Journal of Arthropod-Borne Diseases最新文献

Background: Given the significance of climate change and its substantial effects on mosquitoes' habitats, this study was aimed to model the spatial distribution of the main malaria vectors in the south east of Iran.

Methods: Several scientific databases between 1980 and 2019 were reviewed to find mosquito species and their spatial information in this area. The archived folders in the center for diseases control and prevention were used to exploit essential data on malaria cases and foci. Three representative concentration pathways (RCP2.6, RCP4.5 and RCP8.5) were chosen to stand for three possible climate scenarios. Finally the potential species distribution of Anopheles stephensi and An. culicifacies s.l. in the 2030s and 2050s horizons were estimated by the Maximum Entropy Model.

Results: So far, a total of 39 mosquito species belonging to the family Culicidae have been reported from the study area. In 2019, the total malaria cases have increased by 91% compared to 2015, as well as a sharp rise than 2018 (249%). In that year, 91% of cases were imported from other countries, which caused 40% increase in the new potential foci than in 2018. The Jackknife test demonstrated the annual mean temperature and precipitation of the coldest quarter with the greatest impact on the environmental suitability of the mentioned two species.

Conclusion: The effect of climate change on the appearance and recurrence of mosquito-borne diseases has been demonstrated in various studies. Collecting further data and conducting investigation on this issue will improve control management, especially for the malaria vectors.

Background: Extensive use of chemical larvicides to control larvae, has led to resistance in vectors. More efforts have been conducted the use of natural products such as plant essential oils and their new formulations against disease vectors. Nanoformulation techniques are expected to reduce volatility and increase larvicidal efficacy of essential oils. In this study for the first time, a larvicide nanoemulsion from the essential oil of Acroptilon repens was developed and evaluated against Anopheles stephensi larvae under laboratory conditions.

Methods: Fresh samples of A. repens plant were collected from Urmia, West Azarbaijan Province, Iran. A clevenger type apparatus was used for extracting oil. Components of A. repens essential oil (AEO) were identified by gas chromatography-mass spectrometry (GC-MS). All larvicidal bioassay tests were performed according to the method recommended by the World Health Organization under laboratory condition. Particle size and the morphologies of all prepared nanoformulations determined by DLS and TEM analysis.

Results: A total of 111 compounds were identified in plant. The LC₅₀ and LC₉₀ values of AEO calculated as 7 ppm and 35 ppm respectively. AEO was able to kill 100% of the larvae in 4 days.

Conclusion: The nanoemulsion of AEO showed a weak effect on the larvar mortality. It may therefore be suggested that this kind of nanoemulsion is not appropriate for the formulation as a larvicide. It is important to screen native plant natural products, search for new materials and prepare new formulations to develop alternative interventions with a long-lasting impact.

Background: Head lice infestation is known as a serious health problem in developing and developed countries. The prevalence of pediculosis in children and females is higher than others. The infestation may cause the absence of student from school and make their parents upset. The aim of current study was to evaluate the WHO recommended insecticides for control of head lice in Islamshahr health center.

Methods: In the current study infested individuals were older than 6 years old and have been diagnosed with at least 3 head lice adult and 10 live nits from less than 0.7 cm scalp. The pediculicides was applied randomly among groups. Permethrin shampoo as a golden standard was used. Dimethicone lotion 4% and Ivermectin lotion was compared with it. This study was conducted on 179 infested people. Results of infestation were evaluated after one month of intervention. Different indicators such as: present of head lice adult or live nit, redness and irritation in head skin were invested.

Results: All the participants were female and 72.6% of them were in the age group of 6-11. The result revealed that aging not only decreases the infection rate but also raised the recovery percentage. The results showed that 79.5% permethrin receiver, 83% of people who treated with Dimethicone lotion and 90.6% of Ivermectin receiver had no head lice. There was no significant difference among these three pediculicides.

Conclusion: There was no significant difference among tested pediculicides. An appropriate pediculicide can be selected by training people.

Background: Cockroaches are one of the most common pests in many residential areas. In this study, the simultaneous effects of fungi, Metarhizium anisopliae and fenitrothion-coated baits on the mortality rate of the German cockroach nymphs were investigated.

Methods: To determine the lethal level of fenitrothion insecticide, a bioassay test was performed on the last instar nymphs of the German cockroach reared at insectarium conditions. Various toxic concentrations of fenitrothion (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.5%, and 2%) were used. Different concentrations of M. anisopliae (1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸ Conidia/ml) were also applied to nymphs. Eventually, we combined the effective dose of fenitrothion (0.93%) with the effective concentration of M. anisopliae (6.6 ×10⁶ Conidia/ml) to provide the fungus-coated bait to attract insects. Mortality was recorded 24-96 hours after exposure to the toxic bait. The resulting data were subjected to Probit analysis.

Results: The results of applying M. anisopliae spores with fenitrothion composition showed that the mortality rate of German cockroach nymphs was significant. Therefore, the optimal dose of fenitrothion used in combination with M. anisopliae seems essential to reduce the German cockroach nymphs.

Conclusion: The results of this study can be considered a suitable method as a mixture with low cost and minimal damage to the environment and other organisms.

