Risk factors associated with scabies infestation among primary schoolchildren in a low socio-economic area in southeast of Iran.

BACKGROUND: Scabies is a neglected tropical disease caused by the mite Sarcoptes scabiei that burrows under the skin. It is a major health problem in tropical areas, largely affecting children. Scabies is common and highly contagious and in schoolchildren spreads quite rapidly, due to overcrowding and close contact within the schools. This study aimed to determine the risk factors associated with scabies infestation among primary schoolchildren in Bashagard County, one of the low socio-economic areas in southeast of Iran. METHODS: To conduct this community-based, descriptive, and cross-sectional study, four primary schools were randomly selected in the Bashagard County. All students in these schools were selected and examined for scabies. Clinical examination and sociodemographic profile of students were assessed using a pre-tested structured questionnaire. Chi-square test, and binary logistic regression were used to analyse the factors associated with scabies infestation by SPSS version 21 software. RESULTS: Out of 480 studied schoolchildren, 15 cases of scabies with a prevalence of 3.1 % were observed. The frequency of infestation in males was 1.6 % and it was 4.7 % in females. Independent factors associated with a high risk of scabies infestation in unadjusted analysis were being student of grade 5-6 (cOR = 13.12, 95 % CI 2.92-58.89, p = 0.0001), low educational level of father (cOR = 4.37, 95 % CI 0.97-19.59, p = 0.036), low educational level of mother (cOR = 4.14, 95 % CI 1.92-18.57, p = 0.045), joblessness of father (cOR = 14.77, 95 % CI 4.97-43.89, p = 0.0001), employment of mother (cOR = 5.28, 95 % CI 1.38-20.16, p = 0.007), large family size (cOR = 3.34, 95 % CI 1.05-10.64, p = 0.031), use of shared articles (cOR = 33.37, 95 % CI 10.82-102.90, p = 0.0001), and absence of bathroom in the house (cOR = 11.77, 95 % CI 2.16-63.94, p = 0.0001). CONCLUSIONS: Results of this study confirmed that scabies is still one of the most important health problems in the primary schools of the Bashagard County. Low socioeconomic status and personal hygiene of the schoolchildren were the most important factors influencing the prevalence of scabies. Improvement of socioeconomic conditions and implementation of appropriate educational programs and active surveillance system to quickly detect and treat scabies cases are necessary in order to reduce the prevalence of scabies in schoolchildren in this area.

Species composition, seasonal abundance and distribution of potential anopheline vectors in a malaria endemic area of Iran: field assessment for malaria elimination.

BACKGROUND: Despite decreases in incidence, malaria remains a major public health challenge in south and southeast Iran, where vector control is considered one of the main strategies for elimination of the disease. The efficacy of this strategy depends on understanding malaria vector ecology, which varies by species. This study was conducted to determine the species composition, seasonal abundance and distribution of potential anopheline vectors in Bashagard County, one of the important malaria-endemic areas in south Iran. METHODS: In this cross-sectional study, four typical foothill and mountainous villages were selected by simple random sampling. Anopheline mosquitoes were collected by the standard dipping method for larvae and total catch for adults. Anopheline specimens were morphologically identified using taxonomic keys. Statistical analyses were performed using SPSS ver.20 software. RESULTS: In total, 1211 anopheline specimens, including 1055 (87.12%) larvae and 156 (12.88%) adults, were collected and identified. They consisted of 9 species: Anopheles moghulensis (27.89%), Anopheles dthali (18.91%), Anopheles culicifacies (16.60%), Anopheles stephensi (15.38%), Anopheles turkhudi (9.83%), Anopheles superpictus (9.66%), Anopheles apoci (1.40%), Anopheles fluviatilis (0.17%), and Anopheles sergentii (0.08%). The most prevalent species in adult catches were An. culicifacies (44.23%), An. dthali (21.15%) and An. stephensi (16.03%), and the most prevalent species caught as larvae were An. moghulensis (31.94%), An. dthali (18.85%) and An. stephensi (15.26%). Most of the anopheline species were distributed in different topographical areas and two proven malaria vectors, An. culicifacies and An. superpictus, were significantly associated with altitude and collected more frequently in the foothill regions. Most of the anopheline species were present almost throughout the year with a major peak in April and a smaller peak in October. CONCLUSION: The results of this study revealed that there are five malaria vectors in Bashagard County and some of them are more abundant in areas with special topographic features and are reproductively active throughout the year. These findings can be applied to successful planning and providing effective control measures in problematic areas during the malaria elimination phase in Iran.

