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Created page with "<p><b><span style="color: #000000">Haemophilus influenzae,</span></b><span style="color: #000000"> formerly called <b>Pfeiffer's bacillus</b> or <i><b>Bacillus influenza..."
<p><b><span style="color: #000000">[[Haemophilus influenzae]],</span></b><span style="color: #000000"> formerly called <b>Pfeiffer's bacillus</b> or <i><b>Bacillus influenzae</b></i>, is a non-motile Gram-negative rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the <i>Pasteurellaceae</i> family, it is generally aerobic, but can grow as a facultative anaerobe.<sup id="cite_ref-KuhnertChristensen_0-0" class="reference"><font size="2">[1]</font></sup> <i>H. influenzae</i> was mistakenly considered to be the cause of influenza until 1933, when the viral etiology of the flu became apparent. Still, <i>H. influenzae</i> is responsible for a wide range of clinical diseases.</span></p>
<p><span style="color: #000000"><i>H. influenzae</i> was the first free-living organism to have its entire genome sequenced. The sequencing project was completed and published in 1995.</span></p>
<p> </p>
<h2><span style="color: #000000"><span id="Serotypes" class="mw-headline">Serotypes</span></span></h2>
<p><span style="color: #000000">In 1930, 2 major categories of <i>H. influenzae</i> were defined: the unencapsulated strains and the encapsulated strains. Encapsulated strains were classified on the basis of their distinct capsular antigens. There are six generally recognized types of encapsulated <i>H. influenzae</i>: a, b, c, d, e, and f.<sup id="cite_ref-Sherris_1-0" class="reference"><font size="2">[2]</font></sup> Genetic diversity among unencapsulated strains is greater than within the encapsulated group. Unencapsulated strains are termed nontypable (NTHi) because they lack capsular serotypes, however they can be classified by multi-locus sequence typing. The pathogenesis of <i>H. influenzae</i> infections is not completely understood, although the presence of the capsule in encapsulated type b (Hib), a serotype causing conditions such as epiglottitis, is known to be a major factor in virulence. Their capsule allows them to resist phagocytosis and complement-mediated lysis in the non-immune host. The unencapsulated strains are almost always less invasive, however they can produce an inflammatory response in humans which can lead to many symptoms. Vaccination with Hib conjugate vaccine is effective in preventing Hib infection. Several vaccines are now available for routine use against Hib, however vaccines are not yet available against NTHi.</span></p>
<h2><span style="color: #000000"><span id="Diseases" class="mw-headline">Diseases</span></span></h2>
<p>
<table style="text-align: left; line-height: 1.5em; width: 22em; font-size: 88%" class="infobox" cellspacing="5">
<tbody>
<tr>
<th style="text-align: center; background-color: lightgrey; font-size: 125%; font-weight: bold" colspan="2"><span style="color: #000000">Haemophilus influenzae infection</span></th>
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<tr>
<td style="text-align: center" colspan="2"><span style="color: #000000"><i>Classification and external resources</i></span></td>
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<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">ICD-10</span></th>
<td><span style="color: #000000">A49.2</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">ICD-9</span></th>
<td><span style="color: #000000">041.5</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">DiseasesDB</span></th>
<td><span style="color: #000000">5570</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">MedlinePlus</span></th>
<td><span style="color: #000000">000612 (Meningitis)</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">eMedicine</span></th>
<td><span style="color: #000000">topic list</span></td>
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</tbody>
</table>
</p>
<p><span style="color: #000000">Most strains of <i>H. influenzae</i> are opportunistic pathogens - that is, they usually live in their host without causing disease, but cause problems only when other factors (such as a viral infection or reduced immune function) create an opportunity.</span></p>
<p><span style="color: #000000">Naturally-acquired disease caused by <i>H. influenzae</i> seems to occur in humans only. In infants and young children, <i>H. influenzae</i> type b (Hib) causes bacteremia, pneumonia, and acute bacterial meningitis. Occasionally, it causes cellulitis, osteomyelitis, epiglottitis, and infectious arthritis. Due to routine use of the Hib conjugate vaccine in the U.S. since 1990, the incidence of invasive Hib disease has decreased to 1.3/100,000 in children. However, Hib remains a major cause of lower respiratory tract infections in infants and children in developing countries where vaccine is not widely used. Unencapsulated <i>H. influenzae</i> causes ear infections (otitis media), eye infections (conjunctivitis), and sinusitis in children and is associated with pneumonia.</span></p>
<h2><span style="color: #000000"><span id="Diagnosis" class="mw-headline">Diagnosis</span></span></h2>
<div class="thumb tright">
<div style="width: 252px" class="thumbinner"><span style="color: #000000"><img class="thumbimage" alt="" width="250" height="209" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Haemophilus_influenzae_Gram.JPG/250px-Haemophilus_influenzae_Gram.JPG" /> </span>
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<div class="magnify"><span style="color: #000000"><img alt="" width="15" height="11" src="http://bits.wikimedia.org/skins-1.5/common/images/magnify-clip.png" /></span></div>
<span style="color: #000000"><i>H. influenzae</i> Gram stain of a sputum sample, appear as Gram negative cocco-bacilli.<sup id="cite_ref-2" class="reference"><font size="1">[3]</font></sup></span></div>
</div>
</div>