Cutaneous leishmaniasis is a neglected and parasitic vector borne diseases that is endemic in tropical and subtropical countries, including Iran. The aim of this study was to explain the present status of CL in Iran. This report is based on data that recorded by cutaneous leishmaniasis surveillance system in 2019, and evaluated in Center for Communicable Diseases Management in Ministry of Health in Iran. Iran has been considered an endemic area for cutaneous leishmaniasis in the world. Dependent to activities for cutaneous leishmaniasis control the number of cases decreased from 23202 in 2008 (Incidence rate 32 per 100000) to 13124 in 2019 (Incidence rate 15.8 per 100000), more cases reported from September to December, in 2019, 46% of cases had one lesion and 21% had 2 lesions, 85% of cases diagnosed when the diameter of lesions had 3 centimeters and bellows. Although the Leishmania control program began in 1977, the incidence of the disease has dropped dramatically since 2008 when the new cutaneous leishmaniasis control program have been implemented. Although in some areas the incidence of the disease increased, but the implementation of the new program has reduced the number of cases, in order to continue reducing the disease, permanent support for the control programs is needed.

Background: Any mosquito control methods requires precise information about population dynamics, variety, biology and mosquito habitat. This research assessed Culicid mosquitoes' attraction to a human host and a calf to better understand their behavior.

Methods: Adult mosquitoes were sampled in 22 weeks in southwestern Iran's Nur Ali Village from May to October 2015. The mosquitoes were drawn to the person and calf as bait, while the unbaited trap was also used. A substantial statistical difference between attracted mosquitoes to the hosts was determined in the T-test.

Results: Within 22 weeks, 29821 mosquitoes were captured. Only 9% were collected from the human baited net trap, 89.1% from the calf baited net trap, and 1.9% from the unbaited net trap. The number of collected female mosquitoes was statistically significantly higher using the calf baited net trap of the total mosquitoes, 916 were randomly identified at the species level by local identification keys. Of these, 63 were Anopheles stephensi (human: 16%, calf: 75% and unbaited: 9%), 83 An. pulcherrimus (human: 27%, calf: 60% and unbaited: 13%), 118 Aedes caspius (human: 24%, calf: 69% and unbaited: 7%), 493 Culex tritaeniorhynchus (human: 52%, calf: 37% and unbaited: 11%), 153 Cx. quinquefasciatus (human: 44%, calf: 47% and unbaited: 9%), and 6 Cx. theileri (human: 33%, calf: 50% and unbaited: 17%).

Conclusion: The obtained results here provide useful insights into the mosquito population and the possibility of using this information as an essential part of integrated vector management regarding the reemergence of malaria or other mosquito-borne.

Background: Phlebotomus papatasi is known as the main vector of zoonotic cutaneous leishmaniasis. This study aimed to investigate the effect of geographical and bioclimatic factors on the Ph. papatasi distribution.

Methods: A total of 34 villages were selected, and sampling was performed three times using 120 sticky traps in each selected village. All the collected species were mounted and identified their species. The densities of Ph. papatasi were measured in all the villages and entered into ArcMap as a point layer. The required bioclimatic and environmental variables were extracted from the global climate database and The normalized difference vegetation index was obtained from the MODIS satellite imagery, also, all variables entered into ArcMap as raster layers, so The numerical value of each independent variable in the cell where the selected village is located in this, was extracted using spatial analyst tools and the value to point submenu. All the data were finally entered into IBM SPSS, and the relationship was examined between the number of collected Ph. papatasi and the independent variables using Spearman's correlation test.

Results: A total of 1773 specimens of Ph. papatasi were collected. The findings of this study showed that max temperature of warmest month, temperature annual range, temperature seasonality, mean diurnal range, precipitation seasonality, mean temperature of driest and warmest quarter were positively associated with the density of Ph. papatasi.

Conclusion: Air temperature and precipitation were shown as the most significant factors in the distribution of Ph. papatasi.

Background: Ticks are forced vertebrate ectoparasites, including humans, and are vectors of serious diseases such as Crimean Congo Hemorrhagic Fever, Relapsing Fever, and various forms of encephalitis. Spatial assessment of the prevalence of ticks and detection of high risk areas for tick-borne disease transmission and evaluation of ecological measures are key aims of this research.

Methods: Ticks were collected using standard methods from 27 villages in the region of Sarab County in north-eastern Iran during the four seasons of 2018-2019 and identified using valid keys. The calculations of indices for biodiversity were based on the Margalef index, Shannon-Weiner index and Simpson index. R2.15 Statistical software was used for statistical analysis of indices of biodiversity, and ArcMap10.4.1 software, IDW and GeneralG methods were used. Analysis were used to investigate spatial distribution and to determine important tick hotspots.

Results: A total of 2500 animals surveyed, 35% of them were infected. In total, 1416 ticks were caught, 74.6 %, 23.9% and 1.4 % were adult, nymph and larvae respectively. 94% of the ticks were hard ticks including 6 genera. According to the Margalef diversity index, the highest species biodiversity was related to summer (1.4234), and the lowest was related to winter (0.7379).

Conclusion: Large hotspot area was found in the central part of the study area. The area of study was very prone to tick-borne disease transmission in terms of tick diversity and tick species richness. Tick-borne disease control is an important measure.