Prevalence of head lice infestation and pediculicidal effect of permethrine shampoo in primary school girls in a low-income area in southeast of Iran.

BACKGROUND: Head lice infestation is a common public health problem that is most prevalent in primary school children throughout the world, especially in developing countries including different parts of Iran. This study aimed to determine the prevalence and risk factors associated with head lice infestation and pediculicidal effect of 1% permethrin shampoo in primary schools girls of Bashagard County, one of the low socioeconomic areas in southeast of Iran. METHODS: In this interventional study six villages with similar demographical situations were selected and randomly assigned into intervention and control areas. In each area 150 girl students aged 7-12 years were selected randomly and screened for head lice infestation by visual scalp examination. In intervention area, treatment efficacy of 1% permethrin shampoo was evaluated via re-examination for infestation after one, two, and three weeks. Pre-tested structured questionnaire was used to collect data on socio-demographic and associated factors of head lice infestation. RESULTS: The prevalence of head lice infestation was 67.3%. There was significant association between head lice infestation and school grade, family size, parents' literacy, bathing facilities, frequency of hair washing, and use of shared articles (p < 0.05). The effectiveness of 1% permethrin shampoo for head lice treatment was 29.2, 68.9, and 90.3% after the first, second, and third weeks, respectively. CONCLUSION: The head lice infestation is a health problem in primary school girls of Bashagard County. Improvement of socioeconomic status and providing appropriate educational programs about head lice risk factors and prevention can be effective for reduction of infestation in this area. TRIAL REGISTRATION: This trial has been registered and approved by Hormozgan University of Medical Sciences ethical committee (Trial No.764). Trial registration date: March 17 2014.

Topographical distribution of anopheline mosquitoes in an area under elimination programme in the south of Iran.

BACKGROUND: Malaria is a major vector-borne disease in tropical and sub-tropical countries caused by Plasmodium infection. It is one the most important health problem in south and southeast of Iran. Since Iran has recently launched to the elimination phase of malaria and vector control is one of the main strategies for elimination, this study was conducted to determine the topographical distribution of malaria vectors in Minab County, one of the important malaria endemic areas in south of Iran. METHODS: In this cross-sectional study, six villages in three topographically different sites namely coastal plain, foothill and mountainous areas were selected by simple random sampling. The anopheline larvae were collected using the standard dipping method. The specimens were identified using a morphology based-key. Statistical analyses were performed using SPSS ver.16 software. RESULTS: In total, 3,841 anopheles larvae were collected from 24 larval habitats. They consisted of ten species: Anopheles moghulensis (25.23%), Anopheles stephensi (24.47%), Anopheles dthali (19.14%), Anopheles culicifacies (9.63%), Anopheles fluviatilis (7.52%), Anopheles superpictus (5.62%), Anopheles turkhudi (5.55%), Anopheles pulcherrimus (1.93%), Anopheles multicolor (0.47%), and Anopheles apoci (0.44%). Most species were distributed in different topographies and only An. Stephensi and An. culicifacies, the main malaria vectors in Iran, were significantly associated with the altitude of studied areas. An. moghulensis, An. stephensi and An. dthali were the most widespread species and were, respectively predominant in Coastal plain, foothill and mountainous areas. CONCLUSION: Results of this study have revealed that there are many malaria vectors that are distributed in Minab County and some of them are expected to be predominant in areas with special topographic characteristics. This finding can provide a basis for effective planning and implementation of evidence-based malaria vector intervention strategies towards vector control, which may help in malaria elimination in the study area.

Knowledge and Practices of Women Regarding Malaria and Its Prevention: A Community-Based Study in an Area under Malaria Elimination Programme in Iran.

