Healthcare Workers and Staph: Why Carriage Is Common

Carrying staph is normal

About one in three people have Staphylococcus aureus on their skin or in their nose.¹ Most never know it, because carrying staph, called colonization, usually causes no symptoms at all. It is not the same as having an infection, and for ordinary staph it reflects how common the germ is, not how clean you are.

Carriage also changes over time. A classic review of the research described three patterns in healthy people: about 20% carry staph persistently, about 60% carry it on and off, and about 20% almost never carry it.² To learn more, read Staph in your nose: what it means to be a carrier.

Carriage does matter to the carrier, though. A 2018 review reported that people who carry staph in their nose have roughly 2 to 10 times the risk of a staph infection compared with non-carriers.³ The same review noted that in infections after surgery, about 80% of the staph strains matched the strain found in the patient’s own nose.³ In other words, the staph most likely to cause you trouble is often your own.

Do healthcare workers carry more staph?

For ordinary staph, maybe not. A 2018 review noted that reports of higher nasal carriage among hospital workers than among everyone else have not been confirmed.³

MRSA, the type of staph that doesn’t respond to some common antibiotics, is a different story. The CDC estimates that about 2 in 100 people carry MRSA, and says the rate can be higher in some groups.⁴ A review of screening results from 33,318 healthcare workers found an average MRSA carriage rate of 4.6%.⁵ That is higher, but it still means the large majority of healthcare workers don’t carry MRSA.

The same review named three main risk factors for MRSA carriage among staff: chronic skin disease, poor hygiene practices, and having worked in countries where MRSA is common.⁵

Put simply: ordinary staph seems about as common among hospital staff as anyone else, while MRSA carriage is somewhat more common among staff. Several of the risk factors behind that gap are ones you can do something about.

Hands, not noses, are the main route

In healthcare settings, MRSA usually spreads through direct contact with an infected wound or on contaminated hands. People who carry MRSA without symptoms can pass it on too.⁴

The 2008 review concluded that healthcare workers most often act as a bridge between patients, carrying germs on their hands for a short time, rather than being the main source. When outbreaks were traced with genetic testing, spread from staff to patients was judged likely in most of the studies that looked, usually with staff acting as the link in between.⁵ The authors stressed that good hand hygiene remains essential.⁵ In other words, what your hands do between patients matters more than whether you happen to be a carrier.

Screening and decolonization

Most healthcare workers are never tested for staph. In some situations, such as an outbreak investigation, an infection-prevention team may screen staff and offer treatment to clear carriage. In the review, that treatment cleared MRSA in 88% of the workers who received it (449 of 510).⁵

Whether to screen or treat is a decision for your facility’s infection-prevention team and your doctor. It isn’t something to try on your own, and a positive swab on its own isn’t a reason to worry. It simply tells you what many people already carry.

Habits that make the difference

• Clean your hands before and after every patient contact, after touching a patient’s surroundings, and right after taking off gloves.⁶
• Remember that gloves are not a substitute for hand hygiene.⁶
• Protect your skin with a lotion your facility approves. Chronic skin conditions are a risk factor for MRSA carriage.⁵⁶
• Keep natural nails short, and skip artificial nails around high-risk patients.⁶
• Cover cuts, and talk to employee health about any skin infection before you work.

For the routine after you clock out, see Nurses and MRSA.

When to see a doctor

Being a carrier usually isn’t a problem on its own. An infection is different. See a doctor if you notice:

• A bump or sore that is red, swollen, warm, painful or full of pus¹
• A skin infection with a fever¹
• A skin infection that isn’t better within 48 hours¹
• Boils that keep coming back

Get urgent care or call 911 for fever with fast-spreading redness, confusion or trouble breathing. Don’t squeeze a sore. Keep it covered with a clean, dry bandage.¹