Project description:Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging highly pathogenic respiratory virus. Although MERS-CoV only emerged in 2012, we and others have developed assays to grow and quantify infectious MERS-CoV and RNA products of replication in vitro. MERS-CoV is able to infect a range of cell types, but replicates to high titers in Vero E6 cells. Protocols for the propagation and quantification of MERS-CoV are presented.
Project description:With more than 1,700 laboratory-confirmed infections, Middle East respiratory syndrome coronavirus (MERS-CoV) remains a significant threat for public health. However, the lack of detailed data on modes of transmission from the animal reservoir and between humans means that the drivers of MERS-CoV epidemics remain poorly characterized. Here, we develop a statistical framework to provide a comprehensive analysis of the transmission patterns underlying the 681 MERS-CoV cases detected in the Kingdom of Saudi Arabia (KSA) between January 2013 and July 2014. We assess how infections from the animal reservoir, the different levels of mixing, and heterogeneities in transmission have contributed to the buildup of MERS-CoV epidemics in KSA. We estimate that 12% [95% credible interval (CI): 9%, 15%] of cases were infected from the reservoir, the rest via human-to-human transmission in clusters (60%; CI: 57%, 63%), within (23%; CI: 20%, 27%), or between (5%; CI: 2%, 8%) regions. The reproduction number at the start of a cluster was 0.45 (CI: 0.33, 0.58) on average, but with large SD (0.53; CI: 0.35, 0.78). It was >1 in 12% (CI: 6%, 18%) of clusters but fell by approximately one-half (47% CI: 34%, 63%) its original value after 10 cases on average. The ongoing exposure of humans to MERS-CoV from the reservoir is of major concern, given the continued risk of substantial outbreaks in health care systems. The approach we present allows the study of infectious disease transmission when data linking cases to each other remain limited and uncertain.
Project description:With >1600 documented human infections with Middle East respiratory syndrome coronavirus (MERS-CoV) and a case fatality rate of approximately 36%, medical countermeasures are needed to prevent and limit the disease. We examined the in vivo efficacy of the human monoclonal antibody m336, which has high neutralizing activity against MERS-CoV in vitro. m336 was administered to rabbits intravenously or intranasally before infection with MERS-CoV. Prophylaxis with m336 resulted in a reduction of pulmonary viral RNA titers by 40-9000-fold, compared with an irrelevant control antibody with little to no inflammation or viral antigen detected. This protection in rabbits supports further clinical development of m336.
Project description:BACKGROUND:The Kingdom of Saudi Arabia (KSA) reported 170,639 cases and 1430 deaths from COVID-19 since the first case emerged in the country on March 2 through June 25, 2020. The objective of this report is to describe the characteristics and outcome observed among 99 hospitalized COVID-19 patients in the largest academic hospital in KSA, and assess co-infection with the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). METHODS:This single-center case series data included select epidemiological, clinical, radiological features and laboratory findings of all confirmed hospitalized cases of COVID-19 in King Saud University Medical City (KSUMC), Riyadh, KSA, from March 22 until May 31, 2020, followed through June 6, 2020. We conducted retrospective analysis of listed data from 99 hospitalized patients and present characteristics and factors associated with severity in percentages and univariate odds ratios. Cases were confirmed using nasopharyngeal or throat swab by real-time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and MERS-CoV by RT-PCR. RESULTS:The 99 hospitalized COVID-19 patients included in this analysis constitute 16% of 632 positive SARS-CoV-2 among 6633 persons who were tested at the KSUMC (positivity rate, 9.4%). MERS-CoV PCR was negative in all 99 patients tested. The majority of these 99 hospitalized patients were males (66%), had a mean age of 44 years (range, 19-87), and a quarter (25.3%) were health care workers. Patients with comorbid conditions accounted for 52.5% of patients including the 8.1% who were asymptomatic; diabetes mellitus being the most frequent (31.3%), followed by hypertension (22.2%). The most common presenting symptoms were fever (67.7%), cough (60.6%), dyspnea (43.4%), upper respiratory symptoms (27.3%), fatigue (26.3%), diarrhea (19.2%) and loss of smell (9.1%). The clinical conditions among these 99 patients included upper respiratory tract infection (47.5%), abnormal chest X-ray, lymphopenia, high inflammatory markers a fifth (21%) of patients had moderate pneumonia, while 7% had severe pneumonia with 22.2% requiring admission to the intensive care unit and 12.1% died. Late presentation with severe disease, an abnormal chest X-ray, lymphopenia, high inflammatory markers (C-reactive protein, ferritin, and procalcitonin), and end organ damage (high creatinine or high aspartate aminotransferase) were predictors for admission to critical care unit or died. CONCLUSION:We observed no MERS-CoV co-infection in this early cohort of hospitalized COVID-19 patients who were relatively young, more than half had comorbid conditions, presented with fever and/or cough, an abnormal chest X-ray, lymphopenia, and high inflammatory markers. Given MERS-CoV endemicity in the country, co-monitoring of MERS-CoV and SARS-CoV-2 coinfection is critical.
