Can the detection dog alert on COVID-19 positive persons by sniffing axillary sweat samples? A proof-of-concept study.

The aim of this proof-of-concept study was to evaluate if trained dogs could discriminate between sweat samples from symptomatic COVID-19 positive individuals (SARS-CoV-2 PCR positive) and those from asymptomatic COVID-19 negative individuals. The study was conducted at 2 sites (Paris, France, and Beirut, Lebanon), followed the same training and testing protocols, and involved six detection dogs (three explosive detection dogs, one search and rescue dog, and two colon cancer detection dogs). A total of 177 individuals were recruited for the study (95 symptomatic COVID-19 positive and 82 asymptomatic COVID-19 negative individuals) from five hospitals, and one underarm sweat sample per individual was collected. The dog training sessions lasted between one and three weeks. Once trained, the dog had to mark the COVID-19 positive sample randomly placed behind one of three or four olfactory cones (the other cones contained at least one COVID-19 negative sample and between zero and two mocks). During the testing session, a COVID-19 positive sample could be used up to a maximum of three times for one dog. The dog and its handler were both blinded to the COVID-positive sample location. The success rate per dog (i.e., the number of correct indications divided by the number of trials) ranged from 76% to 100%. The lower bound of the 95% confidence interval of the estimated success rate was most of the time higher than the success rate obtained by chance after removing the number of mocks from calculations. These results provide some evidence that detection dogs may be able to discriminate between sweat samples from symptomatic COVID-19 individuals and those from asymptomatic COVID-19 negative individuals. However, due to the limitations of this proof-of-concept study (including using some COVID-19 samples more than once and potential confounding biases), these results must be confirmed in validation studies.

[Aging and HIV infection: 4 years follow-up of 149 HIV infected patients older than 60 years in West Paris agglomeration (COREVIH Île-de-France Ouest)]. / Vieillissement et infection par le VIH: suivi de 149 patients âgés de plus de 60ans infectés par le VIH (COREVIH Île-de-France Ouest).

UNLABELLED: In France, patients over 50 years represent more than 23.6% of all registered cases in the French Hospital Database for HIV (FHDH), and 18% of newly HIV-diagnosed patients. OBJECTIVE: To describe the long-term evolution after 4 years of a cohort of HIV infected patients older than 60 years recruited in COREVIH Île-de-France Ouest. RESULTS: One hundred and forty-nine participants, 115 men (77%) and 34 women (23%), were included in the cohort analysis in 2004, and baseline characteristics were: median age 65.4 years (60.3-86.3), CDC stage C: 36%, HBV and HCV co-infections: four (2.7%) and eight (5.4%) patients, median time from first HIV infection diagnosis: 8.5 years (0.25-19.5), ongoing HAART regimen: 88%, median duration of ARV treatment: 7.5 years (0.2-15.5), baseline CD4 cells count: 372/mm(3) (18-1860), HIV viral load less than 200 c/ml: 104 (70%). After a 4-year follow-up, 111 patients were alive, all but one treated with HAART, 17/149 (11.5%) were lost for follow-up, and 21/149 were deceased (14%). Causes of death were acute cardiovascular disease (4/21), neoplasia (11/21), neurological disease 1/21, end stage liver disease 3/21, unknown 2/21. The prevalence of co-morbidities after 4 years of follow-up were: arterial hypertension 40/111 (36%), hypercholesterolemia 48/111 (43%), diabetes 23/111 (21%), kidney disease with renal insufficiency (creatinine clairance<60 ml/min): 36/111 (32%). At the end of follow-up, median CD4 cells count was 494/mm(3), and viral load was undetectable less than 200 c/ml in 107/111 patients (96%). No new opportunistic infection occurred during the 4-year follow-up, but 24 patients had a new diagnosis of neoplasia (incidence 40/1000 person-year). Cancer was the cause of death in 11/24. CONCLUSION: Clinical and immunological improvement was continuous under HAART in these aged HIV infected patients, but co-morbidities are frequently observed in this population, with high incidence of cardiovascular disease and neoplasia, and related mortality. A multidisciplinary approach, with preventive consultations, oncology and cardiovascular screening, as done in geriatrics, is warranted in the aging HIV population.