RESUMEN
BACKGROUND: Among indigenous populations with high incidence and early onset of invasive Haemophilus influenzae type b (Hib) disease, PRP-OMP vaccines are used in the United States and PRP-T vaccines in Canada. In Australia, PRP-OMP vaccines were exclusively used in indigenous children from 1993 until they were replaced by PRP-T between late 2005 and 2009. METHODS: Analytic descriptive study of 20 years of enhanced surveillance data (1993-2013) for invasive Hib disease in Australian children <10 years of age was conducted. RESULTS: Of 579 Hib cases under 10 years of age reported from vaccine introduction in 1993 to 2013, 78 (13%) were in indigenous children, 47 (60%) of whom lived in regions with high prevaccine incidence. In this population, incidence per 100,000 declined from 18.1 (95% confidence interval [CI]: 10.4, 29.4) in the early PRP-OMP period (1993-1996) to 6.2 (95% CI: 4.0, 9.2) and 4.7 (95% CI: 1.7, 10.3) in the later PRP-OMP (1996-2009) and PRP-T periods (2009-2013), respectively. The indigenous:nonindigenous incidence rate ratio increased to 43 (95% CI: 16, 145) and 58 (95% CI: 7, 2660) in the later PRP-OMP and PRP-T periods, respectively, more than 10-fold higher than in lesser-incidence Australian regions. CONCLUSIONS: We found no change in Hib incidence among indigenous Australian children living in high-incidence regions in the first 4 years following a change to PRP-T-containing combination vaccines. This may be of relevance to North American indigenous populations characterized by suboptimal living conditions and young age of onset for whom PRP-OMP continues to be recommended, such as Alaska Natives.
Asunto(s)
Bacteriemia/epidemiología , Bacteriemia/prevención & control , Proteínas de la Membrana Bacteriana Externa/inmunología , Infecciones por Haemophilus/epidemiología , Infecciones por Haemophilus/prevención & control , Vacunas contra Haemophilus/inmunología , Haemophilus influenzae tipo b/aislamiento & purificación , Polisacáridos Bacterianos/inmunología , Toxoide Tetánico/inmunología , Australia/epidemiología , Bacteriemia/microbiología , Proteínas de la Membrana Bacteriana Externa/administración & dosificación , Niño , Preescolar , Infecciones por Haemophilus/microbiología , Vacunas contra Haemophilus/administración & dosificación , Humanos , Incidencia , Lactante , Recién Nacido , Polisacáridos Bacterianos/administración & dosificación , Grupos de Población , Toxoide Tetánico/administración & dosificaciónRESUMEN
Streptococcus pneumoniae is the most common cause of community-acquired pneumonia and a major cause of morbidity and mortality throughout the world. It has been a major research priority to identify gene polymorphisms responsible for/associated with susceptibility and severity of S. pneumoniae infection to gain a better understanding of host genetic variants and their influence and clinical relevance to pneumococcal infections. In the present study, polymorphisms in several candidate genes, including TLR2-Arg/Gln753, TLR4-Asp/Gly299, TLR4-Thr/Ile399, CD14-159C/T and FcgammaRIIA-R/H131, were examined in 85 children with pneumococcal sepsis as an invasive pneumococcal disease and 409 healthy blood donors as controls. The prevalence of the TLR4-299/399 polymorphisms was significantly lower in the patient population than in controls (4 vs 11%; P<0.05; odds ratio (OR) 0.3; 95% confidence interval (CI) 0.1-1), while the prevalence of the CD14-159CC and FcgammaRIIA-R/R131 genotypes was significantly higher (35 vs 25%; P<0.05; OR 1.7; 95% CI 1-2.8 and 39 vs 21%; P<0.001; OR 2.5; 95% CI 1.4-4, respectively). Further, only 35% of patients carried either low-risk genotypes or protective genotypes in contrast to 61% of controls (P<0.0001; OR 2.8; 95% CI 1.7-4.6). We conclude that genetic variability in the TLR4, CD14 and FcgammaRIIA genes is associated with an increased risk of developing invasive disease in patients who are infected with S. pneumoniae.