---

ABSTRACT Background and Aim: Strategies to manage resistance to insecticides have usually been designed when resistance has already been developed. However, if the likelihood of resistance development to novel insecticides can be predicted before their use, it should be possible to establish an effective resistance management program. The current study was designed to investigate the effect of fipronil against permethrin sensitive and permethrin resistant strains of Blattella germanica (L.) for effective control of this pest in Iran in the future. Materials & Methods: In order to conduct this study eleven feral German cockroach strains were collected from infested student dormitories of Tehran University of Medical Sciences, Sanatee Sharif, Tarbiat Modares and Tehran Universities and also residential Saman Apartments, and two infested hospitals in Tehran. Their sensitivity to permethrin and fipronil were compared with that of a standard susceptible strain. Tests were conducted on newly emerged adult males (ultimately 21 years old) by topical application. Results: LD50`s of permethrin and fipronil for the susceptible strain were 0.43µg and 0.96 ng respectively. The resistance of feral strains to permethrin was 8.6 to 17.7 times as much as that of the susceptible strain. According to this investigation all strains are resistant to permethrin, whereas resistance rates of the strains from Bustan-10, Zanjan Fatemiyeh dormitories and residential Saman Apartments were 2 to 2.6 times more than that of the susceptible strain. Other strains were completely susceptible to fipronil. Conclusion: According to the results of this study and considering ever-increasing infestation of human habitations by German cockroach and the resistance to insecticides fipronil especially its toxic bait formulations can be regarded as the appropriate candidate to control this pest in Iran. Key words: German cockroach, Susceptibility level, Fipronil, Permethrin

---

ABSTRACT Background and Aim: Pyrethroids are commonly used as insecticides for both household and agricultural purposes, and recently have been shown to have detrimental effects on endocrine system. Permethrin is a type I pyrethroid which is used widely in Iran. In the present study the effects of permethrin on sexual behaviour and plasma level of PG (pituitary-gonadal) hormones of adult male mice were investigated. Material and Methods: Mice received daily Intra peritoneal injection of permethrin (10, 15, 20 mg/kg) for 5 weeks. Using receptive females, permethrin-treated male mice exhibited reduced sexual behavior (i.e. decrease in the number of sniffing, following, mounting and mating). Results: The concentrations of plasma testosterone, LH and FSH were measured by means of ELISA method. Serum testosterone levels were reduced significantly (p<0.05) in the experimental group versus control group, whereas FSH and LH values were not altered significantly. Conclusion: The results of this study indicate permethrin can have detrimental effects on plasma testosterone level and sexual behavior. In regard to considerable use of this insecticide in Iran, it’s necessary to restrain its use and extent of human contact to prevent hazards of this insecticide on human body tissues. Key words: Insecticide, Permethrin, Sexual hormones, sexual behavior. Conflict of Interest: Nill Received: January 14, 2007 Accepted: July 13, 2008

---

Background and Aim: Nowadays, there are many challenges in the treatment of head lice infestation and the efficacy of anti-lice products is a very important factor. The aim of this study was to determine the effectiveness of using vinegar before and after application of permethrin shampoo for the treatment of head lice infestation in the elementary school students in Qom Province.
Materials and Methods: Our study inclueded 200 female students infested with head lice referring to two comprehensive urban health centers of Qom University of Medical Sciences from September to February 2020. The patients were between 13 and 17 years of age. Using blocked randomization with randomly selected block sizes, the patients were treated with either application of vinegar before or after using 1% permethrin shampoo. Removal of adult human head lice, nymphs, and nits were considered as the outcome of the treatment methods.

Results: The current standard treatment method proposed by the Ministry of Health (use of vinegar after applying permethrin shampoo 1%) resulted in the treatment of the infestation in 45% of cases. But the experimental treatment method (using vinegar before applying permethrin shampoo 1%) led to successful treatment of 79% of the participants and showed a high Odds Ratio (OR = 4.6 CI = 2.5-8.5 p = .000). 

Conclusion: This study did not approve the current standard treatment method of the Ministry of Health (use of vinegar after consuming permethrin shampoo 1% for removal of head lice infestation). Therefore, we recommend application of vinegar before using permethrin shampoo 1%.