Epidemiology of Haemophilus influenzae Serotype a in the North American Arctic (2000–2005)
Author Information
Author(s): Bruce Michael G., Deeks Shelley L., Zulz Tammy, Navarro Christine, Palacios Carolina, Case Cheryl, Hemsley Colleen, Hennessy Tom, Corriveau Andre, Larke Bryce, Sobel Isaac, Lovgren Marguerite, DeByle Carolynn, Tsang Raymond, Parkinson Alan J.
Primary Institution: Centers for Disease Control and Prevention
Hypothesis
What are the incidence rates and characteristics of invasive Haemophilus influenzae serotype a disease in the North American Arctic?
Conclusion
Serotype a is now the most common H. influenzae serotype in the North American Arctic, particularly affecting indigenous children.
Supporting Evidence
- Among 88 typeable isolates, 42 (48%) were H. influenzae type a (Hia); 35 (83%) occurred in indigenous peoples.
- Overall annual incidence was 0.9 cases per 100,000 population.
- Incidence among indigenous children <2 years of age in Alaska and northern Canada was 21 and 102, respectively.
Takeaway
This study found that a type of bacteria called Haemophilus influenzae type a is making more kids sick in the Arctic, especially among native children.
Methodology
Population-based surveillance data were reviewed from Alaska and northern Canada for invasive H. influenzae cases from 2000 to 2005.
Potential Biases
Most H. influenzae isolates are serotyped by slide agglutination only, which may misclassify nontypeable strains.
Limitations
Data on non-b invasive H. influenzae disease were not collected in the pre-Hib conjugate vaccine era, making it difficult to determine baseline incidence.
Participant Demographics
Among 42 Hia isolates, 35 (92%) occurred in indigenous people, with a median age of 1.1 years.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.001
Digital Object Identifier (DOI)
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