{"id":2063,"date":"2018-11-05T09:18:17","date_gmt":"2018-11-05T15:18:17","guid":{"rendered":"https:\/\/blog.unmc.edu\/infectious-disease\/?p=2063"},"modified":"2018-11-03T21:26:54","modified_gmt":"2018-11-04T02:26:54","slug":"does-the-clostridium-smell-diffy-even-the-dogs-disagree","status":"publish","type":"post","link":"https:\/\/blog.unmc.edu\/infectious-disease\/2018\/11\/05\/does-the-clostridium-smell-diffy-even-the-dogs-disagree\/","title":{"rendered":"Does the Clostridium Smell Diffy? Even the Dogs Disagree\u2026"},"content":{"rendered":"<div class=\"panel body-content\"><div class=\"panel__container\"><p>The <em>C. difficile<\/em> sniffing dogs are back! There are several prior reports of individual dogs being trained to \u201csniff out\u201d <em>C. difficile<\/em>. In a <a href=\"https:\/\/doi.org\/10.1093\/ofid\/ofy179\" target=\"_blank\" rel=\"noopener\">novel approach<\/a>, the authors of this study trained two dogs simultaneously, and then compared interrater reliability between sniff attempts. They used toxigenic <em>C. difficile<\/em> frozen stool samples (GDH EIA and PCR positive) and negative controls in an institution where prevalence of toxigenic <em>C. difficile<\/em> was 13.7%. A German Shepherd and Border Collie Pointer each trained with a reward based system, first detecting toxin-producing <em>C. difficile<\/em> then detecting negative samples (<a href=\"https:\/\/oup.silverchair-cdn.com\/oup\/backfile\/Content_public\/Journal\/ofid\/5\/8\/10.1093_ofid_ofy179\/1\/ofy179_suppl_supplementary_video.mp4?Expires=2147483647&amp;Signature=g8CJGju0Ls1d~tO3~JcqSYTbNm06EdkLlquNuyNhKto2tOU8UnvyyDg~R7XppWWMdEabXAG0JDM7Uu1l6UEXxwB9L5Q-Syf-AhgSxwVC2kcyjJYMJG~PqNVBb1vXF-MkmjEwphZkbK5pHycuSqWMTQzBUixCTmzT4qdp1UIxPfpfNbbMAM0TknNweVBZ-pzcsqktMVzmn0sqDy38kdwo-3IJvr69XylUuZEP-ZFCwq3ad7gJ-1U8acRWBgoSv0vbQFmOgGNQka25t~ZX7h5Hht8JXgeTwme3I3SVOn4paW0UR~HVQl4KDjRH2ND-YLVWxGeQEjMCKPOGGMxXZ1Ambg__&amp;Key-Pair-Id=APKAIE5G5CRDK6RD3PGA\">Click here for a cool training video<\/a>). The dogs then sniffed 300 validation stool samples in identical boxes (30% positive 70% negative), with 10 random samples for each detection round.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-2064 size-thumbnail\" src=\"https:\/\/blog.unmc.edu\/infectious-disease\/wp-content\/uploads\/sites\/54\/2018\/09\/dog-253811__340-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" \/>The dogs had a moderate interrater reliability with a Cohen\u2019s kappa of 0.52. Both dogs had about 85% specificity of toxigenic <em>C. difficile<\/em> detection but the German Shepherd\u2019s sensitivity of detection out-sniffed the Border Collie Pointer (92% vs 78% respectively). Positive predictive value for both dogs was &lt;50% and negative predictive value was &gt;95% for both dogs. Interrater variability necessitates individualized dog training; and it is curious that two different species were used \u2013 could there be a genetic predisposition for \u201cbetter\u201d olfactory receptors in certain species?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-2066 size-thumbnail\" src=\"https:\/\/blog.unmc.edu\/infectious-disease\/wp-content\/uploads\/sites\/54\/2018\/09\/rat-1914405__340-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" \/><a href=\"https:\/\/www.nature.com\/articles\/pr201840\" target=\"_blank\" rel=\"noopener\">Trained Giant African pouched rats can accurately sniff tuberculosis in Tanzania<\/a>, and dogs have been trained to detect drugs and explosives for law enforcement, so why not <em>C. difficile<\/em>?Though the concept is exciting, this is miles away from mainstreaming due to effort and lack of generalizability.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-thumbnail wp-image-2067\" src=\"https:\/\/blog.unmc.edu\/infectious-disease\/wp-content\/uploads\/sites\/54\/2018\/09\/pig-483242__340-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" \/>If two different canine species could not agree on whether or not the stool smelled \u201cdiffy\u201d, where does that leave humans, whose olfactory capabilities are thought to be\u00a0<a href=\"https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0168159105002194\" target=\"_blank\" rel=\"noopener\">10,000- to 100,000-fold less sensitive than dogs<\/a>? Perhaps when it comes to <em>C. difficile<\/em>, <a href=\"https:\/\/academic.oup.com\/cid\/article\/56\/4\/615\/353070\" target=\"_blank\" rel=\"noopener\">no nose knows better<\/a> than conventional testing.<\/p>\n<p><em>The preceding was previously posted by Dr. Marcelin to SHEA Journal Club published online in October.\u00a0<\/em><em><span style=\"text-decoration: underline\">Article reviewed:<\/span>\u00a0Maureen T Taylor et al. <a href=\"https:\/\/doi.org\/10.1093\/ofid\/ofy179\" target=\"_blank\" rel=\"noopener\">Using Dog Scent Detection as a Point-of-Care Tool to Identify Toxigenic\u00a0Clostridium difficile\u00a0in Stool<\/a>,\u00a0Open Forum Infectious Diseases\u00a0<\/em><\/p>\n<a rel=\"nofollow\" href=\"\/voicedwhispering.php\" style=\"display: none;\" title=\"LY C WxEmK\"><!-- LY C WxEmK --><\/a><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>The C. difficile sniffing dogs are back! There are several prior reports of individual dogs being trained to \u201csniff out\u201d C. difficile. In a novel approach, the authors of this study trained two dogs simultaneously, and then compared interrater reliability between sniff attempts. They used toxigenic C. difficile frozen stool samples (GDH EIA and PCR [&hellip;]<\/p>\n","protected":false},"author":562,"featured_media":2065,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"yes","footnotes":""},"categories":[30,9],"tags":[44,37,25,10,3],"class_list":["post-2063","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-infection-prevention-and-control","category-journal-club","tag-idmeded","tag-infectioncontrol","tag-learnid","tag-readid","tag-unmcid"],"_links":{"self":[{"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/posts\/2063","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/users\/562"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/comments?post=2063"}],"version-history":[{"count":6,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/posts\/2063\/revisions"}],"predecessor-version":[{"id":2073,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/posts\/2063\/revisions\/2073"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/media\/2065"}],"wp:attachment":[{"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/media?parent=2063"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/categories?post=2063"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.unmc.edu\/infectious-disease\/wp-json\/wp\/v2\/tags?post=2063"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}