Development of a degree-day model to predict the growth of Anopheles stephensi (Diptera: Culicidae): implication for vector control management.

Anopheles stephensi is an efficient vector of malaria parasites in Iran. Despite its importance in malaria transmission, there is a scarcity of accurate predictive models of its rates of development at different temperatures. A laboratory colony of An. stephensi, collected from Bandar Abbas County, southern Iran, was established, and all its developmental stages were maintained in temperature-controlled incubators so that the water temperature set at 5, 8, 10, 12.5, 14, 28, 38, 39.5, 42, and 45(±0.2) °C for different treatments until subsequent adult emergence. The Lower and Upper Developmental Temperatures (LDT and UDT) and the growth degree-day (GDD) were calculated for each development stage. A 12-mo population dynamics survey of the larvae and adults of An. stephensi was performed in 3 malaria-endemic villages (Geno, Hormoodar, and Sarkhoon) of Bandar Abbas County, and the obtained data were matched with the constructed GDD model. Based on the field meteorological and dynamics data, the model was verified in the field and used to determine the appropriate date to start spraying. The LDT was determined to be 8.19, 9.74, 8.42, 5.6, 13.57, and 10.03 °C for egg hatching, first, second, and third ecdysis, pupation, and eclosion events, respectively. The UDT was 38 °C for all developmental stages. The thermal requirement for the development of all immature stages of An stephensi was determined to be 187.7 (±56.3) GDD above the LDT. Therefore, the appropriate date to start residual spraying is when the region's GDD reaches 187.7 (±56.3). Given the climatic conditions in Bandar Abbas County, it is expected that the first activity peak of adult An. stephensi would be in March. Field observations showed that An. stephensi activity starts in February and peaks in March. The GDD model can provide a good estimate for peak An. stephensi activity and indicate the optimal deployment time of residual spraying operations against the multiplication and development of malaria parasites inside the vector.

Global haplotype distribution of Babesia ovis inferred by 18S rRNA sequences; a phylogeographical systematic review.

The genetic variability of apicomplexan parasite Babesia species is a principal strategy used by piroplasma to evade their hosts' immune responses. The purpose of this review was to evaluate our current knowledge on global haplotype distribution and phylogeography of Babesia ovis derived from sheep, goat, horse and ixodid (hard) ticks. Bibliographic English databases were searched from 2017 to 2023, identifying a total of 11 publications. The 18S ribosomal RNA (18S rRNA) sequences of B. ovis from Asia, Europe, and Africa were retrieved and subjected to estimate the genetic diversity and phylogenetic assessment. A haplotype network indicated a total of 29 haplotypes being classified into two distinct geographical haplogroups I and II including Nigeria and Uganda-derived B. ovis isolates. A moderately high level of genetic diversity was characterized in sheep/tick-derived B. ovis isolates originating from Iraq (Haplotype diversity: 0.781) and Turkey (Hd: 0.841). Based on the cladistic phylogenetic tree, two geographically different lineages of A and B were genetically differentiated except for Turkish isolates, indicating haplotype migration occurred between various geographical clades. In addition, the topology of UPGMA tree indicated that B. ovis population has a distinct clade compared to the rest clades of ovine babesiosis (B. crassa and B. motasi). The present results strengthen our knowledge to evaluate the evolutionary paradigms and transmission dynamics of B. ovis in different regions of the world; also it will provide groundwork for public health policy to control ovine babesiosis.

Pediculosis capitis among school-age students worldwide as an emerging public health concern: a systematic review and meta-analysis of past five decades.

