Slow Clearance of Norovirus following Infection with Emerging Variants of Genotype GII.4 Strains

ABSTRACT The emergence of new norovirus genotype GII.4 strains is associated with widespread norovirus epidemics. Extended periods of viral shedding can contribute to the epidemic potential of norovirus. To describe the duration of viral shedding in infections with novel emerging GII.4 strains versus infections with previously circulating strains, we performed a prospective cohort study of patients hospitalized with norovirus gastroenteritis during separate winter seasons. Rectal swab samples were obtained at the time of inclusion and weekly during follow-ups. The subgenotype strain was determined from capsid sequences. The outcome was defined by the detection of virus for >14 days (slow clearance) or by the detection of negative samples within 14 days (rapid clearance). Two major epidemic GII.4 strains emerged during the study period, GII.4 New Orleans 2009, in 2010, and GII.4 Sydney 2012, in 2012. From these two seasons, sequences were available from 24 cases where the duration of shedding could be determined. The median age of the patients was 83 years and 50% were women. The majority of patients were infected with virus that clustered with the respective season's epidemic strain ( n = 19), whereas 5 patients had previously circulating strains (3 were Den Haag 2006b, in 2010, and 2 were New Orleans 2009, in 2012). Among the patients infected with an epidemic strain, the proportion who shed virus for >14 days was significantly higher (16/19 [84%] versus 1/5 [20%], P = 0.01). In summary, a slow clearance of norovirus from stool was more common in infections with novel epidemic GII.4 strains. This suggests that the average duration of shedding may be longer during seasons when new GII.4 strains have emerged.

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Test Characteristics of Perirectal and Rectal Swab Compared to Stool Sample for Detection of Fluoroquinolone-Resistant Escherichia coli in the Gastrointestinal Tract

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.2.798-800.2005 ◽

2005 ◽

Vol 49 (2) ◽

pp. 798-800 ◽

Cited By ~ 51

Author(s):

Ebbing Lautenbach ◽

Anthony D. Harris ◽

Eli N. Perencevich ◽

Irving Nachamkin ◽

Pam Tolomeo ◽

...

Keyword(s):

Escherichia Coli ◽

Cohort Study ◽

Gastrointestinal Tract ◽

Confidence Interval ◽

Stool Sample ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Rectal Swab ◽

Test Characteristics ◽

Gut Colonization

ABSTRACT Among 63 patients enrolled in a prospective cohort study of gut colonization with fluoroquinolone-resistant Escherichia coli, the sensitivity of perirectal swab compared to stool sample was 90% (95% confidence interval [CI], 70 to 99%) and the specificity was 100% (95% CI, 91 to 100%). For rectal swab, the sensitivity was 90% (95% CI, 68 to 99%) and the specificity was 100% (95% CI, 91 to 100%).

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Determinants of Time to Convalescence among COVID-19 Patients at Millennium COVID-19 Care Center in Ethiopia: A prospective cohort study

10.1101/2020.10.07.20208413 ◽

2020 ◽

Cited By ~ 3

Author(s):

Tigist W. Leulseged ◽

Ishmael S. Hassen ◽

Endalkachew H. Maru ◽

Wuletaw C. Zewde ◽

Nigat W. Chamesew ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Care Center ◽

Viral Clearance ◽

Rank Test ◽

P Value ◽

Treatment Practice ◽

Viral Shedding ◽

Log Rank Test

ABSTRACTAimTo estimate time to recovery/convalescence and identify determinants among COVID-19 infected patients admitted to Millennium COVID-19 Care Center in Addis Ababa, Ethiopia.MethodsA prospective cohort study was conducted among a randomly selected sample of 360 COVID-19 patients who were on follow up from 2nd June to 5th July 2020. Kaplan Meier plots, median survival times, and Log-rank test were used to describe the data and compare survival distribution between groups. Association between time to recovery/ convalescence and determinants was assessed using the Cox proportional hazard survival model, where hazard ratio, P-value, and 95% CI for hazard ratio were used for testing significance.ResultsThe mean age of the participants was 32.4 years (± 12.5 years). On admission, 86.9 % had mild COVID-19, 78.6% were asymptomatic and 11.4% of the patients had a history of pre-existing co-morbid illness. The Median time to recovery/ convalescence among the study population was 16 days. The log-rank test shows that having non-mild (moderate and severe) disease, having one or more symptoms at presentation, and presenting with respiratory and constitutional symptoms seems to extend the time needed to achieve recovery. The Final Cox regression result shows that the presence of symptom at presentation was found to be a significant factor that affects time to recovery/ convalescence, the rate of achieving recovery/ convalescence among symptomatic patients was 44% lower than patients who were asymptomatic at presentation (HR= 0.560, 95% CI= 0.322-0.975, p-value=0.040).ConclusionsPresence of symptom was found to be associated with delayed viral clearance. This implies symptomatic patients are more likely to be infectious because of the prolonged viral shedding in addition to the presence of a more concentrated virus in the upper respiratory tract that enhances the transmission. Therefore, attention should be given in the isolation and treatment practice of COVID-19 patients with regard to presence of symptom.Key MessagesThe study assessed the time to RT-PCR proven recovery (two consecutive negative viral shedding) and identified determinants that affected the time.Symptomatic infection is associated with delayed viral clearance.The finding of the study could be used to guide the isolation and treatment practice.

