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Chulalongkorn Medical Journal, 67, 3, 161-165

Background: Head lice is a worldwide parasitic disease that can be considered a threat to public health. The majority of its prevalence is among children aged from 6 to 11 years. Due to students’ low attention to personal hygiene tips, and presence in populated places such as schools, they are more prone to head lice infestation; thus, studying this disease among students is a hygienic priority. The current study was undertaken among primary girl students in Doroud County with the aim to determine the prevalence of head lice infestation and its relations with epidemiologic factors and to evaluate the treatment efficay of permethrin shampoo 1% and dimethicone. Methods: The present study was performed in two phases: observational (cross-sectional) and interventional (clinical trial). Five schools were selected from five geographical areas for sampling. Other information was collected from student records or by direct inquiry. Eighty girls infested were randomly allocated in two groups and received either one of the mentioned treatments. The results of the interventions were evaluated on days 7 and 14. Results: The prevalence of head lice infestation was10.3%. The most involved group (40 %) were students of third grade. The father’s education and shower times per week showed significant effects among epidemiologic factors (p value = 0.05). The outcome of treatment in the first week did not show a significant difference between the groups. Treatment with dimethicone lotion in the second week (p value = 0.025) and in general during two weeks (p value = 0.006) was more effective in removing the head lice than permethrin shampoo. Conclusion: Head pediculosis is more prevalent among girl students whose fathers are less educated and take less showers in a week. Thus it is crucial to deal with head lice by social health education among families. In addition, dimethicone lotion is more effective than permethrin shampoo in eradicating this external parasite.

Blattella germanica (L.) (Blattaria: Blattellidae), the German cockroach, is worldwide the most invasive pest of dwellings, with an increasing resistance to various groups of insecticides. To prevent this problem, special attention is being paid to the new bait insecticides with novel action mechanisms. Therefore, a survey was designed to consider bait efficacy containing abamectin (Vendetta®), dinotefuran (Alpine®), imidacloprid (Invict Gold™) and pyriproxyfen + abamectin (Vendetta Plus®) against the German cockroach. Six cockroach strains including susceptible (reference strain), and five fresh field strains were used in the study. To achieve bait efficacy, the experiments and bait placements were designed according to the WHO (World Health Organisation) method. Although the cockroach strains fed on and were attracted to all investigated baits, baits containing abamectin B1 and pyriproxyfen + abamectin B1 were ingested at higher rates than baits containing dinotefuran and imidacloprid. Based on rank of bait consumption it was concluded that the rank of the bait attractiveness are baits containing abamectin, pyriproxyfen + abamectin, dinotefuran and imidacloprid in this order. While it seems that the efficacy of the dinotefuran and imidacloprid baits would be better than the pyriproxyfen + abamectin and abamectin baits due to them achieving 100 % cumulative mortality rates after cockroach feeding of 2 days (48 h) and 2 days (48 h) than 6 days (164 h) and 7 days (188 h), respectively. Based on results of the study, baits containing abamectin, dinotefuran, imidacloprid and abamectin + pyriproxyfen can be recommended to control B. germanica.

In this study, salt-assisted liquid–liquid extraction (SALLE) method is coupled with reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) as a novel method for the determination of paraquat in various samples. Firstly, paraquat was extracted from the aqueous phase into the acetonitrile and then it pre-concentrated into the aqueous phase using the RP-DLLME method. Influential parameters of SALLE such as extracting solvent, volume of extracting solvent, sample pH, salt and its concentration were optimized. Also, effective parameters of RP-DLLME including immiscible solvent and its volume, and water volume as extracting solvent were investigated. Under the optimized conditions recoveries and relative standard deviations were in the range of 80.0–96.0 and 3.5–7.5, respectively. The limit of detection and limit of quantification of method were 0.02 and 0.09 µg/mL, respectively. The proposed method successfully was applied for the determination of paraquat in food and environmental samples.

