Species composition of Phlebotomine sandflies (Diptera: Psychodidae) in Nikshahr county, south-eastern Iran.

Background & objectives: Sandflies are reported as the vectors of different kinds of leishmaniasis to human. There are foci of the disease in Iran. The aim of this study was to determine the fauna and species composition of sandflies to find the probable vectors of leishmaniasis in Nikshahr county, south-east of Iran, where cutaneous leishmaniasis is endemic. Methods: Sandflies were collected by sticky paper traps from 20 collection stations located in plain and mountainous area of Nikshahr county. The sex ratio and relative abundance of different species were also determined. Results: A total of 11,455 sandflies revealed 23 species collected and identified. Phlebotomus alexandri, P. sergenti, P. papatasi, P. salehi, and P. keshishiani were the most important vector species found in this study. Interpretation & conclusion: During this survey 13 species are identified for the first time from Nikshahr county—P. bergeroti, P. eleanorae, P. keshishiani, P. halepensis, S. hodgsoni, S. christophersi, S. mervynae, S. dentata, S. dreyfussi, S. iranica, S. africana, S. grekovi and S. palestinensis, while P. keshishiani is an important vector of visceral leishmaniasis in south of Iran. These data demonstrate five vectors of leishmaniasis are active in the study area.

Monitoring of insecticides resistance in main malaria vectors in a malarious area of Kahnooj district, Kerman province, southeastern Iran.

BACKGROUND AND OBJECTIVES: Kahnooj district in south of Iran is an endemic area for malaria where Anopheles stephensi (Liston) is a main malaria vector and An. dthali (Patton) a secondary vector. According to the national strategy plan on monitoring of insecticides resistance, this study was performed on susceptibility and irritability levels of An. stephensi and An. dthali to different insecticides in the district. METHODS: The susceptibility and irritability levels of field strains of An. stephensi and An. dthali at the adult and larval stages to discriminative dose of different imagicides was determined as recommended by WHO. RESULTS: Using discriminative dose and WHO criteria it was found that An. stephensi is resistant to DDT and dieldrin with 36.1 +/- 2.3 and 62.2 +/- 1.95 mortality rates, respectively; but susceptible to other insecticides. An. dthali was found to susceptible to all tested insecticides. The larvae of An. stephensi, exhibited 100% mortality for temephos and malathion, but 44 +/- 4.32 for discriminative dose of fenitrothion. The results of irritability level for DDT and pyrethroids showed that permethrin had the most irritancy effect on An. stephensi and An. dthali. DDT and deltamethrin showed the least irritancy effect against An. stephensi with 0.42 +/- 0.08 and 0.77 +/- 0.12 take-offs/min/adult, respectively, however, lambdacyhalothrin had the least irritancy effect against An. dthali with 0.096 +/- 0.02 take-offs/min/ adult. The mean number of take-offs/min/adult with permethrin showed significant difference to DDT, lambdacyhalothrin, cyfluthrin and deltamethrin. INTERPRETATION AND CONCLUSION: Pyrethroid insecticides are being used as indoor residual sprays in Iran. Based on our results, the main malaria vectors in the region are still susceptible to pyrethroid insecticides. Therefore, we propose the use of pyrethroids with low irritancy effect in rotation with carbamate insecticides in two interval seasonal peaks of malaria transmission. Biological control including larvivorous fishes, using of local made Bacillus thuringiensis and larvicides such as chlorpyrifos-methyl are the main larval control in the region. Result on larval test exhibited the susceptibility of main vectors to some larvicides, although the 100% mortality was not obtained using fenitrothion and this is postulated the use of this insecticide in agriculture pest control. Monitoring and evaluation of insecticides resistance in malaria vectors in the region could provide an essential clue for judicious use of insecticides.

Larval habitats of main malaria vectors in Hormozgan province and their susceptibility to different larvicides.

Hormozgan Province is located in the south of Iran bordering the Persian Gulf. In this area, malaria is still considered a major health problem. In the province, eleven species of Anopheles were identified: An. pulcherrimus, An. sergenti, An. apoci, An. multicolor, An. subpictus, An. turkhudi, An. fluviatilis, An. stephensi, An. d'thali, An. superpictus, and An. culicifacies, among which only the last five species play an important role in malaria transmission. Larval habitats of malaria vectors varied from clean to brackish water, as well as sewage water, under palm trees, marshland, pools, pounds, drainage, irrigation canals, wells, and water containers. Malathion, fenitrothion, chlorpyrifos, and temephos were tested against An. stephensi, An. fluviatilis and An. d' thali larvae at diagnostic doses recommended by WHO. The results showed susceptibility to malathion, chlorpyrifos and temephos, but fenitrothion was not able to yield 100% mortality.