Congo Hemorrhagic Fever Virus in a Highland Province, SW Iran
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Hosseini Z, Salehi-Vaziri M, Ahmadnia S, Fakoorziba MR, Jalali T, Telmadarraiy Z, Moemenbellah-Fard MD Original article Hard Ticks Infesting Domestic Ruminants, Species Composition and Infection with Crimean- Congo Hemorrhagic Fever Virus in a Highland Province, SW Iran Zahra Hosseini1, MSc; Abstract Mostafa Salehi-Vaziri2,3, PhD; Background: Crimean-Congo hemorrhagic fever (CCHF) is a Sara Ahmadnia4, MSc; neglected tick-borne viral zoonotic disease. The aim was to detect Mohammad Reza Fakoorziba1, CCHF virus (CCHFV) among wild ticks from Artiodactyla, Bos PhD; Tahmineh Jalali2, PhD; taurus, Ovis aries, and Capra hircus, in a previously declared 5 Zakkyeh Telmadarraiy , PhD; CCHFV-free province of Kohgiluyeh Boyer-Ahmad, southwest Mohammad Djaefar Iran. Moemenbellah-Fard6, PhD Methods: From April to November 2015, hard ticks were 1Department of Medical Entomology collected in a cross-sectional study and checked by microscope and Vector Control, School of Health, Shiraz University of Medical Sciences, for species identity from ungulates in 51 study villages. Shiraz, Iran About 55% of the ticks were then subjected to reverse- 2Research Center for Emerging and transcription polymerase chain reaction (RT-PCR) to detect Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran CCHFV genome. 3Department of Arboviruses and Viral Results: Overall, 859 hard ticks were captured, from which Hemorrhagic Fevers (National Reference Laboratory), Pasteur Institute of Iran, 8 different species in two genera were identified. The genus Tehran, Iran Rhipicephalus was distributed in half (#26) of the study 4Department of Veterinary Sciences, School of Veterinary Medicine, University villages. It was the most frequent (≈60%) tick genus. Hyalomma of Shiraz, Shiraz, Iran anatolicum, H. asiaticum, H. excavatum, H. marginatum, H. 5Department of Medical Entomology and Vector Control, School of Public Health, scupense, Rhipicephalus sanguineus, R. turanicus, and R. bursa Tehran University of Medical Sciences, were identified on the ruminants. From 469 adult ticks subjected Tehran, Iran 6Research Center for Health Sciences, to RT-PCR, one (0.2%) tick, R. bursa, was positive with CCHFV Institute of Health, Department of Medical genome. It was from a cold hardy highland village in Dena Entomology and Vector Control, School of Health, Shiraz University of Medical County. It had CCHFV RNA for the first time from this region. Sciences, Shiraz, Iran Conclusion: The detection of CCHF viral RNA in one hard tick species, R. bursa, was confirmed in the southwest of Iran, thus Correspondence: Mohammad Djaefar Moemenbellah-Fard, partially indicating CCHFV presence of ticks in this region. PhD; Research Center for Health Sciences, Institute of Health, Department of Medical Please cite this article as: Hosseini Z, Salehi-Vaziri M, Ahmadnia S, Fakoorziba Entomology and Vector Control, School MR, Jalali T, Telmadarraiy Z, Moemenbellah-Fard MD. Hard Ticks Infesting of Health, Shiraz University of Medical Domestic Ruminants, Species Composition and Infection with Crimean- Sciences, Shiraz, Iran Congo Hemorrhagic Fever Virus in a Highland Province, SW Iran. J Health Sci Tel: +98 71 37251001-8 Ext: 348 Surveillance Sys. 2019;7(2):52-59. Fax: +98 71 37260225 Email: [email protected] [email protected] Keywords: Tick, Crimean-congo hemorrhagic fever, Rhipicephalus, Received: 4 January 2019 Hyalomma, Iran Revised: 10 February 2019 Accepted: 20 March 2019 Introduction importance to incriminate them as potential reservoirs of CCHFV infection. It is mainly transmitted to man by Crimean-Congo hemorrhagic fever (CCHF) is a neglected hard tick (family: Ixodidae) bites. CCHF is caused by a tick-borne viral zoonotic disease endemic in many parts Nairovirus (family: Bunyaviridae) and transmitted, in 1 of the world, including Iran. With a case fatality rate particular, by the two-host tick, Hyalomma genus. (CFR) of about 14% in Iran, the detection of CCHF Ticks can have a long duration of bloodsucking virus (CCHFV) genome in vectors is of fundamental on briefly viremic vertebrate hosts.2 This potentially 52 J Health Sci Surveillance Sys April 2019; Vol 7; No 2 CCHFV in ticks of highland SW Iran lethal arboviral infection presents unique challenges ticks collected from domestic herbivores (cattle, Bos to public health infrastructure, particularly in taurus; sheep, Ovis aries; and goat, Capra hircus) in tropical areas. Despite being an enzootic infection, Kohgiluyeh Boyer-Ahmad province, Iran, in 2015. its human sporadic epidemics have been recorded To the best of the authors’ knowledge, this is the first from many regions including the Balkan, the Middle report of detecting CCHF viral RNA in hard ticks of East, Indo-Pakistan subcontinent, China, southwest this province in Iran. Europe, Bulgarian-Turkish region, and southwest Russia.3-6 CCHFV is asymptomatically transmitted Materials and Methods to an extensive variety of vertebrates; it is, however, life-threatening only in humans.3 The high burden Study Area of disease in Iran and its