Post lockdown COVID-19 seroprevalence and circulation at the time of delivery, France

Abstract

Background To fight the COVID-19 pandemic, lockdown has been decreed in many countries worldwide. The impact of pregnancy as a severity risk factor is still debated, but strict lockdown measures have been recommended for pregnant women. Objectives To evaluate the impact of the COVID-19 pandemic and lockdown on the seroprevalence and circulation of SARS-CoV-2 in a maternity ward in an area that has been significantly affected by the virus. Study design Prospective study at the Antoine Beclere Hospital maternity ward (Paris area, France) from May 4 (one week before the end of lockdown) to May 31, 2020 (three weeks after the end of lockdown). All patients admitted to the delivery room during this period were offered a SARS-CoV-2 serology test as well concomitant SARS-CoV-2 RT-PCR on a nasopharyngeal sample. Results A total of 249 women were included. Seroprevalence of SARS-CoV-2 was 8%. The RT-PCR positive rate was 0.5%. 47.4% of the SARS-CoV-2-IgG-positive pregnant women never experienced any symptoms. A history of symptoms during the epidemic, such as fever, myalgia and anosmia, was suggestive of previous infection. Conclusions Three weeks after the end of lockdown, SARS-CoV-2 infections were scarce in our region. A high proportion of SARS-CoV-2-IgG-negative pregnant women must be taken into consideration in the event of a resurgence of the pandemic in order to adapt public health measures to reduce exposure to the virus, such as social distancing and teleworking for this specific population.

SARS-CoV-2 antibody prevalence, titres and neutralising activity in an antenatal cohort, United Kingdom, 14 April to 15 June 2020

“…The IMD of the region sampled is not representative of the UK, as Oxfordshire ranks 142/151 of upper tier local authority districts, putting it in the 10% least deprived areas of the UK. Other studies of SARS-CoV-2 IgG seroprevalence in pregnancy have generated higher point estimates than in our setting, for example seroprevalence was 8% in a study in France [14], 10% in Italy [15], and 14% in Spain [16]; differences may reflect timing of sample collection and local population epidemiology, as well as different performance characteristics of the assays used to measure antibodies.…”

A single-center observational study on clinical features and outcomes of 21 SARS-CoV-2-infected neonates from India

“…The prevalence of SARS-CoV-2 infection during pregnancy was reported to be between 0 and 40% in the state [20]. This was in contrast to the global literature, where a seroprevalence of 8% by SARS-CoV-2 IgG serology and 0.5% positivity by RT-PCR was described [21].…”

Sero-surveillance for IgG to SARS-CoV-2 at antenatal care clinics in two Kenyan referral hospitals

“…Surveillance for IgG antibodies to SARS-CoV-2 among mothers attending ANC services in two county referral hospitals in Kenya has revealed evidence of a substantial amount of prior infection in mid-late 2020. Surveillance of pregnant women has been used as a proxy for population-based SARS-CoV-2 surveillance in high income countries [15][16][17][18][19][20][21] . This indicates much higher seroprevalence in Kenya than previously reported in samples from blood transfusion donors in the same counties earlier in 2020 12 .…”

“…For example, sero-surveillance for HIV among mothers attending antenatal care was used to track the progress of the HIV pandemic and showed prevalence estimates that were similar to population samples from the same areas 13,14 . In high income countries, a number of seroprevalence studies have indicated that the proportion of pregnant women who have been infected by SARS-CoV-2 is much greater than the cumulative prevalence identified by PCR testing of symptomatic individuals; seroprevalence estimates range from 5-20% but samples differ in time since the virus first emerged [15][16][17][18][19][20][21] . It remains unclear whether pregnancy alters susceptibility to SARS-CoV-2 infection 22 ; however, a large systematic review has found no difference in risk of becoming symptomatic when comparing pregnant women with confirmed SARS-CoV-2 infection with women of the same age 23 .…”