Prevalence of Middle East Respiratory Syndrome Coronavirus in Dromedary Camels, Tunisia.
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ABSTRACT:
SUBMITTER: Eckstein S
PROVIDER: S-EPMC8237907 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar linked to two human cases of the infection in October, 2013. METHODS:We took nose swabs, rectal swabs, and blood samples from all camels on the Qatari farm. We tested swabs with RT-PCR, with amplification targeting the E gene (upE), nucleocapsid (N) gene, and open reading frame (ORF) 1a. PCR positive samples were tested by different MERS-CoV specific PCRs and obtained sequences were used for phylogentic analysis together with sequences from the linked human cases and other human cases. We tested serum samples from the camels for IgG immunofluorescence assay, protein microarray, and virus neutralisation assay. FINDINGS:We obtained samples from 14 camels on Oct 17, 2013. We detected MERS-CoV in nose swabs from three camels by three independent RT-PCRs and sequencing. The nucleotide sequence of an ORF1a fragment (940 nucleotides) and a 4·2 kb concatenated fragment were very similar to the MERS-CoV from two human cases on the same farm and a MERS-CoV isolate from Hafr-Al-Batin. Eight additional camel nose swabs were positive on one or more RT-PCRs, but could not be confirmed by sequencing. All camels had MERS-CoV spike-binding antibodies that correlated well with the presence of neutralising antibodies to MERS-CoV. INTERPRETATION:Our study provides virological confirmation of MERS-CoV in camels and suggests a recent outbreak affecting both human beings and camels. We cannot conclude whether the people on the farm were infected by the camels or vice versa, or if a third source was responsible. FUNDING:European Union projects EMPERIE (contract number 223498), ANTIGONE (contract number 278976), and the VIRGO consortium.
| S-EPMC7106553 | biostudies-literature
Project description:Dromedary camels are bred domestically and imported into Bangladesh. In 2015, of 55 camels tested for Middle East respiratory syndrome coronavirus in Dhaka, 17 (31%) were seropositive, including 1 bred locally. None were PCR positive. The potential for infected camels in urban markets could have public health implications and warrants further investigation.
| S-EPMC5938793 | biostudies-literature
Project description:The Middle East respiratory syndrome (MERS) is proposed to be a zoonotic disease; however, the reservoir and mechanism for transmission of the causative agent, the MERS coronavirus, are unknown. Dromedary camels have been implicated through reports that some victims have been exposed to camels, camels in areas where the disease has emerged have antibodies to the virus, and viral sequences have been recovered from camels in association with outbreaks of the disease among humans. Nonetheless, whether camels mediate transmission to humans is unresolved. Here we provide evidence from a geographic and temporal survey of camels in the Kingdom of Saudi Arabia that MERS coronaviruses have been circulating in camels since at least 1992, are distributed countrywide, and can be phylogenetically classified into clades that correlate with outbreaks of the disease among humans. We found no evidence of infection in domestic sheep or domestic goats. IMPORTANCE This study was undertaken to determine the historical and current prevalence of Middle East respiratory syndrome (MERS) coronavirus infection in dromedary camels and other livestock in the Kingdom of Saudi Arabia, where the index case and the majority of cases of MERS have been reported.
| S-EPMC3940034 | biostudies-literature
Project description:Prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) was determined in 45 dromedary camels from two geographically separated herds in Jordan. Virus shedding was only detected in swabs obtained from the respiratory tract and primarily observed in camels younger than 3 years. MERS-CoV seroprevalence increased with age of camels. Bovine and sheep sera were seronegative. Phylogenetic analysis of partial S2 clustered the Jordanian MERS-CoV strains with contemporary MERS-CoV strains associated with nosocomial outbreaks.
