Invasive
            <i>Haemophilus influenzae</i>
            in Manitoba, Canada, in the Postvaccination Era

Tsang, Raymond S. W.; Mubareka, Samira; Sill, Michelle L.; Wylie, John; Skinner, Stuart; Law, Dennis K. S.

doi:10.1128/jcm.44.4.1530-1535.2006

Cited by 53 publications

(62 citation statements)

References 25 publications

(26 reference statements)

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“…Hia disease has also been reported in aboriginal populations in the United States and Australia (30)(31)(32). A possible shift in disease epidemiology to non-b serotypes has been suggested from fi ndings in an adjacent Canadian region (33), whereas a sustained increase in non-b serotypes has not been detected in Alaska (4). The incidence of GAS in the ICS region has been increasing since 2001.…”

Section: Discussionmentioning

confidence: 99%

Invasive Bacterial Diseases in Northern Canada

Degani

Navarro

Deeks

et al. 2008

Emerg. Infect. Dis.

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International Circumpolar Surveillance (ICS) is a population-based invasive bacterial disease surveillance network. Participating Canadian regions include Yukon, Northwest Territories, Nunavut, and northern regions of Québec and Labrador (total population 132,956, 59% aboriginal). Clinical and demographic information were collected by using standardized surveillance forms. Bacterial isolates were forwarded to reference laboratories for confi rmation and serotyping. After pneumococcal conjugate vaccine introduction, crude annual incidence rates of invasive Streptococcus pneumoniae decreased from 34.0/100,000 population (1999)(2000)(2001)(2002)) to 23.6/100,000 population (2003)(2004)(2005); substantial reductions were shown among aboriginals. However, incidence rates of S. pneumoniae, Haemophilus infl uenzae, and group A streptococci were higher in aboriginal populations than in non-aboriginal populations. H. infl uenzae type b was rare; 52% of all H. infl uenzae cases were caused by type a. Data collected by ICS contribute to the understanding of the epidemiology of invasive bacterial diseases among northern populations, which assists in formulation of prevention and control strategies, including immunization recommendations.

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Section: Discussionmentioning

confidence: 99%

Invasive Bacterial Diseases in Northern Canada

Degani

Navarro

Deeks

et al. 2008

Emerg. Infect. Dis.

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“…In the post-Hib vaccine era, invasive disease in children due to H. influenzae is uncommon, with the majority of these infections due to unencapsulated strains, with the remainder being non-b encapsulated strains, predominantly serotypes f and a in North America and serotypes f and e in Europe (Tsang et al, 2006;Adam et al, 2010;Ladhani et al, 2010Ladhani et al, , 2012Agrawal & Murphy, 2011;Resman et al, 2011a;Rubach et al, 2011). To understand better the ability of serotype f strains to produce invasive infection, we assembled a panel of Hif isolates from a diversity of clinical sources for factors related to pathogenesis.…”