Project description:We analyzed data for 170 patients in South Korea who had laboratory-confirmed infection with Middle East respiratory syndrome coronavirus. A longer incubation period was associated with a reduction in the risk for death (adjusted odds ratio/1-day increase in incubation period 0.83, 95% credibility interval 0.68-1.03).
Project description:To evaluate host susceptibility factors to Middle East respiratory syndrome coronavirus (MERS-CoV) infection, we conducted a retrospective cohort study from the single largest exposure event of the 2015 Korean MERS outbreak. A total of 175 patients were closely exposed to a super-spreader, 26 of which were infected (14.9%). In a multivariate analysis, history of autologous stem cell transplantation (HR, 31.151; 95% CI, 5.447-178.145; P < 0.001) and tachypnea at ED (HR, 4.392; 95% CI, 1.402-13.761; P = 0.011) were significantly associated with MERS-CoV infection.
Project description:Middle East respiratory syndrome (MERS) coronavirus (Co-V) contains a single spike (S) protein, which binds to a receptor molecule, dipeptidyl peptidase 4 (DPP4; also known as CD26), and serves as a neutralizing antigen. Pseudotyped viruses are useful for measuring neutralization titers against highly infectious viruses as well as for studying their mechanism of entry. In this study, we constructed a series of cytoplasmic deletion mutants of MERS-CoV S and compared the efficiency with which they formed pseudotypes with vesicular stomatitis virus. A pseudotype bearing an S protein with the C-terminal 16 amino acids deleted (MERSpv-St16) reached a maximum titer that was approximately tenfold higher than that of a pseudotype bearing a non-truncated full-length S protein. Using MERSpv-St16, we demonstrated the inability of rat DPP4 to serve as a functional receptor for MERS-CoV, suggesting that rats are not susceptible to MERS-CoV infection. This study provides novel information that enhances our understanding of the host range of MERS-CoV.
Project description:Dromedary camels are important reservoir hosts of various coronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV) that cause human infections. CoV genomes regularly undergo recombination during infection as observed in bat SARS-related CoVs. Here we report for the first time that only a small proportion of MERS-CoV receptor-binding domain positive (RBD) of spike protein positive camel sera in Kenya were also seropositive to MERS-CoV nucleocapsid (NP). In contrast, many of them contain antibodies against bat HKU8-related (HKU8r)-CoVs. Among 584 camel samples that were positive against MERS-CoV RBD, we found only 0.48 (8.22%) samples were also positive for NP. Furthermore, we found bat HKU8r-CoV NP antibody in 73 (12.5%) of the MERS-CoV RBD positive and NP negative samples, yet found only 3 (0.43%) of the HKU8r-CoV S1 antibody in the same samples. These findings may indicate co-infection with MERS-CoV and a HKU8r-CoV in camels. It may also raise the possibility of the circulation of a recombinant coronavirus virus with the spike of MERS-CoV and the NP of a HKU8r-CoV in Kenya. We failed to find molecular evidence of an HKU8r-CoV or a putative recombinant virus. Our findings should alert other investigators to look for molecular evidence of HKU8r-CoV or recombinants.