Coronavirus-like particles in adults in Melbourne, Australia

Features of enteric disease from human coronaviruses: Implications for COVID-19

Coronaviruses have long been studied in both human and veterinary fields. Whereas the initial detection of endemic human respiratory coronaviruses was problematic, detection of these and newly discovered human coronaviruses has been greatly facilitated with major advances in the laboratory. Nevertheless, technological factors can affect the accuracy and timeliness of virus detection. Many human coronaviruses can be variably found in stool samples. All human coronaviruses have been variably associated with symptoms of gastroenteritis. Coronaviruses can occasionally be cultured from enteric specimens, but most detection is accomplished with genetic amplification technologies. Excretion of viral RNA in stool can extend for a prolonged period. Culture‐positive stool samples have been found to exceed a fourteen day period after onset of infection for some coronaviruses. Virus can also sometimes be cultured from patients' respiratory samples during the late incubation period. Relatively asymptomatic patients may excrete virus. Both viable and nonviable virus can be found in the immediate environment of the patient, the health care worker, and less often the public. These lessons from the past study of animal and human coronaviruses can be extended to presumptions for severe acute respiratory syndrome coronavirus 2. Already, the early reports from the coronavirus disease‐2019 pandemic are confirming some concerns. These data have the cumulative potential to cause us to rethink some current and common public health and infection control strategies.

coronaviruses are variably found in human enteric samples during the course of infection.

abdominal and intestinal illnesses are associated with coronavirus infections.

enteric excretion of live virus and viral RNA have been confirmed.

occasionally, live virus can be found in stool samples to exceed a fourteen day period after disease onset, and virus can also be cultured from these samples during the late incubation period or from asymptomatic individuals.

Foodborne viral illness--status in Australia

Norwalk-like virus contamination of oysters and orange juice, and hepatitis A virus contamination of oysters have been responsible for large outbreaks of foodborne viral disease in Australia. Rotavirus, adenovirus, astrovirus, parvovirus and other enteroviruses also contribute to the incidence of gastroenteritis in this country but the role of foods and waters in transmitting these viruses is unclear. Protocols for the investigation, surveillance and reporting of foodborne viral illness require further development to enable a more accurate description of the problem. Few laboratories have the capability to analyse foods for viruses and specific training in this technology is needed. Management of food safety in Australia largely relies on the implementation of HACCP principles, but these need to be adapted to address the specific risks from viruses.

Biological and genetic characterization of a hemagglutinating coronavirus isolated from a diarrhoeic child

The coronavirus strain HECV-4408 was isolated from diarrhea fluid of a 6-year-old child with acute diarrhea and propagated in human rectal tumor (HRT-18) cells. Electron microscopy revealed coronavirus particles in the diarrhea fluid sample and the infected HRT-18 cell cultures. This virus possessed hemagglutinating and acetylesterase activities and caused cytopathic effects in HRT-18 cells but not in MDBK, GBK and FE cells. One of four S-specific monoclonal antibodies reacted in Western blots with HECV-4408, BCV-L9 and BCV-LY138 but not with HCV-OC43, and two reacted with BCV-L9 but not with HECV-4408, BCV-LY138 and HCV-OC43. One S-specific and two N-specific monoclonal antibodies reacted with all of these strains. cDNA encompassing the 3' 8.5 kb of the viral RNA genome was isolated by reverse transcription followed by polymerase chain reaction amplification had size and restriction endonuclease patterns similar to those of BCV-L9 and BCV-LY138. In contrast, the M gene of HCV-OC43 differed in restriction patterns from HECV-4408 and BCV. A genomic deletion located between the S and M within the non-structural genes of HCV-OC43 was not detected in HECV-4408. DNA sequence analyses of the S and HE genes revealed more than 99% nucleotide and deduced amino acid homologies between HECV-4408 and the virulent wild-type BCV. Forty-nine nucleotide and 22 amino acid differences were found between the HE genes of HECV-4408 and HCV-OC43, while only 16 nucleotide and 3 amino acid differences occurred between the HE genes of HECV-4408 and BCV-LY138. We thus conclude that the strain HECV-4408 is a hemagglutinating enteric coronavirus that is biologically, antigenically and genomically more closely related to the virulent BCV-LY138 than to HCV-OC43.