Ironic as they may be, hospital-acquired infections make a strange kind of sense - after all, hospitals are full of sick people whose germs are floating all over the place.

In fact, studies have shown that bacteria that cause serious illness have been found on medical equipment, lab coats, stethoscopes, even the pens doctors write with. It's not that most hospitals are willing to accept an environment teeming with microscopic vermin - in fact, these infections cost the health-care system an estimated $4.5 billion a year. Part of the cost is picked up by hospitals themselves, because insurers, including the government, won't pay for a person's illness if they get sick in the hospital - the institution has to eat the cost.

So there's an economic incentive to keep the place clean and sanitary, not just a professional one. Hospitals must have an infection-control program that meets certain standards in order to maintain their accreditation.

Nevertheless, the problem is getting worse, according to a study released in March by the Centers for Disease Control and Prevention. It found that the rate of in-hospital infections rose 36 percent over the past 20 years. One possible reason: It could be because hospitals admit only the sickest patients, many of whom have weakened immune systems that leave them vulnerable to whatever's lurking in the hospital.

What's really scary is the fact that the microbes themselves are mutating so much that they can resist every antibiotic thrown at them. The CDC study indicated that as many as 70 percent of the infections examined involved organisms that were resistant to one or more antibiotics.

That's all the more reason for doctors and other hospital workers to take every precaution to keep from spreading infectious agents from one patient to another.

Unfortunately, not every medical professional is as careful as they should be to do the one thing that's been shown to dramatically reduce the transmission of germs: Wash their hands. Information from the American Medical Association indicates that between 14 and 59 percent of doctors don't wash their hands between patients, with a similar number of nurses doing the same.

So if you're lying defenseless in the hospital, how do you protect yourself from these nasty bugs? Here are a few tips to keep them at bay:

• If a doctor, nurse, aide or orderly arrives to give you a pill, a shot, new linens or an examination, ask a simple question: "Did you have a chance to wash your hands?" Ask nicely, but do ask. People get so busy in the hospital they may simply forget, and you are the last line of defense before some other patient shares their staph infection with you. There ought to be a wash basin in your room that makes it easy for them. (A particular giveaway is if they're already wearing protective latex gloves. "If you see somebody walk into your room with gloves on, ask if they just cared for a patient and if so, could they put on new gloves," recommends Ann Kobs, associate director of standards for the Joint Commission on Accreditation of Healthcare Organizations.)

• Be sure to wash your own hands regularly while hospitalized, even if you need to ask someone to bring a wash basin over to the bed.

• Don't share your roommate's towel, drinking glass or other personal item.

• Ask relatives who are sick to stay home - they can bring unwanted germs into the hospital with them.

• If you're scheduling elective surgery and are fighting the flu, be sure you're completely well before coming into the hospital, for the same reason.

• You could also consider investigating the hospital's infection control program. You can't be expected to ask knowledgeably about the details, of course. But at least ask whether there's an infection-control professional on staff, particularly if you have some reason to feel things aren't quite up to snuff, suggests "Health Care Choices for Today's Consumer," a comprehensive manual published by the consumer advocacy group Families USA.

Hospitals keep track of the number of infections patients get while under their care. These figures are often kept close to the vest by hospitals. Kobs contends that the numbers would be meaningless to a patient, because different institutions count infections differently. But some consumer advocates would like to see this information made public. Eventually, Kobs said, all hospitals will be using the same definitions so they can be compared with one another.

More patients are being cared for in their own homes, and cleanliness is just as important there, notes Janet Franck, a St. Louis-based infection-control practitioner and consultant. Oftentimes people are sent home with oxygen equipment or a home intravenous line with occasional visits from a home health nurse.

"Be sure to request written information about how to appropriately clean the device and to see that it's properly maintained," Franck suggests. Also, if a nurse comes to give you an injection, make sure there's an appropriate way to throw away the needle so no one in your household - or the garbageman - gets stuck. You can get a "sharps" container to hold used needles from a medical supply store.

Also watch out for cleanliness if you or a loved one is going to stay at a skilled nursing facility, also known as a nursing home. The first test uses your nose - "When you walk in the door, determine if there's an odor," recommends Franck. "It could be a short-term situation, but if it's something lingering you need to evaluate the reason why." Also ask to see where food is prepared and how linens are disposed of, and watch to see if soap and paper towels are readily available for staff hand-washing.

The Association for Practitioners in Infection Control has detailed brochures on these issues. Check the group's web site for more information.

Meanwhile, you can do your part to keep from breeding bacteria that are resistant to antibiotics. Super-bugs with super-resistance are being created by the overuse and misuse of antibiotics. When you have a simple cold or flu virus, don't insist on getting antibiotics - the drugs don't affect viruses. And when you do have a reason to take antibiotics, don't stop taking them mid-way through the prescription.

So, as your grandmother might have said, wash your hands and take your medicine.