Molecular detection of Crimean-Congo haemorrhagic fever virus in ticks collected from infested livestock populations in a New Endemic Area, South of Iran

Hard Tick Species Parasitism Levels in Domestic Ruminants with Their Distribution and Role as Vectors: A Detailed Global Meta-analysis and Systematic Review

PURPOSE

This comprehensive global meta-analysis reviews the parasitism levels of tick genera and species, life stages, seasonality, attachment sites, the global mean ranks of tick species parasitism rates and records, and their distribution and role as vectors.

METHODS

From the 418 papers identified, 390 papers were selected to become part of the study.

RESULTS

The genera recorded as infesting domestic ruminants were Rhipicephalus (42 species), Haemaphysalis (32 species), Hyalomma (19 species), Amblyomma (18 species), Ixodes (10 species), Dermacentor (8 species), Margaropus and Nosomma (1 species). Globally, domestic ruminants are more infested by adult females and males than by the nymphal and larval stages of the tick species. The global tick species parasitism levels at the attachment sites of domestic ruminants were, in order, tail and anal region, neck and dewlap, scrotum or udder, ear region, thigh and abdomen, and dorsal surface.

CONCLUSIONS

Among 131 species of eight genera of hard ticks recorded infesting domestic ruminants, 42 species had mean ranks of tick species parasitism rates up to 10%, and 37 species had mean ranks of tick species parasitism up to 10 records. Briefly, the higher the indexes of tick species parasitism rates and records, the more important their role as vectors. In addition, the majority of them are found among tick species-infested humans with nearly high ranks of tick species parasitism rates and records that double their medical, veterinary, and zoonotic importance to be the most common vectors and reservoirs of bacterial, protozoan, and viral pathogenic microorganisms, causing severe infectious diseases, and as a result, can be more dangerous to humans and domestic ruminants.

Medically Significant Vector-Borne Viral Diseases in Iran

Vector-borne viral diseases (VBVDs) continue to pose a considerable public health risk to animals and humans globally. Vectors have integral roles in autochthonous circulation and dissemination of VBVDs worldwide. The interplay of agricultural activities, population expansion, urbanization, host/pathogen evolution, and climate change, all contribute to the continual flux in shaping the epidemiology of VBVDs. In recent decades, VBVDs, once endemic to particular countries, have expanded into new regions such as Iran and its neighbors, increasing the risk of outbreaks and other public health concerns. Both Iran and its neighboring countries are known to host a number of VBVDs that are endemic to these countries or newly circulating. The proximity of Iran to countries hosting regional diseases, along with increased global socioeconomic activities, e.g., international trade and travel, potentially increases the risk for introduction of new VBVDs into Iran. In this review, we examined the epidemiology of numerous VBVDs circulating in Iran, such as Chikungunya virus, Dengue virus, Sindbis virus, West Nile virus, Crimean-Congo hemorrhagic fever virus, Sandfly-borne phleboviruses, and Hantavirus, in relation to their vectors, specifically mosquitoes, ticks, sandflies, and rodents. In addition, we discussed the interplay of factors, e.g., urbanization and climate change on VBVD dissemination patterns and the consequent public health risks in Iran, highlighting the importance of a One Health approach to further surveil and to evolve mitigation strategies.

Monitoring of hard tick parasitism in domestic ruminants: A scale evidence for policymakers

Domestic ruminants such as camels, cattle, goats, and sheep represent a substantial part of the global world economy. Hard ticks are well-known as obligatory bloodsucking ectoparasites of domestic ruminants. Policymakers need to get results that show the global distribution of tick genera and species, their parasitic levels, and their roles as disease vectors in camels, cattle, goats, and sheep. Iran is endemic to a broad range of hard tick-borne diseases. A study that reviews the tick genera and species, life stage, seasonal and attachment site parasitism levels, the global mean ranks of tick species parasitism rates and records, and their distribution in target animals would be of particular importance. Accordingly, this review aims to summarize the above objectives. After evaluating the identified articles, 147 were selected to be part of the survey based on the study objectives. Globally, tick parasitism levels were 28.7, 29.9, 36.0 and 47.6% for goats, cattle, sheep, and camels, respectively. The tick parasitism trends have exhibited an increasing trend for camels and sheep over the years while remaining constant for cattle and goats, indicating that current tick control measures are not being properly followed. Ticks tend to parasitize females more than males because males are more resistant to certain pests than females. The distribution of tick genera and species, their parasitism levels, and their roles as disease vectors provided. This information addresses the needs of decision-makers to make decisions.

Molecular detection of tick-borne pathogens in Rhipicephalus sanguineus sensu stricto collected from dogs in the steppe and high plateau regions of Algeria

Epidemiology and distributions of canine tick-borne diseases as well as their veterinary and zoonotic significance are poorly understood in Algeria. The present study describes a molecular investigation of important tick-borne pathogens in Rhipicephalus sanguineus sensu stricto collected from domestic dogs in steppe and high plateau areas of central and eastern Algeria. In total, 1,043 ticks were collected from 147 domestic dogs, including 756 ticks from 124 dogs in the steppe region of Djelfa, and 287 ticks from 23 dogs in the high plateau area of Bordj Bou Arreridj. Ticks were divided into 384 pools (309 pools from Djelfa and 75 pools from Bordj Bou Arreridj) and tested for genomic materials of Crimean-Congo hemorrhagic fever virus (CCHFV) as well as DNA for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Rickettsia spp., Babesia spp., and Hepatozoon spp. using PCR, sequencing and phylogenetic analysis. Hepatozoon spp. was most prevalent, with 160 positive pools (41.70%), and 12 of these were sequenced and identified as Hepatozoon canis. Babesia spp. was detected in 50 samples (13.0%), of which 11 were sequenced and identified as Babesia vogeli. A. platys and E. canis were detected in 92 (24.0%) and 15 (3.9%) of tested samples, respectively. Rickettsia spp. were detected in 24 (6.3%) samples, including 11 samples identified as R. massiliae, 6 samples identified as R. conorii conorii, and 7 samples could not be identified to species level. All 384 pools tested negative for CCHFV and A. phagocytophilum. In addition to detection of R. conorii conorii, R. massiliae, and E. canis, the present study provides the first molecular data for occurrence of A. platys, B. vogeli, and H. canis in Rh. sanguineus s.s. infesting dogs in Algeria. Further large scale studies should be conducted to better understand the epidemiology, distributions and importance of canine tick-borne pathogens in Algeria.

Detection of Crimean-Congo hemorrhagic fever virus in ticks collected from South Russia

Crimean-Congo hemorrhagic fever (CCHF) has a central role among tick-borne infections in southern Russia. Multiple cases of disease are recorded annually in most regions with the СCHF foci; moreover, an expansion of the geographic range of the disease has been noted. Since 1999, more than 2300 people have fallen ill in Russia. Ticks are the main vectors and reservoirs of the Crimean-Congo hemorrhagic fever virus (CCHFV). As it is currently known, CCHFV has been detected in ticks of 33 species. In the period 2012-2019 in the south of the European part of Russia, more than 38,000 ticks of 14 species of the genera Hyalomma, Rhipicephalus, Dermacentor, Haemaphysalis and Ixodes were tested for the presence of CCHFV. Among 4,188 tick pools studied, the virus was detected in 252 (6%). The main vector, as expected, is H. marginatum (81% of positive pools). The same species is the most numerous among the studied ticks (66%). Apart from H. marginatum, the virus was detected in the following species: H. scupense, R. rossicus, R. turanicus, R. bursa, R. annulatus, D. marginatus, Haem. punctata and Ixodes ricinus. Most of the positive results were obtained from ticks collected from vertebrate hosts. As for H. marginatum, R. rossicus, D. marginatus, and Haem. punctata, the virus was detected in questing unfed specimens collected from vegetation and soil surface, which indicates the participation of these ticks in the circulation of the virus.

Crimean-Congo Hemorrhagic Fever Virus in Asia, Africa and Europe

The global spread of ticks and various tick-borne viruses (TBVs) suggests the possibility of new tick-borne diseases emerging. Crimean-Congo hemorrhagic fever virus (CCHFV) is an emerging TBV of the Nairoviridae family that causes serious disease that can be fatal in humans. CCHFV endemic foci can be found in Africa, Asia, the Middle East, and South-Eastern Europe, and has spread to previously unaffected regions and nations, such as Spain, over the last two decades. In this review, we discuss the current situation of CCHFV in Asia, Africa and Europe based on existing knowledge, and we discuss driving factors in the distribution and transmission of the virus, such as the spread of tick vector species and host reservoirs.