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Temporal profile and determinants of viral shedding and of viral clearance confirmation on nasopharyngeal swabs from SARS-CoV-2-positive subjects: a population-based prospective cohort study in Reggio Emilia, Italy.

BMJ Open ◽

10.1136/bmjopen-2020-040380 ◽

2020 ◽

Vol 10 (8) ◽

pp. e040380 ◽

Cited By ~ 2

Author(s):

Pamela Mancuso ◽

Francesco Venturelli ◽

Massimo Vicentini ◽

Cinzia Perilli ◽

Elisabetta Larosa ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Population Based ◽

Reggio Emilia ◽

Viral Clearance ◽

Temporal Profile ◽

Viral Shedding

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Duration of viral shedding and factors associated with prolonged shedding among inpatients with influenza treated with oseltamivir: a prospective cohort study

European Journal of Clinical Microbiology & Infectious Diseases ◽

10.1007/s10096-017-3135-0 ◽

2017 ◽

Vol 37 (2) ◽

pp. 319-323 ◽

Cited By ~ 1

Author(s):

J. Khoury ◽

M. Szwarcwort ◽

Z. Kra-oz ◽

M. Saffuri ◽

K. Seh ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Factors Associated ◽

Viral Shedding

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Relationship Between Enteropathogen and Acute Gastroenteritis Disease Severity: A Prospective Cohort Study

Open Forum Infectious Diseases ◽

10.1093/ofid/ofx163.886 ◽

2017 ◽

Vol 4 (suppl_1) ◽

pp. S364-S364

Author(s):

Stephen Freedman ◽

Jianling Xie ◽

Alberto Nettel-Aguirre ◽

Bonita Lee ◽

Linda Chui ◽

...

Keyword(s):

Cohort Study ◽

Disease Severity ◽

Prospective Cohort Study ◽

Acute Gastroenteritis ◽

Prospective Cohort ◽

Rectal Swab ◽

Severe Disease ◽

Molecular Diagnostic ◽

Emergency Department Care ◽

Norovirus Gii

Abstract Background Little is known about the association between specific enteropathogens and disease severity in outpatient children with acute gastroenteritis. Recent advances in diagnostics enabling the rapid and simultaneous detection of common enteropathogens have become readily available. While such knowledge can be used to optimize therapy it also has the potential to predict disease severity. Such knowledge can aid clinical decision making, can clarify guidance and expectations provided to families, and can guide public health policy. Methods We conducted a prospective cohort study of children with acute gastroenteritis who were brought for emergency department care. The primary outcome measure was the 20-point Modified Vesikari Scale (MVS) score calculated from symptom onset until day14 of follow-up (total MVS score). Stool and/or rectal swab specimens were collected and analyzed for 18 unique pathogens by molecular diagnostic assays (in-house 5 virus panel, Luminex xTAG Gastrointestinal Pathogen Panel) and/or bacterial culture. An enteropathogen was deemed to be present if a candidate pathogen was identified in the rectal swab or stool specimens by any testing method. Binary logistic regression was performed to assess the association between pathogens (including all pathogens as present or not) and disease severity with the dependent variable being the total MVS score categorized as severe (11–20 points) vs.. non-severe (0–10 points). Results The mean total MVS score (SD) was 12.8 (3.2) and 73.0% (807/1102) of participants experienced severe disease. A pathogen was identified in 72.8% (802/1102) of study participants. Rotavirus, norovirus GII and adenovirus were identified in 26.6% (293/1102), 23.0% (253/1102) and 16.0% (176/1102) of participants respectively. After adjusting for other pathogens significant predictors of severe disease were: rotavirus (OR=8.0; 95% CI: 4.8, 13.2), Salmonella (OR=5.4; 95% CI: 1.2, 24.4), adenovirus (OR=2.1; 95% CI: 1.3, 3.3), and norovirus GII (OR=1.8; 95% CI: 1.3, 2.6). Clostridium difficile (OR=1.6; 95% CI: 0.96, 2.6) and Aeromonas (OR=0.97; 95% CI: 0.2, 4.7) were not significantly associated with severe disease. Conclusion In children with acute gastroenteritis, the enteropathogens associated with severe disease included rotavirus, Salmonella, adenovirus and norovirus GII. Disclosures All authors: No reported disclosures.

