Unilateral Photorefractive Surgery in a Keratoconus Patient with Anisometropia and History of Corneal Cross-Linking: a Case Report

Photorefractive keratectomy (PRK) is a common procedure for correction of refractive errors. Corneal collagen crosslinking (CXL) is a procedure used to strengthen a weakened ectatic cornea and is mainly used as a therapeutic procedure in keratoconus (KC) patients, to prevent deterioration and improve visual acuity. PRK-CXL combination performed simultaneously or sequentially, has been suggested in KC patients to provide improved visual acuity, in addition to halting the ectatic progression. Our case was a patient with KCN and visual deterioration that underwent accelerated CXL with good results and 1 year later, his right eye was subjected to PRK due to anisometropia. The patient achieved an uncorrected visual acuity of 10/10 without any complications for both eyes. Our good results suggest that PRK-CXL combination might be considered for correction of decreased visual acuity and anisometropia in patients with KCN. However, more studies are required to further evaluate the surgical outcome and safety of this procedure.Keywords: Keratoconus; Cross-Linking; Photorefractive Keratectomy; Surgery

Chemical Composition and Repellency of Origanum vulgare Essential Oil against Cimex lectularius under Laboratory Conditions

Background: The common bed bug (Cimex lectularius), a nocturnal blood-feeding ectoparasite, is considered an urban pest with public health importance in human environments. We aimed to determine the repellency effect of oregano essential oil, Origanum vulgare, against this pest under laboratory conditions. Methods: The essential oil was prepared from dried leaves using hydro-distillation method. A gas chromatography-mass spectrometer (GC-MS) was used for analysis and identification of oregano essential oil compounds. Treated surface method in Petri dish was carried out to evaluate repellency potential of the oil using 4th and 5th instar nymphs and adults. The concentration-repellency response of oregano essential oil was calculated and compared with a commercial insect repellent stick containing 33% N, N-diethyl-meta-toluamide (DEET). Results: The oregano essential oil consisted of 158 compounds with terpineol (22.85%) and α–terpinene (20.60%) being the major components by volume. The EC50 and EC99 of oregano oil (effective concentrations causing 50% and 90% repellency of bed bugs) were 1.61 and 6.57mg/cm2 at 9h after application, respectively. The 40% oregano es­sential oil exhibited 100% repellency against bed bug at 3, 5, 9 and 24h after application while the repellency index of DEET 33% was 100% at 3 and 5h and it decreased to 80% and 27% at 9 and 24 hours. Conclusion: Oregano oil 40% exhibited more repellency compared to commercial insect repellent stick containing 33% DEET. Further studies are warranted to confirm the effectiveness of oregano essential oil in personal protecting against bed bug biting

Effects of resident education and self-implementation of integrated pest management strategy for eliminating bed bug infestation in Ahvaz city, southwestern Iran

Background: Bed bugs as blood-sucking insects have become a public health problem in urban communities throughout the world. The objective of this study was to determine the effects of resident education and self-implementation of Integrated Pest Management (IPM) strategy for eliminating bed bug infestation in infected apartments in Ahvaz City, Iran. Methods: This interventional study was conducted in seventy apartments infested with bed bug (Cimex lectularius) in Ahvaz City, southwest Iran, during a 6-month period. The bed bug infestations reported to Health centers were inspected visually and confirmed by medical entomology experts. Then, the heads of the households were received techniques/tools of the IPM program and trained by medical entomology experts before self-implementation of control methods. Finally, the infected apartments were inspected by the experts at 1, 3, and 6 months after intervention and data were recorded in a checklist. Results: From the seventy infected apartments, 57, 28 and 15 were considered as low, moderate, and high level infestation respectively. The bed bug infestation was eliminated from 53 apartments (76) after one month and it reached to 62 apartments (88) by the end of third month. Finally, after six months of applying IPM program, bed bugs infestation was eliminated from all infected apartments (100). Residents expressed their 100 satisfaction with applying the bed bug IPM strategy. Conclusion: Training residents to implement the IPM program can reduce pest control costs, the volume of pesticides consumed, and human exposure to chemical pesticides, resulting in increased human and environmental health and safety. © 2020 Tehran University of Medical Sciences. All rights reserved

Applying Network Analysis Process (ANP) and Geographic Information System (GIS) in Modeling the Probability of Crimean-Congo Hemorrhagic Fever (CCHF) Vector: Case Study in Ahvaz, Hamidiyeh, Bavy and Karoon Counties

Background and purpose: Ticks, as ectoparasites, biological vectors and reservoirs of various diseases, are involved in transmission of pathogens to humans and animals. This research aimed at modeling the probability of tick vectors presence in Ahvaz, Hamidiyeh, Bavy, and Karoon in southwest of Iran. Materials and methods: To perform the modeling, eight criteria (slope, elevation, soil texture, land use, land cover, temperature, humidity, and rainfall) that strongly affect the distribution of ticks were selected. After pairwise comparisons, Super Decision Software was used to determine the significance of each criteria and the weight of sub-criteria was calculated using Expert Choice11. Weighted maps were obtained based on the effect of sub-criteria weights on maps. The final map of the probability of tick vectors presence was prepared based on the weight effect of each criteria in the weighted maps. Results: Average relative humidity (0.252), average rainfall (0.179), and land cover (0.151) were found to have the greatest effect on the probability of tick presence. Also, the highest probability of tick presence was seen in following cities and rural districts: Ahvaz, Hamidiyeh, Karoon, Bavy, Meshrahat, Karkheh, Qaleh Chenan, and Anafcheh. Conclusion: In current modelling, considering ecological, topographic, and climatic factors, the probability of the presence of vectors of Crimean-Congo haemorrhagic fever (CCHF) virus was seen to be very high in two rural districts, including Mashrahat (Ahvaz) and Karkheh (Hamidiyeh)

