J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 179 http://jad.tums.ac.ir Published Online: June 30, 2021 Original Article Diversity of Hard Tick Populations and Their Geographical Variations in Northwestern Iran Rohollah Moradi1; Eslam Moradi-Asl2; Zakkyeh Telmadarraiy1; Seyedeh Zahra Parkhideh1; *Yavar Rassi1 1Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2Department of Public Health, School of Public Health, Ardabil University of Medical Sciences, Ardabil, Iran *Corresponding Author: Prof Yavar Rassi, E-mail: rassiy@tums.ac.ir (Received 19 Jan 2021; accepted 28 Jun 2021) Abstract Background: Ticks are forced vertebrate ectoparasites, including humans, and are vectors of serious diseases such as Crimean Congo Hemorrhagic Fever, Relapsing Fever, and various forms of encephalitis. Spatial assessment of the prevalence of ticks and detection of high risk areas for tick-borne disease transmission and evaluation of ecological measures are key aims of this research. Methods: Ticks were collected using standard methods from 27 villages in the region of Sarab County in north-eastern Iran during the four seasons of 2018–2019 and identified using valid keys. The calculations of indices for biodiversity were based on the Margalef index, Shannon-Weiner index and Simpson index. R2.15 Statistical software was used for statistical analysis of indices of biodiversity, and ArcMap10.4.1 software, IDW and GeneralG methods were used. Analysis were used to investigate spatial distribution and to determine important tick hotspots. Results: A total of 2500 animals surveyed, 35% of them were infected. In total, 1416 ticks were caught, 74.6 %, 23.9% and 1.4 % were adult, nymph and larvae respectively. 94% of the ticks were hard ticks including 6 genera. According to the Margalef diversity index, the highest species biodiversity was related to summer (1.4234), and the lowest was relat- ed to winter (0.7379), Conclusion: Large hotspot area was found in the central part of the study area. The area of study was very prone to tick-borne disease transmission in terms of tick diversity and tick species richness. Tick-borne disease control is an im- portant measure. Keywords: Ticks; Species biodiversity; GIS; Iran Introduction Ticks are the most important medical and veterinary ectoparasites and are one of the most important arthropod groups (1). Ticks belong to the order of metastigmata which feeds on animals and humans and play an important role in the transmission of the disease. This order is composed of two common Argasidae and Ix- odidae families (2). There are about 899 hard tick species, and 185 soft tick species (3). In Iran 14, 5, 8, 11, 1 and 3 hard tick species of Hyalomma, Rhipicephalus, Ixodes, Haemaphy- salis, Bophilus and Dermacentor has been rec- orded respectively. 10% of ticks feed on domes- tic animals, particularly cattle, sheep and goats. These are of major health significance due to the conditions that cause human and animal dis- eases (4-6). Tick-borne diseases are among the most common emerging and re-emerging dis- eases in recent years that have spread to dif- ferent geographic areas (7). Several diseases including tick-borne fever, Rocky mountain spotted fever, Q fever, Lyme disease, and Cri- mean-Congo Hemorrhagic Fever (CCHF) are among the known tick-borne human diseases Copyright © 2021 The Authors. Published by Tehran University of Medical Sciences. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International license (https://creativecommons.org/licenses/by- nc/4.0/). Non-commercial uses of the work are permitted, provided the original work is properly cited. http://jad.tums.ac.ir/ mailto:rassiy@tums.ac.ir https://creativecommons.org/licenses/by-nc/4.0/ https://creativecommons.org/licenses/by-nc/4.0/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 180 http://jad.tums.ac.ir Published Online: June 30, 2021 (8-10). Regardless of the importance of ticks in spreading different pathogens, its population structure, relative abundance and frequency, hosts type, habitats, ecology and diversity of species must be regulated. The study of tick biodiversity using various scientific indices seems to be very helpful (11-12). The aims of this study was to determine the status of spe- cies diversity and richness of hard ticks and their geographical distribution in the livestock of Sarab region in northwestern Iran using Simpson, Shannon Weiner, Margalef Indices and GIS software indicators. Materials and Methods Study area The county of Saraba is located in