Lessons from Dairy Farmers for Occupational Allergy and Respiratory Disease.

PURPOSE OF REVIEW: Exposure to bioaerosols at dairies has long been associated with allergy, respiratory disease, and decreases in lung function. Recent advancements in exposure assessments have aided our understanding on the size distribution and composition of these bioaerosols, but investigations focusing solely on exposures may overlook important intrinsic factors impacting worker's susceptibility to disease. RECENT FINDINGS: In our review, we discuss the most recent studies examining the exposures and genetic factors that contribute to occupational disease in dairy work. We also review more recent concerns in livestock work associated with zoonotic pathogens, antimicrobial resistant genes, and the role of the human microbiome. The studies highlighted in this review demonstrate the need for further research to better understand bioaerosol exposure-response relationships in the context of extrinsic and intrinsic factors, antibiotic-resistant genes, viral pathogens, and the human microbiome to help inform effective interventions that improve respiratory health among dairy farmers.

A method for the improved detection of aerosolized influenza viruses and the male-specific (F+) RNA coliphage MS2.

The detection of aerosolized viruses can serve as an important surveillance and control tool in agriculture, human health, and environmental settings. Here, we adapted an anion exchange resin-based method, initially developed to concentrate negatively charged viruses from water, to liquid impingement-based bioaerosol sampling. In this method, aerosolized viruses are collected in a 20ml liquid sample contained within widely used impingers, BioSamplers (SKC Inc., Eighty Four, PA), and further concentrated via adsorption to an anion exchange resin that is suspended within this liquid. Viral nucleic acids are then extracted from the resin to facilitate molecular analyses through a reduction in the effective sample volume. For this study, various quantities of two negatively charged viruses, type A and type B influenza viruses (FluMist Quadrivalent vaccine) and the male-specific (F+) RNA coliphage MS2 (MS2), were nebulized into a custom-built bioaerosolization chamber, and sampled using BioSamplers with and without anion exchange resin. Compared to direct testing of the BioSampler liquid, detection was improved by 6.77× and 3.33× for type A and type B influenza viruses, respectively, by using the anion exchange resin. For MS2, the anion exchange resin method allowed for an average improvement in detection of 8.26×.

Pseudo left axis deviation and the S1S2S3 syndrome in chronic airway obstruction.

Pseudo left axis deviation (not true left axis deviation and the S1S2S3 syndrome are infrequently reported electrocardiographic findings in chronic airway obstruction. One hundred fifty-eight patients with severe chronic airway obstruction documented by pulmonary function testing were evaluated for these electrocardiographic findings. Pseudo left axis deviation was found in 23 patients (15 percent), and the S1S2S3 syndrome was found in 14 patients (9 percent). The electrocardiographic and vectorcardiographic findings are illustrated.

Systemic embolization of the disk occluder of the Wada-Cutter prosthetic valve. A late complication.

The results in 22 patients in the Denver area with Wada-Cutter prostheses were reviewed. There were 14 late deaths, with an average follow-up of six years. Four cases of valve malfunction not related to thrombosis were documented. There were three cases of embolization of the occluder. A survivor is reported. Clinical evaluation of the group suggested new mitral regurgitation to be a sensitive indicator of impending embolization of the occluder. Documentation of valve malfunction warrants valvular replacement.