Pediculosis by Pediculus humanus capitis is still an important health issue in school-age students worldwide. Although pediculicidal agents effectively kill head lice, the re-infestation rate is still high. This study was conducted to provide a summary of evidence about the prevalence of pediculosis capitis among school-age students worldwide. Different databases including MEDLINE/PubMed, Scopus, and Web of Science were searched for publications related to pediculosis capitis in school-age students from 1977 to 2020. All peer-reviewed original research articles describing pediculosis capitis among school-age students were included. Statistical heterogeneity of the different years among studies was assessed using the standard chi squared and I2 tests. Due to the significant heterogeneity, a random effect model was adopted to estimate the pooled, continent, and gender-specific prevalence of pediculosis. Two hundred and one papers met the inclusion criteria of this review and entered into the meta-analysis including 1,218,351 individuals. Through a random effect model, the prevalence of pediculosis capitis among school students was estimated as 19% (CI 95% = 0.18-0.20%, I2 = 99.89%). The prevalence of pediculosis capitis among boys was 7% (CI 95% = 0.05-0.10) compared to 19% (CI 95% = 0.15-0.24) in girls. The highest prevalence was in Central and South America (33%, CI 95% = 0.22-0.44, I2 = 99.81%) and the lowest was in Europe (5%, CI 95% = 4-6, I2 = 99.28%). Relatively high pediculosis capitis prevalence among school-age students observed in this study emphasizes the need for implementing screening and prophylaxis tailored to the local context.

First Record of Human Urogenital Myiasis Caused by Psychoda albipennis Larvae (Diptera: Psychodidae) in Miandoab, West Azerbaijan Province, Iran: A Case Report.

BACKGROUND: Myiasis is a disease caused by infections of tissues and organs of human and vertebrates body by the larvae of real flies of Diptera which feeding on living or dead tissues of host for a period of time. This report aims to present a case of urogenital myiasis caused by the larvae of Psychoda albipennis (Diptera: Psychodidae) for the first time in Iran. METHODS: In this case report, we present a case of a 9-year-old girl with urogenital myiasis caused by P. albipennis. She presented to Sina Hospital with dysuria and claimed that he had observed several black-grayish colored mobile particles in his urine at different times. The patient lived in Miandoab, West Azerbaijan Province, Iran. RESULTS: In the hospital her urine sample, containing 3 larvae was referred to Entomology lab of the Medical Faculty for identification and characterization. According to morphological factors, the larvae were identified to approximate size of 8-10mm long, white to gray color, thorns and pale scales and a siphon at the posterior end of the body. By comparing the larvae with the reported ones from Turkey, diagnosis was confirmed. CONCLUSION: According to our survey, this is the first observation of urogenital myiasis in East Azerbaijan Province, Iran. Our case illustrates urogenital myiasis caused by P. albipennis in Iran. Urogenital myiasis has not been previously reported from Iran as a human disease.

Biodiversity of Mosquitoes (Diptera: Culicidae) with Emphasis on Potential Arbovirus Vectors in East Azerbaijan Province, Northwestern Iran.

BACKGROUND: The abundance, diversity, distribution and ecology of mosquitoes (Diptera: Culicidae), especially arbovirus vectors are important indices for arthropod-borne diseases control. METHODS: Larvae and adult mosquitoes were collected using the standard methods from different habitats in nine localities of three counties in the East Azerbaijan Province, Northwestern Iran during June to October 2017. In addition, species richness (R), Simpson's diversity index (D), Shannon-Wiener index (H') and evenness (E) as measures of diversity, were calculated. RESULTS: Overall, 1401 mosquito specimens including 1015 adults and 386 larvae were collected in the study area. The properties of geographical larval habitats were recorded. Four genera along with 10 species were collected and identified, including Anopheles hyrcanus, An. maculipennis s.l., An. superpictus s.l., Aedes caspius, Ae. vexans, Culex pipiens, Cx. theileri, Cx. perexiguus, Culiseta longiareolata and Cs. subochrea. Among the three counties, Ahar region presented the highest species richness (R: 1.5) and diversity values (D: 0.79, H': 1.74, E: 0.73). CONCLUSION: This study provides important information on the diversity, distribution and ecology of ten mosquito species in the region. This information leads to a better understanding of mosquito population dynamics in relation to vector control measures.

Baseline Susceptibility of Culiseta longiareolata (Diptera: Culicidae) to Different Imagicides, in Eastern Azerbaijan, Iran.

