[Period Prevalence of SARS-CoV-2 in an Unselected Sample of Pregnant Women in Jena, Thuringia]. / Periodenprävalenz von SARS-CoV-2 in einer unselektierten Stichprobe schwangerer Frauen in Jena, Thüringen.

INTRODUCTION: Following an exponential increase in SARS-CoV-2 infections, the city of Jena, Thuringia, was the first in Germany to introduce mandatory mouth and nose coverings. An estimation of the SARS-CoV-2 period prevalence was achieved by screening an unselected cohort of pregnant women. Of interest was the number of unreported cases. METHODS: Upon admission to hospital, patients were screened for SARS-CoV-2 by a specific real-time PCR and antibodies determined by a specific SARS-CoV-2 IgG in serum by ELISA. The SARS-CoV-2 period prevalence was estimated using the Clopper-Pearson exact method, the group comparison with Fischer's exact test. RESULTS: From 6 April to 13 May 2020, 234 pregnant women were admitted to the Department of Obstetrics. A total of 225 (96.2%) SARS-CoV-2 PCRs were carried out and all remained negative. Specific IgG antibodies were detected in one (0.6%) of 180 (76.9%) antibody tests performed. The interval estimate of the period prevalence thus results in a 95% confidence interval between 0-1.7%. For 96 households with children, the period prevalence is 0-3.8%, which does not differ from the 0-4.8% for 76 households without children (p=1.00). DISCUSSION: This is the first report on the SARS-CoV-2 period prevalence of an unselected sample of pregnant women in Germany. Antibody testing showed no evidence of the feared high number of unreported asymptomatic SARS-CoV-2 infections. The seroconversion rate was below 1% (0.6%).

Engineered liposomes sequester bacterial exotoxins and protect from severe invasive infections in mice.

Gram-positive bacterial pathogens that secrete cytotoxic pore-forming toxins, such as Staphylococcus aureus and Streptococcus pneumoniae, cause a substantial burden of disease. Inspired by the principles that govern natural toxin-host interactions, we have engineered artificial liposomes that are tailored to effectively compete with host cells for toxin binding. Liposome-bound toxins are unable to lyse mammalian cells in vitro. We use these artificial liposomes as decoy targets to sequester bacterial toxins that are produced during active infection in vivo. Administration of artificial liposomes within 10 h after infection rescues mice from septicemia caused by S. aureus and S. pneumoniae, whereas untreated mice die within 24-33 h. Furthermore, liposomes protect mice against invasive pneumococcal pneumonia. Composed exclusively of naturally occurring lipids, tailored liposomes are not bactericidal and could be used therapeutically either alone or in conjunction with antibiotics to combat bacterial infections and to minimize toxin-induced tissue damage that occurs during bacterial clearance.