Mucosal swabs detect HPV in laryngeal papillomatosis patients but not family members.

Seven patients, aged 2-7 years, with active recurrent respiratory papillomatosis (RRP) attending the University of Michigan Pediatric Otolaryngology Clinic were studied to determine if human papillomavirus (HPV) is harbored in sites of the upper aerodigestive tract other than in the laryngeal papilloma itself. We also determined if close family members had detectable virus in their oral cavities. Noninvasive swabs of buccal mucosa, posterior pharynx, nasal vestibule, and tonsillar pillar of patients, as well as buccal mucosa and posterior pharyngeal swabs of family members were studied. Swabs of the patients' papillomas served as the positive controls. HPV was detected using polymerase chain reaction (PCR) amplification and Southern hybridization techniques. Six of seven patients had detectable HPV in papilloma and endolaryngeal swabs. Four were HPV type 6, and two were HPV type 11. The patient whose swab was negative for HPV was found to be biopsy negative for papilloma 3 weeks after a single laser excision which was performed 6 months prior to the endolaryngeal swab. HPV types 16, 18 and 31 were not found in any of the patients. No swabs from other sites in patients or family members were HPV positive despite the presence of adequate DNA in the swabbed material for successful amplification of beta-actin sequences. The absence of HPV (other than in the papilloma itself) in the upper aerodigestive tract of patients and caregivers is consistent with the absence of reported cases of horizontal transmission to siblings or other family members. The findings are also consistent with the conventional view that juvenile respiratory HPV is transmitted vertically from vaginal condylomas in the mother.