Vol 14 No 2 (2020)

Published: 2020-07-01

Original Article

  • XML | PDF | downloads: 216 | views: 217 | pages: 126–133
    Background: Anaplasmosis and Ehrlichiosis are the most important tick-borne diseases. This study was conducted in three cities of Kerman Province in Iran to investigate the circulation of the bacteria in ticks collected from sheep.Methods: Ticks were collected from animals using Srkj forceps and transferred to the Entomology lab in cold chain. After specimen’s identification, they kept at -70 ºC. Tick DNA was extracted using Bioneers DNA extraction kits followed by Nested PCR technique to amplify ribosomal 16S rRNA gene to detect Anaplasma infection in ticks.Results: 472 sheep were examined from which 349 ticks were collected and identified in laboratory using valid keys. Tick specimens belonged to two genera and four species; Hyalomma marginatum (62.47%) was the most frequent and Hylomma asiaticum (5.73%) showed the least abundance. The infestation rate to different tick species was different in three regions of Kerman Province. Observation revealed that 24 specimens (58.3%) were positive for Anaplasma. There is a significant difference between male and female infection rate. However, there is no sig­nificant difference between these variables in each of these cities.Conclusion: This study shows high infection rates to Anaplasma in hard ticks. It is essential for health and veteri­nary authorities and farmers to use appropriate strategies to control ticks to reduce the infestation.
  • XML | PDF | downloads: 199 | views: 154 | pages: 134–143
    Background: Esfahan Province is considered as one of the main focus of zoonotic cutaneous leishmaniasis (ZCL) in Iran. Recently, ZCL distribution is expanding through this province leading to report of new cases in non-endemic areas. In the current study epidemiological aspects of ZCL has been investigated in Naein County in Esfahan Prov­ince.Methods: Adult sand flies were collected from beginning to the end of their seasonal activity. Rodents were caught by Sherman live traps once a month for one year. To active case detection, a hundred households in each selected village were visited in November and December 2016. Nested-PCR was employed to detect Leishmania parasite in the vector, reservoir and human.Results: Totally 1562 sand flies including Phlebotomus sergenti, Phlebotomus papatasi, Sergentomyia sintoni and Sergentomyia mervinae were collected and identified. No Leishmania infection was detected in the collected sand flies. All of the 30 collected rodents were identified as Rhombomys opimus and of these 3.3% and 26.7% were in­fected by Leishmania major using microscopic and molecular technique respectively. Totally, 914 individuals were investigated and the ulcer and scar rate of ZCL calculated to be at 1.1 and 15.3per 1000 population, respectively. Molecular results confirmed L. major infection in human and reservoir samples.Conclusion: It is concluded that ZCL is established in the area in low endemicity, and it is extrapolated the disease will not be a serious increasing health problem in near future in this region.
  • XML | PDF | downloads: 92 | views: 97 | pages: 144–152
    Background: Lectin molecules have crucial biological role in insects’ immune system. The aim of present study was to find the agglutinin activities in haemolymph of German cockroach, Belatella germanica with appropriate screening and purification.Methods: The heamolymph of cockroach was collected and agglutinin test performed against different animal and human red blood cells (RBC). Then sugar inhibition assay was carried out to find carbohydrate specific binding lec¬tin. The proteins of haemolymph was purified using ion-exchange chromatography (HPLC) and each fraction was tested for agglutinin activity. Finally the molecular weight of the agglutinin protein was determined using SDS-page.Results: The most agglutinin activity of haemolymph was found against RBC of mouse at titer 1/128ml/L dilution and sugar inhibition assay showed that fucos, N-acetyglucoseamine and galactose reduced titer of agglutinin to ½ml/L. Only one fraction of heamolymph at rotation time of 36 minute showed agglutinin activity. The molecular weight of this lectin was measured as 120Kds. Conclusion: The range of agglutinin activities against different RBC indicates that the isolated lectin is not specific for a particular carbohydrate. In addition, the isolated lectin at low concentration present in heamolymph should be an innate lactin not secreted, because we found it without any trigger immunity of the insect.
