Journal of Arthropod-Borne Diseases最新文献

Background: Hemiscorpius lepturus is one of the most dangerous scorpions in Iran and the world. Numerous studies have been conducted on phospholipases, especially phospholipase D, in this scorpion's venom, and the results have shown this protein to be the main cause of death. Therefore, one of the most effective ways of preventing fatalities is to produce a toxoid vaccine from the deadly toxin of the venom. The present study was conducted to assess the non-toxicity of this toxoid and the safety of the vaccine candidate in BALB/c mice.

Methods: The production of interferon-gamma and interleukin-4 cytokines in the spleen cells of the mice was measured using ELISpot assay 28 days following immunization with rPLD toxoid.

Results: The unpaired t-test results showed a significant increase in the concentration of IFN-γ cytokine in the vaccinated mice (P= 0.001), indicating that the immune system is directed toward the Th1 pattern, while no significant difference was observed in the levels of IL-4 (P= 0.16) despite an increase in this cytokine. The in-vivo tests showed that the mice immunized with interval doses of 80µg of toxoid were completely protected against 10 × the LD₁₀₀ of the venom. Moreover, the toxoid had no dermonecrotic effects and caused no necrotic and inflammatory complications in the rabbit skin.

Conclusion: As a vaccine, the toxoid has the potential to increase the Th1 cytokine response and, subsequently, increase acquired cellular immunity. Thus, this toxoid appears to be able to provide an effective vaccine against the venom of Hemiscorpius lepturus.

Background: Leishmania major is the etiologic agent of zoonotic cutaneous leishmaniasis in Iran, and glucantime injection is currently used for its treatment. This study aimed to evaluate the anti-leishmanial effect of topical Plantago psyllium and white vinegar in L. major infected BALB/c mice.

Methods: Thirty infected mice were divided into five groups as follows: Group 1: treated with the combination of ovata powder and white vinegar, Group 2: treated with glucantime, Group 3: treated with white vinegar, Group 4: treated with the combination of ovata powder and water, and Group 5: without any treatment. All the groups were treated for 18 days. Lesion size was measured, and final smears were prepared for microscopic examination.

Results: The findings indicated that the difference in the mean areas of the ulcers in all the groups before and after treatment was not significant, except for the second (glucantime) and third (vinegar) groups. Also, the results showed that in the first, second, third, and fourth group, 6 (60%), 4 (80%), 3 (60%), and 2 (40%) mice were healed, respectively. However, ulcers remained in all the five mice of the control group.

Conclusion: The combination of ovata powder and white vinegar has been traditionally used to treat leishmanial lesions in Iran. It seems the most anti-leishmanial effect is related to vinegar and supported by Plantago. The route of treatment with this combination is very simple and painless in comparison with injection. Thus, further studies on this issue could help to design more effective and easy-to-use drugs.

Background: Androctonus crassicauda is the most medically relevant animal and understanding its morphological characteristics is essential in the production of antiscorpion sera.

Methods: Adults of A. crassicauda were collected from different areas of Zanjan Province and the morphometric parameters and the cuticular fluorescence patterns of samples were studied. The crude venom of samples was extracted by electric stimulation, and their biochemical properties were analyzed by the SDS-PAGE method.

Results: Values of the morphometric parameters depended on sex and altitude of the area. Except for values of the pectinal organ, these parameters in females were higher than in males. No significant difference was in the number, shape, and intensity of cuticular fluorescence patterns. The body length of males in high and lowlands was 72.53±1.53 and 77.33±2.70mm, respectively. Females' body lengths in that area were 81.66±2.19 and 86.55±2.33mm, respectively. Analysis of toxin proteins showed two isotypes that the 12, 13, 15, 16, 18, and 19kDa proteins were in all areas. However, the 41 and 74kDa proteins, and 46 and 63kDa proteins were detected in low and highlands, respectively.

Conclusion: Black fat-tailed scorpion has a considerable dominancy and developing preventive programs and providing treatment facilities in studied areas are necessary. Values of the morphological parameters and venom electrophoresis patterns depended on the geographical location. Therefore, pool crude toxin is suggested for the production of effective antivenoms. Moreover, additional field complementary works in the geographic information system based niche modeling and mass fingerprinting of scorpion venoms are suggested for screening effective isotypes.

Background: Mosquitoes (Diptera: Culicidae) are haemotophagus insects and are vectors of many arthropod-borne diseases. Present study aimed to explore species composition, seasonal abundance, spatial distribution and physio-chemical properties of larval breeding sites of mosquitoes in District Mardan, Khyber Pakhtunkhwa, Pakistan.

