Texas Isolates Closely Related to Bacillus anthracis Ames

1494 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 14, No. 9, September 2008 Most studies underestimate overall prevalence by assessing it in a specifi c timeframe; to the contrary, head lice infestation is a dynamic process that can spread hypergeometrically in closed environments such as schools and in the community (7). The pointprevalence reported by Heukelbach et al (8) may represent a more accurate indicator. Although socioeconomic status seems to be an indicator of the magnitude of lice infestation, more specifi c determinants are the dynamic processes of hygienic status and overcrowding. A recent study in Turkey compared 2 neighboring villages with different socioeconomic status. The only factor that was statistically signifi cantly related to pediculosis capitis was size of the household; >6 inhabitants was associated with increased prevalence (9). Another parameter that may indirectly infl uence overall prevalence and account for the leveling of the prevalence gradient between rich and poor is awareness of head lice and preventive and therapeutic practices. A study in Australia showed that although parents prefer to play a major role in prevention and treatment, they may lack insight into recent advances and dilemmas regarding these measures (10). Variations in reported prevalence were found even in data from the same country. These differences can result from surveys being conducted during different seasons, various examination techniques, reporting of active infestation or presence of nits, and potential introduction of effective pediculicides. Although head lice account for a substantial number of missed schooldays in children, among others, it is surprising that pediculosis capitis is not monitored and prevalence is not regularly reported. Although we cannot extinguish the parasite, effective monitoring and planning will enable us to limit the prevalence and distribution of this parasitosis. Matthew E. Falagas, Dimitrios K. Matthaiou, Petros I. Rafailidis, George Panos, and Georgios Pappas Author affi liations: Alfa Institute of Biomedical Sciences, Athens, Greece (M.E. Falagas, D.K. Matthaiou, P.I. Rafailidis, G. Panos, G. Pappas); Henry Dunant Hospital, Athens (M.E. Falagas, P.I. Rafailidis); Tufts University School of Medicine, Boston, Massachusetts, USA (M.E. Falagas); and Institute of Continuing Medical Education of Ioannina, Ioannina, Greece (G. Pappas)