Every year 48,000 US citizens die of infections they pick up in hospitals, says a report published in the Archives of Internal Medicine.

While most people go into a hospital hoping to get well, the new study showed that American hospitals can kill even relatively healthy patients.

Some 99,000 infection-associated deaths are reported each year, half of which can be linked directly to hospital care.

The study also shows that 1.7 million patients pick up various kinds of infections during a hospital stay, costing billions of dollars. Hospital-acquired blood poisoning and pneumonia are the deadliest, claiming the lives of 48,000 in 2006 alone.

Such infections forced patients to spend an extra 2.3 million days in the hospital and cost $8.1 billion to treat during that year, the study found.