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1.
Ann Epidemiol ; 2023 May 18.
Article in English | MEDLINE | ID: covidwho-2324891

ABSTRACT

Coronavirus disease 2019 (COVID-19) developed into a pandemic within months. SARS-CoV-2 testing measures and vaccines became quickly accessible. However, due to pre- or asymptomatic transmission, effective disease control remains challenging. To complement conventional testing methods, scientists around the world have investigated dogs' olfactory capability for true real-time detection. Several diseases are known to produce specific scents in affected individuals, excreted as volatile organic compounds, which can be easily detected by dogs within seconds. This systematic review evaluates the current evidence for using dogs' olfactory system as a reliable COVID-19-screening tool. Two independent procedures for study quality assessment were used: the QUADAS-2 tool for the evaluation of laboratory tests' diagnostic accuracy, designed for systematic reviews, and a second system for the general evaluation of canine scent detection studies, adapted with a focus on medical scent detection. Twenty-seven studies from thirteen countries were evaluated. Particular attention was paid to potential confounding factors, e.g., study design, patient/sample selection, dog characteristics, training protocols, and sample types/treatment. These analysis systems revealed that respectively four and six studies had low risk of bias and high quality. The four QUADAS-2 non-biased studies resulted in sensitivity and specificity ranges of 81-97% and 91-100%, whereas the six high quality studies according to the general evaluation system revealed sensitivity and specificity ranges of 82-97% and 83-100%, respectively. The other studies contained high risk of bias, concerns about the methodological applicability and/or quality concerns. Standardization and certification procedures as used for canine explosives detection should be established for medical scent detection dogs in order to use their undoubtful potential in an optimal and structured way. '.

3.
BMJ Glob Health ; 7(11)2022 11.
Article in English | MEDLINE | ID: covidwho-2119458

ABSTRACT

INTRODUCTION: Previous research demonstrated that medical scent detection dogs have the ability to distinguish SARS-CoV-2 positive from negative samples with high diagnostic accuracy. To deploy these dogs as a reliable screening method, it is mandatory to examine if canines maintain their high diagnostic accuracy in real-life screening settings. We conducted a study to evaluate the performance of medical scent detection dogs under real-life circumstances. METHODS: Eight dogs were trained to detect SARS-CoV-2 RT-qPCR-positive samples. Four concerts with a total of 2802 participants were held to evaluate canines' performance in screening individuals for SARS-CoV-2 infection. Sweat samples were taken from all participants and presented in a line-up setting. In addition, every participant had been tested with a SARS-CoV-2 specific rapid antigen test and a RT-qPCR and they provided information regarding age, sex, vaccination status and medical disease history. The participants' infection status was unknown at the time of canine testing. Safety measures such as mask wearing and distance keeping were ensured. RESULTS: The SARS-CoV-2 detection dogs achieved a diagnostic specificity of 99.93% (95% CI 99.74% to 99.99%) and a sensitivity of 81.58% (95% CI 66.58% to 90.78%), respectively. The overall rate of concordant results was 99.68%. The majority of the study population was vaccinated with varying vaccines and vaccination schemes, while several participants had chronic diseases and were under chronic medication. This did not influence dogs' decisions. CONCLUSION: Our results demonstrate that SARS-CoV-2 scent detection dogs achieved high diagnostic accuracy in a real-life scenario. The vaccination status, previous SARS-CoV-2 infection, chronic disease and medication of the participants did not influence the performance of the dogs in detecting the acute infection. This indicates that dogs provide a fast and reliable screening option for public events in which high-throughput screening is required.


Subject(s)
COVID-19 , Humans , Dogs , Animals , COVID-19/diagnosis , SARS-CoV-2 , Sensitivity and Specificity , Mass Screening
4.
Vaccines (Basel) ; 9(10)2021 Oct 01.
Article in English | MEDLINE | ID: covidwho-1444355

ABSTRACT

To provide initial data on local SARS-CoV-2 epidemiology and spread in indigenous communities in north-eastern Colombia, respiratory swabs and serum samples from volunteers of indigenous communities were examined in March and April 2021. Samples from non-indigenous Colombians from the same villages were included as well. While previous exposure to SARS-CoV-2 was assessed by analysing serum samples for IgG and IgM with a rapid antibody point-of-care-test (POCT), screening for active infections was carried out with an antigen POCT test and real-time PCR from nasal swabs. In 380 indigenous and 72 non-indigenous volunteers, 61 (13.5%) active infections and an additional 113 (25%) previous infections were identified using diagnostic serology and molecular assays. Previous infections were more frequent in non-indigenous volunteers, and relevant associations of clinical features with active or previous SARS-CoV-2 infections were not observed. Symptoms reported were mild to moderate. SARS-CoV-2 was frequent in the assessed Colombian indigenous communities, as 38.5% of the study participants showed signs of exposure to SARS-CoV-2, which confirms the need to include these indigenous communities in screening and vaccination programs.

5.
Emerg Microbes Infect ; 10(1): 1807-1818, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1360311

ABSTRACT

Male sex was repeatedly identified as a risk factor for death and intensive care admission. However, it is yet unclear whether sex hormones are associated with disease severity in COVID-19 patients. In this study, we analysed sex hormone levels (estradiol and testosterone) of male and female COVID-19 patients (n = 50) admitted to an intensive care unit (ICU) in comparison to control non-COVID-19 patients at the ICU (n = 42), non-COVID-19 patients with the most prevalent comorbidity (coronary heart diseases) present within the COVID-19 cohort (n = 39) and healthy individuals (n = 50). We detected significantly elevated estradiol levels in critically ill male COVID-19 patients compared to all control cohorts. Testosterone levels were significantly reduced in critically ill male COVID-19 patients compared to control cohorts. No statistically significant differences in sex hormone levels were detected in critically ill female COVID-19 patients, albeit similar trends towards elevated estradiol levels were observed. Linear regression analysis revealed that among a broad range of cytokines and chemokines analysed, IFN-γ levels are positively associated with estradiol levels in male and female COVID-19 patients. Furthermore, male COVID-19 patients with elevated estradiol levels were more likely to receive ECMO treatment. Thus, we herein identified that disturbance of sex hormone metabolism might present a hallmark in critically ill male COVID-19 patients.


Subject(s)
COVID-19/mortality , COVID-19/pathology , Estradiol/blood , Testosterone/blood , Aged , Aged, 80 and over , COVID-19/blood , Critical Care , Critical Illness , Extracorporeal Membrane Oxygenation , Female , Humans , Hypogonadism/pathology , Intensive Care Units , Interferon-gamma/blood , Male , Middle Aged , Retrospective Studies , Risk Factors , SARS-CoV-2 , Severity of Illness Index , Sex Distribution
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