Background: Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are two core interventions for control and prevention of malaria infection. This descriptive cross-sectional study aimed to determine the knowledge and practices of women regarding malaria and its preventive measures in a malarious area in the Jask County, southeast of Iran. Methods: Data was collected from 400 households through a two-stage random cluster sampling method in six villages. Pre-tested structured questionnaire was used to collect data. During the survey, visual observations were also made by the interviewers to check use of LLINs and IRS. The data were analyzed by SPSS software version 21. Results: The majority of households had a high level of knowledge about symptoms (98%, n=392) and transmission (74.5%, n=298) of malaria. The main preventive measures against malaria were: LLINS (39.5%, n=158), IRS (32%, n=128), and screens on doors/windows (16.7%, n=67). In addition, participants with primary or higher educational level reported that they practice more malaria preventive measures, compared to those who were illiterate (OR=3.3, 95% CI= 1.6-6.6, p=0.0001, Table 6). In spite of positive perceptions about IRS and LLINs, only 35.5% (n=142) and 17% (n=68) of households used IRS and LLINs, respectively. Conclusion: According to the results of this study, despite a high level of knowledge about malaria and its preventive measures, a small number of participants use LLINs and IRS for malaria prevention. Therefore, implementation of effective educational interventions is recommended to improve preventive practices against malaria in the study area.

Epidemiological features of cutaneous leishmaniasis and distribution of sand flies in an endemic area in southeast of Iran.

INTRODUCTION: Cutaneous leishmaniasis (CL) is a widespread tropical infectious disease in the world. It is one of the most important health problem in Iran which is endemic in different parts of country. This study was conducted to determine epidemiological features of CL and distribution of sand flies in Hajiabad County, one of the important CL foci in southeast of Iran. METHODS: This descriptive cross-sectional study was conducted from March 2019 to March 2020.All of the suspected CL cases with skin lesions who referred to Hajiabad County health centers and all actively detected patients were clinically and parasitologically examined for CL. Demographic and clinical data of all patients were recorded. Moreover, in this study, sand flies were collected monthly from four typical plain and foothill villages during their active season (May-November) using sticky trap. Sand flies were mounted as permanent microscopic slides, using Puri's medium, and identified by taxonomic keys. Data were analyzed using SPSS.21 software and descriptive statistics. RESULTS AND DISCUSSION: A total of 70 confirmed cases of CL were recorded; the incidence rate of the disease was 101 per 100,000 people. The most infected age group was 0-10 years, with a rate of 64.3%. Males were infected more than females and the majority of cases (85.7%) were recorded from rural areas. Most of the cases had 1 lesion (51.4%) and the most lesions (55.8%) were in upper extremities. During the study period, 832 sand fly specimens comprised of ten species of Sergentomyia and seven of Phlebotomus were collected and identified. The most prevalent species was P. papatasi (47.12%), followed by P. alexandri (8.41%) and P. salehi (6.25%). Among the collected Phlebotomus species, P. papatasi and P. sergenti are known as the primary vectors of CL and P. alexandri, P. salehi, and P. caucasicus, play the main role as the secondary vectors of CL in Iran. CONCLUSION: This study has revealed that CL is endemic in Hajiabad County and there are five CL vectors that are distributed in this County and some of them are more prevalent in plain areas. These findings can be used as a basis for implementation of interventions toward vector control, which may help in suppression of vector density, and consequently, control of CL in the study area.

The Influence of Indoor Environmental Factors on the Prevalence of House Dust Mites as Aeroallergens in Bandar Abbas Student Dormitories, South of Iran, 2019.

This study was conducted to determine the influence of environmental factors on the prevalence of house dust mites in student dormitories of Bandar Abbas city. In this study, 64 dust samples were collected from seven randomly selected dormitories located in various areas of the Bandar Abbas. The collected mites were isolated and mounted in Hoyer's medium and identified using a morphological key. The associations between the environmental factors and the density of house dust mites were investigated. In total, 1,093 adult mites were collected and identified. They consisted of four species including Dermatophagoides pteronyssinus Trouessart (57.6%), Dermatophagoides farinae Hughes (24.3%) and Dermatophagoides evansi Fain (14.9%) (Acari: Pyroglyphidae), and Cheyletus malaccensis Oudemans (3.2%) (Acari: Cheyletidae). All of the dormitories were contaminated by more than one house dust mites species and the mean density of house dust mites in dormitories was 8.3 ± 0.2 mites/g of dust. There was a significant relationship between average house dust mites density and some of environmental factors such as relative humidity, temperature, floor covering type, and number of occupants (P < 0.05). Results of this study revealed that two major allergenic dust mites, D. pteronyssinus and D. farinae, were the most prevalent and collected from all of dormitories and some of indoor environmental factors found to influence mites' population.

