Surveillance of SARS-CoV-2 transmission in educational institutions, August to December 2020, Germany.

This study aims at providing estimates on the transmission risk of SARS-CoV-2 in schools and day-care centres. We calculated secondary attack rates (SARs) using individual-level data from state-wide mandatory notification of index cases in educational institutions, followed by contact tracing and PCR-testing of high-risk contacts. From August to December 2020, every sixth of overall 784 independent index cases was associated with secondary cases in educational institutions. Monitoring of 14 594 institutional high-risk contacts (89% PCR-tested) of 441 index cases during quarantine revealed 196 secondary cases (SAR 1.34%, 0.99-1.78). SARS-CoV-2 infection among high-risk contacts was more likely around teacher-indexes compared to student-/child-indexes (incidence rate ratio (IRR) 3.17, 1.79-5.59), and in day-care centres compared to secondary schools (IRR 3.23, 1.76-5.91), mainly due to clusters around teacher-indexes in day-care containing a higher mean number of secondary cases per index case (142/113 = 1.26) than clusters around student-indexes in schools (82/474 = 0.17). In 2020, SARS-CoV-2 transmission risk in educational settings was low overall, but varied strongly between setting and role of the index case, indicating the chance for targeted intervention. Surveillance of SARS-CoV-2 transmission in educational institutions can powerfully inform public health policy and improve educational justice during the pandemic.

Deficiency of PORCN, a regulator of Wnt signaling, is associated with focal dermal hypoplasia.

Focal dermal hypoplasia (FDH) is an X-linked dominant multisystem birth defect affecting tissues of ectodermal and mesodermal origin. Using a stepwise approach of (i) genetic mapping of FDH, (ii) high-resolution comparative genome hybridization to seek deletions in candidate chromosome areas and (iii) point mutation analysis in candidate genes, we identified PORCN, encoding a putative O-acyltransferase and potentially crucial for cellular export of Wnt signaling proteins, as the gene mutated in FDH. The findings implicate FDH as a developmental disorder caused by a deficiency in PORCN.

Poor clinical sensitivity of rapid antigen test for influenza A pandemic (H1N1) 2009 virus.

Influenza A pandemic (H1N1) 2009 virus RNA was detected by reverse transcription-PCR in 144 clinical samples from Bonn, Germany. A common rapid antigen-based test detected the virus in only 11.1% of these samples. The paramount feature of rapid test-positive samples was high virus concentration. Antigen-based rapid tests appear unsuitable for virologic diagnostics in the current pandemic.

Acute life threatening event (ALTE) in an infant with human coronavirus HCoV-229E infection.

In this short report we discuss the temporal association between an acute life threatening event (ALTE) and a RT-PCR confirmed coronavirus HCoV-229E infection in a 4 months old otherwise healthy infant. More detailed microbiological investigations of affected children even without apparent signs of a respiratory tract infection may help to clarify the etiology in some patients and extend our understanding of the pathogenesis. PCR-based techniques should be utilized to increase the sensitivity of detection for old and new respiratory viral pathogens in comparable cases.

Regulatory mechanisms underlying agmatine homeostasis in humans.

Regulation of agmatine homeostasis has so far only been poorly defined. In the present study, three mechanisms regulating human agmatine homeostasis were investigated. 1) Enzymatic regulation: expression of arginine decarboxylase, diamine oxidase, and ornithine decarboxylase in human colon neoplastic tissue was, at the mRNA level, about 75% and 50% lower and 150% higher, respectively, than in the adjacent normal tissue; expression of agmatinase was unchanged. 2) Bacteria-derived agmatine: ten representative bacteria strains of the human intestinal microbiota considerably differed in agmatine production and its efflux into their surrounding fluid, suggesting that the composition of the intestinal microbiota influences the agmatine availability in the gut lumen for absorption. 3) Regulation of blood plasma agmatine concentration by the human liver: at low concentrations in portal venous blood plasma, agmatine either slightly increased or further decreased in blood plasma through liver passage. Above a threshold of 14 ng/ml agmatine in the portal venous blood plasma, substantial hepatic agmatine removal from blood occurred. Taken together, a perturbation of agmatine homeostasis has been proven to be involved in the regulation of malignant cell proliferation. The amount of agmatine available for absorption, which is an important physiological source of agmatine in the human organism, should differ considerably depending on the composition of the bacterial flora in the chyme since the various species of intestinal bacteria largely differ in their ability to form agmatine. Finally, evidence has been presented that the liver plays a crucial physiological role in the maintenance of agmatine homeostasis in the human organism.

Abdominal infections in patients with acute leukaemia: a prospective study applying ultrasonography and microbiology.

A prospective study of 62 chemotherapy-induced neutropenic episodes in patients with acute leukaemia was conducted to determine the incidence and causes of abdominal infections, and to assess the diagnostic value of the combined use of ultrasonography (US) and microbiology. Each patient underwent US of liver, gallbladder and complete bowel before chemotherapy, on days 2-4 after the end of chemotherapy and in cases of fever, diarrhoea or abdominal pain. US was combined with a standardized clinical examination and a broad spectrum of microbiological investigations. From January to August 2001, 243 US examinations were performed. The overall incidence of abdominal infectious diseases was 17.7% (11 out of 62, 95% confidence interval (CI): 9-29%). Four patients (6.5%) developed neutropenic enterocolitis; two of them died, two survived. Bowel wall thickening (BWT) > 4 mm in these four patients ranged from 5.8 to 23.6 mm and was detected only in one patient with mucositis. In three other patients (4.8%) Clostridium difficile, and in one patient (1.6%) Campylobacter jejuni, caused enterocolitis without BWT. Cholecystitis was diagnosed in three patients (4.8%) and hepatic candidiasis was strongly suspected in one patient. Abdominal infections caused by gastroenteritis viruses, cytomegalovirus (CMV) or Cryptosporidium were not observed. We conclude that in neutropenic patients with acute leukaemia receiving chemotherapy: (i) BWT is not a feature of chemotherapy-induced mucositis and should therefore be considered as sign of infectious enterocolitis; (ii) viruses, classic bacterial enteric pathogens (Salmonella, Shigella, Yersinia, Campylobacter, Aeromonas, Vibrio subsp., enterohaemorrhagic Escherichia coli) and Cryptosporidium have a very low incidence; and (iii) abdominal infections may be underestimated when US is not used in every patient with abdominal pain.