Journal of Arthropod-Borne Diseases最新文献

Background: Culex pipiens is one of the most important vectors of mosquito-borne pathogens in Iran. This study aimed to predict the distribution of this species in Golestan Province, Iran and to determine the factors affecting its distribution.

Methods: Mosquito larvae were collected by using the dipping method from 56 locations across all 14 counties of the province, between April and October 2016. Species were identified morphologically, and the spatial distribution of Cx. pipiens was modeled using the maximum entropy (MaxEnt software Ver. 3.3.3) model.

Results: The results of our study show that areas located in the central part of Golestan Province are the most environmentally suitable habitat for Cx. pipiens. Jackknife test of variable importance showed that the following factors had the greatest influence on the distribution of Cx. pipiens: proximity to human settlements, precipitation of coldest quarter (mm), precipitation of wettest quarter (mm), precipitation of wettest month (mm), and mean temperature of coldest quarter (°C).

Conclusion: This study concludes that the MaxEnt model is a very suitable model for studying the ecology of Cx. pipiens and precipitation, and temperature play a major role in the distribution of this species.

Background: The body louse spreads diseases such as epidemic typhus and louse-borne relapsing fever and has shown resistance to various insecticides. While deltamethrin is used to treat infestations in some countries, research on its effectiveness against body lice is limited. This study assessed the susceptibility of body lice to deltamethrin using a bioassay.

Methods: Body lice specimens were collected from an addiction treatment camp in Urmia City, West Azerbaijan Province, Iran. They were treated in 5 cm Petri dishes lined with 1 ml of various concentrations of deltamethrin (0.01, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, 1.28, and 2.56 ppm) in acetone. Thirty lice were tested per concentration, with mortality recorded after 24 hours. Lethal concentrations of 50% and 90% (LC₅₀ and LC₉₀) were calculated using Minitab and compared with SPSS. The regression line was plotted in Excel 2013.

Results: A positive correlation was observed between the concentrations of deltamethrin and probit mortality in the regression analysis. The calculated LC₅₀ and LC₉₀ values for deltamethrin against body lice were 0.11 ppm and 2.15 ppm, respectively.

Conclusions: These findings suggest that the body lice population was susceptible to deltamethrin, suggesting its potential as an alternative treatment, pending further clinical studies.

Background: Rosacea is a common chronic and recurrent skin disease whose etiology is not precisely clear. This study aimed to investigate the relationship between rosacea and Demodex mite infestation in patients referred to the medical centers of Tabriz University of Medical Sciences during 2023.

Methods: Patients' information, including age, gender, and clinical symptoms of rosacea diagnosis, was recorded. 60 out of 71 patients underwent standard superficial skin biopsy with a thickness of 5 μm from their faces, with a drop of immersion oil, and were examined under a light microscope.

Results: The mean Demodex density was 19.20 mites/cm². Of these 60 rosacea patients, 47 (78.3%) were female and 13 (21.7%) were male. The highest Demodex mite infestation was in the 31-40 age group (38%). Out of 50 patients with positive Demodex (83.3%), 41 (68.3%) were related to D. folliculorum and 9 (15%) were related to D. brevis. Of the 41 patients infected with Demodex, 31 (out of 47, 66.0%) were women and 10 (out of 13, 76.9%) were men. The p-values for the relationships between age, gender, and mite species with mite count were all greater than 0.05. This indicates no statistically significant evidence of a direct relationship.

Conclusion: Demodex mite density was higher in rosacea than the normal benchmark of <5 mites/cm². This strong association suggests Demodex overpopulation plays a key role in the disease. Therefore, treatment strategies for rosacea should include acaricidal therapy targeting the mites.

Background: Flies play a significant role in public health because of their potential to transmit human pathogens and cause myiasis. This study aimed to investigate the species composition, abundance, biodiversity, and synanthropy of medically important flies in southwest Iran .

Methods: Flies were collected from urban, semi-urban and non-residential ecosystems of Andimeshk county, southwest Iran, from 2020 to 2021 using a bottle trap and sweep net. All collected specimens were identified using taxonomic keys. Biodiversity and synanthropic indices were calculated.

