{"id":294,"date":"2023-09-16T22:20:42","date_gmt":"2023-09-16T21:20:42","guid":{"rendered":"https:\/\/microregistrar.com\/?p=294"},"modified":"2023-09-16T22:20:42","modified_gmt":"2023-09-16T21:20:42","slug":"smi-investigation-of-whooping-cough","status":"publish","type":"post","link":"https:\/\/microregistrar.com\/?p=294","title":{"rendered":"SMI: Investigation of whooping cough"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\" id=\"types-of-specimen\">Types of specimen<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pernasal swab<\/li>\n\n\n\n<li>Nasopharyngeal aspirate<\/li>\n\n\n\n<li>Nasopharyngeal swab<\/li>\n\n\n\n<li>Serum<\/li>\n<\/ul>\n\n\n\n<p>Cough plates are not recommended.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"selective-media\">Selective media<\/h2>\n\n\n\n<p>It contains blood or charcoal or both, along with selective antibiotic supplements \u2013 penicillin, cefalexin or meticillin.<br>It should be able to suppress other nasopharyngeal flora. Meticillin is the least inhibitory, and cefalexin is the most. Cefalexin is the drug of choice for selective media in the UK.<\/p>\n\n\n\n<p>Pertussis selective media \u2013<\/p>\n\n\n\n<p><a rel=\"noreferrer noopener\" href=\"https:\/\/drive.google.com\/file\/d\/1Nt9VOrqp7f-NiWJKC-mCymylQfijBdZ8\/view?usp=sharing\" target=\"_blank\">Regan-Lowe Charcoal Agar&nbsp;<\/a>(Ref&nbsp;<a rel=\"noreferrer noopener\" href=\"https:\/\/www.bd.com\/resource.aspx?IDX=28013\" target=\"_blank\">bd.com<\/a>)<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"safety\">Safety<\/h2>\n\n\n\n<p>Containment level 2.<br>If the procedure is likely to give rise to aerosol, perform it inside a microbiology safety cabinet.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/microregistrar.com\/wp-content\/uploads\/2022\/02\/image.png\" alt=\"Chart showing when to perform culture, PCR or serology.\" class=\"wp-image-9709\"\/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"culture\">Culture<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Good specificity.<\/li>\n\n\n\n<li>It should be performed during the first 2 weeks of cough. Sensitivity decreases after that \u2013 increasing the risk of false negatives.<\/li>\n\n\n\n<li>False negative increases if the culture is performed after 3 weeks\/ in adults or adolescents\/ in cases of processing delay (it is a delicate organism)\/ poorly taken specimens\/ vaccinated patients. Hence a negative culture may not exclude the infection.<\/li>\n\n\n\n<li>Report as \u2013 Bordetella pertussis isolated (if positive) \/ Bordetella pertussis not isolated (or B parapertussis if that is the pathogen) (if negative).<\/li>\n\n\n\n<li>Confirmation can be done using MALDI ToF.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"pcr\">PCR<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>More sensitive than the culture. <\/li>\n\n\n\n<li>Organisms need not be viable.<\/li>\n\n\n\n<li>It should be performed within 4 weeks of symptom onset.<\/li>\n\n\n\n<li>The nasopharyngeal swab is preferred, but a throat swab can be used.<\/li>\n\n\n\n<li>Interpretation is based on the target. Report B pertussis\/B parapertussis\/B holmesii DNA detected or not detected. (see below)<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>IS481<\/td><td>ptxS1<\/td><td>hlS1001<\/td><td>plS1001<\/td><td>Report<\/td><\/tr><tr><td>+<\/td><td>+<\/td><td>\u2013<\/td><td>\u2013<\/td><td><em>B pertussis<\/em>&nbsp;DNA detected<\/td><\/tr><tr><td>\u2013<\/td><td>+<\/td><td>\u2013<\/td><td>+<\/td><td><em>B parapertussis<\/em>&nbsp;DNA detected<\/td><\/tr><tr><td>+<\/td><td>\u2013<\/td><td>+<\/td><td>\u2013<\/td><td><em>B. holmesii<\/em>&nbsp;DNA detected<\/td><\/tr><tr><td>+<\/td><td>+<\/td><td>\u2013<\/td><td>+<\/td><td><em>B. pertussis<\/em>&nbsp;<em>and B. parapertussis<\/em>&nbsp;DNA detected<\/td><\/tr><tr><td>+<\/td><td>+<\/td><td>+<\/td><td>\u2013<\/td><td><em>B. pertussis<\/em>&nbsp;and&nbsp;<em>B.<\/em>&nbsp;<em>holmesii<\/em>&nbsp;DNA detected<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"serology\">Serology<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Should be performed after 2 weeks of symptom onset.<\/li>\n\n\n\n<li>ELISA to detect anti-pertussis toxin (PT) IgG; anti-filamentous hemagglutinin (FHA) can also be tested.<\/li>\n\n\n\n<li>Serology is useful in older childrens and adults.<\/li>\n\n\n\n<li>Maternal antibody (in neonate), primary vaccine (up to 10 months) and booster vaccine (up to 3 years) can confound the serology result. It is recommended that serology should be performed at least perform 1 year after the primary or booster dose of the Pertussis vaccine.<\/li>\n\n\n\n<li>Anti-PT IgG serology test cannot be used to test for immunity.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A case of pertussis is serologically confirmed when anti-PT IgG concentration is &gt;70 International Units per millilitre (IU\/mL) in the absence of recent vaccination (within the past year).<\/li>\n\n\n\n<li>A case of parapertussis is serologically confirmed when there is a significant anti-FHA IgG increase without an increase in anti-PT IgG, IgM, and IgA antibodies.<\/li>\n\n\n\n<li>If both anti-PT IgG and anti-FHA IgG are significantly increased, the results are indicative of infection with&nbsp;Bordetella&nbsp;species.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"reference\">Reference:<\/h2>\n\n\n\n<p><a href=\"https:\/\/www.gov.uk\/government\/publications\/smi-b-6-investigation-of-specimens-for-bordetella-pertussis-and-bordetella-parapertussis\">https:\/\/www.gov.uk\/government\/publications\/smi-b-6-investigation-of-specimens-for-bordetella-pertussis-and-bordetella-parapertussis<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Types of specimen Cough plates are not recommended. Selective media It contains blood or charcoal or both, along with selective [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ngg_post_thumbnail":0,"footnotes":""},"categories":[60],"tags":[69,70,64,68,63,67],"class_list":["post-294","post","type-post","status-publish","format-standard","hentry","category-laboratory","tag-bordetella","tag-bordetella-parapertussis","tag-laboratory","tag-pertussis","tag-smi","tag-whooping-cough"],"_links":{"self":[{"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/posts\/294","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/microregistrar.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=294"}],"version-history":[{"count":3,"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/posts\/294\/revisions"}],"predecessor-version":[{"id":653,"href":"https:\/\/microregistrar.com\/index.php?rest_route=\/wp\/v2\/posts\/294\/revisions\/653"}],"wp:attachment":[{"href":"https:\/\/microregistrar.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microregistrar.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microregistrar.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}