Significant decline of malaria incidence in a low socioeconomic area in the southeast of Iran: 10 years field assessment during malaria elimination programme.

Although malaria burden and its active foci have sharply declined after the implementation of elimination programme since 2010, it is still considered as a major public health problem in southeast Iran. This descriptive-analytical study aimed to determine 10-years of malaria epidemiological trends in Bashagard County. Data were collected from 7 selected malarious region of the county based on active and passive surveillance of clinical cases. For diagnosis of malaria, the examination of microscopic slides and rapid diagnostic test, were used. In total, 237 malaria cases were found from 2009 to 2018. Plasmodium vivax was the dominant parasite species and identified in 232 (97.9%) individuals. Males were infected more than females and the majority of malaria cases (67.4%) were recorded from rural areas. Although about 98% of malaria cases were indigenous, they have decreased form 200 cases in 2009 to zero indigenous transmission in 2018. During the study period, malaria cases had decreased significantly by about 99% and the incidence rate had declined from 5.47/1000 cases in 2009 to 0.002/1000 in 2018. The incidence of malaria, especially indigenous cases, in Bashagard County has decreased dramatically in the past 10 years. However, there is still probability of malaria re-introduction and outbreak in the county due to climatical and geographical conditions. Therefore, it is necessary to implement an active surveillance system to detect and treat malaria cases quickly, during the elimination phase in this county.

A global systematic review and meta-analysis of concentration and prevalence of mycotoxins in birds' egg.

In the current study, the concentration and prevalence of birds' egg's mycotoxins among 11 articles (66 studies) based on countries, part of eggs, and type of mycotoxins subgroups were meta-analyses using a random-effect model. The order of mycotoxin according to concentration of mycotoxin was Deoxynivalenol (20.083 µg/kg) > Zearalenone (2.065 µg/kg) > Enniatin (1.120 µg/kg) > Total aflatoxin (0.371 µg/kg) > Beauvericin (0.223 µg/kg) > Ochratoxins (0.087 µg/kg) > Citrinin (0.010 µg/kg). Further, the mycotoxins' concentration in the yolk part (2.070 µg/kg) was higher than the mixed eggs (0.283 µg/kg). The rank order of mycotoxin based on country was China (14.990 µg/kg) > Cameroon (7.594 µg/kg) > Thailand (1.870 µg/kg) > Finland (0.920 µg/kg) > Iran (0.312 µg/kg) > Jordan (0.202 µg/kg) > Belgium (0.183 µg/kg) > Spain ( South Korea ( DON (85.00%) > AFT (20.15%) > OT (16.00%). The overall prevalence of mycotoxin was equal to 29.65%. Also, the concentration of mycotoxins in China and Cameroon was higher than in other countries. Therefore, the monitoring programs to reduce mycotoxins in bird eggs consumed in some countries such as China and Cameroon should be considered.

The risk factors for intestinal Giardia spp infection: Global systematic review and meta-analysis and meta-regression.

Parasitic infections are a public health concern as they can cause aggression, growth retardation, weight loss, anemia, and other health problems. In this study, a systematic review and meta-analysis were performed to find an association between the probable social-environmental risk factors including lack of safe drinking water, no hand washing, sex, age, no access to education, no access to toilet, and Giardia spp infection. We conducted literature research among international databases including Scopus, PubMed, Web of Science and Cochrane from1 January 1995 to March 15, 2020, including 23 articles with 102 studies while the odds ratio (OR) was calculated using 2 × 2 tables or extracted. The pooled effect size with 95% confidence intervals (CIs) was estimated using a random or fixed-effects model. The results show a significant association between intestinal Giardia spp infection risk and lack of safe drinking water (OR: 1.14; 95%CI: 1.02-1.25); no access to toilet (OR: 1.22; 95%CI: 1.07-1.37); and age (2-10 vs 10-30 year) (OR: 1.42; 95%CI: 1.09-1.78). An insignificant association was observed between intestinal Giardia spp infection risk and age (<2 vs 2-10 year) (OR: 0.89; 95%CI: 0.75-1.02); no access to education (OR: 1.10; 95%CI: 0.80-1.40); Sex (male vs female) (OR: 1.04; 95%CI: 0.74-1.34); and no handwashing (OR: 1.18; 95%CI: 0.87-1.49). The results of meta-regression also indicate that intestinal Giardia spp infection has decreased over time (C= -0.024, p-value = 0.03) significantly, and also by growth of human development index (HDI) (C= - 0.42, p-value = 0.29) insignificantly. Improvement of personal hygiene, sanitation and raising public awareness can be effective in reducing Giardia spp infections.

