Samba II PCR testing for COVID-19 in an unselected cohort of pregnant women in the UK

Abstract

OBJECTIVE: Asymptomatic carriage of COVID-19 in pregnant women has been reported and could lead to outbreaks in maternity units. We sought to ascertain the impact of rapid isothernal nucleic acid based testing for COVID-19 in an unselected cohort of pregnant women attending our maternity unit. We also assessed the correlation between community prevalence and asymptomatic carriage.DESIGN: Retrospective cohort analysis and literature reviewSETTING: Tertiary hospital in Cambridge, UKPOPULATION: Pregnant women (with gestation age between 12-42 weeks) admitted to a single maternity unit over a 4-week period (07/05/2020-06/06/2020) METHODS: Data were collected using computerised hospital records. Literature searches were performed across multiple repositories. COVID-19 prevalence was extracted from online repositories.RESULTS: NP and OP swabs were obtained from 457/465 women during the study period (98%). The median turnaround time for results was 5.3 hours (interquartile range (IQR) 2.6-8.9 hours). 92% of results were returned within 24 hours. In our cohort, only one woman tested positive, giving a screen positive rate of 0.22% (1/457; 95% confidence interval: 0.04-1.23%). One woman who tested negative developed a fever postnatally following discharge but was lost to follow-up. From our literature review, we did not find any correlation between asymptomatic carriage in pregnant women and the reported regional prevalence of COVID-19. CONCLUSIONS: Testing using the SAMBA-II machine was acceptable to the vast majority of pregnant women requiring admission and had a low turnaround time. Asymptomatic carriage is low, but not correlated to community prevalence rates. Screening pregnant women on admission will remain an important component in order to minimise nosocomial infection.

Vertical Virus Transmission from SARS-CoV-2-positive Mothers to Neonates: A Tertiary Care Hospital Experience

“…In a study from New York Presbyterian Allen Hospital and Columbia University Irving Medical Centre, 211 pregnant women were tested through qRT-PCR of nasopharyngeal swabs, of which 210 were asymptomatic (99.5%). Twenty-nine (13.7%) of those women were found confirmed positive for SARS-CoV-2 [7].…”