Sporadic outbreaks of crimean-congo haemorrhagic fever in Uganda, July 2018-January 2019

Introduction

Crimean-Congo haemorrhagic fever (CCHF) is a tick-borne, zoonotic viral disease that causes haemorrhagic symptoms. Despite having eight confirmed outbreaks between 2013 and 2017, all within Uganda’s ‘cattle corridor’, no targeted tick control programs exist in Uganda to prevent disease. During a seven-month-period from July 2018-January 2019, the Ministry of Health confirmed multiple independent CCHF outbreaks. We investigated to identify risk factors and recommend interventions to prevent future outbreaks.

Methods

We defined a confirmed case as sudden onset of fever (≥37.5°C) with ≥4 of the following signs and symptoms: anorexia, vomiting, diarrhoea, headache, abdominal pain, joint pain, or sudden unexplained bleeding in a resident of the affected districts who tested positive for Crimean-Congo haemorrhagic fever virus (CCHFv) by RT-PCR from 1 July 2018–30 January 2019. We reviewed medical records and performed active case-finding. We conducted a case-control study and compared exposures of case-patients with age-, sex-, and sub-county-matched control-persons (1:4).

Results

We identified 14 confirmed cases (64% males) with five deaths (case-fatality rate: 36%) from 11 districts in western and central region. Of these, eight (73%) case-patients resided in Uganda’s ‘cattle corridor’. One outbreak involved two case-patients and the remainder involved one. All case-patients had fever and 93% had unexplained bleeding. Case-patients were aged 6–36 years, with persons aged 20–44 years more affected (AR: 7.2/1,000,000) than persons ≤19 years (2.0/1,000,000), p = 0.015. Most (93%) case-patients had contact with livestock ≤2 weeks before symptom onset. Twelve (86%) lived <1 km from grazing fields compared with 27 (48%) controls (OR_M-H = 18, 95% CI = 3.2-∞) and 10 (71%) of 14 case-patients found ticks attached to their bodies ≤2 weeks before symptom onset, compared to 15 (27%) of 56 control-persons (OR_M-H = 9.3, 95%CI = 1.9–46).

Conclusions

CCHF outbreaks occurred sporadically during 2018–2019, both within and outside ‘cattle corridor’ districts of Uganda. Most cases were associated with tick exposure. The Ministry of Health should partner with the Ministry of Agriculture, Animal Industry and Fisheries to develop joint nationwide tick control programs and strategies with shared responsibilities through a One Health approach.

Uganda has had multiple Crimean-Congo haemorrhagic fever outbreaks since 2013 when the first outbreak was confirmed. Tick exposure has been identified as the major risk factor by our study and this finding was similar with other studies done during outbreaks in Uganda. However, Uganda still lacks national tick control guidelines and indiscriminate use of acaricides (pesticides specially for ticks) has been observed widely. This has been cited to influence increased tick resistance to acaricides. Our study might not indicate whether tick resistance to acaricides has increased tick populations in Uganda however it is imperative that tick control is considered in efforts of prevention and control of CCHF outbreaks. We therefore recommend improved tick control in Uganda through national regulations on acaricide distribution and use, development of strategies to reduce tick resistance to acaricides in the country, and more community-based engagement of tick control in livestock management.

Comparative efficacy of three pediculicides to treat head lice infestation in primary school girls: a randomised controlled assessor blind trial in rural Iran

Background

Head lice infestation (Pediculosis) is one of the most important health challenges particularly in primary school-aged children. It is often present among 6–11-year-old students in various tropical and temperate regions of the world. The aim of this study was to examine epidemiologic indices and comparative analysis of two pyrethroid-based and one non-chemical pediculicide products on head lice treatment of primary school girls in a rural setting of Fars province, south Iran, as part of a randomized controlled assessor blind trial.

Methods

Before treatment, infested students were screened using plastic detection combs to find live head lice. Three independent parallel groups, each with about 25 participants (#77) were eventually twice with a week apart treated with either 1% permethrin, 0.2% parasidose (d-phenothrin) or 4% dimeticone lotion preparations. In each case, a questionnaire form was completed on epidemiologic factors. Data were registered after a fortnight from primary scalp treatment and re-inspection on days 2, 6, 9 and 14. Data analyses were performed using Chi-square test with a P-value < 0.05 being taken as statistically significant.