  • XML | PDF | downloads: 108 | views: 139 | pages: 153–161
    Background: Malaria is one of the major public health concerns in Ethiopia. Control options available for the manage­ment of malaria, include case detection, personal protection and larval source management. Effective control of Anoph­eles larvae largely depends on understanding of the habitats of the vectors. The aims of this study were to identify the breeding habitats of mosquitoes and characterize the larval habitats in Gende Wuha Town in northwestern Ethiopia.Methods: Different aquatic habitats were sampled and characterized for anopheline larvae from November 2012 to June 2013.Results: In total, 2784 larvae of Anopheles mosquitoes were collected from various breeding habitats. Microscopic identification of the III and IV instars revealed the presence of seven Anopheles species. Of the Anopheles spp, Anophe­les gambiae s.l. (80%) was the most predominant species in the study area. Spearman correlation coefficient results also determined that the density of An. gambiae s.l. increased significantly with habitat temperature (r= 0.346, p< 0.01). Significantly higher An. gambiae s.l. larvae were obtained in non-shaded habitats (z= -3.120, p< 0.05) when compared with shaded habitats.Conclusions: The current study demonstrated An. gambiae s.l., the principal malaria vector in the country, is the pre­dominant species in the larval sampling habitats. It was also noted the importance of edge of stream as larva breeding habitats for this species during the dry season of the year. Therefore, attention should be given for this breeding habitat for control of the vector during dry season.
  • XML | PDF | downloads: 170 | views: 195 | pages: 162–172
    Background: Aedes mosquitoes are the most important group of vectors having ability of transmitting pathogens in­cluding arboviruses that can cause serious diseases like Chikungunya fever, Dengue fever and Zika virus in human. Biosynthesis and the use of green silver nanoparticles (AgNPs) is an important step in the search of reliable and eco­friendly control of these vectors.Methods: In this study an aqueous leaves extract of Ricinus communis (castor) and silver nanoparticles (AgNPs) syn­thesized from this extract were evaluated as larvicidal agent for 2nd and 3rd instar larvae of the Aedes albopictus. Differ­ent concentrations (50, 100, 150, 200 and 250ppm) of plant extract and synthesized nanoparticles were prepared and applied on second and third instar larvae. The percent mortality was noted after 6, 12, 18, 24, 30, 36, 42 and 48H of exposure and subjected to probit analysis to calculate LC50 and LC90.Results: Synthesized Ag+ nanoparticles were characterized by UV-Vis spectroscopy, Fourier transform infrared spec­troscopy (FT-IR), and energy-dispersive X-ray spectroscopy (XRD). The nanoparticles were more toxic against larvae of Ae. albopictus with LC50 value (49.43ppm) and LC90 value (93.65ppm) for 2nd instar larvae and LC50 (84.98ppm) and LC90 (163.89ppm) for 3rd instar larvae as compared to the plant extract (149.58ppm, 268.93ppm) and (155.58ppm, 279.93ppm) for 2nd and 3rd instar larvae of Ae. albopictus respectively after 48H.Conclusion: Our results suggest the extract of R. communis and synthesized nanoparticles as excellent replacement of chemical pesticides to control the vector mosquitoes.
  • XML | PDF | downloads: 137 | views: 130 | pages: 173–184
    Background: West Nile Virus, a mosquito-borne flavivirus, causes a variety of symptoms in human, from asymp­tomatic infection to neuroinvasive disease. Several studies have been conducted on the seroprevalence of WNV in­fection in dif­ferent areas from Iran. This study was performed to find the presence of antiviral antibodies in human serum among some high risk population and awareness of health care staff about symptom of the WNV infection.Methods: Study performed in five geographical districts based on high population of immigrant and do­mestic birds and prevalence of the antiviral antibodies in horses which was reported previously. Totally 150 human blood sam­ples were collected during 2018. The samples collected from patients referred to the clinics. The ELISA method used to detect IgG and IgM antibody against WNV. Logistic regression models used to analyze the effect of sex, age, keeping birds and urban/rural residence on the risk of infection. The awareness of health care staff about symp­tom of infection surveyed.Results: From all blood donors, 41 samples (27.33%) showed positive to IgG antibody. From which 56.10% were males and remaining females. None of the mentioned factors had a significant relationship. Health care staff had less attention to the infection. Conclusions: Although the prevalence of antibodies was relatively high, due to the similarity to other viral diseases, health care staff had less attention to the disease. The study showed that people in these areas have been exposed to the virus. Further research activities are recommended for control of this arbovirus.
  • XML | PDF | downloads: 115 | views: 148 | pages: 185–192
    Background: During the past decade, rapid development of insecticide resistance have been reported among many spe­cies of mosquito vectors against four main categories of insecticides worldwide. The aim of the research was to assess the variation trend of susceptibility levels of Culex quinquefasciatus to two insecticides separately for the field popula­tion compared with subsequent generations of the same sample after multiple colonization.Methods: Larvae and pupae of Cx. quinquefasciatus were collected from house sewages and reared to adult which blood-fed on roosters. Ten percent sucrose fed female mosquitoes aged 2–3 days were used for susceptibility tests with DDT and deltamethrin. Susceptibility levels was assessed in the adult stage of field stran Cx. quinquefasciatus against DDT 4.0% and deltamethrin 0.05% and continued up to next six generations undergoing multiple rearing at insectary condition.Results: The susceptibility levels to DDT 4.0% did not change compared to the field with the lab population to six gen­erations. Regarding deltamethrin 0.05%, no significant difference was shown between field strain (58.3%) and 3rd gen­eration (52.7%) compared to the 6th one (33.8%).Conclusion: This finding may reflect the role of the kdr gene in resistance to organochlorine which has cross-re­sistance with pyrethroid insecticides. The results of this study clearly showed the irreversible trend of pyrethroid re­sistance among colonized mosquitoes. This is the first study of the resistance status of Cx. quinquefasciatus in Iran.
