Vol 12 No 4 (2018)

Published: 2018-12-25

Review Article

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    Background: Scorpions are one of the most important venomous animals in Iran. Their sting has more prevalence in the south and southwest areas. The aim of this study was to introduce their sting agent species in the country. Methods: Data were extracted by a mini review on scorpion stinging articles in Iran until early 2018 and then the sting agent species in each area were studied. Geographical and provincial distribution of each species also was provided. Results:  Twelve scorpion species are causative agents of sting. According to their deadly rate and clinical symptoms, some of them are considered the most dangerous venomous animals in Iran. Some death cases have been reported be­cause of the sting of 3 species of Hemiscorpius lepturus, H. acanthocercus and Androctonus crassicauda. Remaining species have not deadly sting but because of their frequency, they encounter the individuals and cause the stinging. Conclusion: The highest number of sting agents is in Khuzestan, however Gilan and Mazandaran have the lowest fre­quency. Because of the high prevalence of sting agent species in that province, the necessity of providing control and prevention programs is very important.

Original Article

  • XML | PDF | downloads: 298 | views: 258 | pages: 334-340
    Background: Rodents perform a crucial role in dispersal of zoonosis causes globally. We aimed to investigation about infection levels of parasitic agents in rodents’ population in Meshkinshahr areas, northwest of Iran from Apr to Sep 2014. Methods: Two hundred four rodents were trapped and anaesthetized. A sample of blood was collected via cardi­opuncture from each one. Thin and thick blood smears were prepared and stained with Giemsa. All stained smear were examined under light microscopy with high magnification by two expert microscopists. Every suspected uni­cellular observed were measured microscopically and compared with key references to diagnose.Results: Captured rodents were identified as three genera including Meriones persicus, Mus musculus, Cricetulus migraturius. Protozoa identified in this study were included of Spironucleus muris and Eperythrozoon coccoides, these parasites were observed in blood smear of 0.98% of rodents. S. muris and E. coccoides were seen in M. mus­culus and C. migraturius, respectively.Conclusion: The present study increases awareness about Eperythrozoonosis in rodents and its potential transmis­sion to domestic animals and even to human in rural districts in Iran. Moreover, the attack of Spironucleus on the mucus of colon and its systemic risk was confirmed.
  • XML | PDF | downloads: 218 | views: 223 | pages: 341-350
    Background: West Nile Virus (WNV) is a mosquito-borne viral pathogen that is the causative agent of West Nile fever and encephalitis. Diagnostic tools for WNV infection in Nigeria are not well established hence the current prevalence rate of WNV infection in Nigeria is unknown. We aimed to establish the serological prevalence of WNV infection in febrile patients in Ilorin, Nigeria in 2016, and to assess the risk factors associated with the acquisition of the virus. Methods: This was a cross-sectional study involving the screening of subjects presenting with febrile illnesses. While specific IgM ELISA was used to determine the seroprevalence, a closed-ended questionnaire was used to as­certain the risk factors associated with this viral infection. Results: Fifteen (7.5%) of the respondents were positive for WNV infection. Subjects living in areas in close prox­imity to trees and bushes (P= 0.011) and stagnant water (P= 0.001) were at a higher risk of having WNV infection. Other risk factors associated with WNV among the respondents include the none use of insecticide (P= 0.001), sitting out at night (P= 0.044), HIV positivity (P= 0.003) and having an organ transplant (P= 0.002). Conclusion: This study clearly shows a considerable WNV infection in Ilorin, with the presence of factors that can promulgate an outbreak, hence a need for further surveillance in the study area.
  • XML | PDF | downloads: 251 | views: 359 | pages: 351-360
    Background: Dengue Haemorrhagic Fever (DHF) is a mosquito-borne disease and remains a major public health problem, especially in tropical and temperate countries. Studying wing morphometric of Aedes aegypti as a mosquito vector of DHF can help to better understand biological process of the mosquito adaptation to the environment. We aimed to study the geometric morphometric of Ae. aegypti from multiple geographical areas.Methods: Samples were collected from Samut Songkhram Province in Thailand, including coastal, residential and cultivated areas, by Ovitrap once per month during Oct to Nov 2016.Results: According to size variation analysis of Ae. aegypti, the female mosquito in a cultivated area was significant­ly different from those in the coastal and residential areas (P< 0.05). Whereas male Ae. aegypti in a cultivated area were significantly different from those in a residential area (P< 0.05). The shape variation of both female and male Ae. aegypti from all areas was statistically different (P< 0.05).Conclusion: Normally, living organisms, including mosquitoes, are adapted to their environment. The studied geo­graphical locations affect Ae. aegypti morphology.
