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Background: Crimean-Congo Hemorrhagic Fever (CCHF) is a feverous and hemorrhagic disease endemic in some parts of Iran and caused by an arbovirus related to Bunyaviridae family and Nairovirusgenus. The main virus reservoir in the nature is ticks, however small vertebrates and a wide range of domestic and wild animals are regarded as reservoir hosts. This study was conducted to determine the infection rate of CCHF virus in hard ticks of Sarpole-Zahab County, Kermanshah province, west of Iran., Methods: From total number of 851 collected ticks from 8 villages, 131 ticks were selected randomlyand investigated for detection of CCHF virus using RT-PCR., Results: The virus was found in 3.8% of the tested ticks. Hyalommaanatolicum, H. asiaticum and Rhipicephalus sanguineus species were found to have viral infection, with the highest infection rate (11.11%) in Rh. sanguineus., Conclusion: These findings provide epidemiological evidence for planning control strategies of the disease in the study area.

Background: This comprehensive study was conducted on multi-purpose one-humped camel (Camelus dromedarius) sera and ticks to assess the epidemiological aspects of the Crimean-Congo hemorrhagic fever virus (CCHFV) in northeast Iran., Methods: From May 2012 to January 2013, eleven cities were randomly selected in the Khorasan Provinces of Iran as "clusters," and at least 14 one-humped camels were sampled from each area. Reverse transcriptase polymerase chain reaction was used for the detection of the CCHFV genome in ticks. Sera were analyzed using specific enzyme-linked immunosorbent assay tests., Results: Four hundred and eighty ixodid ticks were collected, and the genome of the CCHFV was detected in 49 (10.2%) out of 480 ticks. The CCHFV genome was detected in two out of four tick species, and in tick samples from three cities in Khorassan-e-Jonoobi. All three provinces, and six out of eleven cities, were CCHFV-specific IgG-positive. In total, nine (5.3%) out of 170 one-humped camels were IgG-positive. The highest rate of IgG-positive samples was found in Nehbandan (16.67%)., Conclusion: Continued surveillance and strictly enforced importation and quarantine practices should be implemented to prevent human exposure and the on-going dispersal of infected ticks and livestock in these regions. It is recommended that acaricides be used to prevent CCHF transmission to humans, and to reduce the tick population. In addition, care should be taken by abattoirs workers and people who work with one-humped camels.

Background: Crimean Congo hemorrhagic fever virus (CCHFV) is a member of the Bunyaviridae family and Nairovirus genus. It has a negative-sense, single stranded RNA genome approximately 19.2 kb, containing the Small, Medium, and Large segments. CCHFVs are relatively divergent in their genome sequence and grouped in seven distinct clades based on S-segment sequence analysis and six clades based on M-segment sequences. Our aim was to obtain new insights into the molecular epidemiology of CCHFV in Iran., Methods: We analyzed partial and complete nucleotide sequences of the S and M segments derived from 50 Iranian patients. The extracted RNA was amplified using one-step RT-PCR and then sequenced. The sequences were analyzed using Mega5 software., Results: Phylogenetic analysis of partial S segment sequences demonstrated that clade IV-(Asia 1), clade IV-(Asia 2) and clade V-(Europe) accounted for 80 %, 4 % and 14 % of the circulating genomic variants of CCHFV in Iran respectively. However, one of the Iranian strains (Iran-Kerman/22) was associated with none of other sequences and formed a new clade (VII). The phylogenetic analysis of complete S-segment nucleotide sequences from selected Iranian CCHFV strains complemented with representative strains from GenBank revealed similar topology as partial sequences with eight major clusters. A partial M segment phylogeny positioned the Iranian strains in either association with clade III (Asia-Africa) or clade V (Europe)., Conclusion: The phylogenetic analysis revealed subtle links between distant geographic locations, which we propose might originate either from international livestock trade or from long-distance carriage of CCHFV by infected ticks via bird migration.

Background: Crimean-Congo Hemorrhagic Fever Virus (CCHFV) belongs to genus Nairovirus and family Bunyaviridae. The main aim of this study was to investigate the extent of recombination in S-segment genome of CCHFV in Iran., Methods: Samples were isolated from Iranian patients and those available in GenBank, and analyzed by phylogenetic and bootscan methods., Results: Through comparison of the phylogenetic trees based on full length sequences and partial fragments in the S-segment genome of CCHFV, genetic switch was evident, due to recombination event. Moreover, evidence of multiple recombination events was detected in query isolates when bootscan analysis was used by SimPlot software., Conclusion: Switch of different genomic regions between different strains by recombination could contribute to CCHFV diversification and evolution. The occurrence of recombination in CCHFV has a critical impact on epidemiological investigations and vaccine design.

Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF) virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non-human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR) assay., Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper., Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus., Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus, Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease.