A new SARS-CoV-2 variant with high lethality poorly detected by RT-PCR on nasopharyngeal samples: an observational study.

OBJECTIVES: In early January 2021 an outbreak of nosocomial cases of coronavirus disease 2019 (COVID-19) emerged in Western France; RT-PCR tests were repeatedly negative on nasopharyngeal samples but positive on lower respiratory tract samples. Whole-genome sequencing (WGS) revealed a new variant, currently defining a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineage B.1.616. In March, the WHO classified this as a 'variant under investigation' (VUI). We analysed the characteristics and outcomes of COVID-19 cases related to this new variant. METHODS: Clinical, virological, and radiological data were retrospectively collected from medical charts in the two hospitals involved. We enrolled those inpatients with: (a) positive SARS-CoV-2 RT-PCR on a respiratory sample, (b) seroconversion with anti-SARS-CoV-2 IgG/IgM, or (c) suggestive symptoms and typical features of COVID-19 on a chest CT scan. Cases were categorized as B.1.616, a variant of concern (VOC), or unknown. RESULTS: From 1st January to 24th March 2021, 114 patients fulfilled the inclusion criteria: B.1.616 (n = 39), VOC (n = 32), and unknown (n = 43). B.1.616-related cases were older than VOC-related cases (81 years, interquartile range (IQR) 73-88 versus 73 years, IQR 67-82, p < 0.05) and their first RT-PCR tests were rarely positive (6/39, 15% versus 31/32, 97%, p < 0.05). The B.1.616 variant was independently associated with severe disease (multivariable Cox model HR 4.0, 95%CI 1.5-10.9) and increased lethality (28-day mortality 18/39 (46%) for B.1.616 versus 5/32 (16%) for VOC, p = 0.006). CONCLUSION: We report a nosocomial outbreak of COVID-19 cases related to a new variant, B.1.616, which is poorly detected by RT-PCR on nasopharyngeal samples and is associated with high lethality.

Are anti-Chlamydia pneumoniae antibodies prognosis indicators for peripartum cardiomyopathy?

BACKGROUND: The authors recently pointed out an epidemiological relation between specific anti-Chlamydia pneumoniae antibodies and peripartum cardiomyopathy in Niamey (Republic of Niger). DESIGN: In this work, they studied the prognosis value of such specific antibodies. METHODS: The serological status for specific IgG, IgA and IgM anti-C. pneumoniae antibodies of 50 African women (age, mean+/-SD = 30.2 +/- 7 years) hospitalized in Niamey, with peripartum cardiomyopathy, was determined at the time of diagnosis. The diagnosis was categorized as 'complete remission' (13 patients, age = 29.3 +/- 6.5 years, observation delay = 27 months), 'incomplete remission' (27 patients, age = 30.7 +/- 7.6 years, observation delay = 14 months) and 'deceased' (10 patients, age = 30.3 +/- 6.2 years, observation delay = 13 months). The control group comprised 27 African women (age = 25.2 +/- 4.6 years), living in the same area. The Mann-Whitney and Fisher's exact tests were used for the statistical comparison. RESULTS: The dilution of IgG specific anti-C. pneumoniae antibodies was higher (P = 0.047) in the 'incomplete remission' compared with 'complete remission'. The dilution of IgA specific anti-C. pneumoniae antibodies was higher (P = 0.033) in the patients with a severe evolution ('deceased' + 'incomplete remission') compared with 'complete remission'. There was no significant difference between patients in 'complete remission' compared with 'controls'. CONCLUSIONS: At the time of peripartum cardiomyopathy diagnosis the specific IgG and IgA anti-C. pneumoniae antibodies are of prognosis value: a high dilution is more often associated with a poor prognosis. This is the first identified prognosis factor during the precocious evolution of peripartum cardiomyopathy.