The present study evaluated the efficacy of Maxforce gel baits containing 0.01% fipronil (Maxforce), 0.05% fipronil (Maxforce Magnum), 1.0% clothianidin (Maxforce Impact), and 0.6% indoxacarb (Avion gel bait; all from Bayer Environmental Science, Clayton, CA, USA) against reference and wild strains (Mobasher, Andisheh, Tamin‐e Ejtemaei, and Maskoni) of German cockroach collected in 2016. Test design and bait placement were according to World Health Organization (WHO) procedures for efficacy achieving a 95% mortality rate. Although cockroaches fed on all gel baits, gel baits containing clothianidin and indoxacarb were eaten at higher rates than gel baits containing 0.01% and 0.05% fipronil. The cumulative mortality rates reached 100% for all cockroach strains at 32, 28, 28 and 40 h after eating baits containing 0.01% fipronil, 0.05% fipronil, clothianidin, and indoxacarb, respectively. Efficacy (a 95% mortality rate) after exposure (consumption) of gel baits containing 0.05% fipronil and clothianidin was seen after 28 h, compared with 32 h for 0.01% fipronil and 40 h for indoxacarb. In conclusion, commercial gel baits have improved and may be more effective than spray formulations against German cockroaches.

Background Paraquat poisoning leads to lung injury and pulmonary fibrosis. The effect of paraquat encapsulation by previously described Pectin/Chitosan/Tripolyphosphate nanoparticles on its pulmonary toxicity was investigated in present study in a rat model of poison inhalation. Material and method The rats inhaled nebulized different formulation of paraquat (n = 5) for 30 min in various experimental groups. Lung injury and fibrosis scores, Lung tissue enzymatic activities, apoptosis markers were determined compared among groups. Results Encapsulation of paraquat significantly rescued both lung injury and fibrosis scores. Lung MDA level was reduced by encapsulation. Paraquat poisoning led to lung tissue apoptosis as was evidenced by higher Caspase-3 and Bax/Bcl2 expressions in rats subjected to paraquat inhalation instead of normal saline or free nanoparticles. Again, nanoencapsulation reduced these apoptosis markers significantly. Alpha-SMA expression was also reduced by encapsulation. Nanoparticles per se have no or little toxicity as was evidenced by inflammatory and apoptotic markers and histological scores. Conclusion In a rat model of inhalation toxicity of paraquat, loading of this herbicide on PEC/CS/TPP nanoparticles reduced acute lung injury and fibrosis. The encapsulation also led to lower apoptosis, oxidative stress and alpha-SMA expression in the lung tissue.

As a potent herbicide capable of contaminating water and soil environments, paraquat, which is still widely used worldwide, is toxic to mammals, algae, aquatic animals, etc. Paraquat was loaded on novel nanoparticles composed of pectin, chitosan, and sodium tripolyphosphate (PEC/CS/TPP). The size, polydispersity index, and ζ potential of nanoparticles were characterized. Further assessments were carried out by SEM, AFM, FT-IR, and DSC. The encapsulation was highly efficient, and there was a delayed release pattern of paraquat. The encapsulated herbicide was less toxic to alveolar and mouth cell lines. Moreover, the mutagenicity of the formulation was significantly lower than those of pure or commercial forms of paraquat in a Salmonella typhimurium strain model. The soil sorption of paraquat and the deep soil penetration of the nanoparticle-associated herbicide were also decreased. The herbicidal activity of paraquat for maize or mustard was not only preserved but also enhanced after encapsulation. It was concluded that paraquat encapsulation with PEC/CS/TPP nanoparticles is highly efficient and the formulation has significant herbicide activity. It is less toxic to human environment and cells, as was evidenced by less soil sorption, cytotoxicity, and mutagenicity. Hence, paraquat-loaded PEC/CS/TPP nanoparticles have potential advantages for future use in agriculture.

