Seasonality of acquisition of respiratory bacterial pathogens in young children with cystic fibrosis

Abstract

BackgroundSeasonal variations are often observed for respiratory tract infections; however, limited information is available regarding seasonal patterns of acquisition of common cystic fibrosis (CF)-related respiratory pathogens. We previously reported differential seasonal acquisition of Pseudomonas aeruginosa in young children with CF and no such variation for methicillin-susceptible Staphylococcus aureus acquisition. The purpose of this study was to describe and compare the seasonal incidence of acquisition of other respiratory bacterial pathogens in young children with CF.MethodsWe conducted a retrospective study to describe and compare the seasonal incidence of methicillin-resistant Staphylococcus aureus (MRSA), Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Haemophilus influenzae acquisition in young CF patients residing in the U.S. using the Cystic Fibrosis Foundation National Patient Registry, 2003-2009. Log-linear overdispersed Poisson regression was used to evaluate seasonal acquisition of each of these pathogens.ResultsA total of 4552 children met inclusion criteria. During follow-up 910 (20%), 1161 (26%), 228 (5%), and 2148 (47%) children acquired MRSA, S. maltophilia, A. xylosoxidans and H. influenzae, respectively. Compared to winter season, MRSA was less frequently acquired in spring (Incidence Rate Ratio [IRR]: 0.79; 95% Confidence Interval [CI]: 0.65, 0.96) and summer (IRR: 0.69; 95% CI: 0.57, 0.84) seasons. Similarly, a lower rate of A. xylosoxidans acquisition was observed in spring (IRR: 0.59; 95% CI: 0.39, 0.89). For H. influenzae, summer (IRR: 0.88; 95% CI: 0.78, 0.99) and autumn (IRR: 0.78; 95% CI: 0.69, 0.88) seasons were associated with lower acquisition rates compared to winter. No seasonal variation was observed for S. maltophilia acquisition.ConclusionAcquisition of CF-related respiratory pathogens displays seasonal variation in young children with CF, with the highest rate of acquisition for most pathogens occurring in the winter. Investigation of factors underlying these observed associations may contribute to our understanding of the aetiology of these infections and guide future infection control strategies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-017-2511-9) contains supplementary material, which is available to authorized users.

Viral respiratory tract infections in young children with cystic fibrosis: a prospective full-year seasonal study

“…The risk factor that RTI represents for PA colonization was underlined several years ago, particularly after a severe episode of RTI [17,27]. Furthermore, major pathogen acquisition in young children with CF (PA, SA, Achromobacter xylosoxidans) may follow seasonality, underpinning the concept of predisposing seasonal environmental factors such as respiratory virus epidemics [30,31]. However, the trend identified herein for SM seems somewhat new and will need further attention.…”

Respiratory viral infections in Western Australians with cystic fibrosis

“…It has been observed that the range of bacteria infecting the respiratory tract differs between otherwise healthy individuals and those with CF [4]. The most notable bacterial pathogen in CF is Pseudomonas aeruginosa [5,6] with other bacterial pathogens including Staphylococcus aureus, Burkholderia spp and Haemophilus influenzae [4,7,8].…”

Pathogen acquisition in patients with cystic fibrosis receiving ivacaftor or lumacaftor/ivacaftor

“…However, focusing on a single center allows for common exposures that may be risk factors for acquisition and transmission of infections . We selected fixed time intervals for both eras since infections may fluctuate with time . We were not able to control for some potential confounding variables.…”

“…39 We selected fixed time intervals for both eras since infections may fluctuate with time. 40 We were not able to control for some potential confounding variables. Many patients receiving CFTR modulators initiated them later in Era 2, and we did not assess medication compliance.…”