stopped border crossings, the WHO says the situation is more complex.

Local director Daher reports that WHO, which together with the World Bank pays for more than 90% of the Palestinian Authority's essential drugs, has little difficulty getting its shipments through Israeli security checks into Gaza. But bureaucratic failings in the administration of the drugs system, which first broke down in November 2005, were exacerbated by last year's election victory of the Islamist Hamas movement, which refuses to recognise Israel's right to exist or renounce armed resistance.

Israel's subsequent Western-backed economic and diplomatic boycott bankrupted the Hamas-led Palestinian Authority (PA), further paralysing its medical administration. In Gaza, the situation worsened in June this year, when Hamas fighters routed security forces and militias loyal to the US and Israeli-backed former ruling party, Fatah.

In response, Israel further tightened its severe restrictions on Gaza's economy, banning all exports and cutting off imports of all but basic foodstuffs and what it terms "humanitarian supplies".

Yet such is the scale of the Palestinian Authority's internal collapse that even in the Fatah-held West Bank, where Israel has eased its boycott in an effort to further isolate Hamas and preserve Mahmoud Abbas's notional authority, the health system is also in crisis.

"There are shortages in the West Bank as well, but the difference is that in the West Bank you have relative freedom to move about to seek drugs and treatment, but the Gaza Strip is hermetically sealed off from the outside world," says Daher.

He believes that Gaza's health service, like Gaza itself, faces slow strangulation rather than dramatic collapse. "For example, one reason the quality of medical care is deteriorating here is because they can't get permission from Israel to send people out for training."

Similarly, there is little chance of people starving to death as long as Israel continues to allow international donors to bring in basic foodstuffs. Gazans will survive, but as idle prisoners on a diet of little more than bread and water.

"Around 80% of the population is now aid-dependent, and many of the rest work for international organisations or the UN," says Daher.

"Unemployment is increasing, so while you don't have major deterioration in physical health, you do have problems with mental health. There are problems of frustration, depression, insomnia, increased bed-wetting in children and domestic violence, and these are being reported more and more by researchers. It's very alarming. The whole social fabric is being destroyed."

As society in general weakens, it becomes ever more vulnerable to the next complication. Last week it was a fuel crisis sparked by Israel's decision to reduce oil supplies to the Strip by 15% to retaliate against militants who continue to fire missiles at Israeli communities bordering the Strip.

But instead of being cut by 15%, the UN and local garage-owners say supplies of diesel and petrol have been halved, leaving hospitals short of fuel for generators, vital during the frequent power cuts.

"The Israelis are using fuel as a political weapon," says Khaled Radi, a spokesman for the health ministry in Gaza, now a breakaway administration under the Strip's rump Hamas government. "Because of this we've had to stop some external clinics, and we've also stopped operating most ministry vehicles and ambulances. The ambulances can be used only in the most urgent cases."

According to the WHO, some hospitals, including the paediatric hospital where baby Amra is fighting for his life, had by the middle of last week no stores of diesel left for their emergency generators.

The Petroleum and Gas Stations Owners Association of Gaza responded to the fuel cuts by, in effect, going on strike. "We decided to stop accepting their reduced supply as a form of protest against a policy that has killed off commercial life here in Gaza," said vice-chairman, Dr Mahmoud Khozander.

"Two days ago the Israelis said they would improve the supply to half of our basic minimum requirement, but we refused. It's better to die quickly than to drag things out for months."

But an Israeli military spokesman said last week that the sharp decline in fuel supplies to Gaza was the result of the Palestinians' own failure to pay the private Israeli company granted a monopoly to supply fuel to Palestinians.

This, he said on Thursday, had already been resolved, and Israel was pumping fresh supplies into the PA-owned storage tanks just inside the Gaza border.

Yet the restored supply was still unaccountable, about half of Gaza's demand, a much bigger reduction than that officially sanctioned by the government and endorsed by Israel's supreme court.

The Gaza fuel retailers reject claims they failed to pay for their supplies. They say that, in accordance with the status quo before this June's civil conflict, they still pay for their supplies in full and in cash to the rump Fatah government of Palestinian Authority chairman Mahmoud Abbas in the West Bank town of Ramallah.

A state fuel company official in Gaza - now in Hamas's hands - accused Fatah of deliberately failing to pay for Gaza's fuel supply, turning the public into pawns in its war with Hamas. Similar suggestions have been made about the Fatah government's alleged failure to "co-ordinate" shipments of medical supplies to state hospitals in Hamas-run Gaza.

So general is the economic and social malaise in Gaza that even industries that might have been thought to be blockade-proof are feeling the pinch. For thousands of donkey and pony-cart operators the fuel crisis has yet to provide a boom in custom.

"Maybe in the near future when the fuel runs out, business will pick up a little, but for now we're in as much trouble as anybody else," says Hamsa Jalhoun, 22, sitting in a long line of pony-carts waiting for hire at Jabaliya vegetable market.

"A 50kg bag of oats is twice what it was before the Israelis started their siege in June, and business is down because nobody has any money. When we can't feed our animals any more we'll have to turn them loose in the street to find their own food." With 1.5 million people squeezed into 140 sq-miles of concrete buildings and desert, Gaza produces little animal feed of its own.

Mussab Nyasa, 20, a feed merchant in Jabaliya, says the siege has cause the market to collapse. "A lot of people who kept livestock have now slaughtered them and eaten them because they can't afford to feed them any more."

Even Gaza's indefatigable smugglers can find something to complain about. "Last week I smuggled 100 rifles in from Egypt," said "Abu Mussab", one of the operators of smuggling tunnels dug under the border of Gaza and Egypt.

"They cost me $700 each, and when I sold them here I could only get $500 for them. In the past we could smuggle weapons in for both Fatah and Hamas, when they were fighting each other, but now there is no internal fighting and Hamas controls everything. Nobody wants weapons any more," he said.