BACKGROUND: Culiseta longiareolata is an important vector for many human diseases such as brucellosis, avian influenza and West Nile encephalitis. It is likely an intermediate host of avian Plasmodium that can transmit Malta fever. The aim of this study was to determine the susceptibility level of Cs. longiareolata to different classes of imagicides which are recommended by World Health Organization . METHODS: Larval stages of the Cs. longiareolata were collected from their natural habitats in Marand County at East Azerbaijan Province, northwestern of Iran in 2017. Adult susceptibility test were carried out with using impregnated papers to insecticides including DDT 4%, Cyfluthrin 0.15%, Deltamethrin 0.05%, Propoxur 0.1% and Fenitrothion 1% by standard test kits. RESULTS: Results showed that Cs. longiareolata adult is more susceptible to pyrethroid and carbamate insecticides. Among tested insecticides, Cyfluthrin was the most toxic against Cs. longiareolata with LT50 value of 11.53 minutes and Fenitrothion had the least toxic effect (LT50: 63.39 min). CONCLUSIONS: This study provided a guideline for monitoring and evaluation of insecticide susceptibility tests against Cs. longiareolata mosquitoes for further decision making.

Molecular evaluation of pvdhfr and pvmdr-1 mutants in Plasmodium vivax isolates after treatment with sulfadoxine/pyrimethamine and chloroquine in Iran during 2001-2016.

The rising use of sulfadoxine/pyrimethamine (SP) in the treatment of chloroquine (CQ)-resistant Plasmodium falciparum has resulted in increased exposure to P. vivax isolates in Iran, where both species are being circulated. In this investigation, the frequency of pvdhfr and pvmdr-1 mutants was assessed in P. vivax strains during 2001-2016 after the introduction of SP/CQ in malarious areas of Iran. The P. vivax isolates (n, 52) were obtained from autochthonous samples in Southeast Iran during 2015-2016. The genomic DNA was extracted and examined using nested polymerase chain reaction-(PCR) and sequencing. Mutations were detected in pvdhfr codons P33L (21.2%), T61 M (25%), S93H (3.9%), and S117 T (1.9%) and 5 isolates showed double mutations (33 L/61 M, 7.7%; 33 L/117 T, 1.9%). No mutation was identified in pvdhfr codons F57 and S58. The pvmdr-1 1076 L mutation was detected in 93.3% of P. vivax isolates. The findings indicated that the frequency of three codons of pvdhfr F57/S58/S117 has decreased from 2001 (1.05%/7.0%/16.9%) to 2016 (0%/0%/1.9%). Genomic analysis of pvmdr-1 showed that the frequency of 1076 L has gradually increased from 2013 (93%) to 2016 (93.3%) (P > .05). The results demonstrated that P. vivax isolates are probably being exited under SP pressure, which reflects the appropriate level of training for field microscopists, as established by Iranian policymakers. Emergent pvdhfr codons 33L, 61M, and 93H should be noticed in plausible drug tolerance and treatment plans. The high prevalence of pvmdr-1 1076L mutation shows that efficacy of CQ combination with primaquine may be in danger of being compromised, however further investigations are needed to evaluate the clinical importance of CQ-resistant P. vivax isolates.

Pharyngeal Myiasis Caused by Sheep Botfly, Oestrus ovis (Diptera: Oestridae) Larva, Tabriz, East Azarbaijan Province, Iran: a Case Report.

Myiasis is caused by the larvae of flies infesting animal or human tissues and organs. This report aims to present a case of pharyngeal myiasis caused by the larvae of Oestrus ovis (Diptera: Oestridae). A 55-yr old drug addict living in the Shahindeje village of Western Azerbaijan Province, northwestern Iran was referred to the Emam Reza Hospital in Tabriz, having a medical history of Chronic Obstructive Pulmonary Disease (COPD) and hospitalized due to respiratory distress, 20 days ago. He was intubated with a mechanical ventilator (MV) because of his respiratory distress condition. There was an evidence of the presence of pulmonary nodules in his lungs following diagnosis, and a CT scan revealed a cavity in his lung. During the nasogastric intubation procedure, a larva was seen emerging from the patient's mouth by one of the staff of the intensive care unit of the hospital. A laboratory diagnosis was performed in the Entomology Department of the School of Medicine, Tabriz University of Medical Sciences. Interestingly, larvae of O. ovis were identified and confirmed following the laboratory proceedings.

