Duration of fever and PA/I38X-substituted virus emergence in patients treated with baloxavir in the 2018-2019 influenza season.

Duration of fever and virus persistence after baloxavir administration were investigated in 81 outpatients, 16 with A(H1N1)pdm09 and 65 with A(H3N2) in the Japanese 2018-2019 influenza season. Only eight cases of A(H3N2) viruses were detected post-dose. PA/I38T-substituted viruses were detected in four (6.2%) of 65 A(H3N2) patients, at days 3 and 4, constituting 50% (4/8) of A(H3N2) detected post-dose. The median duration of fever was 26.0 h for A(H1N1)pdm09 and 20.3 h for A(H3N2). The median duration of fever for patients with PA/I38T-substituted viruses was 22.0 h, without significant difference to that of the patients in whom the mutated virus was not detected. Emergence of PA/I38T-substituted viruses after treatment with baloxavir was confirmed, but no significant prolongation of fever was observed in the four patients with PA/I38T-substituted virus emergence.

Association between chemical components of PM2.5 and children's primary care night-time visits due to asthma attacks: A case-crossover study.

BACKGROUND: Few papers have examined the association between the chemical components of PM2.5 and health effects. The existence of an association is now under discussion. METHODS: This case-crossover study aimed to examine the association between the chemical components of PM2.5 and night-time primary care visits (PCVs) due to asthma attacks. The subjects were 1251 children aged 0-14 years who received medical care for asthma at a municipal emergency clinic. We measured daily average concentrations of hydrogen ion, sulfate ion, nitrate ion and water-soluble organic compounds (WSOCs), which are components of PM2.5. We estimated the odds ratios (ORs) of PCVs per unit increment (inter quartile ranges) in each chemical component of PM2.5 for the subgroups of warmer months and colder months separately. RESULTS: No association was seen between PCVs and PM2.5 mass concentrations the day before the PCVs in either warmer or colder months. In the warmer months, an association was seen with the concentrations of WSOCs and hydrogen ion the day before the PCVs (OR = 1.33; 95% CI: 1.00-1.76, OR = 1.18; 95% CI: 1.02-1.36, respectively). Furthermore, a negative association was seen between sulfate ion and PCVs (OR = 0.85; 95%CI: 0.74-0.98). No associations were observed in the colder months. CONCLUSIONS: We observed a positive association between PCVs and certain concentrations of WSOCs and hydrogen ions in warmer months. In contrast, sulfate ion showed a negative association.

Comparison of the clinical symptoms and the effectiveness of neuraminidase inhibitors for patients with pandemic influenza H1N1 2009 or seasonal H1N1 influenza in the 2007-2008 and 2008-2009 seasons.

The clinical symptoms and effectiveness of neuraminidase inhibitors (NAI) have not been adequately compared among pandemic H1N1 2009 patients, seasonal H1N1 patients, and patients with H1N1 with the H275Y mutation. The data of 68 seasonal H1N1 patients in 2007-2008, 193 seasonal H1N1 patients in 2008-2009, and 361 pandemic H1N1 2009 patients diagnosed by PCR who received an NAI were analyzed. The duration of fever (body temperature ≥ 37.5 ºC) after the first dose of NAI and from onset was calculated. The H275Y neuraminidase mutation status was determined for 166 patients. Significantly lower mean age (18.4 ± 13.2 years) and a higher percentage of teenagers (53.7%) were found for pandemic 2009 influenza than for seasonal influenza (P < 0.001). The peak body temperature was equivalent (mean, 39.0 ºC) in the three seasons, and the frequency of symptoms was the same or lower for pandemic influenza compared with seasonal H1N1. None of the 34 analyzed pandemic H1N1 virus isolates contained the H275Y mutation, which was commonly detected in the 2008-2009 season. The duration of fever after the start of oseltamivir therapy was significantly shorter for patients with pandemic (23.0 ± 11.6 h) than with seasonal H1N1 in both the 2008-2009 (49.7 ± 32.3 h) and 2007-2008 seasons (32.0 ± 18.9 h). The mean duration of fever after the first dose of zanamivir was not different among the three seasons (26.9-31.5 h). Clinical symptoms were the same or somewhat milder, and oseltamivir was more effective, for pandemic 2009 than for seasonal H1N1 influenza with or without H275Y mutation.

Clinical effectiveness of oseltamivir and zanamivir for treatment of influenza A virus subtype H1N1 with the H274Y mutation: a Japanese, multicenter study of the 2007-2008 and 2008-2009 influenza seasons.

BACKGROUND: Influenza A virus subtype H1N1 with the H274Y mutation emerged and spread worldwide. However, the clinical effectiveness of the neuraminidase inhibitors, oseltamivir and zanamivir, has not been adequately reevaluated. METHODS: Data from 164 patients with H1N1 virus infection and 59 patients with H3N2 virus infection during the 2008-2009 influenza season and 68 patients with H1N1 virus infection during the 2007-2008 influenza season who received a neuraminidase inhibitor were analyzed. The duration of fever (body temperature 37.5 degrees C) after the first dose of oseltamivir or zanamivir and from onset of symptoms was calculated from patient reports. The influenza virus was isolated, and its subtype was determined by hemagglutinin inhibition assay and polymerase chain reaction. The H274Y neuraminidase mutation status was determined by sequencing the neuraminidase segment. RESULTS: Of 68 patients with H1N1 virus infection during the 2007-2008 season, 41 were treated with oseltamivir, and 27 were treated with zanamivir. During the 2008-2009 season, 77 patients with H1N1 virus infection were treated with oseltamivir, and 87 were treated with zanamivir; 31 and 28 patients with H3N2 virus infection were treated with oseltamivir and zanamivir, respectively. All 49 analyzed H1N1 virus isolates obtained during the 2008-2009 season, but none of the isolates obtained during the 2007-2008 season, contained the H274Y mutation. The mean +/- standard deviation duration of fever after the start of oseltamivir therapy was significantly longer for patients with H1N1 virus infection (49.1+/-30.2 h) than it was for patients with H3N2 virus infection (33.7+/-20.1 h; P < .01) during the 2008-2009 season and patients with H1N1 virus infection during the 2007-2008 season (32.0+/-18.9 h; P < .001). The duration of fever was significantly longer after the first dose of oseltamivir than it was after the first dose of zanamivir for patients with H1N1 virus infection during the 2008-2009 season (P <.001). The duration of fever from onset of H1N1 virus infection was significantly longer for children 15 years of age during 2008-2009 (70.6+/-34.5 h) than it was for such children during 2007-2008 (48.4+/-21.2). CONCLUSION: The effectiveness of oseltamivir, but not that of zanamivir, decreased significantly for H1N1 virus infection during the 2008-2009 season.