Methods: Both adults and larvae of mosquitoes were collected through light traps, insecticide spray, mouth aspirator and larval standard dipping method in District Mardan from May to November 2017. Water samples from larval sites were physio-chemically analysed.

Results: 5078 (3704 adults and 1374 larvae) mosquito specimens were collected in Mardan, Katlang and Takhtbhai tehsils. Six species in four genera were reported. Culex pipiens (89.80%) and Armigeres subalbatus (9.20%) were the most abundant species. Diversity was high in Takhtbhai (0.29) followed by Katlang (0.28) and Mardan (0.25). Greater number of specimens were recorded in peridomestic sites (93.97%) as compared to domestic habitats (6.03%). Culex pipiens larval abundance had negative correlation with pH whereas it correlated positively with electric conductivity, salinity, and TDS (total dissolved sulphur). Mosquito abundance peaked in August and July while the lowest was in May. Their monthly abundance had positive correlation with rainfall (r= 0.5069), relative humidity (r= 0.4439) and mean minimum temperature (r= 0.2866). Number of mosquitoes was highest at low elevation < 347m asl (above sea level) in agriculture land and near to water bodies (streams).

Conclusion: Culex pipiens being the most abundant species, was susceptible to high pH. Mosquitoes preferred habitats were at low elevation in agriculture land.

Background: Rodents and shrew living in the vicinity of human beings perform significant role to harbor different species of ectoparasites and thus act as the reservoir host for the spread of diseases to human and animals.

Methods: This study was undertaken to determine the species composition of the medically important ectoparasites present in the scrub typhus affected places of Vellore District using wonder and Sherman traps for trapping of live Rodent/Shrew during September 2017 to August 2018.

Results: Rodent/shrew hosts belonged to two Families, three sub families and five genera and five different species. These animals carried 23 species of ectoparasites including 17 trombiculid mites, two non-trombiculid mites, two ticks and two fleas. A total of 940 chigger mites were collected which belonged to three Tribes, six Genera, two Subgenera and 17 species. Adult mites collected belonged to two families, three genera and three species. Ticks collected were classified under one family, two genera and two species. Fleas fall under one family, one subfamily, one tribe, one genus and two species.

Conclusion: This is the first record of 14 species of chigger mites and three species of adult mites from Vellore District, Tamil Nadu. Surveillance of these keystone ectoparasites helped to identify the medically important disease vectors causing acari-borne zoonotic diseases.

Background: Pediculosis, caused by Pediculus spp is an important public health problem in urban and rural areas around the world. Natural compounds such as plant essential oils (EOs) have been suggested as a potential alternative for insect pest control recently. The purpose of this study was to investigate the toxicity of Foeniculum vulgare essential oil against the head louse, Pediculus capitis under laboratory conditions.

Methods: Fennel essential oil components were analyzed using GC-mass apparatus. Immersion and contact filter paper bioassays were used to evaluate fennel essential oil toxicity at the two-fold concentrations of 2.5, 5, 10, 20, and 40% against nit and nymph/adult stages of the head louse.

Results: Trans-anethole, α-Thujone, and limonene, which consisted of 76.08%, 10.37%, and 5.34% were the most components of fennel oil respectively. The LC₅₀ values for the adult /nymphs were 11.5, 6.4, 3.9, 3.1 and 2.5% and LC₉₉ values were 29.5, 15.2, 12.8, 10.8, and 7.4% at 10, 20, 30, 45 and 60 minutes after exposure respectively. The lethal times (LT₅₀) for adults/nymphs were 5.2, 8.1, 9.5, 20.5, and 45.8 minutes and LT₉₉ were 138.6, 91.3, 23.8, 21.7, and 13.9 minutes in the concentrations of 2.5, 5, 10, 20 and 40%, respectively. LC₅₀ and LC₉₉ values were 2.32% and 7.36% after 5 days for the eggs.

Conclusion: Fennel essential oil at the concentration of 15% after 20min is suggested to develop as an appropriate formulation to evaluate in clinical trials.

Background: Pediculosis is a common parasitic public health issue. Many socio-demographic and economic factors affect the pattern and prevalence of pediculosis. It is widely spread among pupils, particularly those in elementary schools. This study aimed to determine the prevalence of Pediculus capitis infestation and its related risk factors in primary school children in Sulaimani Governorate, Kurdistan Region of Iraq.

Methods: This is a cross-sectional study, overall, 2064 primary school children (aged 5-14 years) during the period from October 2019 to February 2020 were randomly examined for the presence of any stage of Pediculosis capitis in both urban and suburban areas. The schools were selected by multistage sampling methods. A questionnaire was sent to the parents to get consent and fill in for every single pupil. The results were computed using the chi-square test and logistic regression analysis.

