WASHINGTON — Two types of newly recognized coronavirus were identified in stool samples of patients with gastrointestinal disease, and more than half of those patients also had respiratory symptoms, based on data from more than 400 adults and children.
A total of nine stool samples that tested negative for Clostridium difficile instead tested positive for one of two strains of human coronavirus, HCoV-NL63 and HCoV-HKU1, said Dr. Frank Esper, a pediatrician and infectious disease specialist at the Rainbow Babies and Children's Hospital in Cleveland.
Dr. Esper presented the findings at the jointly held annual Interscience Conference on Antimicrobial Agents and Chemotherapy and the annual meeting of the Infectious Diseases Society of America.
These two coronaviruses have been associated with upper and lower respiratory tract disease in previous studies, he said.
During the severe acute respiratory syndrome (SARS) outbreak in 2002–2003, enteric involvement was reported in more than 70% of patients during their illnesses, and coronavirus RNA was found in stool samples from SARS patients, Dr. Esper noted.
In the current study, Dr. Esper and his colleagues examined the association of coronaviruses with gastrointestinal illness in children and adults.
The researchers collected stool samples at a single hospital between Dec. 1, 2007, and March 31, 2008. They examined samples from 328 adults (average age 62 years) and 151 children younger than 18 years (average age 4 years). They extracted nucleic acid from each stool sample and screened for coronavirus using a polymerase chain reaction test.
Nine samples (2.7%) screened positive for coronaviruses, including four samples from adults and five from children. Overall, 78% of the positive samples were HKU1 and 22% were NL63. None of the stool samples screened positive for norovirus or rotavirus, but two samples with coronavirus were also positive for enteric adenovirus, Dr. Esper said.
All of the samples that tested positive for NL63 came from adults, but the majority (five of seven samples) that tested positive for HKU1 came from children.
Clinical gastrointestinal characteristics in patients with coronavirus-positive stool included gastrointestinal illness, diarrhea, and abdominal pain. “Over 50% of the patients with coronavirus also had respiratory tract findings,” Dr. Esper noted. Respiratory symptoms included difficulty breathing, coughing, and rhinorrhea.
More research is needed, but the current study is an important step toward understanding a link between respiratory disease and gastrointestinal disease in coronavirus infections, he said.
Dr. Esper stated that he had no financial conflicts to disclose.