the prov- ince of East Azerbaijan, Iran. The capital of the county is Sarab. The county population at the 2006 census was 132,094, out of 31,977 fami- lies. The county is subdivided into two districts: the Central District and Mehraban District. The county has four cities: Sarab, Mehraban, Shara- bian, and Duzduzan. At the 2006 census, it had a population of 42,057 in 11,045 families. Livestock and animal husbandry has tradition- ally been common in most rural households (Fig. 1). Tick collection A total of 27 villages were selected from 9 districts. Ten locations were selected in each village (human, animal and livestock storage areas, traditional and modern grain deposits, farmland attached to the village and prefera- bly attached to active livestock sables, estimat- ed at 300 places). During the study, 441000 cat- tle (331000 sheep and goats) and (95000 cows and oxen) (8000 horses) and (7000 donkeys) were in the Sarab County. Therefore, ticks from a total of 2500 livestock were collected in this study, of which 75% of the sample size were sheep and goats, 23% were cows and oxen, and 2% were horses and donkeys. Valid keys were used to identify species of the ticks (13). This experiment was carried out under the guidance of the Ethics Committee of the Tehran Univer- sity of Medical Sciences (IR.TUMS.SPH.REC. 1398.058). Biodiversity Indices Different indices of biodiversity were used in this study including species richness (Mar- galef's richness index), species diversity (Simp- son's and Shannon Weiner's index). Calculation of tick dispersion Arcmap 10.4.1 software and interpolation with Inverse Distance Weighted (IDW) were used to analyze tick dispersion and to assess the distribution of disease vectors hot spots. The General G formula was used to determine the pattern of distribution of all CCHF disease spe- cies and main vectors including Hyalomma mar- ginatum and H.anatolicum in the study region. Results For a total of 2500 animals examined, ticks infested 763 animals (30.5 %). In total, 300 stalls and stables were inspected in 27 villag- es, 75 of which were infested with ticks (25%). A total of 1,416 ticks have been collected, of which 30% were male, 44.6% were female, 23% were nymphs and 1.4% were also tick larvae. Of the 94% of the ticks collected, 11 species have been classified as hard ticks, be- longing to 4 genera: Hyalomma (65%), Haem- aphysalis (11%), Rhipicephalus (6%), and Der- macentor (12%). Three species of soft ticks from two genera of Ornithodoros and Argas were identified (Table1). Sheep and goats with 58.68%, cows and ox with 13.23%, horses and donkeys with 2.14% respectively were the most infested animals with ticks. In terms of age, ticks were observed more in animals under 3 years of age (49 %) and the lowest infection (10 %) was observed in ani- http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 181 http://jad.tums.ac.ir Published Online: June 30, 2021 mals over 7 years of age, and the most infest- ed section of the animals were sub-tail (29.89 %) and animal ears (25.69 %). Biodiversity and species richness Tick diversity and species richness were cal- culated on the basis of two factors: seasonal ac- tivity and the host. The Margalf species rich- ness index showed that the highest richness was related to summer (1.4234), and the lowest rich- ness was related to winter (0.7379). The spe- cies diversity of ticks collected at different sea- sons in the research region were also signifi- cantly different (P< 0.05). The highest species diversity was related to summer (2.1709), and the lowest species diversity was related to win- ter (0.781), according to the Shannon-Wiener index measurements. The index of evenness of ticks collected during different seasons in the research region was significantly different (P< 0.05). The evenness index analysis found that the highest uniformity was in relation to the summer season (0.9428) and the lowest uni- formity was in relation to the autumn season (0.4428). The Simpson species diversity index also showed that the highest diversity was cor- related with summer (0.8622), and the lowest diversity was associated with autumn (0.3549). The results of this study found that the species richness of ticks collected in the Sarab Region during the first and second six months of the year had a significant difference (P< 0.05), and the first six months of the year had higher and more diversity and richness of species than the second six months of the year (Table 2). According to the Simpson Species Diversity