  • XML | PDF | downloads: 298 | views: 249 | pages: 361-369
    Background: In this study, larvicidal activity of clove essential oil (EO), as a green and relatively potent larvicide, was compared with its main constituent, Eugenol, against Anopheles stephensi.Methods: High-performance liquid chromatography (HPLC) was used to determine the amount of eugenol, major constituent of clove EO. In addition, larvicidal activity of clove EO and eugenol was evaluated against An. stephensi.Results: The amount of eugenol in clove EO was determined as 67% using HPLC analysis. LC50 and LC90 of clove EO (57.49 and 93.14ppm, respectively) were significantly lower than those of eugenol (86.96 and 128.18 ppm, re­spectively).Conclusion: EO showed more effective than its major component. Considering the lower cost of the essential oil and lower risk in occurrence of resistance in larvae, use of clove EO is preferred as larvicide in comparison with eugenol, against An. stephensi.
  • XML | PDF | downloads: 213 | views: 246 | pages: 370-377
    Background: Mosquitoes, being a nuisance species, are considered as one of the most important species in public health control programs due to their role as a vector in mosquito-borne diseases observed in humans and animals. We evaluated the susceptibility status of Culex pipiens collected from northern Izmir, Turkey in 2011-16. Methods: Mosquito larvae, collected from three different locations in northern İzmir, were reared in the laboratory. Adult susceptibility bioassays were performed using the WHO insecticide-impregnated papers including deltamethrin 0.05%, permethrin 0.75%, α-cypermethrin 0.05% and cyfluthrin 0.15%. In addition, adult bioassays were performed after the pre-exposure to piperonyl butoxide (PBO) to determine the contribution of P450 detoxification enzymes to the phenotypic resistance. Results: In all of the three populations, high levels of resistance were observed (mortalities<63%) to all of the four pyrethroids. Different pyrethroids but with the same mode of action can exhibit significantly different phenotypic re­sistance in a single population. PBO bioassays also showed that P450 detoxification enzymes can have diverse effects on different pyrethroids. Conclusion: Using just one chemical in a class of insecticide can be misleading for resistance studies.
  • XML | PDF | downloads: 257 | views: 240 | pages: 378-386
    Background: We aimed to determine the geographical features and seroprevalence of Borrelia burgdorferi in Erzincan, Turkey, which has a high tick population due to its geographical position and climatic conditions. Methods: From January to December 2014, 368 people living in Erzincan, northeastern Turkey were enrolled. B. burgdorferi IgG antibodies were investigated in the collected serum samples using the ELISA method in 2015. Positive and borderline results were confirmed using the Western Blot (WB) method.  Results: Borrelia burgdorferi IgG positivity was found to be 4.1% by ELISA and 2.17% by WB. Of the seropositive people according to WB, 25% resided in areas within 2000m of rivers, 50% in areas with a slope of 0–5°, and 62.5% in areas with an altitude of lower than 1500 meters. Conclusion: The seroprevalence of Lyme borreliosis was high in Erzincan, particularly among people engaged in animal husbandry in rural areas. In addition, the seroprevalence of Borrelia varied according to geographical features, increasing in areas with a lower slope and altitude.
  • XML | PDF | downloads: 317 | views: 1442 | pages: 387-397
    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.
  • XML | PDF | downloads: 273 | views: 250 | pages: 398-413
    Background: Mosquito-borne arboviruses such as West Nile, dengue, Rift Valley fever, and Sindbis viruses and the nematode Dirofilaria are reported in Iran, but there is little information on the seasonal activity of their vectors in the country. We aimed to determine the seasonal activity of adult mosquitoes (Diptera: Culicidae) in a focus of diro-filariasis and West Nile infection in Guilan Province, northern Iran.Methods: Collections were carried out using light traps in seven counties at least two times from random sites and every two weeks from a fixed site (Pareh Village, Rudbar County) during Aug–Dec 2015 and Apr–Oct 2016.Results: Overall, 16327 adult mosquitoes comprising 18 species representing seven genera were identified. The most prevalent species