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1.
medrxiv; 2023.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2023.01.30.23285219

ABSTRACT

Rationale for the review: COVID-19 treatment can worsen parasitic disease in patients with coinfection. Consequently, there is a need to investigate the infection with SARS CoV 2 and Strongyloides. We aim to systematically review clinical and laboratory features of COVID 19 and Strongyloides coinfection, to investigate possible interventions and outcomes in this pathology. Also, we aim to identify difficulties in managing the parasitic disease manifestations in this context and to emphasize research gaps requiring further attention. Methods: We will search two electronic databases (LitCOVID, and WHO COVID 19) and will include studies on SARS CoV 2 and Strongyloides coinfection. We will adapt the WHO UMC system for standardized case causality assessment to evaluate if using corticosteroids or other immunosuppressive drugs in COVID 19 patients determined acute strongyloidiasis manifestations. Expected results: We will present the evidence in three distinct packages: study description, methodological quality assessment and data extracted. We will summarize the evidence and will draw conclusions as to the quality of the evidence.


Subject(s)
COVID-19 , Strongyloidiasis , Severe Acute Respiratory Syndrome , Parasitic Diseases
2.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.01.26.22269917

ABSTRACT

This is a protocol for a systematic review to assess fomite transmission in SARS-CoV-2. Our research questions are as follows: 1. Are fomite samples infectious? 2 If so, what proportion are infectious, and what is the distance and duration of infectiousness in the air? 3. What is the relationship between fomites, infectiousness and PCR cycle threshold (Ct)? 4. Is there evidence of a chain of transmission that establishes an actual instance of fomite transmission of SARS-CoV-2? We will include studies of any design (and in any setting) that investigate fomite transmission (defined as any inanimate object that, when contaminated with or exposed to infectious agents, can transfer the agent to a new host). We will only include studies that performed viral culture which assessed cytopathic effect and verification techniques to ensure the cultured virus is SARS-CoV-2. We will assess the risk of bias using a checklist modified from the QUADAS-2 criteria.

3.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.10.11.21264724

ABSTRACT

Background: Maritime and river travel, including cruise ships, have been implicated with spreading viruses through infected passengers and crew. Given the novelty of the SARS-CoV-2 infection, early cruise ship travel transmission models of spread are based on what is known of the dynamics of other respiratory viral infections. Our objective is to provide a rapid summary and evaluation of relevant data on SARS-CoV-2 transmission aboard cruise ships, report policy implications, and highlight research gaps requiring attention. Methods: We will search LitCovid, medRxiv, Google Scholar, and the WHO Covid-19 database using COVID-19, SARS-CoV-2, transmission, and cruise ship appropriate synonyms. We will also search the reference lists of included studies for additional relevant studies. We will include studies reporting onboard SARS-CoV-2 transmission from passengers and/or crew to passengers and/or crew. We will consider any potential transmission mode. We will assess study quality based on five criteria and report important findings. The outcome will consist of the onboard cruise ships transmission of SARS-CoV-2. We will provide a narrative summary of the data and report the outcomes, including quantitative estimates where feasible and relevant. Where possible, compatible datasets may be pooled for meta-analysis. Expected results: We will present the evidence in three distinct packages: study description, methodological quality assessment and data extracted. We will summarize the evidence and will draw conclusions as to the quality of the evidence.


Subject(s)
COVID-19 , Respiratory Tract Infections , Pasteurellosis, Pneumonic
4.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.07.08.21259744