Metal oxide nanoparticles (NPs), such as TiO2 and CuO, are widely applied in an increasing number of products and applications, and therefore their release to the aquatic ecosystems is unavoidable. However, little is known about joint toxicity of different NPs on tissues of aquatic organisms, such as fish. This study was conducted to assess the uptake and depuration of Cu following exposure to CuO NPs in the presence of TiO2 NPs in the liver, intestine, muscle, and gill of common carp, Cyprinus carpio. Carps with a mean total length of 23 ± 1.5 cm and mean weight of 13 ± 1.3 g were divided into 6 groups of 15 each (1 control group) and exposed to TiO2 NPs, CuO NPs, and a mixture of TiO2 and CuO NPs for periods of 20 days for uptake and 10 days for depuration. The determination of total Cu concentration was carried out by an ICP-OES. The order of Cu uptake in different tissues of the carps was liver > gill > muscle > intestine in both levels of CuO NPs alone; results showed that the total Cu concentrations in the presence of TiO2 nanoparticles were increased and were in the sequence of liver > gill > intestine > muscle. In depuration period, Cu concentrations were decreased in all treatments in the sequence of gill > intestine > muscle > liver. Uptake of Cu in different tissues of common carp increased with increasing concentration and time and was tissues- and time-dependent. In conclusion, this study suggested that the uptake of Cu in the tissues of common carp increased in the joint presence of TiO2 NPs.

Cockroaches have been associated with human environments threatening human health. A cross-sectional study about cockroach fungal contamination in the hospital, restaurant and household environments from Khorramabad, Lorestan province of Iran between August 2015 and March 2016 was done. Sampling was uniformly carried out monthly from the randomly selected sites. Fungi were isolated from the external surfaces of cockroaches using standard method. Periplaneta americana (66.7%) was found the most infested cockroach, less percentage were observed in Blattella germanica (18.6%) and Blatta orientalis (14.7%). Hospitals (66.7%) were found the most infested places in comparison with households (18.6%) and restaurants (14.7%). Households (64.3%) were found the most cockroach fungal contaminated places than hospitals (49.0%) and restaurants (59.1%). The highest and the lowest infestation of cockroaches were observed in January (30.0%) and March (7.0%) respectively, while the highest and the lowest cockroach fungal contamination were observed in November (73.3%) and March (14.3%). B. germanica (60.7%) was the most fungal contaminated cockroach. Candida , Geotrichum and Penicillium were the most frequent cockroach fungal contaminating genera. Statistical analysis revealed significant differences between cockroach infestation places (P=0.022), locality (P=0.03), and monthly (P=0.0001) cockroach fungal contamination, respectively. As a conclusion, the highest cockroach fungal contamination was observed in B. germanica, followed by P. americana and B. orientalis. Some human fungal opportunistic pathogens were also found among the fungal contaminated cockroaches. Recent epidemiological survey showed that the mortality rates of the infective diseases were increased, indicating cockroaches involved in their transferring.

Metal oxide nanoparticles (NPs), such as TiO

Background Leishmaniases are important diseases in many parts of the world, which are transmitted by bites of sand flies. Objectives This study aimed at investigating some ecological aspects of sand flies in Hamadan. Materials and Methods In this descriptive cross-sectional study, sand flies were collected weekly by sticky traps. Results For this study, 3305 sand flies were collected and identified during 2013. Sand flies active season began from May till October in Hamadan. The greatest activity occurring between 08:00 pm till 12:00 pm. Conclusions In order to avoid the possible transmission of diseases and reduction of harassments of sand flies, especially in the period of greatest activity, personal protection is recommended.

Objective To determine the faunal diversity of Muscidae and Fanniidae flies in Tehran, Iran. Methods A net-capturing by direct observing method and fly trap were used to capture adult flies. To determine the fauna of flies in different habitats, 4 biotopes including corpse (human, birds, livestock), garbage and decaying organic matters, animal carcasses and human indoor habitat were selected. Big hashing nets (95 cm in diameter) have been used for adult flies capture in these biotopes. Results In this study, totally 2 418 adult flies from 8 families including Muscidae, Fanniidae, Calliphoridae, Sarcophagidae, Tachinidae, Syrphidae, Anthomyiidae and Conopidae were captured. Among these, 1 279 belong to Muscidae and Fanniidae families. Four genera and 5 medically important species captured from two above mentioned families. Conclusions Based on scientific documentation, 2 species of Muscina stabulans (M. stabulans) and Fannia scalaris (F. scalaris) are reported for the first time in Iran. However M. stabulans is a cosmopolitan species and its presence in Iran was probable.

