Background: The common bed bug (Cimex lectularius), a nocturnal blood-feeding ectoparasite, is considered an urban pest with public health importance in human environments. We aimed to determine the repellency effect of oregano essential oil, Origanum vulgare, against this pest under laboratory conditions. Methods: The essential oil was prepared from dried leaves using hydro-distillation method. A gas chromatography-mass spectrometer (GC-MS) was used for analysis and identification of oregano essential oil compounds. Treated surface method in Petri dish was carried out to evaluate repellency potential of the oil using 4th and 5th instar nymphs and adults. The concentration-repellency response of oregano essential oil was calculated and compared with a commercial insect repellent stick containing 33% N, N-diethyl-meta-toluamide (DEET). Results: The oregano essential oil consisted of 158 compounds with terpineol (22.85%) and α–terpinene (20.60%) being the major components by volume. The EC50 and EC99 of oregano oil (effective concentrations causing 50% and 90% repellency of bed bugs) were 1.61 and 6.57mg/cm2 at 9h after application, respectively. The 40% oregano es­sential oil exhibited 100% repellency against bed bug at 3, 5, 9 and 24h after application while the repellency index of DEET 33% was 100% at 3 and 5h and it decreased to 80% and 27% at 9 and 24 hours. Conclusion: Oregano oil 40% exhibited more repellency compared to commercial insect repellent stick containing 33% DEET. Further studies are warranted to confirm the effectiveness of oregano essential oil in personal protecting against bed bug biting.

Background: Cimex lectularius belongs to the family of Cimicidae and its infestation to the man is a public health problem. Recently, bed bug infestation increased world-wide. Psychological distress is one of the bed bug infestations. Regarding its biting, awareness and knowledge are the keys to reduce bed bug prevalence in the society. Objectives: The current study aimed at evaluating of this investigation was to evaluate awareness, and knowledge of residents toward the bed bug in southwest Southwest of Iran. Methods: The current descriptive cross sectional study was conducted on Ahvaz residents, from June to July 2016. The questionnaire consisted of demographic characteristics, identification, knowledge about the bed bug, and awareness related to the prevention and control of the insect completed by 180 participants. Collected data were analyzed with SPSS version 16. Results: A total of 180 participants were divided into three groups that responded to the questions. The findings showed that the percentage of correctly identify the bed bug in a vial, in three groups of respondents in Ahvaz city, people, medical and pharmacy students and health workers were 13%, 25%, and 72%, respectively. The results showed that 55% of participants were male. A few of the respondents were illiterate and most of them were in the age range of 20 -29 years approximately, 13%, 25%, and 72% of the residents, university students and health staff knew the bed bug, respectively. Totally, 72% of health workers and 33% of students had good knowledge about the prevention of the insect, respectively. The results revealed that 92% of health workers were very concerned about bed bug infestation. The habitat of C. lectularius was recognized by 78% of health staff, while 23% of people did not know the pest. Conclusions: Scarce knowledge of people on nuisance insect, C. lectularius, is one of the critical causes of high infestation in Ahvaz.

Background: Bed bugs as blood-sucking insects have become a public health problem in urban communities through­out the world. The objective of this study was to determine the effects of resident education and self-implementation of Integrated Pest Management (IPM) strategy for eliminating bed bug infestation in infected apartments in Ahvaz City, Iran. Methods: This interventional study was conducted in seventy apartments infested with bed bug (Cimex lectularius) in Ahvaz City, southwest Iran, during a 6-month period. The bed bug infestations reported to Health centers were in­spect­ed visually and confirmed by medical entomology experts. Then, the heads of the households were received tech­niques/ tools of the IPM program and trained by medical entomology experts before self-implementation of control methods. Finally, the infected apartments were inspected by the experts at 1, 3, and 6 months after intervention and data were rec­orded in a checklist. Results: From the seventy infected apartments, 57%, 28% and 15% were considered as low, moderate, and high level infestation respectively. The bed bug infestation was eliminated from 53 apartments (76%) after one month and it reached to 62 apartments (88%) by the end of third month. Finally, after six months of applying IPM program, bed bugs infestation was eliminated from all infected apartments (100%). Residents expressed their 100% satisfaction with ap­plying the bed bug IPM strategy. Conclusion: Training residents to implement the IPM program can reduce pest control costs, the volume of pesticides consumed, and human exposure to chemical pesticides, resulting in increased human and environmental health and safety.

Background: Plant essential oils (EOs) as natural agents have broad activity, including antibacterial, antifungal, antiviral, insecticidal, and repellency activities because of their chemical compositions. Objectives: The objective of this study was to increase the stability of Origanum vulgar subsp. viride EOs by encapsulation in chitosan-carbomer nanoparticles by ionic gelation method. Methods: The EOs from dried leaves of O. vulgar subsp. Viride were extracted by hydro-distillation method, and EO components were determined by gas chromatography-mass spectrometry (GC-MS). Besides, OEO-loaded chitosan (CS) nano-capsules were prepared using the ionic gelation method. The molecular structure and morphology of nanoparticles were characterized by Fourier Transform-Infrared (FTIR) and scanning electron microscopy (SEM), respectively. The encapsulation efficiency (EE), loading capacity (LC) of the OEO-loaded CS nanoparticles, and their release profiles were determined using UV/Vis spectrophotometry. Results: The major components of OEO were thymol (20.53%), 4-terpinenol (20.28%), and γ-terpinene (12.22%). The percentages of EE and LC of OEO ranged from 99.25 ± 0.74 to 93.84 ± 0.71 and 38.02 ± 0.18 to 66.73 ± 0.51, respectively, with increasing the OEO to chitosan ratio from 1:0.0.01 to 1:0.0.04 W/V. The nanoparticles were regular, uniform, and spherical in shape with an average size of 134 to 181 nm, which were dispersed throughout the solution. The zeta potential values for blank chitosan nanoparticles (CSNPs) and OEO-loaded CSNPs were +23.4 and +38.5 mV, respectively. Conclusions: The results confirmed the suitability of the CS-carbomer complex for OEO- CSNPs formation. It is recommended to evaluate the antimicrobial activity of developed OEO nanoparticles in laboratory and field studies.

Background:The common bed bug (Cimex lectularius) is a small hematophagous and wingless insect of the order of Hemiptera and the Cimex genus. This insect is mainly nocturnal and feeds specifically on humans. Objectives: This systematic review reflects the distribution of the bed bug and this is a hypothesis about the relationship between the mean of humidity and temperature with the bed bug infestation that the meta-analysis evaluates. Data Sources: Various electronic databases were investigated for choosing reliable research by suitable keywords during 1995 to 2019. Relevant studies were accepted regarding to the inclusion criteria. Cochrane Q and I2 statistics were used to evaluate heterogeneity and inconsistency. Small study effects were assessed by Egger's regression test. Statistical analysis was performed using STATA12 software. Results: Four researches were entered in this review based on inclusion criteria. According to previous studies, the prevalence of bed bug infestation was reported to be from 2.8% to 90.1% in Iran. Despite of an extensive range of insect infestation, only the reports of the bed bug distribution were published in the Kohgiluye-and-Buyer Ahmad, Esfahan and Mazandaran provinces. The weighted mean of prevalence of common bed bug infestation was obtained using random effects method. The summary estimate of the prevalence was 0.28 [95% CI: (-0.01 -0.71)]. Conclusions:The current study showed that the prevalence of the common bed bug is mainly focused on the southern, southwestern and northern provinces of Iran. Moreover, the bed bug can be called a neglected urban pest, which needs further investigation to know its distribution in the country.