Head lice infestation in some urban localities of NWFP, Pakistan.

The prevalence of head lice infestation was estimated among the general population of four urban localities in the North West Frontier Province of Pakistan during 1986. Altogether 1002 persons (656 females, 346 males) were screened by visual inspection and combing of the head. The overall infestation rate was 36.7%, with females showing a higher prevalence (41.5%) than males (27.7%). The prevalence did not differ significantly with locality, and exhibited only a slight seasonal variation. Pediculosis was high in the five to 19 year old age-group, beyond which it decreased, gradually in females and abruptly in males. Higher rate of infestation in females could be attributed to their long hair. A significant negative association between pediculosis and dandruff was noticed in males but not in females. Crowding and low level of education, which reflect poor socio-economic status, apparently contributed to higher rate of infestation. Prevalence was directly related to the number of children per family, suggesting that school children perhaps play an important role in the distribution of lice. Intensity of infestation, like prevalence, was higher in females than males, and decreased with age in both sexes.