Evaluation of the Time Course on the Effectiveness of WHO Standard Pyrethroid and Carbamate Impregnated Test Papers against Anopheles stephensi, the Main Malaria Vector in Iran

Background: Anopheles stephensi is a major vector of malaria in some parts of the world. A standard method for de­termining resistance in adult mosquito populations is the bioassay test recommended by the world health organization (WHO). The papers used in this method have an expiry date. This study aimed to determine the effectiveness of outdat­ed susceptibility test papers for use in insecticide resistance monitoring programs. Methods: Beech and Bandar Abbas strains of An. stephensi were reared in the insectary. Permethrin 0.75%, Deltame­thrin 0.05%, and Bendiocarb 0.1% impregnated test papers prepared by Universiti Sains Malaysia were used. Probit analysis was used to analyze the results and prepare time-mortality regression lines of LT50 and LT90. Results: There was a difference in the mortality of both tested strains of An. stephensi was exposed to all tested insecti­cides. Both expired and not expired Permethrin and Deltamethrin papers induced 100% mortality at the diagnostic time (60min), but their insecticidal properties were reduced gradually in serial times. The highest efficacy of test papers was in the first trimester after the expiry date and decreased over time. Conclusion: At the diagnostic time of 60 minutes, the mortality rate of both dated and expired papers was 100% in the pyrethroid insecticides, even three years after expiry dates, if stored in the package provided by the producer, in a re­frigerator. This value was reduced to less than 100% in the expired papers of Bendiocarb comparing the dated papers that induced 100% mortality

An investigation on permethrin-treated military uniforms against diurnal mosquitoes under field conditions

Background: Military forces are exposed to mosquito bites because of their duties. In addition to the nuisance caused by mosquito bites, they are the vector of some vector-borne diseases in many countries of the world. Impregnation of military uniforms with permethrin is one of the most effective methods of protecting military personnel. The purpose of this study was to evaluate the effect of permethrin-impregnated uniforms against diurnal mosquitoes under field conditions.Methods:  In this study, one of the most common uniforms used in the Iranian military was treated by permethrin (0.125 mg. permethrin ai/cm2) and evaluated against the natural population of day-biting mosquitoes, in the rural area with Eight participants, three of them put on the treated uniforms and the other one of them wore the untreated uniforms and Four officers were also appointed as collectors.Results: The average number of bites in those who wore untreated uniforms (control) was 1.8/min/person (107.8/hr), while it was 0.16 (9.83/hr) for treated uniforms. The protection of treated uniforms was about 91%. The knockdown rate for Culex and Aedes mosquitoes was 95.92% and 94.44%, respectively. The mortality rate in Culex was 98.59% and 98.61% in Aedes mosquitoes when exposed to treated uniforms.Conclusion: In this study, military uniforms impregnated with permethrin showed significant protection against the bites of Culex and Aedes mosquitoes. This intervention can be used to protect military personnel from the bites of Culex and Aedes these mosquitoes and to reduce the diseases transmitted by these mosquitoes.Keywords: Permethrin; Military uniforms; Impregnation; Mosquitoe

The Ecological Aspects of Culex pipiens (Diptera: Culicidae) in Central Iran.

Background: The aim was to survey the specific factors, which cause to decrease blood feeding of mosquitoes important to succeed vector control. Methods: Larval collection was carried out from fixed and variable breeding places of Yazd County, central Iran in 2009. Autogeny-Anautogeny, Stenogamy-Eurygamy, and blood preference of Culex pipiens were studied using standard mosquito cages blood meal source for Cx. pipiens females considered as the chickens and human and fed females were kept in insectary condition (16:8 L: D, 27±3 °C and 70±10% RH). The data were analyzed using SPSS Ver. 11.5 soft ware. Results: Totally, 96 females' mosquitoes were tested for Stenogamy versus Eurygamy and 122 for blood preference assay. In the small cages (20× 20× 20cm) and large cage (60× 40× 60cm), the ability of mating and insemination rates were 60.0 and 67.0%, respectively. In spite of Cx. pipiens fed from sucrose 5%, none of them laying eggs in 60× 40× 60 cages during the study. This finding indicated the Anautogeny behavior of this species. This species was found of low tendency to human blood and almost 4 fold fed on chicken. Conclusion: The occurrence of Steno-Eurygamy, Anautogeny, and Ornithophilic behaviors of Cx. Pipiens was noted. More studies need to  be  carried out about the bionomics of this species to  gain more data about the ecophysiological and behavioral characteristics in other parts of Iran

