Study Shows MRSA Highly Prevalent in Vulvar Abscesses

   Methicillin-resistant Staphylococcus aureus (MRSA) was the most common organism isolated from vulvar abscesses in research conducted at Eastern Virginia Medical School in Norfolk. David E. Soper, MD, and Tiffany Satterfield, DO, presented the results of their study at the American College of Obstetricians and Gynecologists' 58th Annual Clinical Meeting in San Francisco.

   They set out not only to estimate the prevalence of MRSA among women with vulvar abscesses but to describe clinical factors associated with inpatient vs outpatient treatment. Drs. Soper and Satterfield reviewed all women with a vulvar abscess who were treated with incision and drainage between the months of October 2006 and March 2008. They reviewed abscess cultures and evaluated clinical and laboratory variables associated with inpatient vs outpatient treatment.

   During the 80‐week study period, 162 women were treated for a vulvar abscess. Methicillin resistant Staph aureus  was isolated from 85/133 (64%) of cultured vulvar abscesses. No presenting signs or symptoms were more common among patients with MRSA abscesses. Women with a MRSA vulvar abscess were not more likely to require inpatient admission or experience treatment complications, the researchers found. Inpatient treatment occurred in 64/162 (40%) of patients and was predicted by medical comorbidities: diabetes (odds ratio [OR] 2.29; 95% confidence interval [CI], 1.12 to 4.72), hypertension (OR 2.33; 95% CI, 1.06 to 5.13), initial serum glucose >200 (OR 3.32; 95% CI, 1.48 to 7.51), and signs of worse infection (larger abscesses [mean 5.2 centimeters], P<.001) and white blood count >12,000/mm3 (OR 3.04; 95% CI, 1.44 to 6.43).

   Inpatient treatment is more common in women with medical comorbidities, larger abscesses, and signs of systemic illness, the researchers found. An antibiotic regimen with activity against MRSA, such as trimethoprim‐sulfamethoxazole, should be considered in similar populations with vulvar abscesses.