Actinomyces naeslundii as an agent of pelvic actinomycosis in the presence of an intrauterine device

Abstract

Actinomyces naeslundii is a saprophyte, sometimes a pathogen, of the human oral cavity. Very few extra-oral infections related to this agent have been described. We report the first instance of A. naeslundii as an etiological agent of pelvic actinomycosis in a user of an intrauterine device, an infection so far exclusively attributed to Actinomyces israelii.

PIP: This paper presents the 1st reported case of Actinomyces naeslundii isolation in pelvic actinomycosis in an IUD user. Up until this point, all such cases of infection had been linked to A. israelii. The patient was a 39-year old woman who had had a Dalkon Shield device inserted 10 years prior to her admission with sharp, progressive abdominal pain. Scanning revealed a midline, posterior, extrauterine, large, complex mass which was reduced dramatically in size after treatment with penicillin and probenecid. Direct immunofluorescence clearly identified the organism recovered from the IUD as A. naeslundii, although the clinocopathologic presentation in this case was similar to that found in A. israelii-related pelvic actinomycosis. Most infections with this agent are restricted to the oral cavity. However, these findings suggest that A. naeslundii is an occasional saprophyte of the lower genital tract as well. Orogenital sexual practices are believed to provide actinomycetes with access to the genital tract. The patient in this case had 2 risk factors for developing pelvic actinomycosis: use of the Dalkon Shield (the model associated with the highest incidence of infection) and longterm IUD use.