Biodiversity of Medically Important Calyptratae Flies (Diptera: Schizophora) in Hospitals in the Northern Coastline of the Persian Gulf, Iran.

Domestic filth flies play a significant role in the transmission of nosocomial infections and cause nosocomial myiasis in hospitals worldwide. This descriptive cross-sectional study was conducted in five hospitals of the Hormozgan province, of southern Iran. Adult flies were collected by bottle fly traps. Specimens were pinned and morphologically identified using the relevant keys. Species biodiversity indices including Menhinick (M), Shannon-Wiener (H'), Pielou's Evenness (E), and Simpson's diversity (D) were calculated. Totally 2,298 individuals of 18 species of flies belonging to nine genera and four families were collected. Chrysomya megacephala was the most frequent species (37.3%), followed by Chrysoma albiceps (24.8%), Fannia canicularis (5.1%), Musca domestica (4.8%), Sarcophaga aegyptica (3.7%), and 15 other species (24.4%). Our results show a high diversity and abundance of domestic filth flies in the studied hospitals. Relatively similar data derived from various hospitals in this study can show the uniformity in sanitary conditions of hospitals. On the other hand, estimation of diversity indices alarmed for potential of dominant species in fly communities in hospital environments.

Effect of A Mobile-Phone Mediated Based Education on Self-Care Behaviors of Patients With Thalassemia Major.

Introduction: One way to improve the quality of life of the patients with thalassemia major is to enable them through education. The present research aimed to explore the effects of an educational intervention through mobile phones on self-care behaviors of the patients with thalassemia major Methods: In this quasi experimental study, which was done from May to January in 2017, 91 patients were enrolled who were suffering from thalassemia major.The census sampling method was performed with random allocation of interventional and control groups. Educational intervention was only applied to the intervention group. The study instrument was a questionnaire which was filled out by the patients before and two months after the educational intervention. For data analysis, statistical tests including independent samples t-test, paired-samples t-test, Mann-Whitney test and Wilcoxon test, were used through SPSS ver.13 software. Results: Prior to the intervention, the mean scores of knowledge, attitude and self-care behaviors were not significantly different between the intervention and control groups. After the intervention, , however, there was a statistically significant increase in the aforementioned scores in the intervention group, but there was no statistically significant increase in scores of the control group. Conclusion: The present findings showed the positive effect of the mobile-phone mediated education on knowledge, attitude and self-care behaviors of the patients with thalassemia major. Therefore, the use of mobile phone is recommended as an effective way of transferring instructional material as related to self-care to patients with thalassemia major particularly when access to them is limited.

Species Composition of Sand Flies (Diptera: Psychodidae) and Modeling the Spatial Distribution of Main Vectors of Cutaneous Leishmaniasis in Hormozgan Province, Southern Iran.

Cutaneous Leishmaniasis (CL) is one of the main neglected vector-borne diseases in the Middle East, including Iran. This study aimed to map the spatial distribution and species composition of sand flies in Hormozgan Province and to predict the best ecological niches for main CL vectors in this area. A database that included all earlier studies on sand flies in Hormozgan Province was established. Sand flies were also collected from some localities across the province. Prediction maps for main vectors were developed using MaxEnt model. A total of 27 sand fly species were reported from the study area. Phlebotomus papatasi Scopoli, Phlebotomus sergenti s.l. Parrot, Phlebotomus alexandri Sinton, Sergentomyia sintoni Pringle, Sergentomyia clydei Sinton, Sergentomyia tiberiadis Adler, and Sergentomyia baghdadis Adler (Diptera: Psychodidae) had the widest distribution range. The probability of their presence as the main vectors of CL was calculated to be 0.0003-0.9410 and 0.0031-0.8880 for P. papatasi and P. sergenti s.l., respectively. The best ecological niches for P. papatasi were found in the central south, southeast, and a narrow area in southwest, whereas central south to northern area had better niches for P. sergenti s.l. The endemic areas are in Bandar-e Jask, where transmission occurs, whereas in Bastak, the cases were imported from endemic foci of Fars province. In conclusion, proven and suspected vectors of CL and VL were recorded in this study. Due to the existence of endemic foci of CL, and favorite ecological niches for its vectors, there is potential risk of emerging CL in new areas.