Diagnostic Accuracy of Loop-mediated Isothermal Amplification Assay as a Field Molecular Tool for Rapid Mass Screening of Old World Leishmania Infections in Sand Flies and In Vitro Culture.

BACKGROUND: We employed a highly sensitive loop-mediated isothermal amplification (LAMP) by targeting 18S rRNA gene to identify the rapid mass screening of Leishmania infections in captured sand flies of southwest Iran and In vitro culture. METHODS: One hundred fifty sand flies were collected from 11 sites adjacent to Iraqi's borders in southern parts of Khuzestan Province by using sticky sheets of paper and CDC miniature light traps during late May 2014 to Nov 2015. Following morphological identification of sand flies species, the DNA of infected samples was extracted and amplified by PCR and LAMP assays by targeting ITS-rDNA and 18S rRNA genes. The PCR amplicons were directly sequenced to conduct the phylogenetic analysis. RESULTS: Ten (6.6%) Leishmania infections were identified by LAMP assay (detection limit 0.01 parasites DNA) among infected Sergentomyia baghdadis, S. sintoni and Phlebotomus papatasi sand flies that was more sensitive than PCR (n=6.4%; (detection limit 101 parasites DNA). LAMP can identify 101-106 promastigotes/100 µl RPMI 1640 while PCR recognized 104-106 promastigotes. The majority infection rate of sand flies was confirmed to L. major inferred by phylogenetic analysis. CONCLUSION: This is the first exploration characterized the Old World Leishmania infections by LAMP technique in both infected sand flies and In vitro conditions. The LAMP method because of its shorter reaction time, robustness, more sensitivity, lack of requirement of complicated equipment and visual discriminatory of positivity can be appeared a promising tool instead of PCR to identify low Leishmania loads and entomological monitoring of leishmaniasis in resource-limited endemic of the world.

Diversity of Sand Flies (Diptera: Psychodidae) in Endemic Focus of Visceral Leishmaniasis in Azar Shahr District, East Azarbaijan Province, North West of Iran.

BACKGROUND: There are nearly 1000 species of Phlebotomine sand flies in 6 genera, of which only two, Phlebotomus in the old world and Lutzomyia in the new world are medically important. Globally, leishmaniasis prevalent in 98 countries and affects estimated 12 million people with almost two million new cases per year. Some rural areas of Azarshahr District in East Azarbaijan Province have been reported to be endemic for visceral leishmaniasis. This study is the first attempt to determine the species diversity and density in a new focus of visceral leishmaniasis in Azarshahr District, East Azarbaijan Province, Iran. METHODS: Sand flies were collected form indoor and outdoor biweekly using sticky traps. Diversity index of the collected sand flies within different villages were estimated by the Shannon-Weaver. RESULTS: The activity of the sand flies extended from April to October with one peak in August. Diversity of sand flies within study area were estimated as 0.917, 1.867, 1.339, 1.673, and 1.562 in Almalodash, Jaragil, Segaiesh, Amirdizaj, and Germezgol Vvillages, respectively. CONCLUSION: Identifying the diversity and seasonal abundance of the collected species is of importance for prediction of the period of maximum risk for leishmaniasis transmission and for the successful implementation of a control program. Species diversity is one of the most important factors in ecological studies.

Detection of Bendiocarb and Carbaryl Resistance Mechanisms among German Cockroach Blattella germanica (Blattaria: Blattellidae) Collected from Tabriz Hospitals, East Azerbaijan Province, Iran in 2013.