<p><span style="color: #000000">Clinical diagnosis of <i>H. influenzae</i> is typically performed by bacterial culture or latex particle agglutination. Diagnosis is considered confirmed when the organism is isolated from a sterile body site. In this respect, <i>H. influenzae</i> cultured from the nasopharyngeal cavity or sputum would not indicate <i>H. influenzae</i> disease because these sites are colonized in disease free individuals.<sup id="cite_ref-Puri_1999_3-0" class="reference"><font size="2">[4]</font></sup> However <i>H. influenzae</i> isolated from cerebrospinal fluid or blood would indicate a <i>H. influenzae</i> infection.</span></p>
<h3><span style="color: #000000"><span id="Culture" class="mw-headline">Culture</span></span></h3>
<p><span style="color: #000000">Bacterial culture of <i>H. influenzae</i> is performed on agar plates, preferably Chocolate agar, plate with added X(Hemin) & V(NAD) factors at 37°C in an enriched CO2 incubator.<sup id="cite_ref-4" class="reference"><font size="2">[5]</font></sup> Blood agar growth is only achieved as a satellite phenomenon around other bacteria. Colonies of <i>H. influenzae</i> appear as convex, smooth, pale, grey or transparent colonies. Gram-stained and microscopic observation of a specimen of <i>H. influenzae</i> will show Gram-negative, coccobacilli, with no specific arrangement. The cultured organism can be further characterized using catalase and oxidase tests, both of which should be positive. Further serological is necessary to distinguish the capsular polysaccharide and differentiate between <i>H. influenzae</i> b and non-encapsulated species.</span></p>
<p><span style="color: #000000">Although highly specific, bacterial culture of <i>H. influenzae</i> lacks in sensitivity. Use of antibiotics prior to sample collection greatly reduces the isolation rate by killing the bacteria before identification is possible.<sup id="cite_ref-John_1991_5-0" class="reference"><font size="2">[6]</font></sup> Beyond this, <i>H. influenzae</i> is a finicky bacterium to culture, and any modification of culture procedures can greatly reduce isolation rates. Poor quality of laboratories in developing countries has resulted in poor isolation rates of <i>H. influenzae</i>.</span></p>
<p><span style="color: #000000">H. influenzae will grow in the hemolytic zone of Staphylococcus aureus on Blood Agar plates. The hemolysis of cells by Staph. aureus releases nutrients vital to the growth of H. influenzae. H. influenzae will not grow outside the hemolytic zone of Staph. aureus due to the lack of nutrients in these areas.</span></p>
<h3><span style="color: #000000"><span id="Latex_particle_agglutination" class="mw-headline">Latex particle agglutination</span></span></h3>
<p><span style="color: #000000">Latex particle agglutination test (LAT) is a more sensitive method to detect <i>H. influenzae</i> than culture.<sup id="cite_ref-Kennedy_2007_6-0" class="reference"><font size="2">[7]</font></sup> Because the method relies on antigen rather than viable bacteria, the results are not disrupted by prior antibiotic use. It also has the added benefit of being much quicker than culture methods. However, antibiotic sensitivity is not possible with LAT, so a parallel culture is necessary.</span></p>
<h3><span style="color: #000000"><span id="Molecular_Methods" class="mw-headline">Molecular Methods</span></span></h3>
<p><span style="color: #000000">Polymerase chain reaction (PCR) assays have been proven to be more sensitive than either LAT or culture tests and highly specific.<sup id="cite_ref-Kennedy_2007_6-1" class="reference"><font size="2">[7]</font></sup> However, PCR assays have not yet become routine in clinical settings. Counter-current immunoelectrophoresis has been shown to be an effective research diagnostic method, but has been largely supplanted by PCR.</span></p>
<h2><span style="color: #000000"><span id="Interaction_with_Streptococcus_pneumoniae" class="mw-headline">Interaction with <i>Streptococcus pneumoniae</i></span></span></h2>
<p><span style="color: #000000">Both <i>H. influenzae</i> and <i>S. pneumoniae</i> can be found in the upper respiratory system of humans. A study of competition in a laboratory revealed that, in a petri dish, <i>S. pneumoniae</i> always overpowered <i>H. influenzae</i> by attacking it with hydrogen peroxide and stripping off the surface molecules that <i>H. influenzae</i> needs for survival.</span></p>
<p><span style="color: #000000">When both bacteria are placed together into a nasal cavity, within 2 weeks, only <i>H. influenzae</i> survives. When either is placed separately into a nasal cavity, each one survives. Upon examining the upper respiratory tissue from mice exposed to both bacteria species, an extraordinarily large number of neutrophils (immune cells) was found. In mice exposed to only one bacteria, the cells were not present.</span></p>
<p><span style="color: #000000">Lab tests showed that neutrophils exposed to dead <i>H. influenzae</i> were more aggressive in attacking <i>S. pneumoniae</i> than unexposed neutrophils. Exposure to dead <i>H. influenzae</i> had no effect on live <i>H. influenzae</i>.</span></p>
<p><span style="color: #000000">Two scenarios may be responsible for this response:</span></p>
<ol>
<li><span style="color: #000000">When <i>H. influenzae</i> is attacked by <i>S. pneumoniae</i>, it signals the immune system to attack the <i>S. pneumoniae</i> </span></li>
<li><span style="color: #000000">The combination of the two species together triggers an immune system response that is not set off by either species individually. </span></li>
</ol>
<p><span style="color: #000000">It is unclear why <i>H. influenzae</i> is not affected by the immune response.<sup id="cite_ref-Lysenko_2005_7-0" class="reference"><font size="2">[8]</font></sup></span></p>
<h2><span style="color: #000000"><span id="Treatment" class="mw-headline">Treatment</span></span></h2>