Results

From 3728 inspected students, 87 (2.33%) girls were infested with head lice, Pediculus humanus capitis De Geer, 1778. Ten students dropped out pertaining to exclusion criteria. No significant correlation was found between head lice infestation level and hair length, hair style, itching, nationality, age, settlement site and baths; but there was a significant relationship between age and hair style (P = 0.027). The efficacy values on each of the above re-inspection days from each of the three treatments were 81, 74, 70 and 63% for permethrin; 83, 92, 100 and 100% for dimeticone; and 96, 88, 96 and 92% for d-phenothrin; respectively. A quartile difference in efficacy of permethrin relative to dimeticone on day 14 represented the scale of head lice resistance to permethrin treatment. There were significant statistical differences in case re-inspection days 9 (P = 0.008) and 14 (P = 0.003) post treatment. Only two dropout cases, one non-compliant and the other lost before the second-week treatment, from permethrin trial were observed following two applications a week apart.

Conclusions

Dimeticone lotion had the fullest efficacy (100%) among all treatments. This high cure rate was attributed to the low level of infestation and the extent of patients’ involvement. Parasidose swiftly ameliorated the infested cases by the second day since initial treatment. Female third grade students were the most infested cohort.

Trial registration

Current Controlled Trials- IRCT2016041627408N1, Dated: 21-08-2017.

Crimean-Congo Haemorrhagic Fever: Case study analysis of a sporadic outbreak from Chakwal, Pakistan

Crimean-Congo Haemorrhagic Fever (CCHF) is a deadly viral zoonotic disease, which is endemic in Pakistan. We report a case study analysis of three cases of CCHF which occurred in Chakwal, Pakistan in 2016. The disease was suspected in three patients exhibiting clinical symptoms suggestive of CCHF; two of the three patients died. The presence of CCHF was detected by seroconversion (IgG) from the surviving patient, while the antigen was detected in Hyalomma ticks originating from animals in the vicinity. This report indicates increase threat emergence of CCHF in Pakistan and highlights its zoonotic implications requiring immediate interventions under the "One-Health" concept.

Sandflies species composition, activity, and natural infection with Leishmania, parasite identity in lesion isolates of cutaneous leishmaniasis, central Iran

Zoonotic cutaneous leishmaniosis (ZCL) is a crucial public health challenge in Iran. Sandflies feed on reservoir rodents' blood infected with Leishmania parasite and transmit it to other hosts. This study was conducted to find out the composition and monthly activity of sandflies as well as to identify the protozoan pathogens (Leishmania/Crithidia) by polymerase chain reaction (PCR) in an emerging ZCL focus of Abarkooh, Yazd province, Iran, in 2016. A cross-sectional study was done in rural areas of Abarkooh. From April to November 2016, sticky traps were used indoor and outdoor to capture sandflies once every fortnight. Their composition and monthly activity were recorded. Following identification of sandflies and DNA extraction from them, PCR was used to identify their parasite and match it against samples taken from ZCL confirmed and suspected patients' lesions. After collection, a total of 2045 sandflies (779 indoor, 1266 outdoor) were identified to species level. Sandfly activity started early April in this area with two active peaks (one late May and the other late August) terminated about mid-November. Seven Phlebotomus species and three Sergentomyia species were identified. The most and the least abundant species were P. papatasi (40.1%) and P. alexandri (0.09%), respectively. Using PCR, only 6% (12:200) of P. papatasi sandflies were infected with Leishmania parasite. No Crithidia was detected in either sandflies or human lesions (176 specimen). Based on the highest abundance both indoor and outdoor of P. papatasi, this sandfly was considered the main vector of ZCL in this area. The capture of P. caucasicus, P. mongolensis, and P. ansarii from rodent burrows showed these species were likely involved in pathogen transmission in reservoir rodents' burrows.

