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1.
Middle East respiratory syndrome coronavirus, MERS‐CoV, was identified in Saudi Arabia in 2012, and as of January 29, 2018, there were 2,123 laboratory‐confirmed MERS‐CoV cases reported to WHO (WHO, 2018, https://www.who.int/emergencies/mers-cov/en/ ). Multiple studies suggest that dromedary camels are a source for human MERS‐CoV infection. MERS‐CoV‐specific antibodies have been detected in the serum of dromedary camels across Northern Africa and across the Arabian Peninsula. Israel's geographic location places Israel at risk for MERS‐CoV infection. To date, MERS‐CoV‐related illness has not been reported and the burden of MERS‐CoV infection in the Israeli population is unknown. The seroprevalence of MERS‐CoV‐specific antibodies in Israeli dromedary camels is unknown. The objective of this study was to determine the prevalence of MERS‐CoV seropositivity in dromedary camels in Israel. The prevalence of MERS‐CoV antibodies in Israeli camels was examined in 71 camel sera collected from four farms across Israel by MERS‐CoV‐specific microneutralization (Mnt) assay and confirmed by MERS‐CoV‐specific immunofluorescence assay (IFA). Although this study cannot rule out potential antibody cross‐reactivity by IFA, the presence of bovine coronavirus‐specific antibodies do not appear to impact detection of MERS‐CoV antibodies by Mnt. MERS‐CoV neutralizing antibodies were detectable in 51 (71.8%) camel sera, and no association was observed between the presence of neutralizing antibodies and camel age or gender. These findings extend the known range of MERS‐CoV circulation in Middle Eastern camels. The high rate of MERS‐CoV‐specific antibody seropositivity in dromedary camels in the absence of any reported human MERS cases suggests that there is still much to be learned about the dynamics of camel‐to‐human transmission of MERS‐CoV.  相似文献   

2.
Middle East respiratory syndrome coronavirus (MERS‐CoV) cases without documented contact with another human MERS‐CoV case make up 61% (517/853) of all reported cases. These primary cases are of particular interest for understanding the source(s) and route(s) of transmission and for designing long‐term disease control measures. Dromedary camels are the only animal species for which there is convincing evidence that it is a host species for MERS‐CoV and hence a potential source of human infections. However, only a small proportion of the primary cases have reported contact with camels. Other possible sources and vehicles of infection include food‐borne transmission through consumption of unpasteurized camel milk and raw meat, medicinal use of camel urine and zoonotic transmission from other species. There are critical knowledge gaps around this new disease which can only be closed through traditional field epidemiological investigations and studies designed to test hypothesis regarding sources of infection and risk factors for disease. Since the 1960s, there has been a radical change in dromedary camel farming practices in the Arabian Peninsula with an intensification of the production and a concentration of the production around cities. It is possible that the recent intensification of camel herding in the Arabian Peninsula has increased the virus' reproductive number and attack rate in camel herds while the ‘urbanization’ of camel herding increased the frequency of zoonotic ‘spillover’ infections from camels to humans. It is reasonable to assume, although difficult to measure, that the sensitivity of public health surveillance to detect previously unknown diseases is lower in East Africa than in Saudi Arabia and that sporadic human cases may have gone undetected there.  相似文献   

3.
Since the emergence of Middle East respiratory syndrome coronavirus (MERS‐CoV) in 2012, there have been a number of clusters of human‐to‐human transmission. These cases of human‐to‐human transmission involve close contact and have occurred primarily in healthcare settings, and they are suspected to result from repeated zoonotic introductions. In this study, we sequenced whole MERS‐CoV genomes directly from respiratory samples collected from 23 confirmed MERS cases in the United Arab Emirates (UAE). These samples included cases from three nosocomial and three household clusters. The sequences were analysed for changes and relatedness with regard to the collected epidemiological data and other available MERS‐CoV genomic data. Sequence analysis supports the epidemiological data within the clusters, and further, suggests that these clusters emerged independently. To understand how and when these clusters emerged, respiratory samples were taken from dromedary camels, a known host of MERS‐CoV, in the same geographic regions as the human clusters. Middle East respiratory syndrome coronavirus genomes from six virus‐positive animals were sequenced, and these genomes were nearly identical to those found in human patients from corresponding regions. These data demonstrate a genetic link for each of these clusters to a camel and support the hypothesis that human MERS‐CoV diversity results from multiple zoonotic introductions.  相似文献   