<p><span style="color: #000000"><i>Haemophilus influenzae</i> produces beta-lactamases, and it is also able to modify its penicillin binding proteins, so it has gained resistance to the penicillin family of antibiotics. In severe cases cefotaxime and ceftriaxone are the elected antibiotics, delivered directly into the bloodstream, and for the less severe cases an association of ampicillin and sulbactam, cephalosporins of the second and third generation, or fluoroquinolones. Macrolide antibiotics (e.g. clarithromycin) may be used in patients with a history of allergy to beta-lactam antibiotics.</span></p>
<h2><span style="color: #000000"><span id="Sequencing" class="mw-headline">Sequencing</span></span></h2>
<p><span style="color: #000000"><i>H. influenzae</i> was the first free-living organism to have its entire genome sequenced. Haemophilus was chosen because one of the project leaders, Nobel laureate Hamilton Smith, had been working on it for decades and was able to provide high-quality DNA libraries. The genome consists of 1,830,140 base pairs of DNA in a single circular chromosome that contains 1740 protein-coding genes, 58 transfer RNA genes tRNA, and 18 other RNA genes. The sequencing method used was Whole genome shotgun. The sequencing project, completed and published in <i>Science</i> in 1995, was conducted at The Institute for Genomic Research.<sup id="cite_ref-Fleichmann_1995_8-0" class="reference"><font size="2">[9]</font></sup></span></p>
<h2><span style="color: #000000"><span id="See_also" class="mw-headline">See also</span></span></h2>
<p> </p>
<ul>
<li><span style="color: #000000">Pasteurellaceae </span></li>
<li><span style="color: #000000">Maurice Hilleman </span></li>
<li><span style="color: #000000">Hattie Alexander </span></li>
<li><span style="color: #000000">Hib vaccine </span></li>
<li><span style="color: #000000">Haemophilus influenzae cellulitis </span></li>
</ul>
<h2><span id="References" class="mw-headline">References</span></h2>
<div class="references-small">
<ol class="references">
<li id="cite_note-KuhnertChristensen-0"><b><a href="#cite_ref-KuhnertChristensen_0-0"><font color="#0645ad">^</font></a></b> <span class="citation book">Kuhnert P; Christensen H (editors). (2008). <i>Pasteurellaceae: Biology, Genomics and Molecular Aspects</i>. Caister Academic Press. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/978-1-904455-34-9" href="/wiki/Special:BookSources/978-1-904455-34-9"><font color="#0645ad">978-1-904455-34-9</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Pasteurellaceae%3A+Biology%2C+Genomics+and+Molecular+Aspects&rft.aulast=Kuhnert+P%3B+Christensen+H+%28editors%29.&rft.au=Kuhnert+P%3B+Christensen+H+%28editors%29.&rft.date=2008&rft.pub=Caister+Academic+Press&rft.isbn=978-1-904455-34-9&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Sherris-1"><b><a href="#cite_ref-Sherris_1-0"><font color="#0645ad">^</font></a></b> <span class="citation book">Ryan KJ; Ray CG (editors) (2004). <i>Sherris Medical Microbiology</i> (4th ed.). McGraw Hill. pp. 396–401. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/0838585299" href="/wiki/Special:BookSources/0838585299"><font color="#0645ad">0838585299</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Sherris+Medical+Microbiology&rft.aulast=Ryan+KJ%3B+Ray+CG+%28editors%29&rft.au=Ryan+KJ%3B+Ray+CG+%28editors%29&rft.date=2004&rft.pages=pp.%26nbsp%3B396%26ndash%3B401&rft.edition=4th&rft.pub=McGraw+Hill&rft.isbn=0838585299&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-2"><b><a href="#cite_ref-2"><font color="#0645ad">^</font></a></b> <span class="citation book">Behrman, Richard E.; Robert M Kliegman and Hal B. Jenson (2004). <a class="external text" rel="nofollow" href="http://books.google.com/?id=6a_lLbxRKwkC"><i><font color="#3366bb">Nelson Tratado de Pediatría</font></i></a>. Elsevier. p. 904. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/8481747475" href="/wiki/Special:BookSources/8481747475"><font color="#0645ad">8481747475</font></a><span class="printonly">. <a class="external free" rel="nofollow" href="http://books.google.com/?id=6a_lLbxRKwkC"><font color="#3366bb">http://books.google.com/?id=6a_lLbxRKwkC</font></a></span><span class="reference-accessdate">. Retrieved 2009-09-11</span>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Nelson+Tratado+de+Pediatr%C3%ADa&rft.aulast=Behrman&rft.aufirst=Richard+E.&rft.au=Behrman%2C%26%2332%3BRichard+E.&rft.date=2004&rft.pages=p.%26nbsp%3B904&rft.pub=Elsevier&rft.isbn=8481747475&rft_id=http%3A%2F%2Fbooks.google.com%2F%3Fid%3D6a_lLbxRKwkC&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Puri_1999-3"><b><a href="#cite_ref-Puri_1999_3-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Puri J, Talwar V, Juneja M, Agarwal KN, Gupta HC (1999). "Prevalence of anti-microbial resistance among respiratory isolates of Haemophilus influenzae". <i>Indian Pediatr</i> <b>36</b> (10): 1029–32. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/10745313"><font color="#3366bb">10745313</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Prevalence+of+anti-microbial+resistance+among+respiratory+isolates+of+Haemophilus+influenzae&rft.jtitle=Indian+Pediatr&rft.aulast=Puri+J%2C+Talwar+V%2C+Juneja+M%2C+Agarwal+KN%2C+Gupta+HC&rft.au=Puri+J%2C+Talwar+V%2C+Juneja+M%2C+Agarwal+KN%2C+Gupta+HC&rft.date=1999&rft.volume=36&rft.issue=10&rft.pages=1029%E2%80%9332&rft_id=info:pmid/10745313&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-4"><b><a href="#cite_ref-4"><font color="#0645ad">^</font></a></b> <span class="citation Journal"><i>Generic protocol for population-based surveillance of Haemophilus influenzae type B</i>. World Health Organization. 1997. WHO/VRD/GEN/95.05.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Generic+protocol+for+population-based++surveillance+of+Haemophilus+influenzae+type+B&rft.date=1997&rft.pub=World+Health+Organization&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-John_1991-5"><b><a href="#cite_ref-John_1991_5-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">John TJ, Cherian T, Steinhoff MC, Simoes EA, John M (1991). "Etiology of acute respiratory infections in children in tropical southern India". <i>Rev Infect Dis</i> <b>13</b>: Suppl 6:S463–9. