Intraoral persistence of Actinobacillus actinomycetemcomitans in periodontally healthy subjects following treatment of diseased family members

A. actinomycetemcomitans (Aa) can be transmitted among family members. The purpose of the present study was, to evaluate, whether A. actinomycetemcomi tans is able to persist for a prolonged period of time in periodontally hea lthy subjects following elimination of this pathogen from diseased family m embers. In 14 periodontitis patients harboring Aa as well as in their 37 fa mily members, the clinical (PPD, PAL, PII, GI) and microbiological status ( TSBV) was evaluated. After study patients received mechanical, surgical and antibiotic (3x375 mg amoxicillin+3x250 mg metronidazole/7 d) treatment, th ey, as well as their family members, were reassessed 3, 6, 9 and 12 months following therapy. From 13 spouses, 4 (31%) had periodontitis associated wi th An, 4 (31%) had periodontitis and no Aa, 2 (15%) were periodontally heal thy and harbored Aa, 3 (23%) were healthy with no detection of An. From 24 off-springs, one (4%) had periodontitis associated with Aa, 8 (33%) were he althy and harbored Aa, 15 (63%) were healthy with no detection of An. In th e 2 spouses and in 7 of the 8 offsprings being healthy, but harboring Aa, t his pathogen still persisted at the 12-month appointment, after it had been eliminated from the diseased family members. Only one child became negativ e for Aa after 12 months. The results of this study indicate that A. actino mycetemcomitans is able to persist in the oral habitats of periodontally-he althy subjects for at least 12 months, after this pathogen had been elimina ted from diseased family members. This might suggest that also in healthy f amily members, A. actinomycetemcomitans as a source of transmission should be eliminated to prevent reinfection.