ABSTRACT

Few studies have assessed for infectious SARS-CoV-2 in multiple types of clinical and environmental samples. In almost 500 samples from 75 hospitalized and community cases, we detected infectious virus with quantitative burdens varying from 5.0 plaque-forming units/mL (PFU/mL) up to 1.0x106 PFU/mL in clinical specimens and up to 1.3x106 PFU/mL on fomites including facial tissues, nasal prongs, call bells/cell phones, dentures, and sputum deposits with confirmation by plaque morphology, PCR, immunohistochemistry, and sequencing. Expectorated sputum samples had the highest percentage of positive samples and virus titers (71%, 2.9x102 to 5.2x105 PFU/mL), followed by saliva (58%, 10 to 4.6x104 PFU/mL), and cough samples without sputum (19%, 5 to 1.9x103 PFU/mL). We also detected infectious SARS-CoV-2 from patients' hands (28%, 60 to 2.3x102 PFU/mL) but no infectious virus was found in continuous speech samples despite finding high levels of infectious virus in the associated nasopharynx, throat, or saliva specimens. We demonstrated infectious virus stability in clinical samples, including those dried for prolonged periods of time. Infectious virus correlated with time since symptom onset with no detection after 7-8 days in immunocompetent hosts and with N-gene based Ct values [≤]25 significantly predictive of yielding plaques in culture. One PFU was associated with ~105 copies of N gene RNA across a diversity of samples and times from symptom onset. Clinical salivary isolates caused illness in a hamster model with a minimum infectious dose of [≤]14 PFU/mL. Our findings of high quantitative burdens of infectious virus, stability even with drying, and a very low minimal infectious dose suggest multiple modes of transmission are exploited by SARS-CoV-2, including direct contact, large respiratory droplet, and fomite transmission and in the context of a high binding avidity to human cellular receptors, offer an explanation of the high contagiousness of this virus.


Subject(s)
Severe Acute Respiratory Syndrome
5.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.06.30.21259750

ABSTRACT

BackgroundVertical transmission of SARS-CoV-2 has been reported but does not appear to be common. This study aims to systematically review the evidence for vertical transmission of SARS-CoV-2. MethodsThis review is part of an Open Evidence Review on the transmission dynamics of SARS-CoV-2 and the role of intrauterine mother to fetus transmission. Literature searches were performed in the WHO Covid-19 Database, LitCovid, medRxiv, and Google Scholar for SARS-CoV-2 using keywords and associated synonyms, search date up to 20 December 2020, no language restrictions. ResultsWe included 106 studies assessing vertical transmission of SARS-CoV-2 from pregnant women to their neonates: these studies comprised 40 reviews (21 fulfilled systematic review methodology, including risk of bias assessment of included studies) and 66 primary studies including 32 case reports (of up to two cases) and 34 prospective and retrospective cohort studies, prospective and retrospective case series, observational studies (including asymptomatic screening), database studies and a quality improvement project. Almost all were conducted in a hospital setting. The 32 case reports were considered to be at high risk of bias, due to the study design; across the 34 remaining primary studies, risk of bias was low to moderate. Sixteen case reports examined vertical transmission, which was not related to maternal symptomatology. For the cohort and case series studies, the percentage of positive neonates ranged from 0% to 22% across the studies. Twenty studies reported no positive vertical transmission. Three studies that reported the highest positivity rates of 11%, 15% and 22% had specifically selected neonates with a positive test (within up to 35 days) within the study population and were therefore more selective populations. Across the cohort and case series studies there were 65/2391 (2.7%) neonates born to mothers with a diagnosis of COVID-19 tested positive for SARS-CoV-2 within 24 hours of birth. No evidence correlated maternal symptomatology to vertical transmission. Mode of delivery did not correlate with rates of vertical transmission. Of 25 studies, 7 identified SARS-CoV-2 in placental tissue; some of these did not demonstrate vertical transmission to the neonate. No study reported the results of viral culture to detect SARS-CoV-2. ConclusionsThe results of these studies indicate that vertical transmission is possible, but is not frequent, and factors that influence when vertical transmission occurs are unknown. Further studies using standardised methods to establish viral infection are needed to establish vertical transmission rates and to assess clinical and other conditions affecting transmission.