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/1862277"><font color="#3366bb">1862277</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Etiology+of+acute+respiratory+infections+in+children+in+tropical+southern+India&rft.jtitle=Rev+Infect+Dis&rft.aulast=John+TJ%2C+Cherian+T%2C+Steinhoff+MC%2C+Simoes+EA%2C+John+M&rft.au=John+TJ%2C+Cherian+T%2C+Steinhoff+MC%2C+Simoes+EA%2C+John+M&rft.date=1991&rft.volume=13&rft.pages=Suppl+6%3AS463%E2%80%939&rft_id=info:pmid/1862277&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Kennedy_2007-6">^ <a href="#cite_ref-Kennedy_2007_6-0"><sup><i><b><font color="#0645ad" size="2">a</font></b></i></sup></a> <a href="#cite_ref-Kennedy_2007_6-1"><sup><i><b><font color="#0645ad" size="2">b</font></b></i></sup></a> <span class="citation Journal">Kennedy WA, Chang SJ, Purdy K, LE T, Kilgore PE, Kim JS et al. (2007). <a class="external text" rel="nofollow" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2870670"><font color="#3366bb">"Incidence of bacterial meningitis in Asia using enhanced CSF testing: polymerase chain reaction, latex agglutination and culture"</font></a>. <i>Epidemiol Infect</i> <b>135</b> (7): 1217–26. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1017%2FS0950268806007734"><font color="#3366bb">10.1017/S0950268806007734</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/17274856"><font color="#3366bb">17274856</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Incidence+of+bacterial+meningitis+in+Asia+using+enhanced+CSF+testing%3A+polymerase+chain+reaction%2C+latex+agglutination+and+culture&rft.jtitle=Epidemiol+Infect&rft.aulast=Kennedy+WA%2C+Chang+SJ%2C+Purdy+K%2C+LE+T%2C+Kilgore+PE%2C+Kim+JS+et+al.&rft.au=Kennedy+WA%2C+Chang+SJ%2C+Purdy+K%2C+LE+T%2C+Kilgore+PE%2C+Kim+JS+et+al.&rft.date=2007&rft.volume=135&rft.issue=7&rft.pages=1217%E2%80%9326&rft_id=info:doi/10.1017%2FS0950268806007734&rft_id=info:pmid/17274856&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Lysenko_2005-7"><b><a href="#cite_ref-Lysenko_2005_7-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Lysenko E, Ratner A, Nelson A, Weiser J (2005). <a class="external text" rel="nofollow" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1238736"><font color="#3366bb">"The role of innate immune responses in the outcome of interspecies competition for colonization of mucosal surfaces"</font></a>. <i>PLoS Pathog</i> <b>1</b> (1): e1. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1371%2Fjournal.ppat.0010001"><font color="#3366bb">10.1371/journal.ppat.0010001</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/16201010"><font color="#3366bb">16201010</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=The+role+of+innate+immune+responses+in+the+outcome+of+interspecies+competition+for+colonization+of+mucosal+surfaces&rft.jtitle=PLoS+Pathog&rft.aulast=Lysenko+E%2C+Ratner+A%2C+Nelson+A%2C+Weiser+J&rft.au=Lysenko+E%2C+Ratner+A%2C+Nelson+A%2C+Weiser+J&rft.date=2005&rft.volume=1&rft.issue=1&rft.pages=e1&rft_id=info:doi/10.1371%2Fjournal.ppat.0010001&rft_id=info:pmid/16201010&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Fleichmann_1995-8"><b><a href="#cite_ref-Fleichmann_1995_8-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Fleischmann R, Adams M, White O, Clayton R, Kirkness E, Kerlavage A, Bult C, Tomb J, Dougherty B, Merrick J (1995). <a class="external text" rel="nofollow" href="http://www.sciencemag.org/cgi/content/abstract/269/5223/496"><font color="#3366bb">"Whole-genome random sequencing and assembly of Haemophilus influenzae Rd"</font></a>. <i>Science</i> <b>269</b> (5223): 496–512. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1126%2Fscience.7542800"><font color="#3366bb">10.1126/science.7542800</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/7542800"><font color="#3366bb">7542800</font></a><span class="printonly">. <a class="external free" rel="nofollow" href="http://www.sciencemag.org/cgi/content/abstract/269/5223/496"><font color="#3366bb">http://www.sciencemag.org/cgi/content/abstract/269/5223/496</font></a></span>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Whole-genome+random+sequencing+and+assembly+of+Haemophilus+influenzae+Rd&rft.jtitle=Science&rft.aulast=Fleischmann+R%2C+Adams+M%2C+White+O%2C+Clayton+R%2C+Kirkness+E%2C+Kerlavage+A%2C+Bult+C%2C+Tomb+J%2C+Dougherty+B%2C+Merrick+J&rft.au=Fleischmann+R%2C+Adams+M%2C+White+O%2C+Clayton+R%2C+Kirkness+E%2C+Kerlavage+A%2C+Bult+C%2C+Tomb+J%2C+Dougherty+B%2C+Merrick+J&rft.date=1995&rft.volume=269&rft.issue=5223&rft.pages=496%E2%80%93512&rft_id=info:doi/10.1126%2Fscience.7542800&rft_id=info:pmid/7542800&rft_id=http%3A%2F%2Fwww.sciencemag.org%2Fcgi%2Fcontent%2Fabstract%2F269%2F5223%2F496&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
</ol>
</div>
<h2> <span id="External_links" class="mw-headline">External links</span></h2>
<ul>
<li><a class="external text" rel="nofollow" href="http://www.who.int/immunization/topics/hib/en/index.html"><font color="#3366bb">Hib information</font></a> on the <a title="World Health Organization" href="/wiki/World_Health_Organization"><font color="#0645ad">World Health Organization</font></a> (WHO) site.</li>
<li><a class="external text" rel="nofollow" href="http://www.cdc.gov/ncidod/dbmd/diseaseinfo/haeminfluserob_t.htm"><font color="#3366bb">Fact sheet</font></a> on the <a title="Centers for Disease Control and Prevention" href="/wiki/Centers_for_Disease_Control_and_Prevention"><font color="#0645ad">Centers for Disease Control and Prevention</font></a> (CDC) site.</li>
<li><a class="external text" rel="nofollow" href="http://www.hibaction.org"><font color="#3366bb">Hib Initiative</font></a> - from <a title="Johns Hopkins University" href="/wiki/Johns_Hopkins_University"><font color="#0645ad">Johns Hopkins University</font></a>, <a title="London School of Hygiene & Tropical Medicine" href="/wiki/London_School_of_Hygiene_%26_Tropical_Medicine"><font color="#0645ad">London School of Hygiene & Tropical Medicine</font></a>, <a title="Centers for Disease Control and Prevention" href="/wiki/Centers_for_Disease_Control_and_Prevention"><font color="#0645ad">CDC</font></a> & <a title="World Health Organization" href="/wiki/World_Health_Organization"><font color="#0645ad">WHO</font></a></li>
