Australian Rotavirus Surveillance Program: Annual Report, 2021.

Abstract: This report from the Australian Rotavirus Surveillance Program describes the circulating rotavirus genotypes identified in children and adults during the period 1 January to 31 December 2021. During this period, 521 faecal specimens had been referred for rotavirus G- and P- genotype analysis, of which 474 were confirmed as rotavirus positive. Of these, 336/474 were wildtype rotavirus strains and 138/474 were identified as vaccine-like. Of the 336 wildtype samples, 87.5% (n = 294/336) were identified as G8P[8], and were detected in five of the six jurisdictions that provided samples for the reporting period. Two rotavirus outbreaks, located in the Northern Territory and Western Australia, were also attributed to G8P[8]. As with the 2020 reporting period, a low number of stool samples were received for this reporting period as a result of the COVID-19 pandemic. However, an unexpectedly high proportion of samples with unusual genotypes were identified which were potentially zoonotic in nature, including feline G3, P[9], bovine-like G8, P[14], and porcine-like G4, G6, P[1], and P[6]. Ongoing rotavirus surveillance is crucial to identify changes in genotypic patterns and to provide diagnostic laboratories with quality assurance by reporting incidences of wildtype, vaccine-like, or false positive rotavirus results.

Australian Rotavirus Surveillance Program: Annual Report, 2020.

ABSTRACT: This report from the Australian Rotavirus Surveillance Network describes the circulating rotavirus genotypes identified in children and adults during the period 1 January - 31 December 2020. During this period, 229 faecal specimens were referred for rotavirus G- and P- genotype analysis, including 189 samples that were confirmed as rotavirus positive. Of these, 98/189 were wildtype rotavirus strains and 86/189 were identified as vaccine-like. A further five samples could not be determined as wildtype or vaccine-like due to poor sequence reads. Genotype analysis of the 98 wildtype rotavirus samples from both children and adults demonstrated that G3P[8] was the dominant genotype identified for the third consecutive year, identified in 27.6% of samples, followed by G2P[4] in 20.4% of samples. Forty-six percent of rotavirus positive samples received were identified as vaccine-like, highlighting the need to add caution in interpreting rotavirus positive results in children aged 0-8 months. This surveillance period was significantly impacted by the coronavirus disease 2019 ( COVID-19 ) pandemic. The reduction in rotavirus notifications reflected reduced healthcare-seeking behaviour and a decrease in community spread, with 'community lockdowns', school and day-care centre closure and improved compliance with hand hygiene. Fewer stool samples were collected throughout Australia during this period. There was a reluctance to store samples at collaborating laboratories and uncertainties regarding the safety and feasibility of the transport of samples to the central laboratory during the closure of state and territory borders. Systems have now been adapted to manage and send biological samples safely and confidently. Ongoing rotavirus surveillance is crucial to identify changes in genotypic patterns and to provide diagnostic laboratories quality assurance by reporting incidences of wildtype, vaccine-like, or false positive rotavirus results.