Viral Inactivation Impacts Microbiome Estimates in a Tissue-Specific Manner.

The global emergence of novel pathogenic viruses presents an important challenge for research, as high biosafety levels are required to process samples. While inactivation of infectious agents facilitates the use of less stringent safety conditions, its effect on other biological entities of interest present in the sample is generally unknown. Here, we analyzed the effect of five inactivation methods (heat, ethanol, formaldehyde, psoralen, and TRIzol) on microbiome composition and diversity in samples collected from four different body sites (gut, nasal, oral, and skin) and compared them against untreated samples from the same tissues. We performed 16S rRNA gene sequencing and estimated abundance and diversity of bacterial taxa present in all samples. Nasal and skin samples were the most affected by inactivation, with ethanol and TRIzol inducing the largest changes in composition, and heat, formaldehyde, TRIzol, and psoralen inducing the largest changes in diversity. Oral and stool microbiomes were more robust to inactivation, with no significant changes in diversity and only moderate changes in composition. Firmicutes was the taxonomic group least affected by inactivation, while Bacteroidetes had a notable enrichment in nasal samples and moderate enrichment in fecal and oral samples. Actinobacteria were more notably depleted in fecal and skin samples, and Proteobacteria exhibited a more variable behavior depending on sample type and inactivation method. Overall, our results demonstrate that inactivation methods can alter the microbiome in a tissue-specific manner and that careful consideration should be given to the choice of method based on the sample type under study. IMPORTANCE Understanding how viral infections impact and are modulated by the microbiome is an important problem in basic research but is also of high clinical relevance under the current pandemic. To facilitate the study of interactions between microbial communities and pathogenic viruses under safe conditions, the infectious agent is generally inactivated prior to processing samples. The effect of this inactivation process in the microbiome is, however, unknown. Further, it is unclear whether biases introduced by inactivation methods are dependent on the sample type under study. Estimating the magnitude and nature of the changes induced by different methods in samples collected from various body sites thus provides important information for current and future studies that require inactivation of pathogenic agents.

Impairments in odour detection and hedonic ratings of unpleasant smells in asymptomatic university students as SARS-Cov-2 emerged locally.

Sudden olfactory loss in the absence of concurrent nasal congestion is now a well-recognized symptom of COVID-19. We examined olfaction using standardized objective tests of odour detection, identification and hedonics collected from asymptomatic university students before and as SARS-CoV-2 emerged locally. Olfactory performance of students who were tested when the virus is known to be endemic (n = 22) was compared to students tested in the month prior to viral circulation (n = 25), a normative sample assessed during the previous 4 years (n = 272) and those tested in prior years during the same time period. Analyses showed significantly reduced odour detection for the virus exposed cohort compared to students tested before (t = 2.60; P = .01; d = 0.77; CI 0.17, 1.36) and to the normative sample (D = 0.38; P = .005). Odour identification scores were similar, but the exposed cohort rated odours as less unpleasant (P < .001, CLES = 0.77). Hyposmia increased 4.4-fold for students tested 2 weeks before school closure (N = 22) and increased 13.6-fold for students tested in the final week (N = 11). While the unavailability of COVID-19 testing is a limitation, this naturalistic study demonstrates week-by-week increase in hyposmia in asymptomatic students as a virus was circulating on campus, consistent with increasing airborne viral loads. The specific hedonic deficit in unpleasantness appraisal suggests a deficit in the TAAR olfactory receptor class, which conveys the social salience of odours. Assessment of odour detection and hedonic ratings may aid in early detection of SARS-CoV-2 exposure in asymptomatic and pre-symptomatic persons.

The kids are not alright: A preliminary report of Post-COVID syndrome in university students.

OBJECTIVE: To investigate the prevalence and features of protracted COVID-19 symptoms in non-hospitalized university students who experienced mild-to-moderate acute illness. PARTICIPANTS: COVID-19 positive participants with symptoms ≥ 28 days (N = 22), herein referred to as post-COVID syndrome, were compared to those who fully recovered (N = 21) and those never diagnosed with the disease (N = 58). METHODS: Students completed online study to earn research credit for class. RESULTS: 51% of COVID-19 positive participants were classified with post-COVID syndrome. During acute illness, those with post-COVID syndrome experienced more chest pain, fatigue, fever, olfactory impairment, headaches, and diarrhea compared to fully recovered participants. They also reported more current exercise intolerance, dyspnea, chest pain, olfactory impairment, lymphadenopathy, gustatory impairment, and appetite loss than students who never contracted COVID-19. CONCLUSIONS: Our results contradict the perception that this yet to be defined post-COVID syndrome predominantly affects middle-aged adults. Student health centers should closely monitor those who contract COVID-19 for lingering effects.

The Kids Are Not Alright: A Preliminary Report of Post-COVID Syndrome in University Students.

BACKGROUND: Post-COVID syndrome is increasingly recognized by the medical community but has not been studied exclusively in young adults. This preliminary report investigates the prevalence and features of protracted symptoms in non-hospitalized university students who experienced mild-to-moderate acute illness. METHODS: 148 students completed an online study to earn research credit for class. Data from COVID-19 positive participants with symptoms ≥28 days (N=22) were compared to those who fully recovered (N=21) and those not diagnosed with COVID-19 (N=58). RESULTS: 51% of participants who contracted COVID-19 (N=43) experienced symptoms ≥28 days and were classified as having post-COVID syndrome; all but one (96%) were female. During acute illness the post-COVID group, compared to those who fully recovered, experienced significantly more chest pain (64% vs 14%; P=.002), fatigue (86% vs 48%; P=.009), fever (82% vs 48%; P=.02), olfactory impairment (82% vs 52%; P=.04), headaches (32% vs 5%; P<.05), and diarrhea (32% vs 5%; P<.05). Compared to those not diagnosed with COVID-19, the post-COVID syndrome group more frequently experienced exercise intolerance (43% vs. 0%; P<.001), dyspnea (43% vs. 0%; P<.001), chest pain (31% vs 7%; P=.002), olfactory impairment (19% vs 0%; P=.004), lymphadenopathy (19% vs 0%; P=.004), gustatory impairment (14% vs 0%; P=.02), and appetite loss (36% vs 14%; P=.02). INTERPRETATION: Our results contradict the perception that this "yet to be defined" post-COVID syndrome predominantly affects middle-aged adults and suggest that exercise intolerance, dyspnea, chest pain, chemosensory impairment, lymphadenopathy, rhinitis, and appetite loss may differentiate post-COVID syndrome from general symptoms of pandemic, age, and academic related stress. These findings are also consistent with previous reports that females are more vulnerable to this post viral syndrome. Large-scale population-based studies are essential to discerning the magnitude and characterization of post-COVID syndrome in young adults as well as more diverse populations.