Modeling the evolution of a lice colony in the school

TOLOZA A; RISAU-GUSMAN S; VASSENA C; LAGUNA F

Conferencia; 5th International Conference on Phthiraptera; 2014

Head lice have been associated with humans throughout ages, probably since our pre-hominid African ancestors. Since then, every year they infest millions of school-age children in both developed and developing countries. However, little is known about the number of lice transferred among children during school activities. In the present study, we analyzed a group of children attending a school and we evaluated the number of infested children and the severity of the infestation. Then, we used that information to estimate the number of transferred lice. Head lice were obtained from heads of infested children of six years old from an elementary school. We performed two collecting visits separated by 11 days. In the lapse between visits, children performed their normal activities. The collected data, reporting the number of infected children and their levels of infestation, were used to perform numerical simulations with a mathematical model of head lice populations. The results allowed us to propose a scenario for the time evolution of the lice colony which reproduces the infestation levels observed in both visits. Moreover, we estimate the number of transferred lice during the lapse between the two visits, and found a value which is consistent with previous estimations of this parameter, obtained from theoretical models.