Nosocomial Outbreak of Upper Respiratory Tract Infection With ß-Lactamase-Negative Ampicillin-Resistant Nontypeable Haemophilus influenzae.

OBJECTIVETo describe the epidemiologic features of an outbreak of an acute respiratory tract infection (ARI) caused by ß-lactamase-negative ampicillin-resistant (BLNAR) nontypeable Haemophilus influenzae (NTHi) in an acute-care ward.DESIGNCross-sectional case-control study.SETTINGAn acute-care ward (ward A) in a general hospital of Kochi in western Japan.METHODSPatients who shared a room with an index patient and all staff in ward A were screened and followed from July 1 to August 31, 2015. Sputum or throat swab samples were collected from participants and tested by culture and polymerase chain reaction (PCR). The association between detected pathogens and ARI development among all participants was examined. A case-control study was conducted to identify risk factors for disease.RESULTSIn total, 78 participants, including the index patient, were enrolled. Of all participants, 27 (34.6%) developed mild respiratory symptoms during a 3-week period: 24 were diagnosed as upper respiratory tract infections, and 3 were diagnosed as lower respiratory tract infections. The presence of BLNAR NTHi was confirmed in 13 participants, and multilocus sequence typing demonstrated that these isolates belonged to sequence type 159. All isolates showed identical pulsed-field gel electrophoresis patterns. The presence of BLNAR NTHi was strongly associated with ARI development, whereas viruses were not associated with the disease. Multivariate analyses demonstrated that a history of contact with the index patient was independently associated with ARI caused by BLNAR NTHi.CONCLUSIONSBLNAR NTHi has the potential to cause upper respiratory tract infections among adults and to spread rapidly in hospital settings.Infect Control Hosp Epidemiol 2018;39:652-659.

Hydrogen Sulfide: A Novel Player in Airway Development, Pathophysiology of Respiratory Diseases, and Antiviral Defenses.

Hydrogen sulfide (H2S) is a biologically relevant signaling molecule in mammals. Along with the volatile substances nitric oxide (NO) and carbon monoxide (CO), H2S is defined as a gasotransmitter. It plays a physiological role in a variety of functions, including synaptic transmission, vascular tone, angiogenesis, inflammation, and cellular signaling. The generation of H2S is catalyzed by cystathionine ß-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST). The expression of CBS and CSE is tissue specific, with CBS being expressed predominantly in the brain, and CSE in peripheral tissues, including lungs. CSE expression and activity are developmentally regulated, and recent studies suggest that CSE plays an important role in lung alveolarization during fetal development. In the respiratory tract, endogenous H2S has been shown to participate in the regulation of important functions such as airway tone, pulmonary circulation, cell proliferation or apoptosis, fibrosis, oxidative stress, and inflammation. In the past few years, changes in the generation of H2S have been linked to the pathogenesis of a variety of acute and chronic inflammatory lung diseases, including asthma and chronic obstructive pulmonary disease. Recently, our laboratory made the critical discovery that cellular H2S exerts broad-spectrum antiviral activity both in vitro and in vivo, in addition to independent antiinflammatory activity. These findings have important implications for the development of novel therapeutic strategies for viral respiratory infections, as well as other inflammatory lung diseases, especially in light of recent significant efforts to generate controlled-release H2S donors for clinical therapeutic applications.

Folic acid supplements in pregnancy and early childhood respiratory health.

BACKGROUND: Folate supplementation is recommended for pregnant women to reduce the risk of congenital malformations. Maternal intake of folate supplements during pregnancy might also influence childhood immune phenotypes via epigenetic mechanisms. OBJECTIVE: To investigate the relationship between folate supplements in pregnancy and risk of lower respiratory tract infections and wheeze in children up to 18 months of age. METHODS: In the Norwegian Mother and Child Cohort Study, questionnaire data collected at several time points during pregnancy and after birth on 32,077 children born between 2000 and 2005 were used to assess the effects of folate supplements during pregnancy on respiratory outcomes up to 18 months of age, while accounting for other supplements in pregnancy and supplementation in infancy. RESULTS: Folate supplements in the first trimester were associated with increased risk of wheeze and respiratory tract infections up to 18 months of age. Adjusting for exposure later in pregnancy and in infancy, the relative risk for wheeze for children exposed to folic acid supplements in the first trimester was 1.06 (95% CI 1.03 to 1.10), the relative risk for lower respiratory tract infections was 1.09 (95% CI 1.02 to 1.15) and the relative risk for hospitalisations for lower respiratory tract infections was 1.24 (95% CI 1.09 to 1.41). CONCLUSIONS: Folic acid supplements in pregnancy were associated with a slightly increased risk of wheeze and lower respiratory tract infections up to 18 months of age. The results suggest that methyl donors in the maternal diet during pregnancy may influence respiratory health in children consistent with epigenetic mechanisms.