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Prospective cohort study showing persistent HSV-2 shedding in women with genital herpes 2 years after acquisition

Sexually Transmitted Infections ◽

10.1136/sextrans-2017-053244 ◽

2017 ◽

Vol 94 (8) ◽

pp. 568-570 ◽

Cited By ~ 2

Author(s):

Meena Ramchandani ◽

Stacy Selke ◽

Amalia Magaret ◽

Gail Barnum ◽

Meei-Li Wu Huang ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Prospective Cohort ◽

Initial Study ◽

Viral Shedding ◽

History Of ◽

Simplex Virus ◽

Study Participants ◽

Over Time

ObjectivesHerpes simplex virus type 2 (HSV-2) is a prevalent infection with great variability in clinical and virological manifestations among individuals. This prospective cohort study aims to evaluate the natural history of HSV-2 reactivation in the genital area in the same group of women over time.MethodsEighteen immunocompetent HSV-2 seropositive women were evaluated for viral shedding for 70 consecutive days within a median of 8 months (range 1–24 months) of HSV-2 acquisition and again approximately 2.5 years later from the original study. Participants obtained daily swabs of genital secretions for HSV PCR and recorded genital symptoms.ResultsThe viral shedding rate was 29% during the initial study and 19% in the follow-up study (32% reduction, P=0.019). Subclinical shedding rate also decreased from 24% to 13% (37% reduction, P=0.032), as did the rate of days with genital lesions from 22% to 15% (33% reduction, P=0.24). The mean copy number during viral shedding remained unchanged over time at 4.8 log10 c/mL (SD=2.0 and 1.6 during each study, respectively, P=0.33). Women with high viral shedding rates in the past were likely to continue to have high shedding rates (r=0.63, P=0.005).ConclusionsDespite some reduction, high viral shedding rates persist in women with genital HSV-2 greater than 2 years after acquisition.

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Time to recovery and its predictors among adults hospitalized with COVID-19: A prospective cohort study in Ethiopia

PLoS ONE ◽

10.1371/journal.pone.0244269 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0244269

Author(s):

Saro Abdella Abrahim ◽

Masresha Tessema ◽

Atkure Defar ◽

Alemayehu Hussen ◽

Eshetu Ejeta ◽

...

Keyword(s):

Cohort Study ◽

Prospective Cohort Study ◽

Median Duration ◽

Prospective Cohort ◽

Average Duration ◽

Viral Clearance ◽

Blood Type ◽

Rate Of Recovery ◽

Study Participants

Background Various factors may determine the duration of viral shedding (the time from infection to viral RNA-negative conversion or recovery) in COVID-19 patients. Understanding the average duration of recovery and its predictors is crucial in formulating preventive measures and optimizing treatment options. Therefore, evidence showing the duration of recovery from COVID-19 in different contexts and settings is necessary for tailoring appropriate treatment and prevention measures. This study aimed to investigate the average duration and the predictors of recovery from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection among COVID-19 patients. Method A hospital-based prospective cohort study was conducted at Eka Kotebe General Hospital, COVID-19 Isolation and Treatment Center from March 18 to June 27, 2020. The Center was the first hospital designated to manage COVID-19 cases in Ethiopia. The study participants were all COVID-19 adult patients who were admitted to the center during the study period. Follow up was done for the participants from the first date of diagnosis to the date of recovery (negative Real-time Reverse Transcriptase Polymerase Chain Reaction (rRT-PCT) test of throat swab). Result A total of 306 COVID-19 cases were followed up to observe the duration of viral clearance by rRT-PCR. Participants’ mean age was 34 years (18–84 years) and 69% were male. The median duration of viral clearance from each participant’s body was 19 days, but the range was wide: 2 to 71 days. Cough followed by headache was the leading sign of illness among the 67 symptomatic COVID-19 patients; and nearly half of those with comorbidities were known cancer and HIV/AIDS patients on clinical follow up. The median duration of recovery from COVID-19 was different for those with and without previous medical conditions or comorbidities. The rate of recovery from SARS-CoV-2 infection was 36% higher in males than in females (p = 0.043, CI: 1.01, 1.85). The rate of recovery was 93% higher in those with at least one comorbidity than in those without any comorbidity. The risk of delayed recovery was not influenced by blood type, BMI and presence of signs or symptoms. The findings showed that study participants without comorbidities recovered more quickly than those with at least one comorbidity. Therefore, isolation and treatment centers should be prepared to manage the delayed stay of patients having comorbidity.

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