BACKGROUND: Insecticide resistance is one of the serious problems for German cockroach control program. This study was conducted to determine the bendiocarb and Carbaryl resistance mechanisms in German cockroaches using the piperonyl butoxide (PBO). METHODS: Bioassay tests were conducted with 4 to 6 different concentrations of both insecticides with four replicates of 10 susceptible strain cockroaches per concentration to determine of discriminative concentration. After determining discriminative concentration, the result was compared to wild strain. The levels of susceptibility and resistance ratio (RR) and synergism ratio (SR) were calculated for each five wild strains. Moreover resistance mechanisms in wild strains were determined using PBO synergist in vivo. RESULTS: Hospital strains showed different levels of resistance to bendiocarb and carbaryl compared to susceptible strain. The bendiocarb and carbaryl resistance ratios ranged from 2.11 to 7.97 and 1.67 to 2 at LD50 levels, respectively. The synergist PBO significantly enhanced the toxicity of bendiocarb and carbaryl to all strains with different degrees of synergist ratio, 1.31, 1.39, 3.61, 1.78, 1.62 and 2.1 fold for bendiocarb, 1.19, 1.18, 1.12. 1.29, 1.45 and 1.11-fold for carbaryl, suggesting monooxygenase involvement in bendiocarb and carbaryl resistance. CONCLUSION: The synergetic effect of PBO had the highest effect on bendiocarb and resistance level was significantly reduced, which indicates the important role of monoxidase enzyme in creating resistance to Bendiocarb. Piperonyl butoxide did not have a significant synergistic effect on carbaryl and did not significantly break the resistance.

Genetic variability and discrimination of low doses of Toxocara spp. from public areas soil inferred by loop-mediated isothermal amplification assay as a field-friendly molecular tool.

ABSTRACT: Aim: One of the main diagnostic problems of conventional polymerase chain reaction (PCR) is indiscrimination of low parasitic loads in soil samples. The aim of this study is to determine the genetic diversity and identification of Toxocara spp. from public areas soil inferred by loop-mediated isothermal amplification (LAMP) assay. MATERIALS AND METHODS: A total of 180 soil samples were collected from various streets and public parks of northwest Iran. The DNA of recovered Toxocara eggs were extracted and amplified by PCR and LAMP following ZnSO4 flotation technique. The amplicons of internal transcribed spacer-2 gene were sequenced to reveal the heterogeneity traits of Toxocara spp. In addition, Toxocara canis sequences of southwest Iran were directly retrieved to compare gene flow between two distinct populations. RESULTS: Toxocara spp. eggs were found in 57, 14 and 77 of soil samples using the microscopy, PCR and LAMP (detection limit 1-3 eggs/200 g soil), respectively. 7.7% of isolates were identified as T. canis by PCR method, while LAMP was able to detect 27.2%, 15.5% and 12.2% as Toxocara cati, T. canis and mixed infections, respectively. The kappa coefficient between LAMP and microscopy indicated a strong agreement (0.765) but indicated a faint agreement among LAMP-PCR (0.203) and PCR-microscopy (0.308) methods. A pairwise fixation index (Fst) as a degree of gene flow was generally low (0.02156) among Toxocara populations of northwest and southwest Iran. CONCLUSIONS: The statistically significant Fst value indicates that the T. canis populations are not genetically well differentiated between northwest and southwest Iran. This shows that here is possibly an epidemiological drift due to the transfer of alleles. The LAMP assay because of its shorter reaction time, more sensitivity, and simultaneous detection of environmental contamination to be appears as valuable field diagnosis compared to PCR. Therefore, the detection of low Toxocara spp. loads from public area soils will help to expand epidemiological understanding of toxocariasis and establishing preventive strategies in resource-limited endemic of Iran.

Nosocomial oral myiasis in ICU patients: occurrence of three sequential cases.

Myiasis is the infestation of living vertebrates or humans tissues by dipterous larvae. The oral cavity is rarely affected by this infestation and the circumstances which can lead to oral myiasis include persistent mouth opening together with poor hygiene. Such infestations have been reported mainly in developing countries such as in Asia. Although rare, nosocomial myiasis must be noted carefully, especially in case of hospitalized patients. This report describes three cases of nosocomial oral myiasis in hospitalized patients in ICU (intensive care unit) in Tabriz, North West of Iran.

