Introduction
Since the first report of an outbreak of pneumonia cases caused by a
novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in
December 2019 in Wuhan, China, the disease has rapidly spread around the
world and was defined as a pandemic by the World Health Organization on
the 11th of March 2020. As of 29thof June, more than ten million infections and over 500,000 deaths
related to coronavirus disease (COVID-19) have been confirmed
worldwide1.
Different countries have adopted varying degrees of physical distancing
and mitigation strategies with diverse impacts on their transmission
rates, death toll and economies2, 3. It has been
proposed that universal testing with the isolation of cases and contact
tracing could reduce the prevalence of the disease and end the
pandemic4. In Australia, restriction measures were
first implemented on the 23rd of March (with the
closure of bars, clubs, cinemas, places of worship, casinos and gyms),
and two days later the country closed its borders. As part of the
mitigation strategy, the Victorian state government implemented a
screening “blitz” in the last week of April. The purpose of this was
to screen a large number of people and therefore allow for contact
tracing and physical isolation of positive asymptomatic individuals
prior to easing of restrictions. After a peak in the number of cases in
the end of March both in Australia and the state of Victoria, a steep
decline in the daily number of new cases became evident, and
restrictions have gradually and progressively been eased since the
second half of May. Nevertheless, estimates of the infection rates among
asymptomatic individuals in Australia are currently unavailable, and
whether universal screening is necessary in low disease prevalence
settings is unclear.
Preliminary data suggests that pregnant women are not at increased risk
of severe disease and its complications compared to the general
population, nor is there convincing evidence of vertical
transmission5, 6. However, within the pandemic
context, pregnancy represents a unique situation as women have multiple
interactions with the health care system and most are ultimately
admitted to hospital for childbirth. Therefore, it is possible that
pregnant women may be a source of infection to others who they encounter
during their frequent attendance to healthcare facilities, so it is
vital to understand the rates of asymptomatic infection in this
population.
This study aims to assess the prevalence of SARS-CoV-2 positive tests
among pregnant women attending routine antenatal care within a defined
study period during the coronavirus disease pandemic in Victoria,
Australia.