4.
Dromedary camels are implicated as reservoirs for the zoonotic transmission of Middle East Respiratory Syndrome coronavirus (MERS‐CoV) with the respiratory route thought to be the main mode of transmission. Knowledge and practices regarding MERS among herders, traders and slaughterhouse workers were assessed at Athi‐River slaughterhouse, Kenya. Questionnaires were administered, and a check list was used to collect information on hygiene practices among slaughterhouse workers. Of 22 persons, all washed hands after handling camels, 82% wore gumboots, and 65% wore overalls/dustcoats. None of the workers wore gloves or facemasks during slaughter processes. Fourteen percent reported drinking raw camel milk; 90% were aware of zoonotic diseases with most reporting common ways of transmission as: eating improperly cooked meat (90%), drinking raw milk (68%) and slaughter processes (50%). Sixteen (73%) were unaware of MERS‐CoV. Use of personal protective clothing to prevent direct contact with discharges and aerosols was lacking. Although few people working with camels were interviewed, those met at this centralized slaughterhouse lacked knowledge about MERS‐CoV but were aware of zoonotic diseases and their transmission. These findings highlight need to disseminate information about MERS‐CoV and enhance hygiene and biosafety practices among camel slaughterhouse workers to reduce opportunities for potential virus transmission.  相似文献   

5.
This study was performed to investigate the presence of bovine herpesvirus-1 (BHV-1), bovine leukemia virus (BLV) and bovine viral diarrhea virus (BVDV) infections in dromedary camels (Camelus dromaderius) kept in mixed herds with sheep and goats in Algeria, since the prevalence of BHV-1, BVDV, and BLV infections among dromedary camels in Algeria is unknown. Totally, 111 camel sera were collected from two provinces (Laghouat and Ghardaia) in Algeria. The sera were analyzed for BHV-1 specific antibodies, BVDV specific antibodies and BVDV antigen using the ELISA, and BLV nucleic acid using PCR. The seropositivity rate was 9.0% for BVDV-specific antibody, although 41.4% of camels tested were positive for BVDV antigen. Moreover, there was no evidence of BHV-1 and BLV infections. The results indicated that camels might represent an important source for BVDV infection in all ruminants, including cattle, sheep, and goats bred in mixed herds in Algeria, since they had a higher BVDV prevalence rates. Therefore, the prevention and control measures for BVDV infection should put in place in camel populations to limit the spread of BVDV infection to ruminant populations in Algeria.  相似文献   

6.
Four dromedaries were infected with a virulent camelpox virus strain which was isolated from the lung of a Saudi Arabian camel. The camels which were infected intradermally and subcutaneously developed severe generalized camelpox. One of these camels had to be euthanized on humane grounds and the second one died 13 days after being infected. This dromedary also developed internal pox. Neither dromedary showed camelpox antibodies before infection. The other two camels which had been vaccinated with Ducapox 6 years prior to the viral challenge did not develop any clinical symptoms when given 5 ml of the field virus intravenously and intramuscularly. They seroconverted after the challenge. Although only two camels were used for this trial, the results indicate that a single dose of Ducapox can protect 1-year-old camels from camelpox infection for several years.  相似文献   

7.
Middle East respiratory syndrome coronavirus (MERS‐CoV) is an emerging zoonotic pathogen discovered in 2012. The purpose of this scoping review was to summarize the empirical evidence for MERS‐CoV in animals in order to map knowledge gaps and to extract data for modelling disease transmission in dromedary camels. A review protocol was developed a priori, and a systematic search, data extraction and summary were conducted using the Arksey and O'Malley framework. Ninety‐nine publications were identified for full review out of 1,368 unique records. Of these publications, 71 were articles in scientific journals. Ninety of the studies were observational and the remaining nine were experimental. We summarize characteristics of animal studies including study design, study population and outcomes of interest for future transmission modelling in the reservoir population. The majority of field studies reported measures of prevalence, while experimental studies provided estimates of transmission parameters that pertain to the natural course of disease.  相似文献   