The first morphometric and phylogenetic perspective on molecular epidemiology of Echinococcus granulosus sensu lato in stray dogs in a hyperendemic Middle East focus, northwestern Iran.

BACKGROUND: Hydatidosis is considered to be a neglected cyclo-zoonotic disease in Middle East countries particularly northwestern Iran which is caused by metacestode of tapeworm Echinococcus granulosus sensu lato. Human hydatidosis is a high public health priority in the area, however there is little known from a morphometric and phylogenetic perspective on molecular epidemiology of adult Echinococcus spp. in Iranian stray dogs. METHODS: 80 dogs (38 males and 42 females) were collected during June 2013 to April 2014 in northwestern Iran. The isolated parasites from each dog were distinguished by morphometric keys including small, large hook length and blade length. Subsequently, isolates were confirmed by sequencing of mitochondrial cytochrome oxidase subunit 1 gene. RESULTS: 16 (8 males and 8 females) (Prevalence 20%) out of 80 dogs were infected to genus Echinococcus. With regard to demographic factors, the frequency of parasitism in both male, female adults and their age groups showed no difference (P > 0.05). The phylogenetic analyses of cox1 sequences firmly revealed the 13 sheep strains (G1), one buffalo strain (G3), one camel strain (G6) and one mixed infection. The findings of rostellar hook morphology show an intraspecies variation range among G1 isolates. However, hook measurements in Echinococcus derived from G1 (sheep strain) were not a significant difference from those G6 and G3 strains. Six unique haplotypes were identified containing a high range of diversity (Haplotype diversity 0.873 vs. Nucleotide diversity 0.02). CONCLUSIONS: First presence of camel strain (G6) in this region seems to indicate that potential intermediate hosts play a secondary role in the maintenance of camel-dog biology. Current findings have heightened our knowledge about determination of Echinococcus prevalence, strains of taxonomy and genotypic trait of parasite in Iranian stray dogs which will also help in the development of strategies for monitoring and control of infected stray dogs in the area.

Phenology and population dynamics of sand flies in a new focus of visceral leishmaniasis in Eastern Azarbaijan Province, North western of Iran.

OBJECTIVE: To investigate species composition, density, accumulated degree-day and diversity of sand flies during April to October 2010 in Azarshahr district, a new focus of visceral leishmaniasis in north western Iran. METHODS: Sand flies were collected using sticky traps biweekly and were stored in 96% ethanol. All specimens were mounted in Puri's medium for species identification using valid keys of sandflies. The density was calculated by the formula: number of specimens/m(2) of sticky traps and number of specimens/number of traps. Degree-day was calculated as follows: (Maximum temperature + Minimum temperature)/2-Minimum threshold. Diversity indices of the collected sand flies within different villages were estimated by the Shannon-weaver formula ( H'=∑i=1sPilog(e)Pi). RESULTS: Totally 5 557 specimens comprising 16 Species (14 Phlebotomus, and 2 Sergentomyia) were indentified. The activity of the species extended from April to October. Common sand-flies in resting places were Phlebotomus papatasi, Phlebotomus sergenti and Phlebotomus mongolensis. The monthly average density was 37.6, 41.1, 40.23, 30.38 and 30.67 for Almalodash, Jaragil, Segaiesh, Amirdizaj and Germezgol villages, respectively. Accumulated degree-day from early January to late May was approximately 289 degree days. The minimum threshold temperature for calculating of accumulated degree-day was 17.32°. According on the Shannon-weaver (H'), diversity of sand flies within area study were estimated as 0.917, 1.867, 1.339, 1.673, and 1.562 in Almalodash, Jaragil, Segaiesh, Amirdizaj and Germezgol villages, respectively. CONCLUSIONS: This study is the first detailed research in terms of species composition, density, accumulated degree-day and diversity of sand flies in an endemic focus of visceral leishamaniasis in Azarshahr district. The population dynamics of sand flies in Azarshahr district were greatly affected by climatic factors. According to this study the highest activity of the collected sand fly species occurs at the teritary week of August. It could help health authorities to predicate period of maximum risk of visceral leishamaniasis transmission and implement control program.