Section: Discussionmentioning

confidence: 99%

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Watson

Nelson

Nguyen

et al. 2013

Journal of Medical Microbiology

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The incidence of invasive infections due to Haemophilus influenzae has decreased significantly in developed countries with high rates of vaccination against H. influenzae serotype b (Hib). This vaccine provides no protection against H. influenzae serotype f (Hif), typically associated with invasive infections in adults with chronic disease and/or immunodeficiency, and rarely in otherwise healthy adults and children. The specific properties of Hif associated with virulence remain largely uncharacterized. A panel of 26 Hif strains consisting of both invasive disease-associated and mucosal surface non-invasive disease-associated isolates was surveyed by DNA fingerprinting, biotyping and PCR detection of hmw1, hmw2, hsf, the hif fimbrial locus and the lipooligosaccharide (LOS) biosynthetic island, and assessment of b-lactamase expression and determination of resistance to the bactericidal activity of normal adult human serum. Repetitive sequence-based PCR fingerprinting differentiated the 26 strains into three clusters, with the majority of isolates (22/26, 84.6 %) clustered into a single indistinguishable group. Most isolates (24/26, 92.3 %) were of biotype I and two isolates produced b-lactamase with detection of a conjugative plasmid, and the isolates displayed a range of resistances to the bactericidal activity of human serum. All 26 isolates carried the adhesin hsf, 21 carried a partial hif fimbrial operon and 4 had the adhesin genes hmw1/2. A LOS biosynthetic island was detected in 20 isolates consisting of the genes lic2BC. It was concluded that Hif has many recognized virulence properties and comprises a relatively homogeneous group independent of the anatomical source from which it was isolated. INTRODUCTIONHaemophilus influenzae, a human-restricted Gram-negative coccobacillus, is a commensal of the upper respiratory mucosa and a pathogen commonly causing airway mucosal disease and occasional invasive disease. Since Margaret Pittman's original description of capsular serotypes among H. influenzae isolates in 1931 (Pittman, 1931), H. influenzae serotype b (Hib) had been the most clinically significant strain causing invasive disease (e.g. meningitis, epiglottitis, septicaemia and osteomyelitis) in previously well infants and children (Aubrey & Tang, 2003). Since the early 1990s, routine administration of the Hib conjugate vaccines (which induce protective levels of anti-capsular antibody) has virtually eliminated Hib disease among infants and young children in developed countries (Agrawal & Murphy, 2011;Ladhani, 2012). However, the vaccine provides no protection from infection due to nonb serotypes, including H. influenzae serotype f (Hif), which remains a rare but significant cause of invasive infection. Given the reduction in Hib carriage among Hib conjugate vaccine recipients, concern exists as to whether invasive disease due to Hif or other non-b encapsulated strains will become more prevalent due to serotype replacement Abbreviations: BLNAR, b-lactamase-negative ampicillin-resistant; CSF, cerebrospinal ...

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“…Hia from among Navajo and White Mountain Apache children, USA 76 cases of invasive Hia disease with commonest presentation being meningitis, followed by pneumonia; others were cellulitis and septic arthritis. Tsang et al (2006) [12] Hia from Manitoba, Canada 20 isolates from children < 24 months and the isolates were from blood and CSF. Other 6 isolates were from adults.…”

Section: Discussionmentioning

confidence: 99%

Pediatric invasive disease due to Haemophilus influenzae serogroup A in Riyadh, Saudi Arabia: case series

Roaa

Abdulsalam

Shahid

et al. 2016

J Infect Dev Ctries

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We describe the first two cases of invasive disease caused by Haemophilus influenzae serotype A in Saudi Arabia. This is the first known reported invasive Haemophilus influenzae serotype A from Saudi Arabia. Case presentation: A ten-month-old and three-month-old male not known to have any past history of any medical illness and who had received H. influenzae type b (Hib) vaccine presented to our hospital mainly with fever of few days' duration. A provisional diagnosis of meningitis with sepsis was made and laboratory tests were requested. The chest radiograph was normal. The laboratory results revealed leukocytosis, but leukopenia was noticed in the younger infant. Blood culture and cerebrospinal fluid specimens yielded a pure culture of Haemophilus influenzae and serotyping showed the isolates to be serogroup A. Both patients were started on vancomycin and third-generation cephalosporin. On receiving the blood culture result, vancomycin was stopped. Fever subsided after 48 hours, while in the second case, it continued for 12 days from the admission date. The repeat blood cultures were negative. Antibiotic therapy was given for 10 days for the first case with an unremarkable hospital course, while the second case was complicated by seizure and received a longer duration of antibiotics. Both infants were discharged home in good condition. Conclusions: Invasive non-typeable H. influenzae strains are emerging and there is a need for surveillance of this disease. This has implications in future vaccine development.

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Invasive Haemophilus influenzae in Manitoba, Canada, in the Postvaccination Era

Cited by 53 publications

References 25 publications

Invasive Bacterial Diseases in Northern Canada

Invasive Bacterial Diseases in Northern Canada

Adhesin genes and serum resistance in Haemophilus influenzae type f isolates

Pediatric invasive disease due to Haemophilus influenzae serogroup A in Riyadh, Saudi Arabia: case series

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