Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 50 1 2020 12 28 101 110 Mustapha Ahmed YUSUF Department of Medical Entomology & Vector Control, School of Public Health, International Campus, Tehran University of Medical Sciences, Tehran, Iran AND Department of Medical Microbiology and Parasitology, College of Health Sciences, Bayero University, Kano, Nigeria Hassan VATANDOOST Department of Medical Entomology & Vector Control, School of Public Health, International Campus, Tehran University of Medical Sciences, Tehran, Iran AND Department of Chemical Pollutants and Pesticides, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran Mohammad Ali OSHAGHI Department of Medical Entomology & Vector Control, School of Public Health, International Campus, Tehran University of Medical Sciences, Tehran, Iran Ahmad Ali HANAFI-BOJD Department of Medical Entomology & Vector Control, School of Public Health, International Campus, Tehran University of Medical Sciences, Tehran, Iran AND Department of Chemical Pollutants and Pesticides, Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran Abdulsalam Yayo MANU Department of Medical Microbiology and Parasitology, College of Health Sciences, Bayero University, Kano, Nigeria AND Center for Infectious Diseases Research, Bayero University, Kano, Nigeria Ahmadali ENAYATI Department of Medical Entomology, School of Public Health and Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran Abduljalal ADO Department of Science, Kano State Polytechnic, Kano, Nigeria Alhassan Sharrif ABDULLAHI Department of Medical Microbiology and Parasitology, College of Health Sciences, Bayero University, Kano, Nigeria Rabiu Ibrahim JALO Department of Community Medicine, College of Health Sciences, Bayero University, Kano, Nigeria Abubakar FIRDAUSI Department of Family Medicine, College of Health Sciences, Bayero University, Kano, Nigeria 2019 09 01 2019 12 01 Background: Malaria is a parasitic vector-borne disease endemic in the tropical and subtropical countries of the world. The aim of this study was to investigate the current activities of the detoxification enzymes in resistant and susceptible Anopheles gambiae s.l. in northern Nigeria. Methods: Anopheles larvae were collected from northeast and northwestern Nigeria between Aug and Nov 2018. Biochemical analyses was carried out on the mosquitoes exposed to various insecticides (deltamethrin, DDT, bendiocarb, malathion) to measure and compare the enzymatic activities of the major detoxification enzymes (P450, GSTs, Esterase). Results: High levels of resistance was observed; DDT 37%-53% (95%, CI: 29-61), bendiocarb 44%-55% (CI: 39-60) and deltamethrin 74%-82% (CI: 70-86). However, these mosquitoes were found to be susceptible to malathion 99%-100% (CI: 98-100). The P450 and GSTs enzymes were found to be elevated in the resistant mosquitoes exposed to deltamethrin (1.0240±0.1902); (1.3088±1.2478), DDT (1.7703±1.4528); (1.7462±0.9418) and bendiocarb (1.1814±0.0918); (1.4479±1.0083) compared to the Kisumu strain (0.764±0.4226); (0.6508±0.6542), (0.3875±0.3482); (0.4072±0.4916) and (0.6672±0.3949); (0.7126±0.7259) at P<0.05. Similarly, the resistant mosquitoes expressed increased activity to esterase (0.7606±1.1477), (0.3269±1.1957) and (2.8203±0.6488) compared to their susceptible counterpart (0.6841±0.7597), (0.7032±0.5380) and (0.6398±0.4159) at P<0.05. The enzyme ratio was found to be: P450 (1.341, 4.568 and 1.77); GSTs (2.011, 4.288 and 2.031); Esterases (1.111, 0.469 and 4.408). One way Anova and single sample t-test were also conducted to determine the effect of the enzymes on the resistant and susceptible strains. Conclusion: High level of insecticide resistance was observed with significant elevation of detoxification enzymes activities in the resistant mosquitoes. https://ijph.tums.ac.ir/index.php/ijph/article/view/18221 https://ijph.tums.ac.ir/index.php/ijph/article/download/18221/7100