The effect of the 2018 Japan Floods on cognitive decline among long-term care insurance users in Japan: a retrospective cohort study

BACKGROUND@#The July 2018 Japan Floods caused enormous damage to western Japan. Such disasters can especially impact elderly persons. Research has shown that natural disasters exacerbated a decline in cognitive function, but to date, there have been no studies examining the effects of this disaster on the elderly. The object of this study was to reveal the effect of this disaster in terms of cognitive decline among the elderly.@*METHODS@#Study participants were certified users of the long-term care insurance (LTCI) system in Hiroshima, Okayama, and Ehime prefectures from May 2018 to June 2018. The observation period was from July 2018 to December 2018. Our primary outcome was cognitive decline after the disaster using a dementia symptomatology assessment. In addition to a crude model, a multivariate Cox proportional hazards model was used to assess the cognitive decline of victims, adjusting for age classification, gender, the level of dementia scale before the disaster occurred, residential environment, whether a participant used facilities shut down after the disaster, and population density. After we confirmed that the interaction term between victims and residential environment was statistically significant, we stratified them for the analysis.@*RESULTS@#The total number of participants was 264,614. Victims accounted for 1.10% of the total participants (n = 2,908). For the Cox proportional hazards model, the hazard ratio of the victims was 1.18 (95% confidential interval (CI): 1.05-1.32) in the crude model and 1.12 (95% CI: 1.00-1.26) in the adjusted model. After being stratified by residential environment, the hazard ratio of home victims was 1.20 (95% CI: 1.06-1.36) and the hazard ratio of facility victims was 0.89 (95% CI: 0.67-1.17).@*CONCLUSIONS@#This study showed that elderly living at home during the 2018 Japan Floods were at risk for cognitive decline. Medical providers, care providers, and local governments should establish a system to check on the cognitive function of elderly victims and provide necessary care support.

Mosquito breeding sites and People's knowledge of mosquitoes and mosquito borne diseases: A comparison of temporary housing and non-damaged village areas in Sri Lanka after the tsunami strike in 2004

Although it is very important in view of public health to understand the mosquito breeding sites and key reservoirs existing around residential areas, such information is lacking in temporary housing sites constructed after the serious tsunami strikes on 26 December 2004 in Sri Lanka. This study clarified the situation regarding mosquito breeding 14 months after the tsunami in Sri Lanka by surveying temporary housing and non-damaged village areas, and also by examining people‘s knowledge related to mosquito breeding sites and mosquito-borne diseases. The relative frequency of mosquito larvae in wastewater pools was significantly higher in temporary housing than in village areas. The prevalence of storage containers at temporary housing and village areas was not significantly different. It was found that wastewater pools in temporary housing sites were the main breeding site of <I>Culex quinquefasciatus</I> Say, <I>Cx. tritaeniorhynchus</I> Giles, and <I>Aedes albopictus</I> Skuse whereas storage containers in village areas were the main breeding site of <I>Cx. quinquefasciatus</I> and <I>Ae. albopictus.</I> No mosquitoes bred in storage containers in the temporary housing but some <I>Ae. albopictus</I> did so in village areas. The questionnaires indicated a significant difference between residents of temporary housing and villages in response to the question: Do you know where mosquitoes breed? The proportion of the “wastewater pools” response was higher among temporary housing residents than among village residents. This knowledge among temporary housing residents may relate to the fact that wastewater pools are latent breeding sites for mosquitoes in temporary housing sites. Although residents in the temporary housing sites put salt and abluent into storage containers to prevent mosquitoes from breeding, wastewater pools receiving a constant supply of wastewater provided the best breeding site for mosquitoes.