SARS-CoV-2 might enter the mind by the nostril
A small German post-mortem examine of COVID-19 victims in Nature Neuroscience at this time demonstrates the presence of SARS-CoV-2—the virus that causes COVID-19—in nasal constructions and the mind, suggesting that the virus crosses into the central nervous system (CNS) through nasal surfaces that comprise nerve endings for odor.
COVID-19 CNS results—lack of odor and style, headache, fatigue, nausea, vomiting, acute cerebrovascular illness, and impaired consciousness—are broadly reported and counsel viral penetration of the CNS, however the mechanism of entry stays unclear.
The researchers assessed nasal olfactory surfaces, related nerve constructions, and several other CNS areas for proof of viral RNA and proteins utilizing in-situ hybridization and immunohistochemical staining in 33 sufferers who died of COVID-19 between March and August. COVID-19–related neurologic signs within the examine sufferers had included impaired consciousness, bleeding within the mind, headache, behavioral adjustments, and strokes.
Of the 33 post-mortem sufferers, 60.6% (20 of 33) confirmed proof of SARS-CoV-2 RNA in olfactory mucosa—the liner of the nasal cavity containing sensory nerve endings for odor. The presence of viral particles within the olfactory tract and the proximity of nerve tissues means that SARS-CoV-2 might invade the CNS by olfactory nerves that management the sense of odor, the authors wrote.
In a information launch emailed to journalists, the authors highlighted the detection of SARS-CoV-2 spike protein in cells expressing markers of neurons. “Olfactory sensory neurons may be infected, as well as in the brain areas that receive smell and taste signals,” they famous.
“The findings are not surprising,” Gitte Moos Knudsen, MD, DMSc, of Copenhagen College, mentioned in a Science Media Centre assertion at this time. “Central nervous system entry through the nasal epithelium is a recognized mode of viral uptake and would not be unique to SARS-CoV-2,” she added.
Dysfunction of the cardiovascular, pulmonary, and renal methods is taken into account a significant reason for extreme or deadly COVID-19 instances. Notably, 18.1% (6 of 33) of autopsies revealed the presence of the virus within the medulla oblongata, or mind stem—a construction that controls respiratory and cardiac operate—suggesting that SARS-CoV-2 invasion of mind constructions might play a job in COVID-19 issues.
“It is possible that SARS-CoV-2 infection, at least in some instances, might aggravate respiratory or cardiac insufficiency—or even cause failure—in a CNS-mediated manner,” the authors wrote.
Nov 30 Nat Neurosci examine
Nov 30 Science Media Centre assertion
Estradiol hormone remedy might defend in opposition to COVID-19 demise
A examine late final week in BMC Drugs discovered that pre-menopausal girls with larger pure ranges of the intercourse hormone estradiol are 15% extra prone to be contaminated with SARS-CoV-2 than males however much less prone to grow to be severely sick or die, pointing to a possible protecting function of intercourse hormones in COVID-19 outcomes. The examine additionally discovered that estradiol hormone remedy for peri- and post-menopausal girls considerably improves survival charges for contaminated girls.
Estradiol is understood to affect the expression of the human angiotensin-converting enzyme 2 (ACE2) protein, which facilitates SARS-CoV-2 mobile entry. It additionally seems to play a job in blocking cytokine manufacturing pathways, which can be implicated within the “cytokine storm”—an immune system overreaction seen in some sufferers with extreme COVID-19.
Researchers collected retrospective knowledge from 68,466 COVID-19 affected person digital well being data within the 17-country TriNetX Actual-World database, classifying sufferers into 5-year age-groups, and two feminine subgroups—girls ages 15 to 49 and people 50 years and older. The 37,086 SARS-CoV-2–contaminated girls have been additional categorised into teams receiving supplementary estradiol within the type of both oral contraceptives or estradiol hormone remedy for peri- and post-menopausal circumstances (“users”) and ladies not taking supplemental hormones (“non-users”).
The COVID-19 fatality threat for peri- and post-menopausal customers was 50% lower than in non-users (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.18 to 0.62; hazard ratio [HR], 0.29; 95% CI; 0.11 to 0.76). Solely 2.3% of older girls customers died from COVID-19, versus 6.6% of non-users.
Youthful, pre-menopausal girls have 15% larger frequencies of COVID-19 than age-matched males, however males have 50% larger fatality charges than girls, suggesting a potential affiliation with larger estrogen ranges, the examine authors wrote.
Smaller results have been noticed for young women taking estradiol hormones than in non-users, with comparable fatality threat for each teams. “This may be the case because endogenous estradiol levels are typically already higher in younger women than for post-menopausal women, thus drowning out any differences between user/not-user groups,” the authors famous.
The authors urge additional examine of the protecting function of estradiol in gentle of its robust impact on COVID-19 fatality in older girls.
“A brief, 7-day course of estradiol, delivered via a transdermal patch, could be a safe approach to reduce symptom severity in adult men and in older women, when administered prior to intubation,” the authors concluded.
Nov 25 BMC Med examine
CDC: Signs not sufficient to inform COVID-19 from comparable infections
A Facilities for Illness Management and Prevention (CDC) examine printed in Open Discussion board Infectious Illnesses late final week discovered huge overlap between signs of COVID-19 and people of different respiratory diseases, demonstrating that scientific signs alone are inadequate to differentiate between them.
The researchers in contrast signs of non-hospitalized sufferers of all ages—with and with out laboratory-confirmed SARS-CoV-2 an infection—who sought medical look after an acute respiratory sickness at US Flu Vaccine Effectiveness (VE) community examine websites in Michigan, Pennsylvania, Texas, Washington, and Wisconsin from Mar 26 to Aug 15.
Of a complete of 4,961 sufferers, 916 examined constructive for SARS-CoV-2 through reverse-transcription polymerase chain response, and 4,045 had respiratory signs however examined adverse for the virus. Cellphone interviews and on-line questionnaires gathered data on demographics, well being behaviors resembling smoking standing, and underlying medical circumstances.
Cough was probably the most generally reported symptom in each SARS-CoV-2–constructive and –adverse sufferers (86% and 83%, respectively; P < 0.01). Shortness of breath/problem respiratory was reported much less typically by these with COVID-19 than with out (40% vs 47%; P < 0.01), and 99% of sufferers reported fever and/or cough.
“Persons with COVID-19 reported a median of 7 (IQR, 5–8) of the assessed symptoms versus 6 (IQR, 4–7) for persons without COVID-19 (P < 0.01),” the authors mentioned. “Among 4102 participants asked, 59% of persons with COVID-19 versus 19% of persons without COVID-19 reported diminished taste or smell (P < 0.01). Generalized symptoms (muscle aches or headache) and gastrointestinal symptoms (vomiting, diarrhea, or abdominal pain) were more common among persons with COVID-19 (91% and 57%, respectively) than among those without COVID-19 (83% and 50%, respectively; P < 0.01 for both).”
“Because of the wide overlap in COVID-19 symptoms with those of other respiratory illnesses, laboratory confirmation of SARS-CoV-2 infection will be critical, not only for limiting disease spread, contact tracing, and monitoring clinical course, but also for assessing the effectiveness of interventions during periods of co-circulation of SARS-CoV-2 and other respiratory viruses, including influenza,” the authors famous.
Nov 26 Open Discussion board Infect Dis examine