8.
A recent publication described finding GB virus C (GBV-C) RNA in 4 of 22 dromedary camel sera, and sequence analysis found that these viruses were phylogenetically clustered within human GBV-C isolates. Since all other GB viruses to date form monophyletic groups according to their host species, the close relationship between the sequences generated from camel sera and human GBV-C isolates seemed implausible, leading us to conduct an independent analysis of the sequences. Our investigation found three lines of evidence arguing against GBV-C infection in dromedary camels. First, strong evidence of artifactual sequence generation was identified for some of the sequences. Secondly, the sequence diversity within individual camel sera was 10-152-fold greater than that described for GBV-C within a human host. Finally, GBV-C sequences generated from each camel shared near complete identity with human isolates previously described by the same laboratory. Taken together, these data strongly suggest laboratory contamination. We suggest that additional validation experiments are needed before it is possible to conclude that camels are permissive for GBV-C infection.  相似文献   

9.
It has been postulated that the one‐humped (Arabian) dromedary and the two‐humped (Bactrian) camel originated from a single ancestor. Consequently, the dromedary was considered a breed of the two‐humped camel, based on an anatomical study by Lombardini L, 1879: Ann. Del. Universita Toscane, 259 , 147, who described a reduced second hump like structure in foetal and adult dromedaries. To resolve this lingering issue, we analysed dromedary foetuses and calves. In contrast to the situation in two‐humped camels, we never observed any rudimentary second hump in the dromedary foetuses or calves.  相似文献   

10.
The fringed tapeworm Thysanosoma actinioides was recovered from the liver of a Najdi camel (Camelus dromedarius) slaughtered in central Saudi Arabia. T. actinioides is recorded for the first time as a parasite of old world camels.  相似文献   

11.
Dromedary camels complaining from conception failure or abortion were investigated and their herders interviewed in Al Ahsa province, Kingdom of Saudi Arabia (KSA) during 2013 and 2015. The most important reproductive disorder according to the responders is uterine infection (60.2%) followed by obesity (22.3%) then physiological conditions (hormonal disturbances; 7.8%), adhesions (3.9%) and repeat breeders (2.9%). Of the camel herders, 78.6% reported previous occurrence of abortion in their herds and 46% reported abortion cases in the last season (2015/2016), while 21.4% reported no history of abortion. Most of the responders (97.1%) do not call a veterinarian for cases of abortion in their herds and 53.4% do not discard aborted materials. The majority of the herders (76.7%) deny that handling aborted materials or touching vaginal fluids can result in human infection, or replied they do not know. Uterine swab samples were collected and tested by PCR for seven potential pathogens and sera tested for antibodies against bovine viral diarrhea virus (BVDV) and Brucella. Five pathogens were identified in infected uterine samples, namely Coxiella burnetii (36%), Campylobacter spp. (27%), Brucella spp. (17%), Salmonella spp. (13%), and Chlamydia spp. (7%). Sero-prevalence of Brucella and BVDV was 8.2 and 29.1% in overall sera, respectively, and varies with regard to the region. The findings of the present study demonstrate that reproductive disorders dominated by uterine infections and abortions are widespread in dromedary camels in KSA.  相似文献   

12.
Infectious bovine rhinotracheitis (IBR), caused by bovine herpesvirus-1 (BHV-1), is a major livestock health concern in many countries of the world. The objectives of this cross-sectional study were (i) to estimate the seroprevalence of BHV-1 infection and (ii) to assess risk factors associated with this disease in dromedary camels in four districts of Algeria. Blood samples were taken from 865 camels from 84 randomly selected herds, and serum was analyzed for presence of antibodies against BHV-1 by indirect enzyme linked immunosorbent assay (ELISA). Logistic regression was used to determine associations between seroprevalence and potential risk factors (collected using a questionnaire). Antibodies against BHV-1 were detected in 3.7 % (32/865) of samples. Eighteen of 84 camel herds had at least one BHV-1 seropositive camel, giving a herd seroprevalence of 21.4 %. Based on univariate analysis, the introduction of purchased animals and contact with others animal herds appeared as major risk factors. By using multivariate analysis, the only important risk factor was introduction of new animals. This study provided, for the first time, evidence of BHV-1 infection in dromedary camels in Algeria; it also provided estimates of seroprevalence of this disease and suggests that camels may serve as a reservoir of BHV-1 for spread to other species.  相似文献   