| S-EPMC5278817 | biostudies-literature
Project description:High seroprevalence of Middle East respiratory syndrome corona virus (MERS-CoV) in dromedary camels has been previously reported in United Arab Emirates (UAE). However, the molecular detection of the virus has never been reported before in UAE. Of the 7,803 nasal swabs tested in the epidemiological survey, MERS-CoV nucleic acid was detected by real-time PCR in a total of 126 (1.6 %) camels. Positive camels were detected at the borders with Saudi Arabia and Oman and in camels' slaughter houses. MERS-CoV partial sequences obtained from UAE camels were clustering with human- and camel-derived MERS-CoV sequences in the same geographic area. Results provide further evidence of MERS-CoV zoonosis.
| S-EPMC7088545 | biostudies-literature
Project description:MERS-CoV is present in dromedary camels throughout the Middle East and Africa. Dromedary camels are the primary zoonotic reservoir for human infections. Interruption of the zoonotic transmission chain from camels to humans, therefore, may be an effective strategy to control the ongoing MERS-CoV outbreak. Here we show that vaccination with an adjuvanted MERS-CoV Spike protein subunit vaccine confers complete protection from MERS-CoV disease in alpaca and results in reduced and delayed viral shedding in the upper airways of dromedary camels. Protection in alpaca correlates with high serum neutralizing antibody titers. Lower titers of serum neutralizing antibodies correlate with delayed and significantly reduced shedding in the nasal turbinates of dromedary camels. Together, these data indicate that induction of robust neutralizing humoral immune responses by vaccination of naïve animals reduces shedding that potentially could diminish the risk of zoonotic transmission.
| S-EPMC6466352 | biostudies-literature
Project description:Middle East respiratory syndrome-related coronavirus (MERS-CoV) is a persistent zoonotic pathogen with frequent spillover from dromedary camels to humans in the Arabian Peninsula, resulting in limited outbreaks of MERS with a high case-fatality rate. Full genome sequence data from camel-derived MERS-CoV variants show diverse lineages circulating in domestic camels with frequent recombination. More than 90% of the available full MERS-CoV genome sequences derived from camels are from just two countries, the Kingdom of Saudi Arabia (KSA) and United Arab Emirates (UAE). In this study, we employ a novel method to amplify and sequence the partial MERS-CoV genome with high sensitivity from nasal swabs of infected camels. We recovered more than 99% of the MERS-CoV genome from field-collected samples with greater than 500 TCID50 equivalent per nasal swab from camel herds sampled in Jordan in May 2016. Our subsequent analyses of 14 camel-derived MERS-CoV genomes show a striking lack of genetic diversity circulating in Jordan camels relative to MERS-CoV genome sequences derived from large camel markets in KSA and UAE. The low genetic diversity detected in Jordan camels during our study is consistent with a lack of endemic circulation in these camel herds and reflective of data from MERS outbreaks in humans dominated by nosocomial transmission following a single introduction as reported during the 2015 MERS outbreak in South Korea. Our data suggest transmission of MERS-CoV among two camel herds in Jordan in 2016 following a single introduction event.
| S-EPMC8067259 | biostudies-literature
Project description:Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging zoonotic disease. Exposure to dromedary camels (Camelus dromedaries) has been consistently considered the main source of primary human infection. Although Saudi Arabia reports the highest rate of human MERS-CoV infection and has one of the largest populations of dromedary camels worldwide, their spatial association has not yet been investigated. Thus, this study aimed to examine the correlation between the spatial distribution of primary MERS-CoV cases with or without a history of camel exposure reported between 2012 and 2019 and dromedary camels at the provincial level in Saudi Arabia. In most provinces, a high proportion of older men develop infections after exposure to camels. Primary human infections during spring and winter were highest in provinces characterized by seasonal breeding and calving, increased camel mobilization and camel-human interactions. A strong and significant association was found between the total number of dromedary camels and the numbers of primary camel-exposed and non-exposed MERS-CoV cases. Furthermore, spatial correlations between MERS-CoV cases and camel sex, age and dairy status were significant. Via a cluster analysis, we identified Riyadh, Makkah and Eastern provinces as having the most primary MERS-CoV cases and the highest number of camels. Transmission of MERS-CoV from camels to humans occurs in most primary cases, but there is still a high proportion of primary infections with an ambiguous link to camels. The results from this study include significant correlations between primary MERS-CoV cases and camel populations in all provinces, regardless of camel exposure history. This supports the hypothesis of the role of an asymptomatic human carrier or, less likely, an unknown animal host that has direct contact with both infected camels and humans. In this study, we performed a preliminary risk assessment of prioritization measures to control the transmission of infection from camels to humans.