Results: A total of 15644 flies belonging to three families of Sarcophagidae, Calliphoridae and Muscidae were collected, comprising 11 genus and 18 species of Sarcophaga ruficornis (0.5%), S. aegyptica (0.9%), S. melanura (0.6%), S. africa (0.6%), Sarcophaga sp. (2.6%), Ravinia pernix (0.4%), Sarcophila sp. (0.3%), Wohlfahrtia sp. (0.6%), Chrysomya albiceps (9%), Chrysomya megacephala (36.3%), Lucilia sericata (2.5%), Calliphora vicina (0.3%), Polenia sp. (0.5%), Musca domestica (30.8%), Musca automnalis (0.6%), Muscina stabulans (2.4%), Muscina prolapse (0.4%), Atherigona sp. (0.6%) were trapped. The synanthropic index (SI) was +52.25, +46.2, +35.1, +35.95, and +21.45 for the myiasis-causing species, including C. vicina, S. africa, C. albispes, C. megalocephala and S. aegyptica, respectively. The biodiversity and evenness indices were 1.82±0.026 and 0.6306±0.0009, indicating a relatively high diversity and moderate/high evenness of flies in the study area.

Conclusion: Given synanthropic behavior and widespread presence of C. megacephala, this species should be prioritized in future surveillance and control programs to reduce public health risks.

Background: Scorpion envenomation represents a significant public health concern worldwide. The telson is located at the distal part of the metasoma, where venom is secreted from a pair of venom glands. The curved stinger is responsible for venom delivery.

Methods: This study conducted a histological examination of five scorpion species, including Hottentotta juliae, Hottentotta zagrosensis, Odontobuthus kermanus, and Scorpio maurus, which were gathered from Fars Province, as well as Hemiscorpius lepturus, collected from Khuzestan Province. The telson histology was assessed using the hematoxylin-eosin method.

Results: The exocuticle, endocuticle, and secretory epithelium, which consists of secretory and supporting cells, were identified in the tissues of all species. Cuticle pores were distributed throughout the telson. Each venom gland possesses a central lumen, where secreted venom accumulates within a venom sac. The intercalated tendon is located beneath the basal membrane and connects the glandular epithelium to the cuticle. The sizes and shapes of the secretory epithelial cells vary depending on the species.

Conclusion: While histology elucidates the structural organization of scorpion venom glands, integrating histological findings with proteomic and histochemical approaches would provide a more comprehensive understanding of venom composition and interspecific variation.

Background: Scabies, caused by Sarcoptes scabiei, is common in Iran; however, epidemiological data from Gonabad City are scarce. Therefore, this study was conducted to determine the prevalence of scabies in patients referred to the dermatology clinic of Allameh Bohlool Gonabadi Hospital in Gonabad City and to investigate its associated risk factors.

Methods: A cross-sectional analysis was conducted in 2024 on 734 patients presenting with pruritic eruptions and itchy rashes. The diagnosis of scabies was confirmed in 98 patients by identifying S. scabiei mites, eggs, or fecal pellets through light microscopic examination of skin scrapings. Data from these confirmed cases were analyzed using SPSS v.25 to describe their characteristics.

Results: Among the 734 patients screened, 98 were confirmed to have scabies (13.4%). Analysis of these 98 cases revealed that the majority were female (64.3%, 63/98). The highest frequency of cases was observed in individuals aged 16 years and younger. Assessment of clinical presentation revealed that 55.1% (54/98) of cases presented with moderate lesions. A high proportion of cases were also among women, people with low levels of education and unemployed people.

Conclusion: This study identified a total of 98 scabies cases among 734 patients screened in Gonabad City. The infestation was significantly associated with being female, having a lower level of education, and unemployment. These findings highlight a distinct epidemiological pattern of scabies in this underserved region and underscore the need for targeted community screening and health education, particularly among the affected demographic groups. Further analytical studies are needed to confirm true risk factors at the population level.

Background: Diseases such as malaria are transmitted by Anopheles species, among which Anopheles stephensi is one of the most important malaria vectors in Iran. Reducing the transmission of mosquito-borne diseases depends on controlling the mosquito vector or minimizing human-vector contact. A promising method for control, surveillance, and monitoring involves using synthetic attractants in traps to target vectors. This study aims to determine the effective dose of octenol, isovaleric acid, lactic acid, hexanoic acid, isoamyl alcohol, myristic acid, and ammonium hydrogen bicarbonate using the high-throughput screening system (HTSS) device in the laboratory.