13.
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14.
A total of 192 male camels of three age groups (young, adult and old) from Saudi Arabia were examined for Onchocerca fasciata infection by detection of microfilariae in skin snips and nodules in the nuchal ligaments and subcutaneous tissues of the neck and shoulder. The overall prevalence rates were 10.9 and 33.3%, respectively. The prevalence rate by the skin snip technique and the number of microfilariae per gram of skin were higher in young and adult camels than in old camels. However, the prevalence rate by the detection of nodules and the number of nodules per infected camel, increased with increase in age of the camels. An increase in size and weight of nodules was reported with an increase in age of the camels. Nodules varied in diameter from 2 to 36 mm and in weight from 0.5 to 5.0 g. The overall percentage of soft viable and calcified nodules was 42.5 and 57.5%, respectively. The viability of worms decreased, but calcification increased with increased age of the camels. Four levels of degeneration and calcification of worms were described following scanning electron microscopy.  相似文献   

15.
The morphological and morphometric characteristics of the ovary are fundamental properties for in vitro oocyte maturation. Nuclear maturation, including first polar body (1PB) extrusion, cytoplasmic maturation and cumulus cell (CC) expansion are the criteria for in vitro maturation (IVM) of oocyte. This study was designed to determine the effect of morphological and morphometric features of the ovary on CC expansion and 1PB extrusion during IVM of oocyte in the adult female dromedary camel. The weight, volume and three dimensions of ovaries from slaughtered dromedary camels and oocytes inside zona diameter and zona pellucida thickness were measured. The follicles were classified in regard to the size and oocytes according to their ooplasm appearance and CC compactness. Aspirated cumulus oocyte complexes (COCs) were incubated for 48 hr (with a 6‐hr interval) in Hams‐F10, and CC expansion and 1PB extrusion were assessed. Significant differences were seen in the shape, weight, volume and three dimensions of the ovaries between ≤4‐year‐old and >4‐year‐old dromedary camel (p < .5). Approximately, 95.82% of follicles were 2–4 mm in diameter. The mean (±SD) of inside zona diameter of the oocyte and zona pellucida thickness was 132.22 ± 13.8 and 14.64 ± 2.24 μm, respectively, in >4‐year‐old dromedary camel. The CC expansion and 1PB extrusion were seen in 86% and 21.88% of COCs, respectively. Age and sexual conditions of dromedary camel influence the morphological and morphometric characteristics of the ovary. Most COCs retrieved from 2–6 mm follicles are cultivable. The most slaughterhouse‐derived COCs retrieved from 2–6 mm follicles of non‐pregnant dromedary camels are excellent and good and yielding a most favourable diameter to achieve the developmental competence for IVM in an optimal time of 24–30 hr; the optimal time for CC expansion is 24–30 hr in this species. However, the CC expansion is a prerequisite process, but not sufficient for IVM.  相似文献   

16.
An outbreak of Trypanosoma evansi infection that occurred in mainland Spain is described. The outbreak occurred on an equine and camel farm to which dromedary camels from an infected area of the Canary Islands had recently been introduced. One of these camels developed clinical signs and T. evansi was discovered in a blood smear examination. The herd was evaluated in order to determine the extent of the disease. The results showed that 76% of the camels, 35% of the donkeys and 2% of the horses were affected. The animals were isolated and treated using Cymelarsan® (0.5 mg/kg). After treatment, three blood analysis using parasitological methods revealed negative results. This is the first T. evansi outbreak to have occurred in mainland Spain and the second in mainland Europe, both occurring after the introduction of dromedary camels from the Canary Islands.  相似文献   