  • XML | PDF | downloads: 123 | views: 132 | pages: 193–201
    Background: There are four medically important scorpion species (Mesobuthus eupeus, Mesobuthus caucasicus, An­droctonus crassicauda and Hottentotta saulcyi) in the West Azerbaijan Province, northwestern Iran. scorpion­ism is con­sidered as a health problem in this region, because there is no information about scorpion envenomation, this study was designed to study epidemiological characteristics of scorpionism to optimize prevention and treatment of scorpion sting in northwest of Iran.Methods: All the data from epidemiological surveys completed in West Azerbaijan hospitals over four years (2014–2017) for scorpion victims were collected. This information includes the number of victims, sex, age, signs and symp­toms, site of sting, body parts of victims, history of previous sting, the condition of the patient in terms of recovery and death, and the time to receive anti venom, all data were analyzed by the Excel software.Results: A total of 2718 cases of scorpionism were reported from March 2014 to March 2017 in the study area. The most cases occur in both sexes in the age groups of 25 to 34 years old. In urban areas 40.3% of people and in rural areas 59.7% of them have suffered. The Poldasht and Chaldoran cities, had the most and least incidence respectively.Conclusion: In this study, the high risk areas in the case of scorpion stings were identified. Results of this study can be used to design preventive programs to educate more people about dangerous areas to prevent scorpion sting and even death.
  • XML | PDF | downloads: 124 | views: 110 | pages: 202–213
    Background: The attraction of phlebotomine sand flies to plant and animal hosts is due to the produced chemical compounds, affecting the olfactory receptors of the insects. Therefore, novel and effective methods, such as Attrac­tive Toxic Sugar Baits (ATSB) and Attractive Toxic Baits (ATB), are based on the effective materials that attract sand flies toward the host. The present study was designed to identify the attractive materials in plants and animals for using in ATSB and ATB.Methods: This cross-sectional study was carried out in July 2018 on endemic areas of leishmaniasis in Iran. Differ­ent baits, including mango, nectarine, grape, banana, melon and watermelon, defibrinated blood of cattle, sheep, goat and chicken, urine of cattle, sheep, goat and ultimately, simple and complex chemicals, such as CO2, 1-octanol, lactic acid and human sweat were placed inside the traps, and the rate of  the sand flies attraction to these materials was studied. Furthermore, data were analyzed using the Kruskal-Wallis test and Mann Whitney U test.Results: There was a significant difference in the sand flies attraction between the traps containing watermelon, urine of cattle, and sheep, and chemicals such as CO2 and human sweat and the control trap (p< 0.05).Conclusion: This study showed that watermelon and CO2 are the potential candidates for using in ATSB and ATB, respectively.
  • XML | PDF | downloads: 114 | views: 107 | pages: 214–227
    Background: Southern part of the country is a high risk for mosquito transmitted Arboviruses. This study was car­ried out to determine the base line susceptibility of the Aedini mosquitoes to the WHO-recommended insecticide.Methods: Larval collection was carried out by dipping method and adult collection occurred by suction tube from January to December 2017. The adult susceptibility test was assessed to Bendiocarb 0.1%, DDT 4%, Deltamethrin 0.05%, Lambda-cyhalothrin 0.05%, Malathion 5% and, Permethrin 0.75% at different interval times as well as at discriminative dose recommended by WHO. The larval susceptibility test was occurred using Temephos and Bacil­lus thuringiensis serotype H-14, at different concentrations. The LT50, LT90 and LC50, LC90 values were calculated for plotting the regression line using Microsoft office Excel software ver. 2007.Results: Aedes caspius was quite resistant to DDT, Malathion, Bendiocarb and showed susceptible or tolerant to other insecticides.The LT50 and LT90 values to DDT in this species were 157.896, and 301.006 minutes, respective­ly. The LC50 and LC90 values of Ae. caspius to Temephos were 0.000068, and 0.000130ppm, the figures for B. thu­ringiensis was 111.62 and 210.2ppm, respectively.Conclusion: A routine and continuous study for monitoring and evaluation of different species of Aedes to insec­tides is recommend at different parts of country for decision making.