The protective effect of rural life on mite sensitization disappears among urban migrants in the South of Vietnam

Abstract

BackgroundRapid urbanization combined with rural migration to urban areas in southern Vietnam could be risk factors for allergen sensitization, contributing to chronic respiratory diseases (CRD). We aimed to evaluate the prevalence of mite sensitization and its relation to house dust characteristics among rural and urban native and migrating populations with CRD.MethodsRural (n = 19) and urban (n = 46) dwellings were defined on the basis of a home typology. Controls were western Belgian houses (n = 14). Besides the house characteristics, both endotoxin and mite allergens were measured in the settled dusts. The sensitization to mite allergens was defined by positive skin prick test (SPT) and concentration of specific IgE (sIgE)≥ 0.7 U/mL. The prevalence of mite sensitization was evaluated among 610 patients with CRD and compared according to both their home types and places of birth and residences.ResultsThe concentration of endotoxin (but not mite allergen) was higher in rural compared to urban dusts (440 (95%CI: 314–566) versus 170 (95%CI: 115–226) EU/mg; p < 0.0001). The prevalence of positive sIgE to Der p1 and Der p2 was significantly lower in rural (9% and 5%) compared to urban (15% and 9%) population, consistent with the positive SPT to mite (14% and 21%, respectively). Among the urban migrants, the risk of mite sensitization (SPT) was higher compared to the rural natives (OR: 1.79 (1.02–3.15), p < 0.05) and not different to the urban ones (OR: 1.35 (0.82–2.23) p NS).ConclusionIn Vietnam, associated with higher endotoxin (but not allergen) dust concentrations, the risk of mite sensitization was lower in rural compared to the native urban population, but this protective effect could disappear among rural to urban migrants.

Association between serum zonulin level and severity of house dust mite allergic asthma

“…Exposure to dust mite allergens is a risk factor for clinical asthma in sensitized subjects. [12] The relationship between allergic asthma and intestinal permeability is a subject of research interest. An increase in the intestinal permeability may result in facilitating the entry of allergenic proteins from the intestinal lumen into the systemic circulation.…”

Association between serum zonulin level and severity of house dust mite allergic asthma

“…Allergic asthma can be sparked by allergen sensitization in which house dust mites (HDM) are among the most prevalent indoor allergens [ 14 ]. Exposure to dust mite allergens is a risk factor for clinical asthma in sensitized subjects [ 15 ].…”

Characteristics of allergen profile, sensitization patterns and Allergic Rhinitis in SouthEast Asia

“…Moreover, the prevalence of HDM sensitization in allergic patients living in urban areas were higher than those living in rural area in Vietnam [8,11], which is consistent with the reports from other Southeast Asia countries. Recently, Chu et al [51] showed that a high endotoxin concentrations in rural houses were associated with a lower risk of HDM sensitization.…”