Methods: After rearing An. stephensi in the insectary, High-Throughput Screening System (HTSS) assay was used to obtain the 50% and 90% effective dose (ED) of the attractive compounds. Probit analysis was used to analyze the results and prepare the regression lines of ED₅₀ and ED₉₀.

Results: This study showed that An. stephensi had the highest absorption to isoamyl alcohol (ED₅₀= 0.57 mL/L, ED₉₀= 1.04 mL/L), followed by isovaleric acid (ED₅₀= 1.96 mL/L, ED₉₀= 3.00 mL/L), myristic acid (ED₅₀= 24.77 g/L, ED₉₀= 47.08 g/L), octenol (ED₅₀= 26.64 mL/L, ED₉₀= 54.36 mL/L) and lactic acid (ED₅₀= 54.98 mL/L, ED₉₀= 132.9 mL/L), while hexanoic acid (ED₅₀= 87.50 mL/L, ED₉₀= 244.49 mL/L) per liter and ammonium hydrogen bicarbonate (ED₅₀= 93.84 g/L, ED₉₀= 234.01 g/L) showed the lowest absorption rate.

Conclusion: Our laboratory results identified isoamyl alcohol and isovaleric acid as highly effective attractants for An. stephensi. These compounds are strong candidates for inclusion in field-deployable traps after further validation.

Background: Mosquitoes (Diptera: Culicidae) are the most important arthropods in public health. Larval habitat features play an important role in their selection by female mosquitoes for oviposition. The purpose of this study was to determine the oviposition sites of mosquitoes in Aqqala County of Golestan Province following the flood of 2019.

Methods: Two categories of larval habitats were defined: those that naturally occurred and those that were a result of flooding. Samples were collected using dippers with a 350 ml capacity. The collected larvae were preserved in lactophenol solution. Microscope slides were prepared using Berlese medium. The specimens were morphologically identified. Larval habitat characteristics were recorded according to the habitat situation (permanent/temporary, running/stagnant), vegetation situation, sunlight situation, substrate type, water situation (turbid/clear) and habitat type (natural/artificial).

Results: In total, 774 third- and fourth-instar mosquito larvae were collected from different larval habitats not affected by the flood, including seven species representing four genera. Culex pusillus was the dominant species (41.2%). The larvae of Aedes caspius, Cx. pipiens, Cx. theileri, Culiseta longiareolata and Uranotaenia unguiculata were collected only from artificial habitats, 96.9% of Cx. tritaeniorhynchus larvae from artificial habitats and 78.7% of Cx. pusillus larvae from natural habitats. No larvae were collected from the larval habitats affected by the flood.

Conclusion: Field observations suggested that the flushing of natural larval habitats may cause such a decrease in larval population in the habitats affected by the flood. The presence of the larvivorous fish Gambusia holbrooki may also be taken into consideration.

Background: This study evaluates a herbal shampoo containing Gharaghorot, vinegar, and Ajwain for managing head lice, particularly in resource-limited settings.

Methods: The herbal shampoo formulation constituted 100% final solution, composed of: 28.85% Gharaghorot extract (prepared from sour yogurt juice), 67.31% apple cider vinegar, 2.88% Ajwain (Trachyspermum ammi) essential oil, and 0.96% xanthan gum (a biocompatible thickening agent). Cell toxicity and sterility were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and fluid thioglycollate and soybean casein digest media, respectively. Irritation and sensitization tests were conducted on rabbits and guinea pigs, respectively. A randomized controlled trial with 114 patients compared the herbal shampoo to standard Permethrin treatment (Permethrin shampoo 1%). Participants applied the shampoo daily for one hour over seven days, with efficacy evaluated by counting live lice and nits before treatment, three days in, and seven days post-treatment.

Results: The herbal shampoo exhibited no significant cytotoxicity at concentrations of 10% or lower. The shampoo did not cause sensitization, edema, or erythema. Microbial contamination analysis showed no detectable levels of aerobic or anaerobic bacteria or fungal spores. In the human study, the intervention group showed a 0% prevalence of live lice by the seventh day, compared to 50% in the permethrin group (P= 0.021), and a significant reduction in lice eggs to 42% versus 100% in the permethrin group (P= 0.025).

Conclusion: The herbal shampoo demonstrated safety, microbiological purity, and notable efficacy in reducing live head lice and partial effectiveness against nits (42% egg viability post-treatment).