Risk of invasive pneumococcal infections among working age adults with asthma

Abstract

Background Information about the risk of invasive pneumococcal infection (IPI) among adults with asthma is limited and inconsistent. To evaluate this association, a population-based caseecontrol study was conducted. Methods Cases of IPI (Streptococcus pneumoniae isolated from blood or cerebrospinal fluid) were identified through national, population-based laboratory surveillance during 1995e2002. To maximise exclusion of chronic obstructive pulmonary disease, the analysis was limited to patients aged 18e49 years and 10 selected age-, sex-and health district-matched controls for each case from the Population Information System. Information on underlying medical conditions was obtained through linking surveillance data to other national health registries. Asthma requiring $1 hospitalisation in the past 12 months was defined as high risk asthma (HRA); low risk asthma (LRA) was defined as entitlement to prescription drug benefits and no hospitalisation for asthma in the past 12 months. Results 1282 patients with IPI and 12 785 control subjects were identified. Overall, 7.1% of cases and 2.5% of controls had asthma (6.0% and 2.4% had LRA whereas 1.1% and 0.1% had HRA, respectively. After adjustment for other independent risk factors in a conditional logistic regression model, IPI was associated with both LRA (matched OR (mOR) 2.8; 95% CI 2.1 to 3.6) and HRA (mOR, 12.3; 95% CI 5.4 to 28.0). The adjusted population-attributable risk was 0.039 (95% CI 0.023 to 0.055) for LRA and 0.01 (95% CI 0.0035 to 0.017) for HRA. Conclusions Working age adults with asthma are at increased risk of IPI. In this population, w5% of disease burden could be attributed to asthma. These findings support adding medicated asthma in adults to the list of indications for pneumococcal vaccination.

Azithromycin for Acute Exacerbations of Asthma

“…People with asthma have increased susceptibility to streptococcal infections, [13][14][15] increased carriage of bacterial pathogens identified by culture 16 and molecular techniques, 17 and impaired interferon and type 1 T helper cell responses to bacterial polysaccharides. 18,19 Viral infection impairs antibacterial innate immune responses 20 and increases bacterial adherence to bronchial epithelium.…”

Arginase 1 activity worsens lung‐protective immunity against Streptococcus pneumoniae infection

“…Various studies have shown that asthmatic patients have an increased risk of acquiring bacterial infections, such as induced by Haemophilus influenzae and Spn, which may cause asthma exacerbation [13,15,16]. At the same time, asthmatic patients exhibit more severe and long-lasting respiratory tract symptoms following viral infections [17,18].…”

“…Importantly, limited availability of L-arginine to iNOS due to increased Arg1 activity results in a deficiency of bronchodilatory and anti-inflammatory NO, while at the same time fostering AHR and L-ornithine-dependent airway fibrogenesis, thus suggesting an important role of Arg1-dependent altered NO metabolism in the development of allergic asthma [12,13]. However, limited availability of NO due to increased Arg1 activity may not only promote asthma progression but may also inhibit NO-dependent lung antibacterial immunity against, for example, pulmonary Streptococcus pneumoniae (Spn) infections [14].…”

“…Importantly, limited availability of L-arginine to iNOS due to increased Arg1 activity results in a deficiency of bronchodilatory and anti-inflammatory NO, while at the same time fostering AHR and L-ornithine-dependent airway fibrogenesis, thus suggesting an important role of Arg1-dependent altered NO metabolism in the development of allergic asthma [12,13]. However, limited availability of NO due to increased Arg1 activity may not only promote asthma progression but may also inhibit NO-dependent lung antibacterial immunity against, for example, pulmonary Streptococcus pneumoniae (Spn) infections [14].Various studies have shown that asthmatic patients have an increased risk of acquiring bacterial infections, such as induced by Haemophilus influenzae and Spn, which may cause asthma exacerbation [13,15,16]. At the same time, asthmatic patients exhibit more severe and long-lasting respiratory tract symptoms following viral infections [17,18].…”

Avaliação dos efeitos da inflamação na infecção respiratória por<i> Streptococcus</i> <i>pneumoniae</i> em camundongos.

“…Entre eles, pode-se destacar a expressão de fatores de virulência pela bactéria ou o desenvolvimento de uma resposta imune inata ineficiente por parte do hospedeiro (Weiser, 2010). Algumas condições predispõem às infecções pneumocócicas, como por exemplo a asma (Jounio et al, 2010;Klemets et al, 2010;Talbot et al, 2005) ou infecções virais, como a influenza (Mina;Mccullers;Klugman, 2014 (Ferreira et al, 2009;Lima et al, 2012;Lima et al, 2013;Oliveira et al, 2010). O controle da inflamação parece ser um componente importante tanto na proteção induzida pelas vacinas estudadas quanto nos mecanismos inatos de eliminação das bactérias do trato respiratório.…”