<li><a class="external text" rel="nofollow" href="http://www.worldpneumoniaday.org"><font color="#3366bb">November 2nd: World Pneumonia Day Website</font></a></li>
</ul>
<p> </p>
<p> </p>
<p><span style="color: #000000"><i>H. influenzae</i> was the first free-living organism to have its entire genome sequenced. The sequencing project was completed and published in 1995.</span></p>
<p> </p>
<h2><span style="color: #000000"><span id="Serotypes" class="mw-headline">Serotypes</span></span></h2>
<p><span style="color: #000000">In 1930, 2 major categories of <i>H. influenzae</i> were defined: the unencapsulated strains and the encapsulated strains. Encapsulated strains were classified on the basis of their distinct capsular antigens. There are six generally recognized types of encapsulated <i>H. influenzae</i>: a, b, c, d, e, and f.<sup id="cite_ref-Sherris_1-0" class="reference"><font size="2">[2]</font></sup> Genetic diversity among unencapsulated strains is greater than within the encapsulated group. Unencapsulated strains are termed nontypable (NTHi) because they lack capsular serotypes, however they can be classified by multi-locus sequence typing. The pathogenesis of <i>H. influenzae</i> infections is not completely understood, although the presence of the capsule in encapsulated type b (Hib), a serotype causing conditions such as epiglottitis, is known to be a major factor in virulence. Their capsule allows them to resist phagocytosis and complement-mediated lysis in the non-immune host. The unencapsulated strains are almost always less invasive, however they can produce an inflammatory response in humans which can lead to many symptoms. Vaccination with Hib conjugate vaccine is effective in preventing Hib infection. Several vaccines are now available for routine use against Hib, however vaccines are not yet available against NTHi.</span></p>
<h2><span style="color: #000000"><span id="Diseases" class="mw-headline">Diseases</span></span></h2>
<p>
<table style="text-align: left; line-height: 1.5em; width: 22em; font-size: 88%" class="infobox" cellspacing="5">
<tbody>
<tr>
<th style="text-align: center; background-color: lightgrey; font-size: 125%; font-weight: bold" colspan="2"><span style="color: #000000">Haemophilus influenzae infection</span></th>
</tr>
<tr>
<td style="text-align: center" colspan="2"><span style="color: #000000"><i>Classification and external resources</i></span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">ICD-10</span></th>
<td><span style="color: #000000">A49.2</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">ICD-9</span></th>
<td><span style="color: #000000">041.5</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">DiseasesDB</span></th>
<td><span style="color: #000000">5570</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">MedlinePlus</span></th>
<td><span style="color: #000000">000612 (Meningitis)</span></td>
</tr>
<tr>
<th style="text-align: left" scope="row"><span style="color: #000000">eMedicine</span></th>
<td><span style="color: #000000">topic list</span></td>
</tr>
</tbody>
</table>
</p>
<p><span style="color: #000000">Most strains of <i>H. influenzae</i> are opportunistic pathogens - that is, they usually live in their host without causing disease, but cause problems only when other factors (such as a viral infection or reduced immune function) create an opportunity.</span></p>
<p><span style="color: #000000">Naturally-acquired disease caused by <i>H. influenzae</i> seems to occur in humans only. In infants and young children, <i>H. influenzae</i> type b (Hib) causes bacteremia, pneumonia, and acute bacterial meningitis. Occasionally, it causes cellulitis, osteomyelitis, epiglottitis, and infectious arthritis. Due to routine use of the Hib conjugate vaccine in the U.S. since 1990, the incidence of invasive Hib disease has decreased to 1.3/100,000 in children. However, Hib remains a major cause of lower respiratory tract infections in infants and children in developing countries where vaccine is not widely used. Unencapsulated <i>H. influenzae</i> causes ear infections (otitis media), eye infections (conjunctivitis), and sinusitis in children and is associated with pneumonia.</span></p>
<h2><span style="color: #000000"><span id="Diagnosis" class="mw-headline">Diagnosis</span></span></h2>
<div class="thumb tright">
<div style="width: 252px" class="thumbinner"><span style="color: #000000"><img class="thumbimage" alt="" width="250" height="209" src="http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Haemophilus_influenzae_Gram.JPG/250px-Haemophilus_influenzae_Gram.JPG" /> </span>
<div class="thumbcaption">
<div class="magnify"><span style="color: #000000"><img alt="" width="15" height="11" src="http://bits.wikimedia.org/skins-1.5/common/images/magnify-clip.png" /></span></div>
<span style="color: #000000"><i>H. influenzae</i> Gram stain of a sputum sample, appear as Gram negative cocco-bacilli.<sup id="cite_ref-2" class="reference"><font size="1">[3]</font></sup></span></div>
</div>
</div>
<p><span style="color: #000000">Clinical diagnosis of <i>H. influenzae</i> is typically performed by bacterial culture or latex particle agglutination. Diagnosis is considered confirmed when the organism is isolated from a sterile body site. In this respect, <i>H. influenzae</i> cultured from the nasopharyngeal cavity or sputum would not indicate <i>H. influenzae</i> disease because these sites are colonized in disease free individuals.<sup id="cite_ref-Puri_1999_3-0" class="reference"><font size="2">[4]</font></sup> However <i>H. influenzae</i> isolated from cerebrospinal fluid or blood would indicate a <i>H. influenzae</i> infection.</span></p>
<h3><span style="color: #000000"><span id="Culture" class="mw-headline">Culture</span></span></h3>
