Bronchiectasis-associated infections and outcomes in a large, geographically diverse electronic health record cohort in the United States

BACKGROUND: Bronchiectasis is a pulmonary disease characterized by irreversible dilation of the bronchi and recurring respiratory infections. Few studies have described the microbiology and prevalence of infections in large patient populations outside of specialized tertiary care centers.METHODS: We used the Cerner HealthFacts Electronic Health Record database to characterize the nature, burden, and frequency of pulmonary infections among persons with bronchiectasis. Chronic infections were defined based on organism-specific guidelines.RESULTS: We identified 7,749 patients who met our incident bronchiectasis case definition. In this study population, the organisms with the highest rates of isolate prevalence were Pseudomonas aeruginosa with 937 (12%) individuals, Staphylococcus aureus with 502 (6%), Mycobacterium avium complex (MAC) with 336 (4%), and Aspergillus sp. with 288 (4%). Among persons with at least one isolate of each respective pathogen, 219 (23%) met criteria for chronic P. aeruginosa colonization, 74 (15%) met criteria for S. aureus chronic colonization, 101 (30%) met criteria for MAC chronic infection, and 50 (17%) met criteria for Aspergillus sp. chronic infection. Of 5,795 persons with at least two years of observation, 1,860 (32%) had a bronchiectasis exacerbation and 3,462 (60%) were hospitalized within two years of bronchiectasis diagnoses. Among patients with chronic respiratory infections, the two-year occurrence of exacerbations was 53% and for hospitalizations was 82%.CONCLUSIONS: Patients with bronchiectasis experiencing chronic respiratory infections have high rates of hospitalization.</p

Data from: Linking the vectorial capacity of multiple vectors to observed patterns of West Nile virus transmission

1. Theoretical models suggest that increased vector species participation in pathogen transmission significantly increases the prevalence of vector and host infections. However, there has been a lack of empirical evidence to support this. 2. We linked transmission potential of multiple vectors species to observed patterns of enzootic pathogen transmission by conducting longitudinal field surveillance of West Nile virus (WNv) infections in Culex spp. mosquitoes and avian host communities in the southeastern U.S. We then used a temperature-dependent vectorial capacity model as a predictor of WNv infections in mosquitoes and birds using general linear mixed effects models. 3. Two WNv-competent Culex spp. mosquitoes were present in our study sites, Culex restuans Theobald during the spring and Culex quinquefasciatus Say during the summer. Empirical evidence of WNv transmission was limited exclusively to time periods when night time temperatures were suitable for accelerated within-vector viral replication, susceptible avian hosts (i.e. hatch year birds) were abundant, and Culex quinquefasciatus was the primary Culex spp. vector in the mosquito community. 4. Contrary to theoretical predictions, increased presence of competent vector species through time did not significantly increase the prevalence of infections in the WNv enzootic system. 5. Synthesis and applications. We extend a commonly used theoretical framework to quantify transmission potential of vector-borne diseases, the vectorial capacity equation, to account for species-specific variations in temperature-dependent development and host feeding preference. By quantifying key vectorial capacity parameters using field data from southeast United States we quantified the relative contribution of two Culex spp. species (Culex pipiens quinquefasciatus and Culex restuans) to the transmission of West Nile virus (WNv). Our findings suggest that to reduce the risk of human exposure to WNv in urban environments, vector control should focus on the primary WNv vector, the members of the Culex pipiens complex. Additionally, vector control may be more effective if it coincides with the onset of the avian breeding season, when most WNv amplification occurs. Moreover, our results highlight relevant knowledge gaps pertaining to WNv transmission by secondary mosquito species that coexist either in time or space with Culex pipiens complex mosquitoes. A better understanding of secondary WNv vector species is greatly needed in order to appropriately gauge their role in pathogen transmission dynamics

Incidence of Nontuberculous Mycobacterial Pulmonary Infection, by Ethnic Group, Hawaii, USA, 2005–2019

To further clarify differences in the risk for nontuberculous mycobacterial pulmonary infection (NTM-PI) among ethnic populations in Hawaii, USA, we conducted a retrospective cohort study among beneficiaries of Kaiser Permanente Hawaii (KPH). We abstracted demographic, socioeconomic, clinical, and microbiological data from KPH electronic health records for 2005–2019. An NTM-PI case-patient was defined as a person from whom >1 NTM pulmonary isolate was obtained. We performed Cox proportional hazards regression to estimate incidence of NTM-PI while controlling for confounders. Across ethnic groups, risk for NTM-PI was higher among persons who were underweight (body mass index [BMI] <18.5 kg/m2). Among beneficiaries who self-identified as any Asian ethnicity, risk for incident NTM-PI was increased by 30%. Low BMI may increase susceptibility to NTM-PI, and risk may be higher for persons who self-identify as Asian, independent of BMI