17.
Hepatitis E is a human disease mainly characterized by acute liver illness, which is caused by infection with the hepatitis E virus (HEV). Large hepatitis E outbreaks have been described in developing countries; however, the disease is also increasingly recognized in industrialized countries. Mortality rates up to 25% have been described for pregnant women during outbreaks in developing countries. In addition, chronic disease courses could be observed in immunocompromised transplant patients. Whereas the HEV genotypes 1 and 2 are mainly confined to humans, genotypes 3 and 4 are also found in animals and can be zoonotically transmitted to humans. Domestic pig and wild boar represent the most important reservoirs for these genotypes. A distinct subtype of genotype 3 has been repeatedly detected in rabbits and a few human patients. Recently, HEV genotype 7 has been identified in dromedary camels and in an immunocompromised transplant patient. The reservoir animals get infected with HEV without showing any clinical symptoms. Besides these well‐known animal reservoirs, HEV‐specific antibodies and/or the genome of HEV or HEV‐related viruses have also been detected in many other animal species, including primates, other mammals and birds. In particular, genotypes 3 and 4 infections are documented in many domestic, wildlife and zoo animal species. In most cases, the presence of HEV in these animals can be explained by spillover infections, but a risk of virus transmission through contact with humans cannot be excluded. This review gives a general overview on the transmission pathways of HEV to humans. It particularly focuses on reported serological and molecular evidence of infections in wild, domestic and zoo animals with HEV or HEV‐related viruses. The role of these animals for transmission of HEV to humans and other animals is discussed.  相似文献   

18.
The purpose of this study was to provide a detailed computed tomographic (CT) anatomic reference for the dromedary camel tarsus. Six cadaver pelvic limbs, obtained from three clinically and radiographically sound dromedary camels, were scanned in both soft tissue and bone windows starting from the calcaneal tuber towards the proximal metatarsus. Limbs were frozen at ?20°C and sectioned transversely via an electric bone saw. The CT images were evaluated and correlated with their corresponding cryosections. The resulting images provided detailed anatomic features for bones, joints and soft tissue components of the tarsus and are intended to serve as a basic reference for the CT scanning of the dromedary camel tarsal pathology.  相似文献   

19.
Chlamydiosis is caused by an obligate intracellular gram-negative bacterium of the genus Chlamydophila which is a zoonotic pathogen. The objectives of the study were to identify the seroprevalence of antibodies against Chlamydophila abortus in dromedary camel herds from four districts in eastern Algeria, as well as to estimate the association between seroprevalence and certain factors present at the animal and herd levels. Blood samples were collected from a random sample of animals within each of 82 camel herds. Serum samples were subjected to a C. abortus ELISA test, and association between the presence of antibodies and potential risk factors was estimated. Animal and herd seroprevalence were 2.5 % and 15.8 %, respectively, indicating substantial exposure of camels to C. abortus in the four districts studied. Age, breed, and sex did not influence seroprevalence in tested animals. Based on the univariate analysis, contact with sheep and goats, contact with other camel herds, and histories of abortion were major risk factors for infection. By using multivariate analysis, contact of camels with sheep and goats and with others camel herds, through shared grazing or watering points, were important factors for transmission of chlamydiosis with an odds ratio of 3.3 and 9.4, respectively. At the herd level the introduction of purchased animals was the major risk factor. This baseline information will be highly useful for launching C. abortus control programs in the region and potentially elsewhere.  相似文献   

20.
Male camel infertility is a heterogeneous disorder. A variety of factors may adversely affect sperm production and function and impair fertility. This study was designed to evaluate the sensitivity and specificity of ultrasonography and testicular biopsy in the evaluation of the breeding soundness of male dromedaries compared with results obtained by clinical examination and semen analysis. Eighty‐four male dromedary camels (5–15 years old) were used in this study during the rutting season (November–May). Four sexually mature male camels were used as controls. These animals were apparently healthy and had histories of normal fertility. Eighty infertile male camels were subjected to an algorithmic approach based on information collected during careful examinations of the camels' breeding histories, clinical examinations, testicular evaluations, testicular ultrasonographies, the results of the semen analyses and testicular biopsies to diagnose the camels' infertilities. The differences in the semen parameters between the control and infertile male camels were highly significant (p < 0.01). Regarding the diagnoses of male camel infertility, the results of testicular ultrasonographies and biopsies were compared with those from the semen analyses, and the accuracies of these tests were 92.5% and 90%, respectively. Additionally, the results of the testicular ultrasonographies were matched with those of the testicular biopsies of the infertile animals, and this comparison resulted in 85% accuracy. Testicular biopsy is a promising method that, along with a carefully performed history, clinical examination, an appropriate testicular ultrasonography procedure and semen analysis, can afford veterinarians the opportunity for more precise diagnosis and treatment of many dromedary infertility disorders.  相似文献   

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