Occurrence of human respiratory syncytial virus in summer in Japan.

In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007-2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.

Characterization of influenza outbreaks in Lebanon during the 2013/14 and 2014/15 seasons.

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A(H3N2) was dominant in the 2013/14 season while the A(H1N1)pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors (oseltamivir, zanamivir, peramivir and laninamivir). Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region.

Characterization of influenza outbreaks in Lebanon during the 2013/14 and 2014/15 seasons

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A[H3N2] was dominant in the 2013/14 season while the A[H1N1]pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors [oseltamivir, zanamivir, peramivir and laninamivir]. Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region

Malgré la lourde charge que représentent les flambées de grippe, la surveillance active de la maladie était jusqu'à présent inexistante au Moyen-Orient, et notamment au Liban. Dans la présente étude, le virus de la grippe a été caractérisé dans 440 sécrétions rhinopharyngées prélevées par écouvillonnage chez des patients ayant souffert d'infections respiratoires aiguës pendant deux saisons grippales au Liban. Le virus de la grippe A[H3N2] était prédominant pendant la saison 2013/2014, tandis que celui de la grippe A[H1N1]pdm09 et les souches de grippe B/Yamagata étaient les plus courants pendant la saison 2014/2015. Tous les isolats testés étaient sensibles à quatre inhibiteurs de la neuraminidase [l'oseltamivir, le zanamivir, le peramivir, et le laninamivir]. L'analyse génétique du gène de l'hémagglutinine a révélé de multiples introductions des virus de la grippe au Liban, depuis différentes sources géographiques au cours de chaque saison. De plus, d'importantes lacunes dans les données ont été constatées dans la région du Moyen-Orient, comme le montre l'absence des séquences génétiques actuelles de la grippe dans les bases de données de nombreux pays de la region

Delayed norovirus epidemic in the 2009-2010 season in Japan: potential relationship with intensive hand sanitizer use for pandemic influenza.

Norovirus (NoV) epidemics normally peak in December in Japan; however, the peak in the 2009-2010 season was delayed until the fourth week of January 2010. We suspected intensive hand hygiene that was conducted for a previous pandemic influenza in 2009 as the cause of this delay. We analysed the NoV epidemic trend, based on national surveillance data, and its associations with monthly output data for hand hygiene products, including alcohol-based skin antiseptics and hand soap. The delayed peak in the NoV incidence in the 2009-2010 season had the lowest number of recorded cases of the five seasons studied (2006-2007 to 2010-2011). GII.4 was the most commonly occurring genotype. The monthly relative risk of NoV and monthly output of both alcohol-based skin antiseptics and hand soap were significantly and negatively correlated. Our findings suggest an association between hand hygiene using these products and prevention of NoV transmission.

The spatial diffusion of norovirus epidemics over three seasons in Tokyo.

We studied the spatial trend of norovirus (NoV) epidemics using sentinel gastroenteritis surveillance data for patients aged <15 years (n = 140) in the Tokyo area for the 2006-2007 to 2008-2009 seasons utilizing the kriging method of geographical information system (GIS). This is the first study of the spreading pattern of NoV epidemics using sentinel surveillance data. Correlations of sentinel cases between the seasons and with demographic data were examined to identify the trend and related factors. A similar pattern of diffusion was observed over the seasons, and its mean correlation between seasons was significantly high. A higher number of cases were found in the peripheral area, which surrounds the most populated central area, and showed a correlation with the ratio of the children population (r = 0·321, P < 0·01) and the ratio of residents in larger families (r = 0·263, P < 0·01). While NoV susceptibility remained, the results suggest a transmission route in the local community as a possible epidemic factor. Prevention with focus on the peripheral area is desirable.