<p><span style="color: #000000">Bacterial culture of <i>H. influenzae</i> is performed on agar plates, preferably Chocolate agar, plate with added X(Hemin) & V(NAD) factors at 37°C in an enriched CO2 incubator.<sup id="cite_ref-4" class="reference"><font size="2">[5]</font></sup> Blood agar growth is only achieved as a satellite phenomenon around other bacteria. Colonies of <i>H. influenzae</i> appear as convex, smooth, pale, grey or transparent colonies. Gram-stained and microscopic observation of a specimen of <i>H. influenzae</i> will show Gram-negative, coccobacilli, with no specific arrangement. The cultured organism can be further characterized using catalase and oxidase tests, both of which should be positive. Further serological is necessary to distinguish the capsular polysaccharide and differentiate between <i>H. influenzae</i> b and non-encapsulated species.</span></p>
<p><span style="color: #000000">Although highly specific, bacterial culture of <i>H. influenzae</i> lacks in sensitivity. Use of antibiotics prior to sample collection greatly reduces the isolation rate by killing the bacteria before identification is possible.<sup id="cite_ref-John_1991_5-0" class="reference"><font size="2">[6]</font></sup> Beyond this, <i>H. influenzae</i> is a finicky bacterium to culture, and any modification of culture procedures can greatly reduce isolation rates. Poor quality of laboratories in developing countries has resulted in poor isolation rates of <i>H. influenzae</i>.</span></p>
<p><span style="color: #000000">H. influenzae will grow in the hemolytic zone of Staphylococcus aureus on Blood Agar plates. The hemolysis of cells by Staph. aureus releases nutrients vital to the growth of H. influenzae. H. influenzae will not grow outside the hemolytic zone of Staph. aureus due to the lack of nutrients in these areas.</span></p>
<h3><span style="color: #000000"><span id="Latex_particle_agglutination" class="mw-headline">Latex particle agglutination</span></span></h3>
<p><span style="color: #000000">Latex particle agglutination test (LAT) is a more sensitive method to detect <i>H. influenzae</i> than culture.<sup id="cite_ref-Kennedy_2007_6-0" class="reference"><font size="2">[7]</font></sup> Because the method relies on antigen rather than viable bacteria, the results are not disrupted by prior antibiotic use. It also has the added benefit of being much quicker than culture methods. However, antibiotic sensitivity is not possible with LAT, so a parallel culture is necessary.</span></p>
<h3><span style="color: #000000"><span id="Molecular_Methods" class="mw-headline">Molecular Methods</span></span></h3>
<p><span style="color: #000000">Polymerase chain reaction (PCR) assays have been proven to be more sensitive than either LAT or culture tests and highly specific.<sup id="cite_ref-Kennedy_2007_6-1" class="reference"><font size="2">[7]</font></sup> However, PCR assays have not yet become routine in clinical settings. Counter-current immunoelectrophoresis has been shown to be an effective research diagnostic method, but has been largely supplanted by PCR.</span></p>
<h2><span style="color: #000000"><span id="Interaction_with_Streptococcus_pneumoniae" class="mw-headline">Interaction with <i>Streptococcus pneumoniae</i></span></span></h2>
<p><span style="color: #000000">Both <i>H. influenzae</i> and <i>S. pneumoniae</i> can be found in the upper respiratory system of humans. A study of competition in a laboratory revealed that, in a petri dish, <i>S. pneumoniae</i> always overpowered <i>H. influenzae</i> by attacking it with hydrogen peroxide and stripping off the surface molecules that <i>H. influenzae</i> needs for survival.</span></p>
<p><span style="color: #000000">When both bacteria are placed together into a nasal cavity, within 2 weeks, only <i>H. influenzae</i> survives. When either is placed separately into a nasal cavity, each one survives. Upon examining the upper respiratory tissue from mice exposed to both bacteria species, an extraordinarily large number of neutrophils (immune cells) was found. In mice exposed to only one bacteria, the cells were not present.</span></p>
<p><span style="color: #000000">Lab tests showed that neutrophils exposed to dead <i>H. influenzae</i> were more aggressive in attacking <i>S. pneumoniae</i> than unexposed neutrophils. Exposure to dead <i>H. influenzae</i> had no effect on live <i>H. influenzae</i>.</span></p>
<p><span style="color: #000000">Two scenarios may be responsible for this response:</span></p>
<ol>
<li><span style="color: #000000">When <i>H. influenzae</i> is attacked by <i>S. pneumoniae</i>, it signals the immune system to attack the <i>S. pneumoniae</i> </span></li>
<li><span style="color: #000000">The combination of the two species together triggers an immune system response that is not set off by either species individually. </span></li>
</ol>
<p><span style="color: #000000">It is unclear why <i>H. influenzae</i> is not affected by the immune response.<sup id="cite_ref-Lysenko_2005_7-0" class="reference"><font size="2">[8]</font></sup></span></p>
<h2><span style="color: #000000"><span id="Treatment" class="mw-headline">Treatment</span></span></h2>
<p><span style="color: #000000"><i>Haemophilus influenzae</i> produces beta-lactamases, and it is also able to modify its penicillin binding proteins, so it has gained resistance to the penicillin family of antibiotics. In severe cases cefotaxime and ceftriaxone are the elected antibiotics, delivered directly into the bloodstream, and for the less severe cases an association of ampicillin and sulbactam, cephalosporins of the second and third generation, or fluoroquinolones. Macrolide antibiotics (e.g. clarithromycin) may be used in patients with a history of allergy to beta-lactam antibiotics.</span></p>
<h2><span style="color: #000000"><span id="Sequencing" class="mw-headline">Sequencing</span></span></h2>