Species Identification and Prevalence of House Dust Mites as Respiratory Allergen in Kindergartens of the Bandar Abbas City.

The aim of this study was to identify the species and prevalence of house dust mites (HDMs) in kindergartens in Bandar Abbas, south of Iran. In this study 10 kindergartens were selected randomly in five areas of Bandar Abbas. Two dust samples were collected from each sampling place with a vacuum cleaner. Mites were isolated and mounted in Hoyer's medium and identified using a morphology-based key. In total, 1758 mites were collected and identified, whichconsisted of five species: Dermatophagoides pteronyssinus (31.06%), D. evansi (23.49%), D. farinae (17.75%), Ornithonyssus bacoti (19.45%), and Cheyletus malaccensis (8.25%). Two main allergenic dust mite species D. pteronyssinus and D. farinae, coinhabited and were collected from all of kindergartens. Results of this study have revealed that D. pteronyssinus is the most prevalent HDMs in Bandar Abbas Kindergartens and all studied areas are contaminated by more than one dust mite Regarding the high prevalence of HDMs in Bandar Abbas kindergartens, implementation of strict control measures is necessary for reduction of mite population and prevention of children respiratory diseases and other allergic disorders in this city.

Household knowledge and practices concerning malaria and indoor residual spraying in an endemic area earmarked for malaria elimination in Iran.

BACKGROUND: Indoor residual spraying of insecticide (IRS) is a key intervention for reducing the burden of malaria infection. Effectiveness and success of this strategy are to a considerable extent dependent on knowledge and practice of the target community regarding the IRS. Iran has entered the malaria elimination phase, and IRS has been considered as the main strategy for malaria vector control. Therefore, this study was conducted to determine the household knowledge and practices about malaria and IRS in Bashagard County, one of the malaria-endemic areas in the southeast of Iran. METHODS: A community-based cross-sectional survey was conducted among 420 households in Bashagard County. The participants who were selected using a two-stage randomized cluster sampling procedure were subjected to a tested structured questionnaire. During the survey, direct observations were made concerning the use of IRS as well as housing conditions. The data were coded and analysed using SPSS version 19. RESULTS: Knowledge levels about malaria as a disease and the mosquito as its vector were high and of equal magnitude (85.5% and 85.4%, respectively), while knowledge levels of IRS were even higher (91.6%). The main source of households' information about malaria and IRS was primarily community health workers (73.3%). Despite positive perceptions towards IRS only 26.7% of respondents had sprayed their houses which is lower than the WHO targeted coverage of 80%. Respiratory disorders and headache (33.3%), food contamination (24.9%), discolouring of inner house walls (17.7%), difficulty in furniture's movement (13.8%), and unpleasant odour (10.4%) were the main reasons for IRS refusal. CONCLUSION: There is a discrepancy between knowledge about symptoms and the transmission route of malaria and control practices related to IRS use. Therefore, IRS campaigns accompanied with education for behaviour change should be considered to ensure householders' participation and cooperation in the IRS programme. Moreover, continuous evaluation and monitoring of IRS as well as conducting more surveys on knowledge, attitude, and practices are recommended to improve malaria control measures and to identify indicators for effective, successful, and sustainable malaria elimination programme.

Insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in an elimination area in Iran.