| S-EPMC7228245 | biostudies-literature
Project description:Middle East respiratory syndrome coronavirus (MERS-CoV) is caused by a novel betacoronavirus that was isolated in late 2012 in Saudi Arabia. The viral infections have been reported in more than 1700 humans, ranging from asymptomatic or mild cases to severe pneumonia with a mortality rate of 40%. It is well documented now that dromedary camels contract the infection and shed the virus without notable symptoms, and such animals had been infected by at least the early 1980s. The mechanism of camel to human transmission is still not clear, but several primary cases have been associated with camel contact. There is no approved antiviral drug or vaccine against MERS-CoV despite the active research in this area. Vaccine candidates have been developed using various platforms and regimens and have been tested in several animal models. Here, this article reviews the published studies on MERS-CoV vaccines with more focus on vaccines tested in large animals, including camels. It is foreseeable that the 1-health approach could be the best way of tackling the MERS-CoV endemic in the Arabian Peninsula, by using the mass vaccination of camels in the affected areas to block camel to human transmission. Camel vaccines can be developed in a faster time with fewer regulations and lower costs and could clear this virus from the Arabian Peninsula if accompanied by efficient public health measures.
| S-EPMC7169231 | biostudies-literature
Project description:BackgroundThe Middle East respiratory syndrome coronavirus (MERS-CoV) is a lethal zoonotic pathogen endemic to the Arabian Peninsula. Dromedary camels are a likely source of infection and the virus probably originated in Africa. We studied the genetic diversity, geographical structure, infection prevalence, and age-associated prevalence among camels at the largest entry port of camels from Africa into the Arabian Peninsula.MethodsIn this prospective genomic study, we took nasal samples from camels imported from Sudan and Djibouti into the Port of Jeddah in Jeddah, Saudi Arabia, over an almost 2-year period and local Arabian camels over 2 months in the year after surveillance of the port. We determined the prevalence of MERS-CoV infection, age-associated patterns of infection, and undertook phylogeographical and migration analyses to determine intercountry virus transmission after local lineage establishment. We compared all virological characteristics between the local and imported cohorts. We compared major gene deletions between African and Arabian strains of the virus. Reproductive numbers were inferred with Bayesian birth death skyline analyses.FindingsBetween Aug 10, 2016, and May 3, 2018, we collected samples from 1196 imported camels, of which 868 originated from Sudan and 328 from Djibouti, and between May 1, and June 25, 2018, we collected samples from 472 local camels, of which 189 were from Riyadh and 283 were from Jeddah, Saudi Arabia. Virus prevalence was higher in local camels than in imported camels (224 [47·5%] of 472 vs 157 [13·1%] of 1196; p<0·0001). Infection prevalence peaked among camels older than 1 year and aged up to 2 years in both groups, with 255 (66·9%) of 381 positive cases in this age group. Although the overall geographical distribution of the virus corresponded with the phylogenetic tree topology, some virus exchange was observed between countries corresponding with trade routes in the region. East and west African strains of the virus appear to be geographically separated, with an origin of west African strains in east Africa. African strains of the virus were not re-sampled in Saudi Arabia despite sampling approximately 1 year after importation from Africa. All local Arabian samples contained strains of the virus that belong to a novel recombinant clade (NRC) first detected in 2014 in Saudi Arabia. Reproduction number estimates informed by the sequences suggest sustained endemicity of NRC, with a mean Re of 1·16.InterpretationDespite frequent imports of MERS-CoV with camels from Africa, African lineages of MERS-CoV do not establish themselves in Saudi Arabia. Arabian strains of the virus should be tested for changes in virulence and transmissibility.FundingGerman Ministry of Research and Education, EU Horizon 2020, and Emerging Diseases Clinical Trials Partnership.
| S-EPMC6926486 | biostudies-literature