Prevalence and spatial distribution of bed bug, Cimex lectularius, infestation in Southwest of Iran: GIS approach

Background: The common bed bug, a nocturnal bloodsucking insect, is known as a human parasite and public health problem in the world. The prevalence and geographical dispersion of bed bug in Ahvaz City, southwest of Iran was measured. Methods: Spatial distribution of Cimex lectularius was determined by surveying 520 houses in 62 areas of Ahvaz City in 2017. Some information like as infested points, the concern level of the residents and allergic reaction to the insect bite were registered in a form using the secondhand instrument. Results: According to the spatial distribution map, of 62 areas, 27 of them are infested with bed bugs. Infestation is scattered throughout the city, but its focus is on the east of the Karun River. The most bed bug infestation was in Asiabad followed by Manbaab areas. Prevalence of bed bug infestation estimated 9.61 in Ahvaz city. It was 5.4 and 11.6 in apartments and single houses, respectively. The lowest and highest infestation rates based on its source were 1.35 and 9.03 in wallpaper and cracks and crevices, respectively. Bedroom and sitting room were the main harborages for bed bug in the houses. The majority of residents who had bitten by a bed bug showed various allergic reactions like redness skin, papules, vesicles, pustules and blisters. Most of the people in the infested houses (62) were very concern about bed bug infestation. Conclusion: Public education and increasing the knowledge of people can lead to successful management, prevention and elimination of this nuisance pest. © 2020 Tehran University of Medical Sciences. All rights reserved

Predicting the Probability of Phlebotomus papatasi Presence in Khuzestan Province: Combining Hierarchical Analysis Process and Geographic Information System

Background and purpose: Khuzestan Province in Iran is one of the endemic foci of zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major and Phlebotomus papatasi as the main vector. The aim of this study was to predict the probability of presence of Ph. papatasi in this province using Hierarchical Analysis Process (AHP) and Geographic Information System (GIS). Materials and methods: In order to determine the distribution of Ph. papatasi, sand flies were collected in five counties, including Izeh, Mahshahr, Ahvaz, Dasht-e-Azadegan, and Andimeshk by sticky paper traps in spring and summer, 2018. Six criteria, including average annual temperature, average annual rainfall, average annual relative humidity, land use, soil texture, and elevation were selected. Maps of criteria were prepared in ArcGIS 10.5 software. The weights of the criteria and sub-criteria were determined using Expert Choice 11. Then, the final map of the probability of vector presence was prepared by combination of weighted maps and including the weight of the criteria. Results: In this study, 13 species of sand flies of two genera, Phlebotomus and Sergentomyia, were collected. The abundance of Ph. papatasi from samples collected in Izeh, Dasht-e-Azadegan, Mahshahr, Andimeshk, and Ahvaz was 55%, 72%, 69.4%, 3%, and 66.5%, respectively. Based on the analysis of matrix tables, average annual temperature (0.406), average annual relative humidity (0.233), and average annual rainfall (0.156) had the highest weight in probability of the vector presence, respectively. Conclusion: This study provides useful information for health authorities in determining the distribution of Ph. papatasi to act properly based on facilities and budget in case of outbreak

Presence probability of Hemiscorpius lepturus Peters, 1861 using maximum entropy approach in the western areas of Zagros Mountains, Iran

Aim: The purpose of this research was to use environmental variables for predicting the probability of Hemiscorpius lepturus existence in the provinces where situated in the west of the Zagros Mountains. Materials and Methods: In this study, 64 occurrence records of the H. lepturus were extracted from the published documents available in electronic databases. MaxEnt model was used for predicting the ecological niches of this species. Normalized difference vegetation index (NDVI) and 19 climatic variables were used as the environmental variables affecting the distribution of this scorpion. The Jackknife test in the model was used to indicate the importance of variables to predict the probability of the presence of the studied species. The logistic threshold that was evaluated using a logistic regression algorithm showed the converting of the probability model into a binary model. The model was evaluated by area under the curve (AUC). The probability presence map of this scorpion was then prepared in ArcGIS 10.5 Software. Results: The results of the analysis showed that the most important environmental factor on the distribution of H. lepturus was the maximum temperature of the warmest month (Bio5) with a contribution rate of 43% and permutation importance of 8%. The Jackknife test revealed that NDVI did not gain any value when it used independently in the model. The logistic threshold was reported 0.255 for the maximum test sensitivity plus specificity. The AUC of the model was 0.7698, shows an acceptable value for model validity. Overall the hot spots for this toxic scorpion seem to be in Khuzestan, Lorestan, and Ilam Provinces of the studied area. Conclusion: Regarding our findings, MaxEnt algorithm, in combination with geographic information system contributed to revealing the effects of environmental variables on the probability of H. lepturus presence in the west of Zagros Mountains. These visualized maps as a warning alarm can be helpful to policymakers for managing, controlling, and monitoring the scorpionism in high-risk areas