Staph remains leading SSTI, expert says

NEW YORK — Staphylococcus aureus remains the leading cause of skin and soft tissue infections, or SSTIs, according to a pediatric infectious diseases expert.

C. Buddy Creech, MD, MPH, professor of pediatric infectious diseases at Vanderbilt University, presented on the topic during this year’s Infectious Diseases in Children Symposium.

“One of the things I want us to think about when we're dealing with kids with recurrent skin and soft tissue infections is it's very hard to keep people from carrying staph,” said Creech, who is also an Infectious Diseases in Children Editorial Board Member. “If you have skin and if you have a nose, you're going to carry staph.”

However, Creech said his institution is seeing fewer and fewer cases of recurring staph infections in the same patients.

“We were draining about 2,500 abscesses a year in our ED, but now we're down to about 150,” Creech said. “Our outpatient urgent cares see a few of those, so I think there has been a little bit of a shift, but our pediatricians in the area have been saying that they have seen fewer cases, and as a result, they've seen a little bit of an improvement in those that are having recurrent infections.”

He mentioned several groups that would greatly benefit from an S. aureus vaccine, particularly patients with comorbidities.

“What we know is that those with HIV, diabetes, those with hematologic or solid tumor malignancies — those [patients] are more likely to not only have disease but more likely to have recurrence,” Creech said.

Creech also discussed research on antibiotic therapy for staph infections, citing a 2015 study he coauthored that involved 524 adults and children with uncomplicated skin infections who had cellulitis, large abscesses (> 5 cm) or both. The patients underwent incision and drainage and were randomly assigned to receive ether clindamycin or trimethoprim-sulfamethoxazole (TMP-SMX). Clinical cure at the end of the 10-day treatment was similar — 90% in the clindamycin group and 88% in the TMP-SMX group — but only 84.7% of patients in the TMP-SMIX group did not experience a recurring infection at 1 month, compared with 91% in the clindamycin group.

“Why would that happen? Well, clindamycin has been shown in one study in the 70s to eradicate carriage [of S. aureus] in the nasal mucosa,” Creech said. “So it may be that in some individuals, we're actually eradicating this problematic strain.”

Creech mentioned a second study published in 2017 that included 786 adults and children with uncomplicated skin infections who had cellulitis or small abscesses (<5 cm) or both and were treated with clindamycin, TMP-SMX or a placebo. Although 83% of patients in the clindamycin group experienced symptom resolution or cure and relatively few (7%) had a recurrence at 1 month, 22% of the group experienced adverse events — the most of any of the three groups.

Creech described it as a trade-off: “There are more adverse events in the clindamycin group, but maybe fewer recurrences [of staph infections] in the same group.”

Creech closed by advocating for decolonization as a preventive measure against S. aureus and recommended mupirocin ointment for affected areas on the body and washing linens and cleaning other household surfaces with chlorhexidine.

References:

Daum R, et al. N Engl J Med. 2017;doi:10.1056/NEJMoa1607033.

Miller G, et al. N Engl J Med. 2015:doi 10.1056/NEJMoa1403789.