A novel coronavirus has been identified in a 60-year-old man with acute pneumonia who died of progressive respiratory and renal failure 11 days after hospital admission, according to a report in the New England Journal of Medicine that was published online on Oct. 17.
The virus, known as HCoV-EMC, is a previously unknown betacoronavirus species. The closest known relatives are two bat coronaviruses: HKU4 and HKU5.
Courtesy NEJMChest radiographs of the patient.
"The clinical picture was remarkably similar to that of the severe acute respiratory distress syndrome [(SARS)] outbreak in 2003 and reminds us that animal coronaviruses can cause severe disease in humans," said lead author Dr. Ali Moh Zaki of the Dr. Soliman Fakeeh Hospital in Jeddah, Saudi Arabia, and his colleagues.
The patient was a 60-year-old Saudi man who first presented with a 7-day history of fever, cough, expectoration, and shortness of breath, the researchers said (N. Engl. J. Med. 2012 [doi:10.1056/NEJMoa211721]). He had no history of heart or kidney disease, did not smoke, and took no medications chronically.
The researchers tested a sputum sample when the patient was admitted to the hospital, and the results suggested that the virus was replicating. Tests of infected cell cultures with indirect immunofluorescence assays were negative for likely viruses including influenza A and B, respiratory syncytial virus, adenovirus, and parainfluenza viruses types 1 to 3. But serum samples collected at 10 and 11 days after the patient was hospitalized "reacted strongly when dilutions of 1:20 were tested on immunofluorescence assay specific for IgG antibodies," the researchers noted. By contrast, 2,400 control samples from other patients at the same hospital between 2010 and 2012 were negative, suggesting that the patient had developed antibodies to a previously unknown virus.
Genetic sequencing of the new virus linked it to a Betacoronavirus genus and set it apart from known human coronaviruses, which belong to the Alphacoronavirus genus, the researchers explained.
At the time of hospital admission, the patient’s body mass index was 35 kg/m2, his blood pressure was 140/80 mm Hg, his pulse was 117 beats per minute, and his temperature was 38.3 C. The patient was initially treated with oseltamivir, levofloxacin, piperacillin-tazobactam, and micafungin; meropenem was started on day 4.
"No symptoms were observed in the hospital among doctors and nurses caring for the patient, which suggests that the disease did not spread readily," the researchers said. However, the more thorough epidemiologic investigations can be conducted with the completion of the genomic sequencing of HCoV-EMC and the development of virus-specific rapid diagnostic tests, they added.
The Center for Infectious Disease Research and Policy at the University of Minnesota (CIDRAP) reported on the gene sequencing and testing methods used to identify the virus, and on the status of a second infected patient – a 49-year-old man from Qatar – who presented with similar symptoms and was last reported to be in stable condition.
"Although HCoV-EMC does not have many of the worrisome characteristics of SARS-CoV, we should take notice of the valuable lessons learned during the 2003 SARS outbreak with respect to outbreak investigations and management," the researchers said.
The study was supported in part by the European Commission Seventh Framework Program for Research and Technology Development Project EMPERIE.
Lead author Dr. Zaki had no financial conflicts to disclose. Several of the study coauthors have financial interest in Viroclinics Biosciences B.V. through a holding company administered by Erasmus Medical Center in Rotterdam, the Netherlands. Viroclinics and Erasmus Medical Center have jointly filed a patent on the new virus genome.