Artificial nails may carry danger of staph infection

Study finds organisms even after hand washing

Artificial nails may make an appealing fashion statement, but researchers have found a nasty element lurking beneath them. Acrylic nails can harbor Staphylococcus aureus, fungus, and other organisms that could be transmitted to patients.

One study of artificial nails among health care workers found that 73% had some kind of organism on the underside of their nails, compared with 32% of those with natural nails.1 Washing with antimicrobial soap or alcohol-based gel had only a modest effect on the colonization of organisms. Of 17 health care workers with artificial nails that harbored pathogens, 94% still had a pathogen present after washing with soap and 67% had a pathogen after gel use.

"I think it’s important that someone educate health care workers that these can be dangerous for patients," says Shelly McNeil, MD, an infectious diseases fellow at the University of Michigan in Ann Arbor. McNeil conducted her research at the VA Ann Arbor Health Care Systems and the University of Michigan Medical Centers.

"We cultured the surface of the nail and underneath the nail for any kind of organism," she says. "We focused on organisms we thought could be dangerous to patients — Staph aureus, any gram-negative bacilli, and yeast. We found that health care workers wearing artificial nails had dramatically more of all three of those things."

Artificial nails, which are applied by salons with a long-lasting paste, are relatively popular. In a survey at the Ann Arbor Veterans Affairs Medical Center, 13% of female health care workers said they routinely wear artificial nails.

Outbreaks have been linked to microbial colonization of the nails. In one case, a postoperative wound infection (Serratia marcescens) was traced to a nurse who wore artificial nails.2 In other cases, patient infections may have been transmitted to the nurse’s hands.

An outbreak among newborns in a neonatal intensive care unit in Oklahoma City was linked to bacteria found under the long fingernails of two nurses. Since the hospital began requiring nurses to keep their nails short, no deaths have occurred in the neonatal ICU that were linked to the bacterial infection.3

"There are one or two outbreaks in which nurse hand flora are the same as infections in babies," says Elaine Larson, RN, PhD, professor of pharmaceutical and therapeutic research at the Columbia University School of Nursing in New York City and an expert on hand washing. "You don’t know which came first. But once a nurse has something like that, if that’s a cause of infections in high-risk patients, the nurse may not be able to work if he or she can’t get it off her hands."

The Association of periOperative Registered Nurses standards state that artificial nails should not be worn in the OR.4 Still, Larson says she has seen OR nurses who wore long artificial nails.

The nails present a potential hazard to employees as well as patients, says Larson. They could infect themselves with the flora under their nails, and they are at a greater risk of nail infections. The long nails also could puncture gloves.

"I just think they have no place in a high-risk health care environment," says Larson.

Whether or not health care workers wear artificial nails, alcohol-based gels will give them the best chance of removing lingering organisms, according to research by McNeil and Larson. One-third of health care workers without artificial nails still had some pathogen identified under their nails in McNeil’s study. In all but one individual, the gel cleansing eradicated the pathogens, while hand washing with soap failed to clear the nails of pathogens in any study participants.

In a study to be presented at AORN’s annual meeting in April, Larson found that alcohol-based gels are more effective than even the traditional surgical scrub. "It only took a minute [to clean the hands]," she says. "The antimicrobial kill was better and the effect on the skin was better without any brush or scrub."


1. McNeil SA, Foster CL, Kauffman CA. The effect of hand cleansing with antimicrobial soap or gel on microbial colonization of artificial nails. Presented at the 39th Interscience Conference on Antimicrobial Agents and Chemotherapy. San Francisco; September 1999.

2. Passaro DJ, Waring L, Armstrong R, et al. Postoperative Serratia marcescens wound infections traced to an out-of-hospital source. J Infect Dis 1997; 175:992-995.

3. Moolenaar RL, Crutcher JM, San Joaquin VH, et al. A prolonged outbreak of Pseudomonas aeruginosa in a neonatal intensive care unit: Did staff fingernails play a role in disease transmission? Infect Control Hosp Epidemiol 2000; 21:80-85.

4. "Recommended Practices for Surgical Attire." In: AORN Standards, Recommended Practices, and Guidelines. Denver: Association of periOperative Registered Nurses; 1999, pp. 183-188.