Most Common Risk Factor for Antibiotic Resistant Hand Infection
The overuse of antibiotics has led to bacteria that have become resistant to the effects of antibiotics. You may have heard of this problem. The term superbugs has been used to describe staphylococcus aureus ("staph") bacteria that are no longer killed off by drugs. The infection that can develop is called methicillin-resistant S. aureus or MRSA (pronounced Mer'-suh).

The number of cases of MRSA continues to rise steadily. The biggest group of patients affected are those in the hospital, nursing homes, or other extended care facilities. Patients on dialysis or who have a weak immune system are also at increased risk for MRSA. But there's another twist to this story. Now there is community-acquired MRSA or CA-MRSA infections.

Community-acquired MRSA (CA-MRSA) is a methicillin-resistant staph infection that occurs in healthy people. These folks are not in the hospital, are not on dialysis, and except for this new infection, are otherwise in good health. The bad news is that studies have shown this type of superbug didn't spread from the hospital to the community. It's a different bacteria with a different genetic makeup compared with the hospital-based MRSA.

The good news is that community-acquired MRSA infections can still be treated using antibiotics. That's good news, indeed, for the many patients who develop hand infections severe enough to require surgery. In order to better understand what's going on, who is at risk, and why, the authors of this study conducted a retrospective chart review. That means they took a look at their medical records and identified all patients who had been treated for hand infections.

There were just over 100 patients who came to the level one trauma unit at the New Jersey Medical School in Newark, New Jersey. The specific time period selected for review was the seven-year period between 2002 and 2009. All patients included had a hand infection that was treated surgically with a procedure called debridement. The surgeon removes any pus and dead tissue to make way for a healthy healing response.

When they tested the infection to find out what type of bacteria was present, one-third of the group had community-acquired MRSA. The rest of the group had a wide variety of different types of bacteria. Some patients had multiple organisms present in the soft tissues of the hand. The next logical question was: Why? What put this particular group of patients at risk for CA-MRSA?

Taking a look at all the data gathered on age, medical history, sex (male or female), type of hand injury, where the people live, lab values, and so on, there was one distinct risk factor. And that was the intravenous use of illicit drugs. And there was a peak in the number of such cases between 2005 and 2006.

The authors suspect the drop in number of infections related to intravenous drug use after 2006 might be the result of educational efforts at that time by the National Institute on Drug Abuse (NIDA). Campaigns aimed at teens and young adults may have led to some changes in behavior with less drug use/abuse.

Recommendations as a result of this study are three-fold:
1. Antibiotics are advised for anyone with a hand infection. Once the culture comes back from the lab, the best antibiotic to best combat the specific bacteria present can be chosen.
2. For patients who have been using intravenous (illicit) drugs, MRSA specific antibiotics should be started immediately until lab results are available. Then the medication can be changed if needed.
3. More studies must be conducted to confirm these recommendations and to find ways to prevent the further spread of community-acquired MRSA.

The authors point out several things about their own study that should be kept in mind when reviewing their results and recommendations. First, the patients they saw might not be the same as patients affected in other facilities or even other areas of the country. As a level-one trauma center in a large city, their patients might be very different from those patients treated in a different setting (e.g., small rural hospital or clinic).

Not all patients seen in this trauma center who came with hand injuries were included in the study. Anyone seen by a plastic surgeon (instead of by the orthopedic surgeon) was not included in the hospital database. Since the orthopedic surgeons share emergency room coverage with the plastic surgeons, that means half the patients (those seen by the plastic surgeons) weren't included. This type of situation can skew the results so further investigation is needed.
Ali Nourbakhsh, MD, et al. Stratification of the Risk Factors of Community-Acquired Methicillin-Resistant Staphylococcus Aureus Hand Infection. In The Journal of Hand Surgery. July 2010. Vol. 35A. No. 7. Pp. 1135-1141.