Determination of Age and Vectorial Capacity of Anopheles Maculipennis Sensu Lato in the Central Plateau of Iran

Background and Purpose: Islamic Republic of Iran has greatly reduced its malaria burden and has a national goal to eliminate malaria by 2025. The aim of this study was to determine the population dynamics of Anopheles maculipennis sensu lato, in relation to probable malaria transmission. For this purpose, the study was conducted in three villages in Isfahan Province of Iran, from April to March 2014. Materials and Methods: Two mosquitoes sampling methods were conducted, comprises human landing catch and human bed net collection. The results of this investigation were subjected to one-way ANOVA using SPSS. Results: A. maculipennis s.l. was found as a dominant vector with exophagic and endophilic behavior. Two peaks of blood feeding were observed, 9.00-10.00 p.m and 1.00-2.00 a.m. The gonotrophic cycle, survival rate, and life expectancy of the species were 4, 0.82, and 5 days, respectively. Malaria vectorial capacity of A. maculipennis was measured 0.0128 and 0.059 for Plasmodium vivax and Plasmodium Falciparum, respectively. Conclusion: The findings indicate that there is a negative correlation between the temperature and daily age of A. maculipennis s.l. The method described can be used as a standard method to determine the daily age of Anopheles, as well as of other mosquito species since it is fast and precise and needs small samples. Survey on the age structure of vectors is very important as it is useful in monitoring the success of large-scale vector control measures

Some Ecological Aspects of Malaria Vectors in Saravan Area, Iran

Please cite this article as: Mehdipour D, Moosa- Kazemi SH, Hosseini M, Zolfi R. Some Ecological Aspects of Malaria Vectors in Saravan Area, Iran. Arch Hyg Sci 2013;2(1):31-41. Background & Aims of the Study: The aim of this study was to determine the ecology of malaria vectors in order to select the vector control masseur in the future. This study was carried out on trend of malaria cases and malaria vectors in Saravan county, Sistan & Baluchestan Province, Iran. Materials & Methods: The adult mosquitoes were collected by standard Pyrethrum space spray collection and larvae by dipping method twice a month in 2011 for 12 months. Samples were identified by systematic keys. The 5-year epidemiological data was collected from Malaria Control Centre, Iranian Ministry of Health and Medical Education. Results: Four Anopheles species identified including; Anopheles (Cellia) stephensi Liston, Anopheles (Cellia) dthali Patton, An. (Cellia) culicifacies Giles, An. (Cellia) fluviatilis James. Anopheles stephensi was predominant species whereas An. fluviatilis was the lowest species in adult collection. A minimum temperature of larval habitat was 14ºC for An. fluviatilis and maximum was 26°C for An. stephensi. Monthly peak activity of An. stephensi larvae found in April and October and in adult form found in May and October. Monthly peak activity of An. culicifacies larvae found in June and September whereas observed in July and November for adults. An. dthali larvae collected more in September and November whereas Adult form found more in July and November. The number of malaria cases between 2007 to 2011 showed the decrease in first 4 years and then increase in the last years. Conclusions: The dominant species was An. stephensi comprised 54.07% of larvae and 49.16% of adults. We suggest studying on biological forms of this species with specific focus on the bordering areas between Iran and Pakistan in the future