and the Shannon-Wiener Indices, the findings of species diversity and richness based on dif- ferent hosts showed that the highest species diversity among the studied hosts were corre- lated to sheep and goats (0.881and 2.333), and the lowest species diversity was found in hors- es and donkeys (0.715 and 1.399) respective- ly. There was a significant difference (Table 3) in the evenness index for livestock hosts that ranging from the highest for sheep and goats (0.9096) to the lowest for cows and oxen (0.7945). Spatial distribution The most ticks were collected in the villag- es of Dozduzan (6.43%), Sharabian (6.28%), Mehraban (6.12%), Kelian (5.6%), Ardha (5.54 %) and Mahin Bijand (5.3%) and the lowest in Dichan village (2.45%). In Mehraban District the highest spatial dispersion as well as the highest density of hard and soft tick species was found. The findings of the interpolation study (IDW) revealed that there was a large hotspot area in the central part and a small hotspot in the north- western part of the county of Sarab in terms of tick abundance, both of which were high-risk areas in the Mehraban Region with 4596 and 1150 households in population (Fig. 2). The results of the analysis of spatial distri- bution patterns for all species and for two spe- cies of H. marginatum and H. anatolicum us- ing the General G index showed that all species were distributed randomly in all areas of study and did not have a specific pattern such as clus- ter or regular (Fig. 3 and Table 4). http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 182 http://jad.tums.ac.ir Published Online: June 30, 2021 Table 1. The total number of ticks collected from hosts and residential places in Sarab County, 2018–2019 T o ta l L a r v a N y m p h Adult ticks Hosts Species Genus Family Ixodidae F e m a le M a le S h e lt e r s D o n k e y a n d H o r se S h e e p a n d G o a t C o w a n d O x 46 0 0 33 13 0 0 17 11 H.anatolicum Hyalomma 319 0 2 111 206 0 12 69 52 H.marginatum Hyalomma 60 0 0 25 35 0 0 22 12 H.scupense Hyalomma 143 0 0 141 2 0 2 67 39 H.sp Hyalomma 55 0 0 17 38 0 2 18 8 H.asiaticum Hyalomma 18 18 0 0 0 0 0 2 0 larva Hyalomma 279 0 279 0 0 0 7 70 32 nymph Hyalomma 104 0 0 87 17 0 0 65 4 He.sulcata Haemaphysalis 31 0 0 18 13 0 0 14 4 He.numidiana (erinacei) Haemaphysalis 23 0 0 23 0 0 0 19 0 He.concinna Haemaphysalis 76 0 0 54 22 3 4 21 8 R.sanguineus Rhipicephalus 20 0 0 10 10 0 0 6 8 R.bursa Rhipicephalus 169 0 0 105 64 0 2 76 42 marginatus Dermasentor 520 0 434 65 21 63 0 42 0 O.lahorensis Ornithodoros Argasidae 7 0 0 3 4 2 0 2 4 A.reflexus Argas 42 0 29 13 0 7 0 0 0 A.persicus Argas 1912 18 744 705 445 75 29 510 224 Table 2. Biodiversity and species richness of ticks captured in the studied areas of Sarab County, based on seasonal activity, 2018–2019 Spring Summer Fall Winter Shannon-Wiener index 2.1267 2.1709 0.7934 0.781 Simpson's index)D( 0.1449 0.1378 0.6451 0.6385 Simpson's index(D-1) 0.8551 0.8622 0.3549 0.3615 Evenness Index 0.9236161 0.942812 0.4428048 0.485265 Margalef diversity index 1.3702635 1.423474 0.8287641 0.7379352 Table 3. Diversity and species richness of ticks caught separately by the host in the study areas in Sarab County, 2018–2019 Cow and Oxen Goat and sheep Donkey and Horse Stables Shannon-Wiener index 1.905 2.333 1.399 0.447 Simpson's index)D( 0.198 0.119 0.285 0.787 Simpson's index(D-1) 0.802 0.881 0.715 0.213 Evennes Index 0.7945 0.9096 0.8693 0.3224 Margalef diversity index 1.807 1.708 1.077 0.483 http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 183 http://jad.tums.ac.ir Published Online: June 30, 2021 Table 4. The results of hot-spot and autocorrelation analysis of tick species in Sarab County, East Azerbaijan, north- west of Iran, 2018–2019 General G Summary Global Moran's I Summary Species Observed General G Expected General G Variance z-score P All species 0.000015 0.000016 0.000000 -0.357036 0.721065 Hyalomma marginatum 0.000014 0.000016 0.000000 -1.464457 0.143069 Hyalomma antalicum 0.000013 0.000016 0.000000 -0.911540 0.362011 Fig. 1. Map of studay area, Sarab County, East Azerbaijan Province, Iran Fig. 2. General distribution of ticks caught in the study areas of Sarab County, 2018–2019 http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 184 http://jad.tums.ac.ir Published Online: June 30, 2021 Fig. 3. Results of scattering pattern analysis of ticks caught in Sarab County, East Azerbaijan, northwest of Iran, 2018– 2019 Discussion In this study, 2500 different livestock were studied and 30.5% of livestock and 