Age-related differences in SARS-CoV-2 testing in the Northern Region of New Zealand.

Chhibber, Aakash V; Muttaiyah, Sharmini; McAuliffe, Gary; Fox-Lewis, Shivani; De Almeida, Mary; Blakiston, Matthew; Playle, Veronica; Fox-Lewis, Andrew; Roberts, Sally

AIM There is concern the low incidence of coronavirus disease 2019 (COVID-19) in children reflects under-testing in this population. This study sought to describe the age-distribution of SARS-CoV-2 testing in the Northern Region of New Zealand. METHODS A retrospective single-centre review of all SARS-CoV-2 tests performed at LabPLUS, Auckland City Hospital, between 12 February and 18 April 2020. RESULTS A total of 22,333 tests were performed, with 313 (1.40%) positive results. The age-adjusted SARS-CoV-2 testing rate was three times higher in adults than in children. The overall proportion of positive tests was lower in children (0.86%) than adults (1.45%). However, within the paediatric population the proportion of tests positive differed significantly between those <10 years old (0.08%) and those 10-14 years old (2.6%). CONCLUSION The lower proportion of tests positive in children <10 years of age suggests they are appropriately tested relative to their rates of disease. A large high school-associated cluster makes the higher proportion of tests positive in children 10-14 years old difficult to interpret. Older children may have a higher risk of infection and increasing testing in intermediate and high school aged children may be indicated.