Ecology of Malaria Vectors in an Endemic Area, Southeast of Iran

Background: Malaria has long been regarded as one of the most important public health issues in Iran. Although the country is now in the elimination phase, some endemic foci of malaria are still present in the southeastern areas of the country. In some endemic foci, there are no data on the malaria vectors. To fill this gap, the present study was designed to provide basic entomological data on malaria vectors in the southeastern areas of Iran. Methods: Adult and larval stages of Anopheles mosquitoes were collected by using different catch methods. Resistance of the main malaria vector in the study area to selected insecticides was evaluated using diagnostic doses advised by the World Health Organization in 2013–2014. Results: A total of 3288 larvae and 1055 adult Anopheles mosquitoes were collected, and identified as: Anopheles ste­phensi (32.1%), Anopheles culicifacies s.l. (23.4%), Anopheles dthali (23.2%), Anopheles superpictus s.l. (12.7%), and Anopheles fluviatilis s.l. (8.6%). Anopheles stephensi was the most predominant mosquito species collected indoors at the study area, with two peaks of activity in May and November. This species was found to be resistant to DDT 4%, tolerant to malathion 5% and susceptible to other tested insecticides. Conclusion: All the five malaria vectors endemic to the south of Iran were collected and identified in the study area. Our findings on the ecology and resting/feeding habitats of these malaria vectors provide information useful for plan­ning vector control program in this malarious area

A Pictorial Key for Culex pipiens Complex (Diptera: Culicidae) In Iran

Background: The aim of this study was to design pictorial key and taxonomic literature of Culex pipiens complex in Iran. Methods: Larvae were collected using standard dipping methods in 13 randomly selected areas of Bushehr, Hame­dan, Kerman, Khorasan-e-Razavi, Khuzistan, Mazandaran, Tehran, Sistan and Baluchistan and Yazd Provinces from April 2009 to October 2010. The data were analyzed using SPSS Ver. 11.5. Results: Culex pipiens larvae were identified based on the Seta 1 of the abdominal segments III–IV in north and central parts of Iran. This diagnostic character had some variation among the Cx. quinquefasciatus collected from south of the country. The identification value of intersection of costa, subcosta and bifurcation of R2+3 of female veins, was calculated as 90–100 % for Cx. pipiens. This diagnostic character was varied among the Cx. quinquefas­ciatus specimens. The male genitalia found as the main characters to distinguish of Cx. quinquefasciatus from Cx. pipiens. Conclusion: It is necessary more studies on the behavior and genetic variations of Cx. pipiens complex in Iran

Correction: DNA barcodes corroborating identification of mosquito species and multiplex real-time PCR differentiating Culex pipiens complex and Culex torrentium in Iran.

[This corrects the article DOI: 10.1371/journal.pone.0207308.]

DNA barcodes corroborating identification of mosquito species and multiplex real-time PCR differentiating Culex pipiens complex and Culex torrentium in Iran.

Identifying mosquito species is a fundamental step in risk assessment and implementation of preventative strategies. Moreover, Culex pipiens is the most widespread mosquito vector in several regions of Iran and is the main vector for transmission of West Nile virus (WNV). Mosquitoes were collected at 14 sites in northern regions of Iran in 2015 and 2016. A subset of mosquito specimens was selected for identification confirmation using a DNA-barcoding technique. Construction of a phylogenetic tree showed clustering of mosquito sequences into three main genera: Aedes, Anopheles and Culex with individuals of a single species clustered closely together, regardless of where and when they were collected. Cx. pipiens complex and Cx. torrentium were identified and differentiated using multiplex real-time PCR targeting the gene locus for acetylcholinesterase 2 (ace2) to discriminate between Cx. pipiens pipiens and Cx. torrentium. The CQ11 microsatellite locus was used for discrimination between Cpp. biotypes. The predominant mosquito species in investigated regions were Cx. pipiens pipiens biotype pipiens, but we also detected Culex pipiens pipiens biotype molestus and hybrids of the two pipiens biotypes, as well as Cx. torrentium. The results of this study represent the first certain evidence of the presence of Cx. pipiens pipiens biotype molestus and hybrids between pipiens and molestus forms, and Cx. torrentium in Iran through a molecular identification approach. This report of a potentially important bridge vector for WNV might have key influence in the risk projections for WNV in Iran