Association of Head Lice Infestation with Staphylococcal Dysbiosis: Molecular Identification of Pediculus capitis and Staphylococcal Profiling in School Children

Background: Head lice infestations are a widespread health problem among school-aged children globally. Neverthe­less, the importance of lice as initiators of scalp microbiome changes and as causes of secondary bacterial superinfec­tions remains poorly understood. The paper aims to examine the PCR-based identification of head lice and to assess the epidemiological relationship between head lice infestation and scalp colonization by Staphylococcus species.

Methods: An analytical cross-sectional study was conducted on 100 primary school children (50 infested and 50 con­trols) aged between 5 and 12 years in the governorate of Nineveh (Iraq). The molecular identification of head lice was performed by amplifying the COX1 gene, and the comprehensive Staphylococcal profiling of scalp swabs was per­formed using culture and 16S rRNA gene amplification.

Results: Molecular analysis using COX1 gene specific amplification showed the presence of P. humanus capitis in 93.9% of the collected samples. The microbiological tests showed profound staphylococcal dysbiosis: Staphylococcus aureus was detected in 74% of infested children and absent in the control group (0%), indicating a highly significant association (χ²=58.73, p<0.001). Conversely, the commensal Staphylococcus epidermidis was found predominantly in healthy controls (66%) but significantly less frequently in infested children (26%).

Conclusion: The pathogenic S. aureus prevails on the scalp of children with head lice with a striking shift, which illus­trates a clinically significant interaction of ectoparasitic infestation with staphylococcal dysbiosis. The results also sug­gest that pediculosis is a risk factor for S. aureus overgrowth and emphasize the need for combined treatment strategies that address lice and bacterial complications.