25% of stalls and stables were infested with different ticks. This is one of the first studies to include more samples and tick populations in Iran. In related surveys, the infestation rate of ticks was 11%, 9.37%, 43% and 24% in northwest, west and north Iran (14-16). The highest fre- quency of captured ticks was related to spring (37.24%) and the lowest frequency was relat- ed to winter (11.83%) and this indicates the seasonal behavior of ticks in the mountainous and northwestern regions of Iran, mainly in spring, which can be attributed to the Nasiri study in Abdanan County, Ilam Province (17). Nonetheless, more seasonal tick activity was recorded in summer and autumn in areas such as Golestan Province northern Iran, which have ecologically different climates and have lower altitudes and higher temperatures than the moun- tainous areas (18). However, more seasonal tick activity was recorded in summer and autumn in areas such as Golestan Province northern Iran, which have ecologically different climates and have lower altitudes and higher tempera- tures than the mountainous areas (18). In the study area, the tick biodiversity, according to the Shannon-Wiener index, was found to be moderate to high (2.432) and the biodiversity index of Simpson (D-1) was also determined to be 0.856. The dominant species in the area therefore had a great diversity. We found the highest richness of ticks captured from cows and oxen and the lowest from horses and don- keys, according to the Margalef species rich- ness index. The findings of this research did not confirm previous studies in the province of Golestan (18) that found more sheep species http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 185 http://jad.tums.ac.ir Published Online: June 30, 2021 compared to cows. The diversity of the species was highest in autumn, and lowest in winter. The findings of this research were consistent with study for seasonal ticks activities in northwestern Iran (19). Six genera and 14 species of hard and soft ticks were collected in this research, of which the dominant genus was Hyalomma (48.12%). The findings of this research revealed that the region was prone to diseases like CCHF. Ac- cording to the study in 2004 (unpublished data), in the eastern province of Azarbaijan, north- western Iran, the Hyalomma genus was con- firmed to have the highest abundance (52.81%) which was consistent with recent study (un- published data). Interestingly, in a survey con- ducted in West Azerbaijan Province, 7 tick spe- cies with more abundant in the Hyalomma ge- nus (unpublished data) were reported to have the highest abundance and distribution, as our recent research did. Based on the findings of this study and the above research, it can be in- ferred that the provinces located in northwest- ern Iran including East Azerbaijan, West Azer- baijan and Ardabil had a high abundance of Hyalomma species and were ecologically suit- able habitat for this tick. Identifying high-risk and low-risk disease and vector areas allows to make appropriate de- cisions on the management of the vectors and diseases transmitted by them, and to arrange for the control and preventive management of the region. Throughout this research, the spread- ing of ticks as the vectors was found ran- domly around the region, but internal analysis revealed that the high-risk area of ticks was very high in the west of the study area as well as being a large hotspot. The high population of livestock and livestock occupation which have been the key hosts of ticks were some of the factors involved in this region. Therefore, in terms of tick-borne diseases, this area is in- deed one of the high-risk areas and control measures should be taken to prevent bites of ticks and diseases that they transmit. Conclusion The main method of application of pesticides against ticks are dipping method, pour-on and sometime oral administration by systemic ac- aricides in Iran as well as in Sarab County, East- ern Azerbaijan Province. The findings of the recent study indicate that the number of tick species caught in this region was varied due to the large abundance of livestock in Sarab Coun- ty and the wealth of animal and livestock hus- bandry practices and the production of dairy products. Because of the small scale of the coun- ty it reveals the richness of different species of ticks in this region. In the study of tick diver- sity in the research region among different hosts, it was observed that all the indices observed on sheep and goats have a