adjacent neighbors (>5000 cases in the first decade of this century) points to the Kohgiluyeh Boyer-Ahmad province is located in 7 Southwestern Iran (30°25ꞌ-31°45ꞌN; 49°57ꞌ-50°42ꞌE) magnitude of this concern. Nosocomial transmission 2 of CCHFV has also been reported with remarkable with an area of 26416 km (Figure 1). This is an implications.8 almost mountainous region (at a mean altitude of 2100 m) with many caves, rivers, and forest refuges, This virus can be transmitted both vertically and a rich composition of wild and domestic animals (from one generation to the next) and horizontally including Reptilia, Aves, Artiodactyla, Rodentia, (simultaneous circulation of the virus from one blood and Carnivora. Two types of climates (subtropical sucking infected tick stage in close proximity to and temperate) are seen in this province. About 43% another uninfected one through synchrony in zoonotic of its northeast flank enjoys a temperate climate. niche conditions or co-feeding on a vertebrate host) Average annual precipitation is <600 mm/year. The among ticks.2 Venereal (trans-sexual), trans-ovarial temperature ranges from -20°C to 36°C in winter (through eggs), and trans-stadial (from one molting and summer, respectively. The mean annual relative tick blood-feeding stage to the next developmental humidity is about 33%. This province is divided into stage) passage of virus is also common.2 The number 8 counties of Boyer-Ahmad, Dena, Gachsaran, Basht, of routes and directions of viral transmission attests Bahmai, Choram, Dehdasht and Lendeh (Figure 1). to the extensive epidemiology of CCHF.9 A total of 58 villages were randomly selected for In Iran, an early viral antibody survey using agar tick collection. Most (#51) of these were infested gel diffusion precipitation test on man and several with ticks. Recently, insecticide-treated husbandry animal species, including few rodents and Chiroptera units and those which did not consent to sampling species, showed differential positivity for CCHFV.10 were excluded from the study. The Zagros mountain The commonest route of CCHFV transmission among range in Dena County has a peak of 4409 m above Iranians is percutaneous contact with viremic tissues, blood, or other infected body fluids of contagious asymptomatic domestic and wild ungulates such as cattle, sheep, goats and camels.11 Many of these livestock are illegally imported via eastern borders, bypassing official surveillance screening. Only a few sporadic cases of direct tick bites are normally reported.12 The zoonotic and ecological niche of CCHF points to those people who are involved in close proximity to the livestock (cattle, sheep, goats, etc.) and a huge proportion of shrub and grass land cover.13 It is postulated that adequate threshold densities of both suitable vertebrate hosts with transient viremia and infected Hyalomma ticks are indispensable to establish a persistent natural CCHFV focus.14 Furthermore, the assumption that non-Hyalomma ticks cannot maintain an active focus of natural CCHFV circulation remains contentious since no sine quae non-evidence exists for the persistence of the virus in the next generation 2 Figure 1: Map shows the location of Kohgiluyeh Boyer-Ahmad of ticks. province in southwest region of Iran (top right map) and the approximate sites of eight counties (thick arrow; top left), The main aim of this investigation was to detect including the county of Dena (grey area) where only one hard CCHFV RNA relics using reverse transcription tick was positive with CCHFV RNA, and the distribution of 58 polymerase chain reaction (RT-PCR) in bloodsucking villages over these counties (solid black lines, bottom inset). J Health Sci Surveillance Sys April 2019; Vol 7; No 2 53 Hosseini Z, Salehi-Vaziri M, Ahmadnia S, Fakoorziba MR, Jalali T, Telmadarraiy Z, Moemenbellah-Fard MD the sea level. This study area is dominantly covered Data were analyzed using SPSS version 16 with oak trees. Most residents of this province are software. Descriptive statistics were used to analyze involved in animal breeding husbandry and associated the results. practices which consequently make them vulnerable to infectious diseases. Results Collection and Identification of Ticks A total of 859 hard ticks were collected from 51 villages in Using finely curved-tip forceps, we promptly and 8 counties. No hard ticks were found in 7 (12%) villages. safely removed the ticks from their hosts so as not to The most (47%) and the least (4.5%) infested counties damage their mouth parts. They were gathered from were Boyer-Ahmad and Lendeh, respectively (Table 1). domestic herbivores (cattle, Bos taurus; sheep, Ovis Moreover, the most infested village was Lema olia in aries; and goat, Capra hircus) from April to November Dena County with 58 Rhipicephalus tick specimens. All 2015. Each ungulate trunk was searched for the study villages were infested with at least one and up to presence of tick infestations by palpation, principally 5 different tick species. The latter condition occurred in on the ears and along the nape of the neck, perineum, Damkore sofla of Boyer-Ahmad County. scrotum or udder, and tail base.