<p><span style="color: #000000"><i>H. influenzae</i> was the first free-living organism to have its entire genome sequenced. Haemophilus was chosen because one of the project leaders, Nobel laureate Hamilton Smith, had been working on it for decades and was able to provide high-quality DNA libraries. The genome consists of 1,830,140 base pairs of DNA in a single circular chromosome that contains 1740 protein-coding genes, 58 transfer RNA genes tRNA, and 18 other RNA genes. The sequencing method used was Whole genome shotgun. The sequencing project, completed and published in <i>Science</i> in 1995, was conducted at The Institute for Genomic Research.<sup id="cite_ref-Fleichmann_1995_8-0" class="reference"><font size="2">[9]</font></sup></span></p>
<h2><span style="color: #000000"><span id="See_also" class="mw-headline">See also</span></span></h2>
<p> </p>
<ul>
<li><span style="color: #000000">Pasteurellaceae </span></li>
<li><span style="color: #000000">Maurice Hilleman </span></li>
<li><span style="color: #000000">Hattie Alexander </span></li>
<li><span style="color: #000000">Hib vaccine </span></li>
<li><span style="color: #000000">Haemophilus influenzae cellulitis </span></li>
</ul>
<h2><span id="References" class="mw-headline">References</span></h2>
<div class="references-small">
<ol class="references">
<li id="cite_note-KuhnertChristensen-0"><b><a href="#cite_ref-KuhnertChristensen_0-0"><font color="#0645ad">^</font></a></b> <span class="citation book">Kuhnert P; Christensen H (editors). (2008). <i>Pasteurellaceae: Biology, Genomics and Molecular Aspects</i>. Caister Academic Press. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/978-1-904455-34-9" href="/wiki/Special:BookSources/978-1-904455-34-9"><font color="#0645ad">978-1-904455-34-9</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Pasteurellaceae%3A+Biology%2C+Genomics+and+Molecular+Aspects&rft.aulast=Kuhnert+P%3B+Christensen+H+%28editors%29.&rft.au=Kuhnert+P%3B+Christensen+H+%28editors%29.&rft.date=2008&rft.pub=Caister+Academic+Press&rft.isbn=978-1-904455-34-9&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Sherris-1"><b><a href="#cite_ref-Sherris_1-0"><font color="#0645ad">^</font></a></b> <span class="citation book">Ryan KJ; Ray CG (editors) (2004). <i>Sherris Medical Microbiology</i> (4th ed.). McGraw Hill. pp. 396–401. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/0838585299" href="/wiki/Special:BookSources/0838585299"><font color="#0645ad">0838585299</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Sherris+Medical+Microbiology&rft.aulast=Ryan+KJ%3B+Ray+CG+%28editors%29&rft.au=Ryan+KJ%3B+Ray+CG+%28editors%29&rft.date=2004&rft.pages=pp.%26nbsp%3B396%26ndash%3B401&rft.edition=4th&rft.pub=McGraw+Hill&rft.isbn=0838585299&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-2"><b><a href="#cite_ref-2"><font color="#0645ad">^</font></a></b> <span class="citation book">Behrman, Richard E.; Robert M Kliegman and Hal B. Jenson (2004). <a class="external text" rel="nofollow" href="http://books.google.com/?id=6a_lLbxRKwkC"><i><font color="#3366bb">Nelson Tratado de Pediatría</font></i></a>. Elsevier. p. 904. <a title="International Standard Book Number" href="/wiki/International_Standard_Book_Number"><font color="#0645ad">ISBN</font></a> <a title="Special:BookSources/8481747475" href="/wiki/Special:BookSources/8481747475"><font color="#0645ad">8481747475</font></a><span class="printonly">. <a class="external free" rel="nofollow" href="http://books.google.com/?id=6a_lLbxRKwkC"><font color="#3366bb">http://books.google.com/?id=6a_lLbxRKwkC</font></a></span><span class="reference-accessdate">. Retrieved 2009-09-11</span>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Nelson+Tratado+de+Pediatr%C3%ADa&rft.aulast=Behrman&rft.aufirst=Richard+E.&rft.au=Behrman%2C%26%2332%3BRichard+E.&rft.date=2004&rft.pages=p.%26nbsp%3B904&rft.pub=Elsevier&rft.isbn=8481747475&rft_id=http%3A%2F%2Fbooks.google.com%2F%3Fid%3D6a_lLbxRKwkC&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Puri_1999-3"><b><a href="#cite_ref-Puri_1999_3-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Puri J, Talwar V, Juneja M, Agarwal KN, Gupta HC (1999). "Prevalence of anti-microbial resistance among respiratory isolates of Haemophilus influenzae". <i>Indian Pediatr</i> <b>36</b> (10): 1029–32. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/10745313"><font color="#3366bb">10745313</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Prevalence+of+anti-microbial+resistance+among+respiratory+isolates+of+Haemophilus+influenzae&rft.jtitle=Indian+Pediatr&rft.aulast=Puri+J%2C+Talwar+V%2C+Juneja+M%2C+Agarwal+KN%2C+Gupta+HC&rft.au=Puri+J%2C+Talwar+V%2C+Juneja+M%2C+Agarwal+KN%2C+Gupta+HC&rft.date=1999&rft.volume=36&rft.issue=10&rft.pages=1029%E2%80%9332&rft_id=info:pmid/10745313&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-4"><b><a href="#cite_ref-4"><font color="#0645ad">^</font></a></b> <span class="citation Journal"><i>Generic protocol for population-based surveillance of Haemophilus influenzae type B</i>. World Health Organization. 1997. WHO/VRD/GEN/95.05.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Generic+protocol+for+population-based++surveillance+of+Haemophilus+influenzae+type+B&rft.date=1997&rft.pub=World+Health+Organization&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-John_1991-5"><b><a href="#cite_ref-John_1991_5-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">John TJ, Cherian T, Steinhoff MC, Simoes EA, John M (1991). "Etiology of acute respiratory infections in children in tropical southern India". <i>Rev Infect Dis</i> <b>13</b>: Suppl 6:S463–9. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/1862277"><font color="#3366bb">1862277</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Etiology+of+acute+respiratory+infections+in+children+in+tropical+southern+India&rft.jtitle=Rev+Infect+Dis&rft.aulast=John+TJ%2C+Cherian+T%2C+Steinhoff+MC%2C+Simoes+EA%2C+John+M&rft.au=John+TJ%2C+Cherian+T%2C+Steinhoff+MC%2C+Simoes+EA%2C+John+M&rft.date=1991&rft.volume=13&rft.pages=Suppl+6%3AS463%E2%80%939&rft_id=info:pmid/1862277&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Kennedy_2007-6">^ <a href="#cite_ref-Kennedy_2007_6-0"><sup><i><b><font color="#0645ad" size="2">a</font></b></i></sup></a> <a href="#cite_ref-Kennedy_2007_6-1"><sup><i><b><font color="#0645ad" size="2">b</font></b></i></sup></a> <span class="citation Journal">Kennedy WA, Chang SJ, Purdy K, LE T, Kilgore PE, Kim JS et al. (2007). <a class="external text" rel="nofollow" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2870670"><font color="#3366bb">"Incidence of bacterial meningitis in Asia using enhanced CSF testing: polymerase chain reaction, latex agglutination and culture"</font></a>. <i>Epidemiol Infect</i> <b>135</b> (7): 1217–26. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1017%2FS0950268806007734"><font color="#3366bb">10.1017/S0950268806007734</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/17274856"><font color="#3366bb">17274856</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Incidence+of+bacterial+meningitis+in+Asia+using+enhanced+CSF+testing%3A+polymerase+chain+reaction%2C+latex+agglutination+and+culture&rft.jtitle=Epidemiol+Infect&rft.aulast=Kennedy+WA%2C+Chang+SJ%2C+Purdy+K%2C+LE+T%2C+Kilgore+PE%2C+Kim+JS+et+al.&rft.au=Kennedy+WA%2C+Chang+SJ%2C+Purdy+K%2C+LE+T%2C+Kilgore+PE%2C+Kim+JS+et+al.&rft.date=2007&rft.volume=135&rft.issue=7&rft.pages=1217%E2%80%9326&rft_id=info:doi/10.1017%2FS0950268806007734&rft_id=info:pmid/17274856&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Lysenko_2005-7"><b><a href="#cite_ref-Lysenko_2005_7-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Lysenko E, Ratner A, Nelson A, Weiser J (2005). <a class="external text" rel="nofollow" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1238736"><font color="#3366bb">"The role of innate immune responses in the outcome of interspecies competition for colonization of mucosal surfaces"</font></a>. <i>PLoS Pathog</i> <b>1</b> (1): e1. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1371%2Fjournal.ppat.0010001"><font color="#3366bb">10.1371/journal.ppat.0010001</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/16201010"><font color="#3366bb">16201010</font></a>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=The+role+of+innate+immune+responses+in+the+outcome+of+interspecies+competition+for+colonization+of+mucosal+surfaces&rft.jtitle=PLoS+Pathog&rft.aulast=Lysenko+E%2C+Ratner+A%2C+Nelson+A%2C+Weiser+J&rft.au=Lysenko+E%2C+Ratner+A%2C+Nelson+A%2C+Weiser+J&rft.date=2005&rft.volume=1&rft.issue=1&rft.pages=e1&rft_id=info:doi/10.1371%2Fjournal.ppat.0010001&rft_id=info:pmid/16201010&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
<li id="cite_note-Fleichmann_1995-8"><b><a href="#cite_ref-Fleichmann_1995_8-0"><font color="#0645ad">^</font></a></b> <span class="citation Journal">Fleischmann R, Adams M, White O, Clayton R, Kirkness E, Kerlavage A, Bult C, Tomb J, Dougherty B, Merrick J (1995). <a class="external text" rel="nofollow" href="http://www.sciencemag.org/cgi/content/abstract/269/5223/496"><font color="#3366bb">"Whole-genome random sequencing and assembly of Haemophilus influenzae Rd"</font></a>. <i>Science</i> <b>269</b> (5223): 496–512. <a title="Digital object identifier" href="/wiki/Digital_object_identifier"><font color="#0645ad">doi</font></a>:<a class="external text" rel="nofollow" href="http://dx.doi.org/10.1126%2Fscience.7542800"><font color="#3366bb">10.1126/science.7542800</font></a>. <a class="mw-redirect" title="PubMed Identifier" href="/wiki/PubMed_Identifier"><font color="#0645ad">PMID</font></a> <a class="external text" rel="nofollow" href="http://www.ncbi.nlm.nih.gov/pubmed/7542800"><font color="#3366bb">7542800</font></a><span class="printonly">. <a class="external free" rel="nofollow" href="http://www.sciencemag.org/cgi/content/abstract/269/5223/496"><font color="#3366bb">http://www.sciencemag.org/cgi/content/abstract/269/5223/496</font></a></span>.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Whole-genome+random+sequencing+and+assembly+of+Haemophilus+influenzae+Rd&rft.jtitle=Science&rft.aulast=Fleischmann+R%2C+Adams+M%2C+White+O%2C+Clayton+R%2C+Kirkness+E%2C+Kerlavage+A%2C+Bult+C%2C+Tomb+J%2C+Dougherty+B%2C+Merrick+J&rft.au=Fleischmann+R%2C+Adams+M%2C+White+O%2C+Clayton+R%2C+Kirkness+E%2C+Kerlavage+A%2C+Bult+C%2C+Tomb+J%2C+Dougherty+B%2C+Merrick+J&rft.date=1995&rft.volume=269&rft.issue=5223&rft.pages=496%E2%80%93512&rft_id=info:doi/10.1126%2Fscience.7542800&rft_id=info:pmid/7542800&rft_id=http%3A%2F%2Fwww.sciencemag.org%2Fcgi%2Fcontent%2Fabstract%2F269%2F5223%2F496&rfr_id=info:sid/en.wikipedia.org:Haemophilus_influenzae"><span style="display: none"> </span></span></li>
</ol>
</div>
<h2> <span id="External_links" class="mw-headline">External links</span></h2>
<ul>
<li><a class="external text" rel="nofollow" href="http://www.who.int/immunization/topics/hib/en/index.html"><font color="#3366bb">Hib information</font></a> on the <a title="World Health Organization" href="/wiki/World_Health_Organization"><font color="#0645ad">World Health Organization</font></a> (WHO) site.</li>
<li><a class="external text" rel="nofollow" href="http://www.cdc.gov/ncidod/dbmd/diseaseinfo/haeminfluserob_t.htm"><font color="#3366bb">Fact sheet</font></a> on the <a title="Centers for Disease Control and Prevention" href="/wiki/Centers_for_Disease_Control_and_Prevention"><font color="#0645ad">Centers for Disease Control and Prevention</font></a> (CDC) site.</li>
<li><a class="external text" rel="nofollow" href="http://www.hibaction.org"><font color="#3366bb">Hib Initiative</font></a> - from <a title="Johns Hopkins University" href="/wiki/Johns_Hopkins_University"><font color="#0645ad">Johns Hopkins University</font></a>, <a title="London School of Hygiene & Tropical Medicine" href="/wiki/London_School_of_Hygiene_%26_Tropical_Medicine"><font color="#0645ad">London School of Hygiene & Tropical Medicine</font></a>, <a title="Centers for Disease Control and Prevention" href="/wiki/Centers_for_Disease_Control_and_Prevention"><font color="#0645ad">CDC</font></a> & <a title="World Health Organization" href="/wiki/World_Health_Organization"><font color="#0645ad">WHO</font></a></li>
<li><a class="external text" rel="nofollow" href="http://www.worldpneumoniaday.org"><font color="#3366bb">November 2nd: World Pneumonia Day Website</font></a></li>
</ul>
<p> </p>
<p> </p>