Results: The overall prevalence of head lice infestation was (9.16%). The study found a significant association of Pediculosis capitis infestation with gender, parents' education level, mother's employment, number of siblings, and previous infestation. The older age of children (≥12 years old) and the higher-grade pupils (4^th to 6^th class) were more infested.

Conclusion: Head lice remain a health problem for school children. It needs collaboration of many sectors for decreasing and early detection and treatment in both urban and suburban areas since they have a close rate of infestation.

Background: A variety of haemoprotozoa including Plasmodium, Haemoproteus and Leucocytozoon cause infections in birds and are transmitted by some known vectors. These parasites cause anemia, low appetite, weakness and ultimately death in birds. The present study was aimed to determine these parasites, in birds of Mazandaran and Golestan provinces in Iran.

Methods: The project was performed on 340 live birds in 2016. The samples were collected from February to September 2016, from each bird, two thin and thick blood smears were prepared and the remaining blood about 1ml was kept in EDTA-containing tubes for molecular studies. The slides were stained with 10% Giemsa, then examined microscopically. About ten percent of the negative samples were considered for Polymerase Chain Reaction (PCR) technique, using specific primers to diagnose Plasmodium and Haemoproteus spp. Electrophoresis was done for PCR products and relevant bands to the parasites were identified based on the size. The considered birds belonged to ducks, chickens, roosters, and pigeons.

Results: From 340 microscopically examined blood samples 32 (9.5%) samples were positive. Twenty-five (7.35%) of them were infected with the genus Haemoproteus. Seven samples (14%) out of 50 microscopically negative samples were found as Haemoproteus or Plasmodium spp when PCR technique was employed.

Conclusion: This study revealed the existence of malaria parasites and other haemosporidia in birds in Iran. Employing molecular methods (PCR examination) could detect more infections.

Background: Due to the confirmation of the presence of the novel coronavirus in the feces and municipal sewerage system, and the feeding of domestic insects from fecal matter, as well as the ability of these insects to mechanically transmit microbes from the sewerage system. This study was aimed at molecular evaluation of the novel coronavirus infection isolated on cockroaches and flies collected from Kamkar-Arabnia Hospital in Qom City, Iran.

Methods: Totally, 18 samples; (12 samples cockroaches and 6 flies) from the external surface of cockroaches and houseflies as well as their digestive system were prepared. After designed and synthetized exogenous heterologous internal control, the RNA was extracted to investigate the contamination of these samples with the novel coronavirus. To detect the virus, the E and RdRp genes were identified.

Results: Investigation of coronavirus E gene using the multiplex one-step qPCR technique on the collected samples showed an amplification plot in CT= 35.70 related to the internal surfaces of cockroaches collected from the treatment and sick room of the hospital. Also, the design of internal control to ensure the accuracy of the extraction process was successful.

Conclusion: According to the findings of the present study regarding detecting the presence of the coronavirus infection in the digestive system of domestic insects such as American cockroaches and considering their ability to mechanically transmit viruses, it is recommended to control the domestic insects that are in close contact with humans in crowded places such as hospitals and health centers during the Covid-19 pandemic.

Background: SScabies is caused by the parasite Sarcoptes scabiei. The disease was first described in ancient Greece, while Ferdinand Von Hebra described the stages of development of the arthropodite from the egg to larvae and the adult form of sarcoptosis. The final stage is characterized by the travel of the female parasite and the laying of eggs in stratum corneum and followed by the death of the causer. The main characteristic symptom of scabies is relentless pruritus which is a result of such an infestation inside the skin, as the body reacts to parasites and their excretions, where mites burrow and lay eggs.

Methods: Here we present the 85-year-old patient with scabies crustosa, latent diabetes and renal insufficiency.

Results: Persistent pruritus and scabies rash, where large numbers of mites were detected, was left untreated and further progressed into sores due to scratching. Weakened immunity and chronic illness in the patient resulted in a more severe form of the disease which was diagnosed as scabies crustosa. After treatment with a supplemented antiscabiotic regimen, the patient remained symptom free.

Conclusion: Large population movements, one of the main factors of spread and frequent incidence of scabies, contact with the sick, hygiene means, exchange of wardrobes, sharing bed with the sick, schools, preschools, old-age-care institutions and hospitals, enable spread of the disease. In addition, severe types of scabies that form thick crusts on the skin and present with pruritus as a symptom should be considered in immunocompromised and elderly patients with renal insufficiency where pruritus is also prevalent.