In the last ten years, Japan has experienced several large-scale earthquakes with devastating social and health impacts. Earthquakes directly and indirectly cause a variety of health problems. Further investigation is required to increase preparedness and preventive efforts. In response to the Hokkaido Eastern Iburi Earthquake on September 6, 2018, 32 Emergency Medical Teams (EMTs) employed the Japanese version of Surveillance in Post-Extreme Emergencies and Disasters (J-SPEED) as a national standard daily reporting template, gathering data on the number and type of health problems treated.

The purpose of the study is to conduct a descriptive epidemiology study using the J-SPEED data to better understand the health problems during the earthquake disaster.

Reported items in J-SPEED (Ver 1.0) form were analyzed by age, gender, and time to better understand the health issues that have arisen from the earthquake.

Most consultations (721; 97.6%) occurred between Day 1 and Day 13 of the 32-day EMT response. During the response period, disaster stress-related symptoms were the most common health event (15.2%), followed by wounds (14.5%) and skin diseases (7.0%).

The most often reported health event during the response period was stress-associated illnesses related to disasters, followed by wounds and skin conditions. The health consequences of natural disasters depend on diverse local environment and population. As a result, this initial study was hard to generalize; however, it is expected that data accumulated using the J-SPEED system in the future will strengthen and extend the conclusions.

Rainfall-induced floods and landslides accounted for 20.7% of all disaster events in Japan from 1985 through 2018 and caused a variety of health problems, both directly and indirectly, including injuries, infectious diseases, exacerbation of pre-existing medical conditions, and psychological issues. More evidence of health problems caused by floods or heavy rain is needed to improve preparedness and preventive measures; however, collecting health data surrounding disaster events is a major challenge due to environmental hazards, logistical constraints, political and economic issues, difficulties in communication among stakeholders, and cultural barriers. In response to the West Japan Heavy Rain in July 2018, Emergency Medical Teams (EMTs) used Japan - Surveillance in Post-Extreme Emergencies and Disasters (J-SPEED) as a daily reporting template, collecting data on the number and type of patients they treated and sending it to an EMT coordination cell (EMTCC) during the response.

The aim of the study was to conduct a descriptive epidemiology study using J-SPEED data to better understand the health problems during floods and heavy rain disasters.

The number and types of health problems treated by EMTs in accordance with the J-SPEED (Ver 1.0) form were reported daily by 85 EMTs to an EMTCC, where data were compiled during the West Japan Heavy Rain from July 8 through September 11, 2018. Reported items in the J-SPEED form were analyzed by age, gender, area (prefecture), and time period.

The analysis of J-SPEED data from the West Japan Heavy Rain 2018 revealed the characteristics of a total of 3,617 consultations with the highest number of consultations (2,579; 71.3%) occurring between Day 5 and Day 12 of the 65-day EMT response. During the response period, skin disease was the most frequently reported health event (17.3%), followed by wounds (14.3%), disaster stress-related symptoms (10.0%), conjunctivitis (6.3%), and acute respiratory infections (ARI; 5.4%).

During the response period, skin disease was the most frequently reported health event, followed by wounds, stress, conjunctivitis, and ARIs. The health impacts of a natural disaster are determined by a variety of factors, and the current study’s findings are highly context dependent; however, it is expected that as more data are gathered, the consistency of finding will increase.

Japan recently experienced two major heavy rain disasters: the West Japan heavy rain disaster in July 2018 and the Kumamoto heavy rain disaster in July 2020. Between the occurrences of these two disasters, Japan began experiencing the wave of the coronavirus disease 2019 (COVID-19) pandemic, providing a unique opportunity to compare the incidence of acute respiratory infection (ARI) between the two disaster responses under distinct conditions.

The data were collected by using the standard disaster medical reporting system used in Japan, so-called the Japan-Surveillance in Post-Extreme Emergencies and Disasters (J-SPEED), which reports number and types of patients treated by Emergency Medical Teams (EMTs). Data for ARI were extracted from daily aggregated data on the J-SPEED form and the frequency of ARI in two disasters was compared.

Acute respiratory infection in the West Japan heavy rain that occurred in the absence of COVID-19 and in the Kumamoto heavy rain that occurred in the presence of COVID-19 were responsible for 5.4% and 1.2% of the total consultation, respectively (P <.001).

Between the occurrence of these two disasters, Japan implemented COVID-19 preventive measures on a personal and organizational level, such as wearing masks, disinfecting hands, maintaining social distance, improving room ventilation, and screening people who entered evacuation centers by using hygiene management checklists. By following the basic prevention measures stated above, ARI can be significantly reduced during a disaster.