BACKGROUND: Iran has recently initiated a malaria elimination program with emphasis on vector control strategies which are heavily reliant on indoor residual spraying and long-lasting insecticidal nets. Insecticide resistance seriously threatens the efficacy of vector control strategies. This study was conducted to determine the insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in Jask county as an active malaria focus in southeastern Iran. METHODS: In this study, the anopheline larvae were collected from different aquatic habitats in Jask county and transported to insectarium, fed with sugar and then 3-day-old adults were used for susceptibility tests. WHO insecticide susceptibility tests were performed with DDT (4 %), malathion (5 %), lambda-cyhalothrin (0.05 %), deltamethrin (0.05 %) and permethrin (0.75 %). RESULTS: The field strain of An. stephensi was found resistant to DDT and lambda-cyhalothrin. The LT50 values for DDT and lambda-cyhalothrin in this species were 130.25, and 37.71 min, respectively. Moreover, An. stephensi was completely susceptible to malathion and permethrin and tolerant to deltamethrin. CONCLUSION: The present study results confirm the resistance of the major malaria vector, An. stephensi, to DDT and lambda-cyhalothrin, and tolerance to deltamethrin, which could gradually increase and spread into other malaria endemic areas. Thus, there is a need for regular monitoring of insecticide resistance in order to select suitable insecticides for vector control interventions towards malaria elimination.

Characterization of larval habitats for anopheline mosquitoes in a malarious area under elimination program in the southeast of Iran.

OBJECTIVE: To determine the effects of environmental characteristics of larval habitats on distribution and abundance of anopheline mosquitoes in Bashagard county, a malarious area in southeast of Iran. METHODS: Larvae were collected monthly using the standard dipping method and identified using a morphological-based key. Environmental characteristics of the larval habitats were recorded. Water samples were taken from habitats during larval collection for physico-chemical characterization. Statistical analyses were performed. RESULTS: In total 5 150 anopheline larvae from 36 larval habitats were collected and identified. They comprised of six species: Anopheles culicifacies (29.36%), Anopheles moghulensis (25.20%), Anopheles dthali (18.02%), Anopheles superpictus (17.24%), Anopheles turkhudi (5.17%) and Anopheles stephensi (5.01%). The most common larval habitats were natural and clear water bodies such as riverbeds with sandy substrates and still water. Furthermore, the anopheline larvae were abundant in permanent and full sunlight habitats without vegetation and algae. Larval density was positively correlated with water temperature. Chemical characteristics including conductivity, total alkalinity, sulphate and chloride had significant effects on distribution and abundance of anopheline species. CONCLUSIONS: The result of this study indicates a correlation between some environmental characteristics and anopheline larvae abundance which can be considered for effective planning and implementing malaria elimination program in Iran.

Environmental characteristics of anopheline mosquito larval habitats in a malaria endemic area in Iran.

OBJECTIVE: To determine the effects of environmental parameters of larval habitats on distribution and abundance of anopheline mosquitoes in Rudan county of Iran. METHODS: This cross-sectional study was conducted during the mosquito breeding season from February 2010 to October 2011. The anopheline larvae were collected using the standard dipping method. The specimens were identified using a morphological-based key. Simultaneously with larval collection, environmental parameters of the larval habitats including water current and turbidity, sunlight situation, and substrate type of habitats were recorded. Water samples were taken from breeding sites during larval collection. Before collection of samples, the water temperature was measured. The water samples were analysed for turbidity, conductivity, total alkalinity, total dissolved solid, pH and ions including chloride, sulphate, calcium, and magnesium. Statistical correlation analysis and ANOVA test were used to analyze the association between environmental parameters and larval mosquito abundance. RESULTS: In total 2 973 larvae of the genus Anopheles were collected from 25 larval habitats and identified using morphological characters. They comprised of six species: An. dthali (53.21%), An. stephensi (24.22%), An. culicifacies (14.06%), An. superpictus (4.07%), An. turkhudi (3.30%), and An. apoci (1.14%). The most abundant species was An. dthali which were collected from all of the study areas. Larvae of two malaria vectors, An. dthali and An. stephensi, co-existed and collected in a wide range of habitats with different physico-chemical parameters. The most common larval habitats were man-made sites such as sand mining pools with clean and still water. The anopheline mosquitoes also preferred permanent habitats in sunlight with sandy substrates. The results indicated that there was a significant relationship between mean physico-chemical parameters such as water temperature, conductivity, total alkalinity, sulphate, chloride, and mosquito distribution and abundance. CONCLUSIONS: The results of this study showed a correlation between certain environmental parameters and mosquito larvae abundance, and these parameters should be considered in planning and implementing larval control programs.