The interaction between viral HA (hemagglutinin) and oligosaccharide of the host plays an important role in the infection and transmission of avian and human flu viruses. Until now, this interaction has been classified by sialyl(alpha2-3) or sialyl(alpha2-6) linkage specificity of oligosaccharide moieties for avian or human virus, respectively. In the case of H5N1 and newly mutated flu viruses, classification based on the linkage type does not correlate with human infection and human-to-human transmission of these viruses. It is newly suggested that flu infection and transmission to humans require high affinity binding to the extended conformation with long length sialyl(alpha2-6)galactose containing oligosaccharides. On the other hand, the avian flu virus requires folded conformation with sialyl(alpha2-3) or short length sialyl(alpha2-6) containing trisaccharides. This suggests a potential future direction for the development of new species-specific antiviral drugs to prevent and treat pandemic flu.
Animals ; Antiviral Agents ; Classification ; Hand ; Humans ; Influenza in Birds ; Influenza, Human* ; Oligosaccharides* ; Oseltamivir* ; Pandemics ; Sensitivity and Specificity ; Trisaccharides

Background: Food allergy (FA) can have a profound effect on quality of life (QoL), stress, and anxiety in the family. We aimed to validate the Korean version of the Food Allergy Quality of Life-Parental Burden (FAQL-PB) and identify factors related to the parental psychosocial burden of caring for children with FAs. Methods: Parents of children aged between 6 months and 17 years with immunoglobulin E (IgE)-mediated FAs from the Pediatric Allergy Department of five university hospitals in Korea were enrolled in the study. Parents were asked to complete the FAQL-PB, Food Allergy Independent Measure-Parent Form (FAIM-PF), Child Health Questionnaire-Parents Form 28 (CHQ-PF28), Beck’s Anxiety Inventory, Connor-Davidson Resilience Scale, and Patient Health Questionnaire-9 for depression. Statistical analyses included internal consistency, test-retest reliability, concurrent validity, discriminative validity, and logistic regression analyses. Results: A total of 190 parents were enrolled. Social activity limitation was the item with the highest FAQL-PB scores. The Cronbach’s α for each item was higher than 0.8. The test-retest reliability was good (intra-class correlation coefficient, 0.716; 95% confidence interval [CI], 0.100–0.935). An increase in the FAQL-PB was significantly associated with an increase in the FAIM-PF (β = 0.765, P < 0.001) (concurrent validity). There was a positive correlation between parental burden, anxiety, and depression, while resilience was inversely correlated with parental burden (all P < 0.001). The total FAQL-PB score in parents of children who had experienced anaphylaxis was significantly higher than that in parents of children who did not experience it (P = 0.008). When adjusting for age, sex, and underlying diseases, anaphylaxis β = 9.32; 95% CI, 2.97 to 15.68), cow’s milk (CM) allergy (β = 8.24; 95% CI, 2.04 to 14.44), soybean allergy (β = 13.91; 95% CI, 1.62 to 26.20), higher anxiety (β = 1.05; 95% CI, 0.07 to 1.41), higher depression (β = 2.15; 95% CI, 1.61 to 2.69), and lower resilience (β = −0.42; 95% CI, −0.61 to −0.2) were significantly associated with greater parental burden in children with IgE-mediated FAs. Conclusion FAQL-PB is a reliable and valid tool for use in Korea. Anaphylaxis, CM or soybean allergies, more anxiety and depression symptoms, and lower resilience are associated with poorer QoL in parents of children with FAs.