Prevalence and Susceptibility Status of Body Louse (Pediculus humanus humanus) (Anoplura: Pediculidae) to Deltamethrin in Urmia City, Iran (2024)

Samira  Firooziyan; Ahmadali  Enayati; Ehsan  Rikhtegar; Tahereh Sadat  Asgarian; Mohammad Mehdi  Sedaghat

doi:10.18502/jad.v19i2.20196

Samira Firooziyan Pathogens and Vectors Research Center, Cellular and Molecular Medicine Research Institute, Urmia University of Medical Sciences, Urmia, Iran
Ahmadali Enayati Department of Medical Entomology and Vector Control, School of Public Health and Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran
Ehsan Rikhtegar Department of Internal Medicine, School of Medicine, Taleghani Hospital, Urmia University of Medical Sciences, Urmia, Iran
Tahereh Sadat Asgarian Department of Vector Biology and Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Mehdi Sedaghat Department of Vector Biology and Control of Diseases, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/jad.v19i2.20196

Keywords: Bioassay; Pediculus humanus; Insecticide resistance; Pyrethroid; Iran

Abstract

Background: The body louse spreads diseases such as epidemic typhus and louse-borne relapsing fever and has shown resistance to various insecticides. While deltamethrin is used to treat infestations in some countries, research on its effectiveness against body lice is limited. This study assessed the susceptibility of body lice to deltamethrin using a bioassay.

Methods: Body lice specimens were collected from an addiction treatment camp in Urmia City, West Azerbaijan Province, Iran. They were treated in 5 cm Petri dishes lined with 1 ml of various concentrations of deltamethrin (0.01, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, 1.28, and 2.56 ppm) in acetone. Thirty lice were tested per concentration, with mortality recorded after 24 hours. Lethal concentrations of 50% and 90% (LC₅₀ and LC₉₀) were calculated using Minitab and compared with SPSS. The regression line was plotted in Excel 2013.

Results: A positive correlation was observed between the concentrations of deltamethrin and probit mortality in the regression analysis. The calculated LC₅₀ and LC₉₀ values for deltamethrin against body lice were 0.11 ppm and 2.15 ppm, respectively.

Conclusions: These findings suggest that the body lice population was susceptible to deltamethrin, suggesting its potential as an alternative treatment, pending further clinical studies.