No abstract

A study of the distribution and ecology of mosquitoes (Diptera: Culicidae) in Ardebil Province of northwestern Iran, with special reference to the known dirofilariasis focus in Meshkinshahr County, was carried out in July-August 2005 and April-October 2006. In total, 17,533 adult mosquitoes and 3090 third- and fourth-instar larvae were collected on 14 occasions and identified using morphological characters and DNA sequence data. Twenty species belonging to seven genera were found: Anopheles claviger (Meigen), An. hyrcanus (Pallas), An. maculipennis Meigen, An. pseudopictus Grassi*, An. sacharovi Favre, An. superpictus Grassi, Aedes vexans (Meigen)*, Coquillettidia richiardii (Ficalbi)*, Culex hortensis Ficalbi, Cx. modestus Ficalbi, Cx. pipiens Linnaeus, Cx. theileri Theobald, Cx. torrentium Martini*, Cx. tritaeniorhynchus Giles, Culiseta longiareolata (Macquart), Cs. annulata (Schrank)*, Cs. subochrea (Edwards), Ochlerotatus caspius (Pallas) s.l.* (= Aedes caspius sensu auctorum), Oc. geniculatus (Olivier)* (= Aedes geniculatus sensu auctorum) and Uranotaenia unguiculata Edwards (asterisks indicate new occurrence records for the province). The most prevalent species in adult catches were An. maculipennis (52%), Cx. theileri (45%) and Cx. hortensis (1%); the most prevalent species caught as larvae were Cx. theileri (27%), Cx. hortensis (21%) and An. maculipennis (19%). Anopheles maculipennis, Cx. pipiens and Cx. theileri were most widely distributed in the province. The occurrence of Cx. torrentium in Iran is verified based on differential characters of fourth-instar larvae. Anopheles maculipennis and An. sacharovi of the Maculipennis Group were identified from their diagnostic ITS2 sequences. For the first time, cytochrome c oxidase I (COI) sequences were obtained from Iranian specimens of An. hyrcanus, An. pseudopictus, Cx. theileri and Oc. caspiuss.l. Culex theileri and An. maculipennis were found naturally infected with third-stage (infective) larvae of Dirofilaria immitis (Leidy) and Setaria labiatopapillosa (Alessandrini) (Spirurida: Onchocercidae), respectively, for the first time in Iran.

The incidence of human visceral leishmaniasis (VL) caused by Leishmania infantum, which is endemic in several parts of Iran, has recently increased in the Nourabad-Mamassani district of Fars province, in the south of the country. Between 2003 and 2005, 12,688 sandflies were caught in this focus, using CDC miniature light traps, sticky traps and aspirators, in an attempt to identify the main vector of L. infantum. When 120 of the parous, female Phlebotomus (Paraphlebotomus) alexandri caught were individually checked for Leishmania infection, in an assay based on PCR and kinetoplast minicircle primers (LINR4 and LIN17), five (4.2%) of the flies were found to be infected with L. infantum. Thirty-nine (32.5%) of the 120 blood-fed Ph. alexandri checked in an ELISA were found positive for human blood. Since Ph. alexandri was the third-most common species caught (representing over 17% of the total catch), was clearly anthropophilic, and was not infrequently infected with L. infantum, it is probably an important vector in the Nourabad-Mamassani focus. Although other sandfly species have been found naturally infected with promastigotes in Iran, Ph. alexandri is the first that has been proven to harbour L. infantum in the country.

Abstract. The prevalence, host preference, and rate of Leishmania spp. infection of sand fly species are important parameters for incrimination of parasite vectors. We applied polymerase chain reaction (PCR)−based and enzyme-linked immunosorbent assay (ELISA) methods to detect Leishmania spp. parasites and blood meals within individual sand flies in the most important visceral leishmaniasis (VL) focus in northwestern Iran. Leishmania spp. minicircles (kinetoplast DNA) were found in 14 (0.9%) of 1,569 female specimens. Sequence analysis of 650 basepairs of an internal transcribed spacer ribosomal DNA gene identified L. infantum/L. donovani in 12 specimens and L. adleri -like parasites in 2 specimens. Nine (64.3%) of 14 of the Leishmania spp.-positive sand flies were Phlebotomus perfeliewi transcaucasicus . Blood meal identification of host DNA within sand flies by PCR-based and ELISA methods showed that 30% and 28%, respectively, were positive for human blood. Results of this study showed that P. perfeliewi transcaucasicus is the most prevalent, infected, and anthropophagic sand fly and plays a major role in VL transmission in the region studied.

Visceral leishmaniasis is caused by Leishmania infantum, which is transmitted to humans by bites of phlebotomine sand flies and is one of the most important public health problems in Iran. To identify the vector(s), an investigation was carried out in Germi district, an important focus of the disease in Ardebil province in northwestern Iran, during July-September 2004 and 2005. Using sticky papers, CDC light traps and aspirators, 3,560 sand flies were collected and identified to species. Host bloodmeal preference and Leishmania infections in female specimens were evaluated using enzyme-linked immunosorbent assay (ELISA) for the former and microscopic examination followed by polymerase chain reaction (PCR) assay using species-specific kinetoplast minicircle primers for the latter. Nine sand fly species are present in the district, including Phlebotomus kandelakii Shchurenkova, Phlebotomus perfiliewi transcaucasicus Perfil'ev, Phlebotomus major Annandale, Phlebotomus balcanicus Theodor, Phlebotomus halepensis Theodor, Phlebotomus brevis Theodor & Meshghali, Phlebotomus papatasi Scopoli, Sergentomyia dentata Sinton, and Sergentomyia sintoni Pringle, with P. p. transcaucasicus being the most prevalent representative of the genus Phlebotomus at 45%. The anthropophilic index for P. p. transcaucasicus was 36.3%, indicating a strong preference for humans. Of 905 female P. p. transcuacasicus dissected, 10 (1.1%) were found naturally infected with promastigotes. Species-specific amplification of promastigotes eluted from Giemsa-stained slides revealed specific PCR products of L. infantum DNA. Based on its high anthropophily and natural infections with L. infantum, and the fact that it was the only species found infected with L. infantum, we conclude that P. p. transcaucasicus is the principal vector of L. infantum in northwestern Iran.