Repeated immune activation and prolonged inflammation by microbiologic exposures may contribute to inflammation-related diseases such as asthma.
Current findings thus cannot define causal microbiologic exposures or dose response relations sufficiently to define safe levels of exposure to dampness-related agents.
On the other hand, an increasing number of studies suggest that early-life microbiologic exposures to endotoxin or specific fungal agents may protect against atopy and allergic disease.
Thus, although a causal role for microbiologic exposures is plausible and likely, the evidence for this is still weak (Douwes and Pearce 2003).
Repeated activation of immune responses and inflammation from microbiologic exposures may contribute to inflammation-related diseases, and the resulting inflamed mucosal tissue may provide a diminished barrier to respiratory infections.
However, conventional quantitative measurements of fungi or other microbiologic exposures, such as counts of culturable airborne fungi, have shown less consistent associations with health effects than have qualitative assessments of visible dampness or water damage, visible mold, or mold odor.
The inflammatory responses demonstrated in many microbiologic exposures include histamine release by non-immunoglobulin E mediated mechanisms, providing plausible mechanisms for the occurrence of allergy-like symptoms in nonsensitized individuals.
In fact, a growing number of studies suggest that early-life microbiologic exposures to endotoxin may protect against later atopy (e.g., Illi et al. 2014; Lawson et al. 2012), although these exposures are also associated with increased wheeze (Celedon et al. 2007).
HPS compiles standardized datasets for all cases, integrating microbiologic, epidemiologic, demographic, and exposure data; datasets include direct clinical reports of HUS under enhanced surveillance of thrombotic microangiopathies since 2003 133 ) and detailed symptom descriptions since 2004.
According to our study, the link between hygiene and childhood asthma rise would lie less in the decreasing exposure to microbiologic agents than in the increasing exposure of children to products of chlorination, the most widely used method to achieve hygiene in industrialized countries.
Epidemiologic exposure data and microbiologic typing information were then collated centrally by the Gastrointestinal Diseases Division of the PHLS Communicable Disease Surveillance Centre.
