Identification of a novel coronavirus in patients with severe acute respiratory syndrome. (1/1050)

BACKGROUND: The severe acute respiratory syndrome (SARS) has recently been identified as a new clinical entity. SARS is thought to be caused by an unknown infectious agent. METHODS: Clinical specimens from patients with SARS were searched for unknown viruses with the use of cell cultures and molecular techniques. RESULTS: A novel coronavirus was identified in patients with SARS. The virus was isolated in cell culture, and a sequence 300 nucleotides in length was obtained by a polymerase-chain-reaction (PCR)-based random-amplification procedure. Genetic characterization indicated that the virus is only distantly related to known coronaviruses (identical in 50 to 60 percent of the nucleotide sequence). On the basis of the obtained sequence, conventional and real-time PCR assays for specific and sensitive detection of the novel virus were established. Virus was detected in a variety of clinical specimens from patients with SARS but not in controls. High concentrations of viral RNA of up to 100 million molecules per milliliter were found in sputum. Viral RNA was also detected at extremely low concentrations in plasma during the acute phase and in feces during the late convalescent phase. Infected patients showed seroconversion on the Vero cells in which the virus was isolated. CONCLUSIONS: The novel coronavirus might have a role in causing SARS.  (+info)

A novel coronavirus associated with severe acute respiratory syndrome. (2/1050)

BACKGROUND: A worldwide outbreak of severe acute respiratory syndrome (SARS) has been associated with exposures originating from a single ill health care worker from Guangdong Province, China. We conducted studies to identify the etiologic agent of this outbreak. METHODS: We received clinical specimens from patients in seven countries and tested them, using virus-isolation techniques, electron-microscopical and histologic studies, and molecular and serologic assays, in an attempt to identify a wide range of potential pathogens. RESULTS: None of the previously described respiratory pathogens were consistently identified. However, a novel coronavirus was isolated from patients who met the case definition of SARS. Cytopathological features were noted in Vero E6 cells inoculated with a throat-swab specimen. Electron-microscopical examination revealed ultrastructural features characteristic of coronaviruses. Immunohistochemical and immunofluorescence staining revealed reactivity with group I coronavirus polyclonal antibodies. Consensus coronavirus primers designed to amplify a fragment of the polymerase gene by reverse transcription-polymerase chain reaction (RT-PCR) were used to obtain a sequence that clearly identified the isolate as a unique coronavirus only distantly related to previously sequenced coronaviruses. With specific diagnostic RT-PCR primers we identified several identical nucleotide sequences in 12 patients from several locations, a finding consistent with a point-source outbreak. Indirect fluorescence antibody tests and enzyme-linked immunosorbent assays made with the new isolate have been used to demonstrate a virus-specific serologic response. This virus may never before have circulated in the U.S. population. CONCLUSIONS: A novel coronavirus is associated with this outbreak, and the evidence indicates that this virus has an etiologic role in SARS. Because of the death of Dr. Carlo Urbani, we propose that our first isolate be named the Urbani strain of SARS-associated coronavirus.  (+info)

Epidemiology, clinical presentation and laboratory investigation of severe acute respiratory syndrome (SARS) in Canada, March 2003. (3/1050)

As of 23 March, 2003, 11 cases of SARS have been reported in Canada. Three patients had travelled to China, including Hong Kong SAR. The remaining eight had a history of close contact with cases. There have been three deaths. To date, evidence for human metapneumovirus has been found in six cases; further studies are ongoing to determine whether this virus is the causative agent of the SARS or whether other, so far undetected, pathogens are responsible. Public health measures are being implemented at the local, provincial, and national levels to identify new cases and prevent secondary transmission of SARS.  (+info)

Update: outbreak of severe acute respiratory syndrome--worldwide, 2003. (4/1050)

CDC and the World Health Qrganization (WHO) are continuing to investigate the multicountry outbreak of unexplained atypical pneumonia referred to as severe acute respiratory syndrome (SARS). Pending development of confirmatory laboratory testing capacity, CDC's interim suspected SARS case definition is based on clinical criteria and epidemiologic linkage to other SARS cases or areas with community transmission of SARS. This case definition will be updated periodically as new information becomes available. Epidemiologic and laboratory investigations of SARS are ongoing. As of April 2, 2003, a total of 2,223 suspected and/or probable SARS cases have been reported to WHO from 16 countries, including the United States. The reported SARS cases include 78 deaths (case-fatality proportion: 3.5%). This report summarizes SARS cases among U.S. residents and surveillance and prevention activities in the United States.  (+info)

Characterization of a novel coronavirus associated with severe acute respiratory syndrome. (5/1050)

In March 2003, a novel coronavirus (SARS-CoV) was discovered in association with cases of severe acute respiratory syndrome (SARS). The sequence of the complete genome of SARS-CoV was determined, and the initial characterization of the viral genome is presented in this report. The genome of SARS-CoV is 29,727 nucleotides in length and has 11 open reading frames, and its genome organization is similar to that of other coronaviruses. Phylogenetic analyses and sequence comparisons showed that SARS-CoV is not closely related to any of the previously characterized coronaviruses.  (+info)

The Genome sequence of the SARS-associated coronavirus. (6/1050)

We sequenced the 29,751-base genome of the severe acute respiratory syndrome (SARS)-associated coronavirus known as the Tor2 isolate. The genome sequence reveals that this coronavirus is only moderately related to other known coronaviruses, including two human coronaviruses, HCoV-OC43 and HCoV-229E. Phylogenetic analysis of the predicted viral proteins indicates that the virus does not closely resemble any of the three previously known groups of coronaviruses. The genome sequence will aid in the diagnosis of SARS virus infection in humans and potential animal hosts (using polymerase chain reaction and immunological tests), in the development of antivirals (including neutralizing antibodies), and in the identification of putative epitopes for vaccine development.  (+info)

Severe acute respiratory syndrome (SARS) and coronavirus testing--United States, 2003. (7/1050)

CDC and the World Health Organization (WHO) are continuing to investigate the multicountry outbreak of severe acute respiratory syndrome (SARS). Infection with a novel coronavirus has been implicated as a possible cause of SARS. This report updates information on U.S. residents with SARS and summarizes the clinical histories of the five U.S. residents identified as of April 9, 2003, who have both suspected SARS and laboratory evidence of infection with a novel coronavirus.  (+info)

Update: Severe acute respiratory syndrome--United States, 2003. (8/1050)

CDC and the World Health Organization (WHO) are continuing to investigate the multicountry outbreak of severe acute respiratory syndrome (SARS). This report updates information on reported SARS cases among U.S. residents and summarizes information on patients with no recent travel outside the United States.  (+info)