COVID-19 death rates low in pregnant, hospitalized women, study finds
Compared with non-pregnant women hospitalized with COVID-19, pregnant women with COVID-19 had lower in-hospital death rates, according to a research letter in the Annals of Internal Medicine today.
University of Texas (UTHealth) and University of Maryland researchers looked at 1,062 pregnant and 9,815 non-pregnant patients hospitalized with COVID-19 and viral pneumonia from April to November 2020. All were 15 to 45 years old.
Pregnant women had a 0.8% mortality rate, compared with 3.5% in the non-pregnant group, and this difference was seen across sensitivity analyses looking only at intensive care unit patients (3.5% vs 14.9%) and those needing mechanical ventilation (8.6% vs 31.4%). The median time from admission to death was 18 days in pregnant women and 12 days in non-pregnant women.
Pregnant women tended to be younger, healthier, and on public health insurance, but no conclusions could be drawn due to the low death count. The researchers also note that pregnancy status was only available for 36% of patients in the Premier Healthcare Database.
Of the 9 pregnant patients who died, they were between the ages of 23 to 44, 8 were Black or Hispanic, 6 were obese, and 7 had at least one comorbidity. All died from April to July, and 7 of 9 of the pregnancies resulted in live births.
“We had expected to confirm the results of the CDC and other U.S. researchers showing that pregnancy increases the risk for dying from COVID-19,” said first author Beth Pineles, MD, PhD, in a UTHealth press release. “However, once we compared our results to data from the UK and reviewed the CDC reports more carefully, we found confirmation that our results were likely to represent the true risks of COVID-19 in these populations, despite the limitation of pregnant women being younger and healthier than non-pregnant women.”
May 11 Ann Intern Med study
May 11 UTHealth press release
Data show 2% of COVID patients may carry 90% of community’s virus
Just 2% of COVID-19–infected individuals could carry 90% of the SARS-CoV-2 virions circulating within communities, according to a Proceedings of the National Academy of Science study comparing presymptomatic and asymptomatic patients with hospitalized patients.
The results, published yesterday, included 1,405 positive COVID-19 cases from the University of Colorado Boulder’s 2020 fall semester testing program and compared them with 404 data points from previous research on hospitalized COVID-19 patients. Overall, more than 72,500 saliva samples were tested for COVID-19 on the college campus, all from people who were asymptomatic or presymptomatic.
The average viral load from campus collections was 2.1 x 107 virions per milliliter (mL), with a median of 1.1 x 106 virions/mL. In comparison, hospitalized patients had an average viral load of 2.5 x 107 virions/mL and a median of 9.4 x 105 virions/mL.
Past research has shown that it’s rare for infectious virions to be isolated from biosamples with less than 1 trillion (106) virions per mL, and the researchers say that approximately half of the patients in both cohorts had lower amounts. While this portion of the study population makes up less than 0.02% of the total virions, the researchers note that the individual with the highest viral load made up 5%.
“By summing the viral load across individuals based on the interpolated probability density function representing each population starting with those with the highest viral loads, we find that just 2% of individuals harbor 90% of the circulating virions,” the researchers write. “This is true in both the university (i.e., asymptomatic) and hospitalized (i.e., symptomatic) populations. Further, 99% of community-circulating virions are accounted for by just 10% of the asymptomatic and 14% of the symptomatic population.”
The researchers conclude that viral supercarriers are likely also superspreaders, and they advocate for screening strategies that target asymptomatic and presymptomatic COVID patients.
May 10 Proc Natl Acad Sci study
COVID-19 antibody rates go up in association with UK vaccine rollout
Real-world effects from the United Kingdom’s vaccine rollout began after the first dose: From late February to late March, 94% of 70- to 84-year-old blood donors had COVID-19 antibodies, but only about 5% were from natural infection, according to a Journal of Infection letter to the editor yesterday.
Out of 7,720 blood donor samples available from Feb 22 to Mar 21, 3,224 (44.7%) were positive for Roche S, which indicates COVID-19 antibodies from either natural infection or vaccine, and 1,111 (14.4%) were Roche N positive, which indicates antibodies only from natural infection. The researchers say the overall weighted seropositivity among blood donors was 46.4% with the Roche S assay, compared with the 54.7% all-cause antibodies reported by the UK Office of National Statistics Infections Survey from Feb 18 to Mar 14.
During this 4-week period, weighted seroprevalence for 70- to 84-year-old blood donors was estimated to be 93.5% (95% confidence interval [CI], 90.9% to 95.4%), with 4.7% caused by natural infection (95% CI, 3.1% to 7.1%). The researchers attribute the rest of the antibodies in this age-group to the first dose of either the Pfizer/BioNTech or the AstraZeneca/Oxford vaccines. (At this time, less than 1% of those 70 to 84 had received a second dose.)
The researchers note that natural-infection antibodies in this older age-group had stabilized at least since the month of January, when it was at 5.2%.
May 10 J Infect study