The aim of this research was to investigate the coexposure of nanoparticles of titanium dioxide (TiO2) and copper oxide (CuO) on the alterations of the gill, intestine, kidney, and liver tissues of carps (Cyprinus carpio). In this study, carps (length 23 ± 1.5 cm; weight 13 ± 1.3 g) were divided into six groups of 15 each and exposed to 2.5 and 5.0 mg L(-1) of CuO nanoparticles (NPs), 10.0 mg L(-1) of TiO2 NPs, and 2.5 and 5.0 mg L(-1) of CuO NPs + 10.0 mg L(-1) of TiO2 NP mixture. Fish were sampled for histopathological studies after hematoxylin-eosin staining. Results indicated that the more kinds of histopathology anomalies observed with CuO NP and TiO2 NP mixture were broadly of the same type as CuO NPs and TiO2 NPs alone, but the severity or incidence of injuries of gill, intestine, liver, and kidney of carps in the mixture of CuO NPs + TiO2 NPs was higher than that of each NP alone. Moreover, behavioral changes in carps exposed to CuO NP and TiO2 NP mixture such as hyperactivity, loss of balance, and convulsions were higher than those to CuO NPs and TiO2 NPs alone. In conclusion, the presence of TiO2 NPs enhanced the effects of NPs of copper oxide in terms of histopathological changes in carps.

Cutaneous leishmaniasis is one of the prevalent health problems in tropical and subtropical areas including Iran. Therefore, it is essential to identify the prevalence and new foci of this disease in different regions of Iran. This study aimed to determine the epidemiology of cutaneous leishmaniasis by active surveillance in elementary schools in Pakdasht City, Southeast of Tehran, Iran 2013-2014.This cross sectional study was carried out on 4800 students from 60 elementary schools in Pakdasht during October 2013 to March 2014. After examining the students, some epidemiological data such as age, gender, date, anatomic location of the lesion(s) in the body, number and size of lesion(s), lesion type, and travel history to endemic areas was recorded in a checklist. Students with active lesions were examined using parasitological and molecular methods (PCR).Totally, 31 students (0.64%) had leishmaniasis, of which 15 (0.31%, 95% CI, 0.15%, 0.47%) had active lesions and 16 (0.33%, 95% CI, 0.17%, 0.49%) had leishmaniasis scars. Molecular testing showed that Leishmania major was the causative agent of leishmaniasis in all patients with active lesion. The highest frequency of cutaneous leishmaniasis was found in the age group 10-12 years (P=0.03). There was a significant difference between the frequency of the disease in different months (P=0.04) and the anatomic location of the lesion/scar (P=0.04). Moreover, t-test revealed that there was a significant relationship between number of lesions/scars and the age group (P0.001).The leishmanial type diagnosed in all patients was L. major. This finding suggests that Pakdasht might be a new focus for zoonotic cutaneous leishmaniasis.

