Avaliação da frequência de parasitismo e da sobrefida de exemplares de Pediculus capitus (De Geer, 1778) (Phthiraptera: Pediculidae) fora do hospedero

During the months of June and July of 2002 an evaluation was made to determine how widespreaded was the infestation by Pediculus capitis in the inmates, aged one to twenty one years, of the "Centro Socio Cultural Nossa Senhora do Rosario de Fatima", Itaperuna, RJ (Boarding school and Nursery). Also it was researched how long the lice survived away from the host. The evaluation was conducted in two stages, as follows: 1- Aspects related to the frequency of parasitic infestations. 2- Aspects related to the parasite itself. A physical examination was performed on the head hair of the subjects and the louse specimens were handpicked. For the second stage the specimens were kept in Petri slides with the proper level of oxygen and the ambient temperature and relative humidity of the air were monitored. The data obtained in both stages were statistically evaluated using the KHI^sup 2^ ([chi]^sup 2^) method. The results obtained were as follows: of the total population subject to the evaluation 37.13% had pediculosis. Of those who had pediculosis 64.44% were females. Of those with pediculosis 84.61 % had white skin, long and straight hair 65.75% and 80.43%, respectively. The most evident clinical manifestation was itching (82.51%) followed by rash (10.14%) and blisters (7.25%). The area with the highest incidence was the occipital-cervical region with 50.00%. With six hours intervals observations were made to determine which variables affected the survival. A higher percentage was found for the period of 12 to 16 hours (57.54%) and a lower percentage for the period of 30 to 36 hours (2.79%), the average survival time away from the host being 16 hours. No sample survived beyond 32 hours.Considering the conditions of the investigation we can come to the conclusion that pediculosis is highly prevalent in the "Centra Socio Cultural Nossa Senhora do Rosario de Fatima", as far as be susceptible to pediculosis the inmate of the boarding school and of the nursery are equally prone.