NHK has learned that only 40 percent of medical institutions in Japan are entering information directly into an online system for sharing data on coronavirus infections nationwide.
The Health Center Real-time information-sharing System on COVID-19, or HER-SYS, was introduced in medical institutions and public health centers in May.
Torrential rain in western Japan has left dozens of hospitals and welfare facilities flooded, without power, or lacking water.
The health ministry says, as of 5:30 a.m. on Wednesday, at least 23 hospitals were affected by flooding, power outages, and disrupted water supplies in the southwestern prefectures of Kumamoto, Fukuoka and Kagoshima, as well as in the western prefecture of Shiga. Officials say water trucks have been sent to the areas. They also say patients are being moved to nearby facilities.
Torrential rains in Japan's southwestern region of Kyushu have left dozens of hospitals and other facilities inundated or without power or water.
Japan's health ministry says at least 22 hospitals in Kumamoto, Kagoshima and Fukuoka prefectures were flooded or had no electricity or water as of 6 a.m. on Tuesday.
Japan's government plans to investigate reports that many hospitals are refusing to admit people suspected of having the coronavirus.
The Fire and Disaster Management Agency will survey 52 fire departments in Tokyo and other big cities. The survey will ask them how many times their ambulances have been turned away by four or more hospitals.
An NHK survey has found that nearly 10 percent of people infected with the coronavirus in Japan are believed to have contracted the pathogen inside hospitals and other medical institutions.
As of Tuesday, the total of confirmed and suspected cases of hospital infections stood at 1,086, across 60 medical institutions nationwide.
A doctor at a Tokyo medical institution for infectious diseases says he fears the capital's hospitals will not be able to treat the growing number of coronavirus patients.
The Tokyo metropolitan government began moving people with mild symptoms to hotels on Tuesday to free up hospital beds for the seriously ill.