Exposure to individual EV serotypes and risk of atopy
Seropositivity for individual EV serotypes is shown in Table 2 . Antibodies against Echo3 and Echo14 were less prevalent among case children as compared to control children (OR 0.11, 95% CI 0.01-0.88,P = 0.037 and OR 0.17, 95% CI 0.04-0.75, P = 0.019, respectively). EV74 antibodies were more prevalent among case children (OR 1.68, 95% CI 1.02-2.76, P = 0.04). In a subgroup analysis of cases with higher likelihood of clinical symptoms (s-IgE-levels over 0.7 kU/L) CAV6 was a strong protective element for atopic sensitization (OR 0.22, 95% CI 0.08-0.66, P = 0.007) while EV74 continued to show a risk association (OR 1.82, 95% CI 1.01-3.29, P = 0.047).
When case children with an allergic disease were compared to their matched controls CAV6, CAV16, and Echo14 seropositivity were significantly less frequent in cases (OR 0.23, 95% CI 0.07-0.81,P = 0.022; OR 0.33, 95% CI 0.12-0.92, P = 0.033 and OR 0.11, 95% CI 0.01,0.88, P = 0.037, respectively).
The prevalence of EV seropositivity was analysed separately in case boys vs. control boys and case girls vs. control girls. Two EV serotypes showed significant inverse assocation with atopic sensitization among boys: CAV6 (OR 0.27, 95% CI 0.09-0.80, P = 0.019) and Echo14 (OR 0.10, 95% CI 0.01-0.78, P = 0.028). In addition, CAV6, CAV16, and Echo5 showed significant inverse assocation with allergic disease among case boys compared to their controls (OR 0.18, 95% CI 0.04-0.82,P = 0.027; OR 0.21, 95% CI 0.06-0.75, P = 0.015 and OR 0.31, 95% CI 0.1-0.94, P = 0.039, respectively). None of the serotypes showed assocation with atopic sensitization or allergic disease among girls.