Haemophilus influenzae Serotype a Invasive Disease, Alaska, USA, 1983–2011

Emerging Infectious Diseases (Impact Factor: 6.75). 06/2013; 19(6):932-7. DOI: 10.3201/eid1906.121805
Source: PubMed

ABSTRACT Before introduction of Haemophilus influenzae type b (Hib) vaccines, rates of Hib disease in Alaska's indigenous people were among the highest in the world. Vaccination reduced rates dramatically; however, invasive H. influenzae type a (Hia) disease has emerged. Cases of invasive disease were identified through Alaska statewide surveillance during1983-2011. Of 866 isolates analyzed for serotype, 32 (4%) were Hia. No Hia disease was identified before 2002; 32 cases occurred during 2002-2011 (p<0.001). Median age of case-patients was 0.7 years; 3 infants died. Incidence of Hia infection (2002-2011) among children <5 years was 5.4/100,000; 27 cases occurred in Alaska Native children (18/100,000) versus 2 cases in non-Native children (0.5/100,000) (risk ratio = 36, p<0.001). From 12/2009 to 12/2011, 15 cases of Hia disease occurred in southwestern Alaska (in children <5 years, rate = 204/100,000). Since introduction of the Hib conjugate vaccine, Hia infection has become a major invasive bacterial disease in Alaska Native children.

Download full-text


Available from: Jay Wenger, Sep 28, 2015
1 Follower
29 Reads
  • Source
    • "(18) "
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: To assess the characteristics of tetanus in previously immunized individuals. Methods: A systematic literature search was undertaken using Ovid MEDLINE(R) and EMBASE databases for articles published between 1946 and September 3, 2013. The search strategy was developed using MESH terms for "tetanus", "immunization" and "vaccination". Inclusion criteria were articles in English or French that described at least one case of tetanus, immunization history and/or the results of anti-tetanus antibodies. Articles were reviewed for relevant references. Results: 51 unique articles published from1946-2013 were included in the review. The articles described 359 cases of clinical tetanus in individuals with prior receipt of one or more doses of tetanus toxoid vaccine and/or levels of tetanus antibody titres generally considered protective. Of the 210 cases that reported patient status at discharge, 180 (85.7%) survived with only three cases reporting residual deficits. Conclusion: Tetanus spores are ubiquitous and this report clearly documents that tetanus cases can occur in individuals previously immunized with tetanus toxoid vaccine. Clinicians should not rule out tetanus when clinical symptoms suggest it, regardless of the vaccination history. When treated, the prognosis for tetanus is good. Further research is needed to assess the incidence of tetanus in partially- and fully-immunized populations and determine whether this is due to waning immunity of vaccine failure.
    • "(18) "
    [Show abstract] [Hide abstract]
    ABSTRACT: Middle East respiratory syndrome – Coronavirus (MERS-CoV) -- is a novel coronavirus that has caused a number of community-acquired cases and health care associated outbreaks in Saudi Arabia and the United Arab Emirates (UAE) as well as sporadic cases in other countries, especially in the Middle East. The evidence to date links MERS-CoV cases with exposure to camels, including camel products or to probable or confirmed human cases of MERS-CoV. It typically presents as an acute respiratory illness and is associated with a 35% mortality rate. Based on available information at this time, the current risk to Canadians for acquiring MERS-CoV infections is considered low. However, the International Health Regulations Committee concerning MERS-CoV has cautioned that the upsurge of cases seen this past spring (2014) may be predictive of an increase in cases related to the Hajj – an annual pilgrimage to Mecca in Saudi Arabia that took place in early October 2014. Although the overall risk is low, the Public Health Agency of Canada and its National Microbiology Laboratory (NML) in close collaboration with provincial and territorial partners, the Canadian Public Health Laboratory Network (CPHLN) and infection prevention and control experts have developed a number of preparedness guidance documents and protocols to address the risk of an imported case of MERS-CoV in Canada.
    Canada communicable disease report = Relevé des maladies transmissibles au Canada 10/2014; 40(17):339.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The incidence of invasive disease caused by encapsulated Haemophilus influenzae type f (Hif) has increased in the post-H. influenzae type b (Hib) vaccine era. We previously annotated the first complete Hif genome from a clinical isolate (KR494) that caused septic shock and necrotizing myositis. Here, the full genome of Hif KR494 was compared to sequenced reference strains Hib 10810, capsule type d (Hid) Rd Kw20, and finally nontypeable H. influenzae 3655. The goal was to identify possible genomic characteristics that may shed light upon the pathogenesis of Hif. The Hif KR494 genome exhibited large regions of synteny with other H. influenzae, but also distinct genome rearrangements. A predicted Hif core genome of 1390 genes was shared with the reference strains, and 6 unique genomic regions comprising half of the 191 unique coding sequences were revealed. The majority of these regions were inserted genetic fragments, most likely derived from the closely-related Haemophilus spp. including H. aegyptius, H. haemolyticus and H. parainfluenzae. Importantly, the KR494 genome possessed several putative virulence genes that were distinct from non-type f strains. These included the sap2 operon, aef3 fimbriae, and genes for kanamycin nucleotidyltranserase, iron-utilization proteins, and putative YadA-like trimeric autotransporters that may increase the bacterial virulence. Furthermore, Hif KR494 lacked a hisABCDEFGH operon for de novo histidine biosynthesis, hmg locus for lipooligosaccharide biosynthesis and biofilm formation, the Haemophilus antibiotic resistance island and a Haemophilus secondary molybdate transport system. We confirmed the histidine auxotrophy and kanamycin resistance in Hif by functional experiments. Moreover, the pattern of unique or missing genes of Hif KR494 was similar in 20 Hif clinical isolates obtained from different years and geographical areas. A cross-species comparison revealed that the Hif genome shared more characteristics with H. aegyptius than Hid and NTHi. The genomic comparative analyses facilitated identification of genotypic characteristics that may be related to the specific virulence of Hif. In relation to non-type f H. influenzae strains, the Hif genome contains differences in components involved in metabolism and survival that may contribute to its invasiveness.
    BMC Genomics 01/2014; 15(1):38. DOI:10.1186/1471-2164-15-38 · 3.99 Impact Factor
Show more