Subject(s)
COVID-19
6.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.06.03.21258274

ABSTRACT

BackgroundAir travel may be associated with the spread of viruses via infected passengers and potentially through in-flight transmission. Given the novelty of the SARS-CoV-2 virus, transmission associated with air travel is based on what is known about the dynamics of transmission of other respiratory virus infections, especially those due to other coronaviruses and influenza. Our objective was to provide a rapid summary and evaluation of relevant data on the transmission of SARS-CoV-2 aboard aircraft, report important policy implications, and highlight research gaps requiring urgent attention. MethodsThis review is part of an Open Evidence Review on Transmission Dynamics of SARS-CoV-2. We searched LitCovid, medRxiv, Google Scholar, and the WHO Covid-19 database from 1 February 2020 to 27 January 2021 and included studies on the transmission of SARS-CoV-2 aboard aircraft. We assessed study quality based on five criteria and reported important findings. ResultsWe included 18 studies on in-flight transmission of SARS-CoV-2, representing 130 unique flights and two studies on wastewater from aircraft. The overall quality of reporting was low. Two wastewater studies reported PCR-positive SARS-CoV-2 samples, but with relatively high Cycle threshold values ranging from 36 to 40. The definition of an index case was very heterogeneous across the studies. The proportion of contacts traced ranged from 0.68% to 100%. In total, the authors successfully traced 2800/19729 passengers, 140/180 crew members, and 8/8 medical staff. Altogether, 273 index cases were reported, with 64 secondary cases. No secondary cases were reported in three studies, each investigating one flight. The secondary attack rate among the studies that followed up >80% of the passengers and crew (including data on 10 flights) varied between 0% and 8.2%. The included studies reported on the possibility of SARS-CoV-2 transmission from asymptomatic, pre-symptomatic, and symptomatic individuals. Viral cultures were performed in two studies, with 10 positive results reported. Genomic sequencing and phylogenetic analysis were performed in individuals from four flights, with the completeness of genomic similarity ranging from 81-100%. ConclusionCurrent evidence suggests that SARS-CoV-2 can be transmitted during aircraft travel, but the published data do not permit any conclusive assessment of the likelihood and extent. Furthermore, the quality of evidence from most published studies is low. The variation in study design and methodology restricts the comparison of findings across studies. Standardized guidelines for conducting and reporting future studies of transmission on aircrafts should be developed.


Subject(s)
COVID-19
7.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.02.20.21251520

ABSTRACT

Background: SARS-CoV-2 has been detected in wastewater and its abundance correlated with community COVID-19 cases, hospitalizations and deaths. We sought to use wastewater-based detection of SARS-CoV-2 to assess the epidemiology of SARS-CoV-2 in hospitals. Methods: Between August and December 2020, twice-weekly wastewater samples from three tertiary-care hospitals (totalling >2100 dedicated inpatient beds) were collected. Wastewater samples were concentrated and cleaned using the 4S-silica column method and assessed for SARS-CoV-2 gene-targets (N1, N2 and E) and controls using RT-qPCR. Wastewater SARS-CoV-2 as measured by quantification cycle (Cq), genome copies and genomes normalized to the fecal biomarker PMMoV were compared to the total daily number of patients hospitalized with active COVID-19, confirmed cases of hospital-acquired infection, and the occurrence of unit-specific outbreaks. Results: Of 165 wastewater samples collected, 159 (96%) were assayable. The N1-gene from SARS-CoV-2 was detected in 64.1% of samples, N2 in 49.7% and E in 10%. N1 and N2 in wastewater increased over time both in terms of amount of detectable virus and the proportion of samples that were positive, consistent with increasing hospitalizations (Pearsons r=0.679, P<0.0001, Pearsons r=0.728, P<0.0001, respectively). Despite increasing hospitalizations through the study period, wastewater analysis was able to identify incident nosocomial-acquired cases of COVID-19 (Pearsons r =0.389, P<0.001) and unit-specific outbreaks by increases in detectable SARS-CoV-2 N1-RNA (median 112 copies/ml) versus outbreak-free periods (0 copies/ml; P<0.0001). Conclusions: Wastewater-based monitoring of SARS-CoV-2 represents a promising tool for SARS-CoV-2 passive surveillance and case identification, containment, and mitigation in acute- care medical facilities.


Subject(s)
COVID-19
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