Co-circulation of Crimean-Congo Hemorrhagic Fever virus strains Asia 1 and 2 between the border of Iran and Pakistan

Crimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne viral disease that is transmitted by numerous species of ticks, which serve both as a reservoir and vector of CCHF virus (CCHFV). Molecular and serological tests were undertaken on hard ticks (Ixodidae spp.) and samples from livestock were collected in 2015 from Chabahar County in Southeast Iran. Using RT-PCR, the ticks were tested for the presence of CCHFV. In addition, seven livestock were serologically tested for the presence of IgG antibodies using an ELISA test. IgG antibodies against CCHFV were detected in one of 7 of the livestock that were tested. In total, 49 ticks including five species: Rhipicephalus sanguineus, Hyalomma anatolicum, Hy. asiaticum, Hy. dromedarii and Hy. marginatum with a prevalence of 46.9%, 32.7%, 4.1%, 4.1% and 2.1% respectively were identified. CCHFV was detected in three ticks among 49 collected ticks. The ticks infected with CCHFV belonged to the genus Hyalomma and Rhipicephalus. Phylogenetic analysis demonstrated that two sequences clustered in clade IV (Asia-1) and one sequence was located within clade IV (Asia-2). Most of the animal and human CCHF cases of the country are reported from Sistan and Baluchistan provinces. Regular monitoring programs in the tick population and livestock are needed in the future.

The role of ticks in the maintenance and transmission of Crimean-Congo hemorrhagic fever virus: A review of published field and laboratory studies

This manuscript is part of a series of reviews that aim to cover published research on Crimean-Congo hemorrhagic fever (CCHF) and its etiological agent, CCHF virus (CCHFV). The virus is maintained and transmitted in a vertical and horizontal transmission cycle involving a variety of wild and domestic vertebrate species that act as amplification hosts, without showing signs of illness. These vertebrates have traditionally been considered reservoirs of CCHFV, but in fact they develop only a transient viremia, while the virus can persist in ticks for their entire lifespan, and can also be transmitted vertically to the next generation. As a result, ticks are now considered to be both the vector and the reservoir for the virus. CCHFV has been detected in a wide range of tick species, but only a few have been proven to be vectors and reservoirs, mainly because most published studies have been performed under a broad variety of conditions, precluding definitive characterization. This article reviews the published literature, summarizes current knowledge of the role of ticks in CCHFV maintenance and transmission and provides guidance for how to fill the knowledge gaps. Special focus is given to existing data on tick species in which vertical passage has been demonstrated under natural or experimental conditions. At the same time, we identify earlier reports that used unreliable methods and perceptions to ascribe a vector role to some species of ticks, and have contributed to confusion regarding viral transmission. We also examine epidemiological pathways of CCHFV circulation and discuss priority areas for future research.

Crimean-Congo hemorrhagic fever cases in the North of Iran have three distinct origins

An on-going surveillance program on Crimean-Congo haemorrhagic fever virus (CCHFV) in Iran has been launched since 2000. An outbreak of CCHF occurred in northern Iran between June and July 2015. Three cases were involved in this outbreak. One patient died after admission to hospital, and the others were treated successfully. Phylogenetic analysis showed that three sequences obtained from Iranian patients grouped within clade IV (Asia-1), clade V (Europe) and clade VI (Greece). The partial sequence of the strain Noshahr59 (KT588642) showed the highest similarity with other strains isolated from Russia, Kosovo and Turkey (Clade V, Europe). The genome sequence of the strain Chalous65 (KT588640) showed 100% homology to the strain AP29 isolated from Greece (DQ211638). The genome sequence of the strain Noshahr43 (KT588641) showed 88% similarity to the Pakistani and previously reported Iranian strains (AF527810, AJ538198, AY366379 and AY366373). These data support previous studies, which showed a distinct similarity between Iranian S segments of CCHFV strains with other strains within clade IV (Asia-1) and clade V (Europe). In addition, clade VI was detected for the first time in Iran. Moreover, strain Chalous65 with similar genetic characteristics to strain AP29 from Greece was isolated from a fatal human case.

Phylogeny of tick-derived Crimean-Congo hemorrhagic fever virus strains in Iran

The presence of Crimean-Congo hemorrhagic fever virus (CCHFV) in Iran was assessed by collecting ticks from Golpayegan, Isfahan Province. Real time RT-PCR was used to detect the CCHFV RNA in the tick population and the origins of the viral sequences were determined. The CCHFV RNA was detected in 5.2% of 492 ticks collected from livestock in different regions of Golpayegan. The tick species that tested positive for the presence of CCHFV RNA included Hyalomma, Rhipicephalus and Haemaphysalis species. Phylogenetic analysis using the partial S-segment indicated that eight sequences clustered in clade IV (Asia-1) and three other sequences aligned within clade VI (Europe) with other CCHFV strains from Kosovo (Kosova1917) and Russia (Kashmanov).