were Cx. theileri (23.59%), Cx. tritaeniorhynchus (20.75%), Cx. pipiens (19.37%), Ae. vexans (18.18%), An. pseudopictus (10.92%) and An. maculipennis s.l. (5.48%). Aedes pulcritarsis and Cx. perexiguus were found for the first time in Guilan Province. The active season of adult mosquitoes extended from early May to early Oct in the fixed site. There was no significant regression between the abundance of adult mosquitoes and the meteor-ological data during active season in the fixed site (P> 0.05, R2= 0.31).Conclusion: Though no significant regression between the abundance of mosquitoes and the meteorological data was observed during active season, temperature and rice fields had a great influence in starting and ending active season in the region.
  • XML | PDF | downloads: 183 | views: 231 | pages: 414-420
    Background: Veratrum nigrum (Liliaceae) is perennial medicinal plant widely used to treat various conditions. To de­ter­mine its insecticidal properties against the German cockroach (Blattella germanica), several laboratory tests were car­ried out. Methods: A 4kg dry sample of V. nigrum root was purchased from the medicinal material market in Yunnan Province in 2015, China. In contact toxicity tests, V. nigrum alkaloidal extract was topically applied to the abdomen of cockroaches using a micro-applicator. In vitro acetylcholinesterase (AChE) activity tests were performed using a modified Ellman method. Results: Veratrum nigrum alkaloidal extract was toxic to male adults and 4th nymphs cockroaches, with median lethal dose (LD50) values of 14.90µg/insect, 14.21µg/insect for adults and 41.45µg/insect, 39.01µg/insect for 4th nymphs after 24h and 48h exposure, respectively. There was a significant difference between adults and nymphs in terms of tolerance to V. nigrum alkaloidal extract. There was no significant difference in mortalities at 24h and 48h, the lethal effect of V. nigrum alkaloidal extract on German cockroach was quick. AChE activity tests showed that V. nigrum alkaloidal extract had an excellent inhibitory effect on AChE: inhibition in the 4th nymphs and male adults had 50% inhibiting concentra­tion (IC50) values of 3.56mg/ml and 5.78mg/ml respectively. The inhibitory effect of AChE activity was positively cor­related with inhibitory time (0–20min), at a concentration of 1mg/ml, inhibition of nymph and adult AChE activity had 50% inhibiting time (IT50) values of 8.34min and 16.75min, respectively. Conclusion: V. nigrum may be explored as a potential natural insecticide for control of the German cockroach.
  • XML | PDF | downloads: 243 | views: 186 | pages: 421-425
    Background: There is a strong interest in tick-borne diseases worldwide due to their negative impact on both human and animal health. Epidemiological studies of tick-borne diseases depend on reliable data on tick population dynamics and activity patterns. Such data are essentially based on tick sampling in the field. This study aimed to evaluate the impact of cloth type on the efficiency of field sampling by the flagging technique. Methods: The impact of cloth type on the efficiency of field sampling by the flagging technique was investigated by comparing tick sampling yields of two different fabrics, the Munich type (MUC) vs. the Oxford type (OX), based on 30 pairs of transect lines. Data analysis included classical statistics and computer modelling. Results: The MUC flag yielded nearly five times more larval ticks than the OX flag, whereas the differences in yields for nymphs and adult ticks were not statistically significant based on classical statistics. Conclusion: The flag made of MUC type fabric, thanks to its tight and relatively flat texture, facilitates detection and collection of ticks from its surface. The OX flag, due to its loose texture, is unsuitable for the quantitative sampling of larval Ixodes ricinus.

Short Communication

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    Background: Due to strict ethical rules, the risk of accidental disease transmission and the most importantly, inconven­ience regarding using of live animals, artificial feeding apparatus has been developed for colonization of haematophagous insects. Rearing of sandfly is more difficult than other haematophagous insects. Methods: In the current study, a new apparatus for membrane feeding of Phlebotomus papatasi was designed, made and compared with available apparatus in Sand Fly Insectary, Tehran University of Medical Sciences, Tehran, Iran, in 2014. Results: In comparison to other apparatus designed for artificial feeding of other arthropods, our designed apparatus had the highest performance which after up to 1h, the majority of sand flies landed and took blood and among tested membranes, chicken skin was proved the most efficient membrane. Conclusion: Sand fly artificial feeding apparatus can be used at least for rearing of Ph. papatasi.

Letter to the Editor