[Effects of school closure during influenza A/H1N1 pandemic in 2009 in Japan]

Urgent need to strengthen school health in Asia and the Pacific islands

In Asia and the Pacific island region, strengthening of school health activities and measures is urgently recommended to deal with the impact of the increasing risk of potential school closures due to continuation of the coronavirus disease 2019 (COVID-19) pandemic in 2021. As the incidence of COVID-19 in 2020 was relatively low in these regions, many of the countries were able to avoid prolonged school closures. However, even if vaccination is expanded in the future and the pandemic tends to come to an end, the risk of SARS-CoV-2 variants spreading among children will also increase, and the possibility of having to close schools again will also increase.

Seasonal influenza among children diagnosed by their guardians: a small pilot study in Japan

AIM

We aimed to elucidate the accuracy and optimal cut-off point of the self-diagnosis of influenza and the associated clinical symptoms of children by their guardians, compared with those of the rapid influenza diagnostic test (RIDT).

BACKGROUND

Seasonal influenza is a common outpatient problem during the winter season. A paediatric influenza epidemic has socio-economic impacts like temporary school closure, school event cancellations, and unscheduled work absences among parents. Hence, early identification and assessment of influenza to prevent its spread is important from a societal perspective.

METHOD

We performed a cross-sectional observational study in a rural clinic in Japan every winter season from December 2013 to March 2016. We retrospectively extracted information from the medical records and pre-examination checklists of 24 patients aged <12 years (mean age, 5.4 years; men, 54.2%). The data extracted from the medical records and pre-examination checklist included the baseline characteristics (age, sex and past medical history of influenza), clinical signs and symptoms, diagnosis by guardians (%) and RIDT results.

FINDINGS

The optimal cut-off point of the self-diagnosis of influenza by guardians was 80%, with a sensitivity and specificity of 63.6% (95% confidence interval: 30.8-89.1) and 92.3% (64.0-99.8). At a 50% cut-off point, the sensitivity and specificity were 90.9% (58.7-99.8) and 53.8% (25.1-80.8). The accuracy of feeling severely sick, as estimated by the guardians showed a sensitivity and specificity of 90.9% (58.7-99.8) and 69.2% (38.6-90.9). Our study indicates that the diagnosis of seasonal influenza by guardians to their children would be useful in the establishment of both confirmatory diagnoses when it has high probability above the optimal cut-off point (80%), and exclusion diagnosis when it has low probability (50%). Not feeling severely sick, estimated by the guardians might be a useful indicator for the exclusion of paediatric influenza.

Evaluation of the spread of pandemic influenza A/H1N1 2009 among Japanese university students

The pandemic influenza A/H1N1 2009 virus is commonly known to affect younger individuals. Several epidemiological studies have clarified the epidemic features of university students in Japan. In this study, we reviewed these studies in Japan in comparison with reports from other countries. The average cumulative incidence rate among university students was 9.6 %, with the major symptoms being cough, sore throat, and rhinorrhea. These epidemiological features were similar between Japan and other countries. Attitudes and behaviors toward pandemic influenza control measures were different before and improved during and after the epidemic. These features were also similar to those in other countries. On the other hand, the epidemic spread through club activities or social events, and transmission was attenuated after temporary closure of such groups in Japan. This transmission pattern was inconsistent among countries, which may have been due to differences in lifestyle and cultural habits. Based on these results, infection control measures of pandemic influenza for university organizations in Japan should be considered.