ABSTRACT
Objective: To determine the diversity of sand flies in different biotopes of mountainous and plain areas of Bam County as the most infected focus of anthroponotic cutaneous leishmaniasis in southeast Iran, and synanthropic index of Phlebotomus sergenti Parrot, and Phlebotomus papatasi Scopoli as the main vectors of cutaneous leishmaniasis in Iran. Methods: Sand flies were captured once a month using sticky traps in domestic, peri-domestic, agricultural, and sylvatic biotopes in the plain and mountainous areas. Alpha diversity indices, including richness, evenness, Shannon-Wiener; beta diversity indices (Jaccard's and Sorensen's similarity indices) and synanthropic index were calculated. Results: A total of 2 664 specimens of 9 sand fly species were collected from mountainous (47%) and plain (53%) areas. Species richness, species evenness, and Shannon-Wiener indices were obtained as 9, 0.637, and 1.399, respectively in the mountainous area. Phlebotomus sergenti and Phlebotomus papatasi were constant species with the synanthropic index of-18.463 and-29.412, respectively. In addition, species richness, species evenness, and Shannon-Wiener indices were 4, 0.690, and 0.956, respectively in the plain area. Phlebotomus sergenti and Phlebotomus papatasi were dominant species with the synanthropic index of +9.695 and +36.207, respectively. Similarity indices were low among different biotopes of plain and mountainous areas. Conclusions: A basic knowledge about the diversity of sand flies in various biotopes is essential to design sound control programs. Biodiversity and synanthropic indices of sand flies are different in plain and mountainous areas due to the difference in biotic and abiotic factors between the two areas.
ABSTRACT
Objective: To evaluate the susceptibility of Anopheles stephensi (An. stephensi) Liston, the main malaria vector in southern Iran, to WHO recommended insecticides. Methods: Larvae of An. stephensi were collected from three different larval habitats in both urban and rural area of Bandar Abbas city and one rural area in Rudan county southern Iran. WHO standard method was used for evaluation of adult and larval mosquito susceptibility. Bendiocarb, permethrin, lambda-cyhalothrin, deltamethrin as insecticide and temephos and chlorpyriphos as larvicide were used at the diagnostic dosages recommended by WHO. Results: Findings of this study showed all larval populations of An. stephensi were completely susceptible to temephos and candidate for resistance to chlorpyriphos. Adult mosquitoes in rural areas of Bandar Abbas city were resistant to pyrethroid and carbamate insecticides. Conclusion: Comparison of the results of this survey with previous studies indicates that the resistance to pyrethroids and carbamates in this malaria endemic region is increasing. Wide use of pesticides in agriculture is certainly effective in increasing resistance. The inter-sectoral coordination and collaboration in health and agriculture seem to be necessary to manage insecticide resistance in malaria vectors.