comparatively higher value that the ticks were more associated with long hair hosts, so periodically picking the wool and hair of these hosts may be a way to reduce tick activity. Throughout this research, the spreading of ticks as the vectors was found randomly around the region, but internal anal- ysis revealed that the high-risk area of ticks was very high in the west of the study area as well as being a large hotspot. Acknowledgements This study was financially supported by the National Institute for Medical Research Devel- opment (NIMAD) Grant No.983031 and Teh- ran University of Medical Sciences, Grant No. 40919. The authors declare that there is no con- flict of interest. References 1. Lane RP, Crosskey RW (1993) Medical in- sects and arachnids. Chapman and Hal, UK, p. 723. 2. Goodman JL, Dennis DT, Sonenshine DE (2005) Tick-borne diseases of humans: ASM press, DC. ISBN: 1-55581-23-4. Washington, p. 440. http://jad.tums.ac.ir/ J Arthropod-Borne Dis, June 2021, 15(2): 179–186 R Moradi et al.: Diversity of … 186 http://jad.tums.ac.ir Published Online: June 30, 2021 3. de la Fuente J (2018) Controlling ticks and tick-borne diseases, looking forward. Ticks Tick Borne Dis. 9(5): 1354–1357. 4. Rahbari S, Nabian S, Shayan P (2007) Pri- mary report on distribution of tick fauna in Iran. Parasitol Res. 101(2): 175–177. 5. Van Vliet T, Kohli J, Demaria M (2019) Consequences of senotherapies for tissue repair and reprogramming. J Transl Med Age. 3: 31–36. 6. Davari B, Alam FN, Nasirian H, Nazari M, Abdigoudarzi M, Salehzadeh A (2017) Seasonal distribution and faunistic of ticks in the Alashtar county (Lorestan Province), Iran. Pan Afr Med J. 27: 284–290. 7. de la Fuente J, Antunes S, Bonnet S, Cabe- zas-Cruz A, Domingos AG, Estrada-Peña A, Johnson N, Kocan KM, Mansfield KL, Nijhof AM, Papa A, Rudenko N, Villar M, Alberdi P, Torina A, Ayllón N, Vancova M, Golovchenko M, Grubhoffer L, Cara- cappa S, Fooks AR, Gortazar Ch, Rego ROM (2017) Tick-pathogen interactions and vector competence: identification of molecular drivers for tick-borne diseases. Front Cell Infect Microbiol. 7: 114. 8. Nava S, Guglielmone AA, Mangold AJ (2009) An overview of systematics and evolution of ticks. J Front Biosci. 14(8): 2857–2877. 9. Otranto D, Dantas-Torres F, Giannelli A, Latrofa MS, Cascio A, Cazzin S, Ravagnan S, Montarsi S, Aurelio Zanzani S, Teresa Manfredi M, Capelli G (2014) Ticks in- festing humans in Italy and associated path- ogens. Parasites Vectors. 7(1): 328–331. 10. Moradi Asl E, Vatandoost H, Telmadar- reiy Z, Mohebali M, Abai MR (2018) Re- pellency effect of flumethrin pour-on for- mulation against vectors of Crimean-Congo haemorrhagic fever. Eeast Meditter Health J. 24(11): 1082–1087. 11. Masoumi Asl H, Goya M, Vatandoost H, Zahraei S, Mafi M, Asmar M (2009) The epidemiology of tick-borne relapsing fe- ver in Iran during 1997–2006. Travel Med Infect Dis. 7(3): 160–164. 12. Wood CL, Lafferty KD (2013) Biodiversi- ty and disease: a synthesis of ecological perspectives on Lyme disease transmission. Trends Ecol Evol. 28(4): 239–247. 13. Keirans JE, Litwak TR (1989) Pictorial key to the adults of hard ticks, family Ix- odidae (Ixodida: Ixodoidea), east of the Mis- sissippi River. J Med Entomol. 26(5): 435– 448 14. Yaser SA, Sadegh C, Zakkyeh T, Vatandoost H, Maryam M, Ali OM (2011) Crimean- Congo hemorrhagic fever: a molecular sur- vey on hard ticks (Ixodidae) in Yazd Prov- ince, Iran. Asian Pac J Trop Dis. 4(1): 61– 63. 15. Bakhshai A, Askari N, Etebar F, Ebrahim- zade E (2012) Hard ticks fauna in the area of domestic ruminants and Kohnuj Jiroft, Kerman Province, Iran. J Vet Lab Res. 4 (1): 145–149. 16. Telmadarreyi Z (2009) Frequency of Ix- odidae and Argasidae ticks and determi- nation of their sensitivity in the toxin cy- permetryn Meshkinshahr. Ardabil Uni Med Sci J. 9(2): 127–133. [In Persian] 17. Nasiri A, Telmadarraiy Z, Vatandoost H, Chinikar S, Moradi M, Oshaghi M (2010) Tick infestation rate of sheep and their dis- tribution in Abdanan County, Ilam Prov- ince, Iran, 2007–2008. Iran J Arthropod Borne Dis. 4(2): 56–60. 18. Sarani M, Telmadarraiy Z, Moghaddam AS, Azam K, Sedaghat MM (2014) Distribu- tion of ticks (Acari: Ixodidae) infesting do- mestic ruminants in mountainous areas of Golestan Province, Iran. Asian Pac J Trop Biomed. 4(Suppl 1): S246–251. 19. Vatandoost H, Moradi-Asl E, Telmadarreiy Z, Mohebali M, Masoumi-Asl H, Abai MR, Zarei Z (2012) Field efficacy of flumethrin pour-on against livestock ticks in Iran. Int J Acarol. 38(6): 457–464. http://jad.tums.ac.ir/