Background: The aim of this study was to obtain new data which would be valuable to develop programs for future planning of mosquito controls in in western Iran. Methods: Larvae and adult collections were carried out from different habitats using standard dipping and animal baited trap methods during May, June and July 2012 in two provinces (Kurdistan and Kermanshah) in the west of Iran. Characteristics of breeding places were studied based on the habitat type (River edge, Ground pool), water conditions (clear or turbid, stagnant or running), vegetation (With or without vegetation), water temperature, sunlight exposure (full or partial sunlight) and so on. Results: Overall, 4081 third- and fourth-instars larvae and 2013 Adult were collected. Five genera and eleven species of the family Culicidae were identified. Mosquitoes collected in larval and adult stages including, Anopheles maculipennis s.l. (4.1%, 4.42%), An. superpictus (1.35%,1.39%), An. turkhudi (1.75%,1.68%), Aedes vexans (2.5%, 8.78%), Culex hortensis (1.59%, 1.04%), Cx. mimeticus (5%, 2.38%), Cx. pipiens (16.5%, 8.15%), Cx. theileri (10%, 46.4%), Culiseta longiareolata (24%, 4.27%), and Cs. subochrea (24%, 4.27%) and Ochlerotatus caspius s.l. (9.1%, 21.46%). Culiseta longiareolata and Cs. subochrea found predominant species in larval collection, whereas Culex theileri was dominant in Adult collection. Anopheles turkhudi is reported for the first time in Kermanshah Province. Conclusion: Due to the geographical location of the two provinces, extensively studies with emphasis on mosquito ecology, to having comprehensive and up to date information is essential.

Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for pathogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the German cockroach was investigated. Methods: Topical bioassay methods were carried out for detecting insecticide susceptibility of adult male cockroaches. For each insecticide, four to six concentrations resulting in >0% and

Since ZnO nanoparticles (ZnO-NPs) exhibit strong antibacterial activities on a broad spectrum of bacteria the aim of this study was to evaluate the antimicrobial activity of Zno-NPs against Pseudomonas aeruginosa as a model for gram-negative bacteria.

Background: The effect of frequent examinations on the students’ learning has had inconsistent results. This study aimed to assess the effectiveness of fre-quent announced quizzes on the learning of a representative sample of Iranian medical students. Methods: This experimental study was conducted among 37 fifth semester medical students who had taken the course in Protozoology and Helminthology, in which the same basic information were provided about different types of pro-tozoa and worms. Initially, in the teaching of helminthology, ten routine sessions were handled with lectures and interactive questions and answers. Then at the beginning of the protozoology topic in the beginning of all of the next 9 ses-sions, the students were informed that they will have a quiz at the end of each session. At the end of the semester, the total scores of quizzes were compared with the mean final scores of protozoology and helminthology using paired t and repeated measure tests. Results: The mean final scores of the protozoology lesson were not significantly different from that of the helminthology (10.45 ± 2.75 vs.11.25 ± 2.56 on the scale of 20, respectively, P=0.13). There was no significant difference in the mean score of the five quizzes compared with the mean final term score of pro-tozoology. The overall mean scores in the helminthology lesson (11.25±2.56), protozoology lesson (10.45±2.75), and the quizzes (9.16 ± 3.55) were signifi-cantly different (P

Introduction. Nosocomial infections remain a major challenge to the health care system and result in significant mortality, morbidity, and economic burden. Intensive care unit (ICU) patients are at great risk of acquiring nosocomial infections. The objective of this study was to determine the contamination rate (bacterial and fungal) of the health care workers? (HCWs?) hands and ring in ICU. Methods. All health care workers were screened during the day shift in Emam hospital ICU. After obtaining informed consent, convenience samples of HCWs? hands and rings were cultured on specific media during their routine work hours, always after a patient care episode. The fungal and bacterial isolates were identified using standard microbiological procedures. Results. A total of 40 subjects were selected in this study (28females, 12males). The rate of contamination of hands and rings was observed in 73.1%. Most of isolates are known to cause nosocomial infections which included: 23% staphylococci, 7.9% Klebsiella spp., 4.7% Enterobacter spp., 3.9% Escherichia coli, 3.1% Acinetobacter spp., 2.3% Pseudomonas spp., and 27.7% were colonized with fungi. The fungal isolates were 16.6% Candida spp., 3.9% Rhodotorula spp., 3.1% Aspergillus niger, and 3.9% Aspergillus flavus. Conclusion. According to these results HCWs? hands and their rings were contaminated with various types of microorganisms. Medical and hospital personals must follow careful hand-washing techniques to minimize transmission of disease and should remove rings, watches, and bracelets before washing their hands and entering the ICU., Journal of Preventive Medicine and Hygiene, Vol 52, No 4 (2011)