ABSTRACT
<p><b>OBJECTIVE</b>To determine ecology and characteristics of the larval habitats of the genus Anopheles (Dipetra: Culicidae) in Aligudarz County, western Iran.</p><p><b>METHODS</b>This descriptive cross-sectional research was carried out to study the anopheline larvae ecology in seven rural districts, Aligudarz County, from late April to late November 1997. Larvae were captured using the dipping method. Larval breeding places characteristics were noted according to water situation (turbid or clean, stagnant or running), substrate type, site type (man-made or natural), sunlight situation, site situation (transient or permanent, with or without vegetation).</p><p><b>RESULTS</b>A total of 9 620 3rd and 4th instar larvae of Anopheles from 115 breeding places in 22 villages were captured, which belonged to the following species: Anopheles stephensi, Anopheles d'thali, Anopheles apoci, Anopheles superpictus (forms A and B), Anopheles marterii sogdianus, Anopheles turkhodi, Anopheles maculipennis S.L and Anopheles claviger. Anopheles stephensi, Anopheles maculipennis S.L and Anopheles apoci were collected for the first time in this county. Anopheles superpictus (93.18%) was the most prevailed one and dispersed over the entire region. Larval habitats consisted of nine natural and three artificial larval habitats. The most important larval habitats were river edges (54.8%), rice fields (12.2%), and grassland (8.7%) with permanent or transient, stagnant or running and clean water, with or without vegetation, sand or mud substrate in full sunlight area.</p><p><b>CONCLUSIONS</b>Regarding this research, river edges and rice fields are the most important breeding places of malaria vectors in Aligudarz County. It is worthy of note in larvicidal programs.</p>
ABSTRACT
OBJECTIVE@#To investigate species composition, density, accumulated degree-day and diversity of sand flies during April to October 2010 in Azarshahr district, a new focus of visceral leishmaniasis in north western Iran.@*METHODS@#Sand flies were collected using sticky traps biweekly and were stored in 96% ethanol. All specimens were mounted in Puri's medium for species identification using valid keys of sandflies. The density was calculated by the formula: number of specimens/m(2) of sticky traps and number of specimens/number of traps. Degree-day was calculated as follows: (Maximum temperature + Minimum temperature)/2-Minimum threshold. Diversity indices of the collected sand flies within different villages were estimated by the Shannon-weaver formula ( H'=∑i=1sPilog(e)Pi).@*RESULTS@#Totally 5 557 specimens comprising 16 Species (14 Phlebotomus, and 2 Sergentomyia) were indentified. The activity of the species extended from April to October. Common sand-flies in resting places were Phlebotomus papatasi, Phlebotomus sergenti and Phlebotomus mongolensis. The monthly average density was 37.6, 41.1, 40.23, 30.38 and 30.67 for Almalodash, Jaragil, Segaiesh, Amirdizaj and Germezgol villages, respectively. Accumulated degree-day from early January to late May was approximately 289 degree days. The minimum threshold temperature for calculating of accumulated degree-day was 17.32°. According on the Shannon-weaver (H'), diversity of sand flies within area study were estimated as 0.917, 1.867, 1.339, 1.673, and 1.562 in Almalodash, Jaragil, Segaiesh, Amirdizaj and Germezgol villages, respectively.@*CONCLUSIONS@#This study is the first detailed research in terms of species composition, density, accumulated degree-day and diversity of sand flies in an endemic focus of visceral leishamaniasis in Azarshahr district. The population dynamics of sand flies in Azarshahr district were greatly affected by climatic factors. According to this study the highest activity of the collected sand fly species occurs at the teritary week of August. It could help health authorities to predicate period of maximum risk of visceral leishamaniasis transmission and implement control program.
Subject(s)
Animals , Biodiversity , Insect Vectors , Classification , Iran , Leishmania donovani , Physiology , Leishmaniasis, Visceral , Epidemiology , Parasitology , Population Dynamics , Psychodidae , Classification , Seasons , TemperatureABSTRACT
Anthroponotic cutaneous leishmaniasis [ACL] has long been a significant public health problem in northeastern Iran. The objective of this study was to determine the efficacy of deltamethrin-impregnated vs. nonimpregnated bed nets [NIBs] and curtains [NICs] in ACL control. Deltamethrin-impregnated bed nets [IBs] and curtains [ICs] with 25 mg ai/m[2] were distributed among 160 households in one district and NIBs and NICs were distributed among the same number of households in another district. A third district with a similar numbers of households served as a control. Health education messages were disseminated to ensure the population's complicance with the proper use of bed nets and curtains. Sticky paper traps were used to assess the effect of insecticide-impregnated