Phthirus pubis in a sexually transmitted diseases unit: a study of 14 years.

Background: There have been few epidemiologic studies of pubic lice in recent times, and the exact incidence is unknown.

Goal: The goal was to determine the trends of pubic lice infestation in a risk group of males and female prostitutes in an STD unit in Spain.

Study Design: This was a prospective 14-year study, from 1988 to 2001, of all patients attending the STD unit in Gijón (Asturias, Spain), investigating crab lice and other STDs.

Results: One hundred ninety-seven patients (2.2%) had pubic lice, with a male/female proportion of 1.8/1. The yearly infestation rate ranged from 1.3% to 4.6%. The mean age was 30.3 years, and 18.8% of patients were older than 35 years. There were more cases involving men who had sex with men (MSM) (P < 0.001) than those involving heterosexual men. Reinfestation occurred in 7.6% of patients, more often in males (P < 0.05) and mainly in MSM (P < 0.01).

Conclusion: Infestation rates were stable during the period of study, with more older patients involved than reported previously, and infestation frequently was associated with STDs. MSM were infested and reinfested more often than heterosexual men, and in general reinfestations occurred more frequently in males than in females.