[Evaluation of a new immunochromatographic kit for enhanced detection of influenza B virus].

We have evaluated a new immunochromatographic kit, "KBM LineCheck Flu AB", which had been developed for enhanced detection of influenza B viruses. Five strains of influenza A and B viruses were tested for reactivity and detection limits of the kit. Compared with the detection limits of commercially available kit of QuickNavi-Flu, "KBM LineCheck Flu AB" showed a nearly equal reactivity to influenza A viruses, but quadruple reactivity to 2 influenza B viruses. Also, "KBM LineCheck Flu AB" exhibited high specificity when tested in 130 influenza-negative culture specimens derived from 24 adult volunteers. Furthermore, "KBM LineCheck Flu AB" was clinically evaluated by using 866 specimens, including 190 nasal swabs, 201 nasal aspirations, 262 self-blown nasal discharges, and 213 pharyngeal swabs. Compared with the results of QuickNavi-Flu for influenza A, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs were calculated to be 95.8%, 92.0%, 95.0%, and 94.8%, respectively. Whereas, as to influenza B, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs was calculated to be 96.3%, 98.5%, 96.2%, and 93.4%, respectively. Similarly, compared with the results of influenza A viral culture, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs was calculated to be 95.3%, 91.0%, 93.9%, and 92.5%, respectively. Regarding influenza B culture, the test efficiency for the nasal swabs, the nasal aspirations, self-blown nasal discharges, and pharyngeal swabs were calculated to be 95.8%, 97.5%, 95.1%, 91.5%, respectively. Overall, we concluded that the "KBM LineCheck Flu AB" is useful and suitable for diagnosis of influenza A and especially influenza B.

Immunomodulator clarithromycin enhances mucosal and systemic immune responses and reduces re-infection rate in pediatric patients with influenza treated with antiviral neuraminidase inhibitors: a retrospective analysis.

BACKGROUND/AIMS: Treatment with antiviral neuraminidase inhibitors suppresses influenza viral replication and antigen production, resulting in marked attenuation of mucosal immunity and mild suppression of systemic immunity in mice. This study investigated the effects of immunomodulator clarithromycin (CAM) supplementation on mucosal and systemic immunity in pediatric patients with influenza treated with neuraminidase inhibitors. METHODS: A retrospective, non-randomized case series study was conducted among five treatment groups of 195 children aged 5.9±3.3 years infected with influenza A in 2008/2009 season. The five treatment groups were oseltamivir (OSV), zanamivir (ZNV), OSV+CAM, ZNV+CAM and untreated groups. Anti-viral secretory IgA (S-IgA) levels in nasal washes and IgG levels in sera were measured. The re-infection rate was analyzed among the same five treatment groups in the 2009/2010 season. RESULTS: Treatment of influenza with OSV and ZNV for 5 days attenuated the induction of anti-viral S-IgA in nasal washes and anti-viral IgG in serum, compared with the untreated group. The combination of CAM plus OSV or ZNV boosted and restored the production of mucosal S-IgA and systemic IgG. The re-infection rates in the subsequent season were significantly higher in the OSV and ZNV groups than the untreated, while CAM+OSV and CAM+ZNV tended to reduce such rate. CONCLUSIONS: CAM restored the attenuated anti-viral mucosal and systemic immunity and reduced the re-infection rate in the subsequent year in pediatric patients with influenza treated with OSV and ZNV.