bed nets and curtains on the density of Phlebotomus sergenti. Deltamethrin susceptibility and also bioassay tests were carried out on the species by WHO standard method. Case findings were done by house-to-house visits once a season and all the inhabitants of the selected households in each district were examined. IBs and ICs provided good protection against sandfly bites and reduced the transmission of ACL in the intervention district, while NIBs and NICs provided no protection. There was no significant difference in monthly density of P. sergenti indoors and outdoors among the districts [P>0.05]. This species was susceptible to delta-methrin in the field population in the area. Bioassays confirmed that the nets treated with deltamethrin remained effective for more than 3 months. Personal protection is an effective and sustainable means of preventing and controlling ACL and can reduce dependence on insecticides. We encourage the use of IBs and ICs to control ACL in other high-risk areas of Iran and Afghanistan during the active season of sandflies
Subject(s)
Pyrethrins , National Health Programs , Health Education , Textiles , InsecticidesABSTRACT
Zoonotic cutaneous leishmaniasis [ZCL] is a serious and increasing public health problem in many rural areas of Iran. Previous studies showed that rodent control operations are effective in destroying rodents and reducing the incidence of ZCL on a small scale and in special circumstances. The objective of this study was to determine suitable timing for rodent control operations in reducing the incidence of ZCL in an endemic area in Badrood, Iran. We conducted rodent control operations by baiting rodent holes using zinc phosphide once a month in May, June, July and September in 1997 within a 500-meter circle of houses in the intervention area. From 1999 to 2002, the numbers of active rodent holes were counted in May and October in the intervention and control areas. When the numbers of rodent holes increased to 30% or more of the number before the first baiting in May 1997, holes in the intervention area were baited again with zinc phosphide in the intervention area; no baiting was done in the control village. Case findings were done by house-to-house visits once every season during 2000 to 2002. Changes in the number of rodent holes over time in the intervention and control villages were statistically significant [P<0.000001]. There were also significant differences in the incidence of ZCL between the intervention and control villages [P<0.005] during 2000 to 2002. The incidence of ZCL was unchanged in the years 2000 and 2001, but increased in one village in 2002 after an increase in the number of rodent holes. We suggest that rodent control operations using zinc phosphide be done within a 500-meter circle of houses once every two years before the beginning of the active season of sandflies, which begins in late April
Subject(s)
Humans , Animals , Leishmaniasis, Cutaneous/prevention & control , Rodent Control , Zoonoses , Rural Health , Incidence , Zinc CompoundsABSTRACT
Background: Reports from the health center of Yazd province of increasing cutaneous leishmaniasis [CL] cases led us to carry out an epidemiological study using standard techniques in Ardakan County, central Iran, during 2001
Patients and Methods: Data was collected on the prevalence of scars and ulcers over a period of 14 months among 621 households in three villages around Ardakan County. Smears were prepared by scraping the edges of the ulcers. We collected the same data on all school children aged 7 to 11 years old in the area. To determine the reservoir host of the disease, rodents and dogs were caught and examined. Sandflies were collected biweekly from indoor and outdoor locations in the study area, and then identified. Parasites isolated from human and rodents were characterized by RAPD-PCR technique
Results: The prevalence of scars and ulcers were 30.4% and 24.6%, respectively, in 3024 individuals in the three villages. Individuals 10 to 14 years of age were the most highly infected age group, with a rate of 28.4%. Males and females were equally infected. Examination of 892 students in primary schools showed a rate of 22.9% for scars and 23.7% for ulcers. Meriones libycus [42.2%] and Rhombomys opimus [57.8%] were present around the villages. Both were infected with Leishmania. Three of 19 M. libycus [15.7%] and 3 out of 26 R. opimus [11.5%] had positive results. The active season of sandflies was late April to late November. Phlebotomus papatasi and Sergentomyia sintoni were the dominant species indoors and outdoors. Natural leptomonad infection was found in P. caucasicus and S. sintoni from gerbil and Jird burrows
Conclusion: Based on this survey, there is an epidemic of zoonotic CL in the area, with Leishmania major as the agent, M. libycus and R. opimus as the reservoir hosts, and most probably Phlebotomus papatasi as the vector because about 77% of indoor sandflies were of this species