The 2009 Japan flu pandemic was an outbreak of the H1N1 and the Influenza A viruses across Japan. The World Health Organization raised the pandemic alert for influenza to level 4 in April 2009 following a worldwide outbreak of the H1N1 influenza strain. The first Japanese infections of H1N1 and Influenza A were both recorded early in May 2009. In August 2009, the government estimated that the virus strains had infected about 760,000 people. At the height of the pandemic in October 2009, it was estimated that 20% of the Japanese population had been infected and that there were on average more than 20 infected people in each Japanese medical facility. The Ministry of Health, Labor and Welfare reported 198 deaths as of March 30, 2010. Japan put several measures in place to attempt to control the spread of infection including quarantining air travellers entering Japan who were suspected of having the virus and closing schools in areas of Japan with high numbers of infection. The pandemic ended in August 2010 when the World Health Organization announced that worldwide influenza infection number were back to the seasonal average before the outbreak occurred.
Government reaction In April, Japan's Ministry of Agriculture, Forestry and Fisheries instructed animal quarantine offices across the country to examine any live pigs being brought into the country to double-check for infection by the H1N1 strain of influenza. Japanese Agriculture Minister Shigeru Ishiba appeared on TV to reassure consumers regarding the safety of pork.MOFA issues red travel alert for Mexico on swine flu . CNA The Japanese farm ministry said that it would not ask for restrictions on pork imports because pork was unlikely to be contaminated with the virus, and any virus would be killed in the cooking process anyway.
Timeline
April
April 28 Following the World Health Organization's raising the pandemic alert level to Phase 4 (April 27 UTC), Japan's Health, Labour, and Welfare Minister, Yoichi Masuzoe, declared the outbreak of a new influenza strain in Mexico, the United States, and Canada. A task force was set up. The Japanese government installed a basic policy to block the virus at borders. At Narita Airport, in-flight quarantine inspection was initiated to check the health of passengers arriving from Mexico, the United States, and Canada.
April 30 At Narita, a Japanese woman tested positive for influenza A on a flight from LA (but was found to be infected with the Hong Kong strain of influenza A, not with H1N1).
May May 1 Another suspected case was announced by Health, Labour, and Welfare Minister in a 17-year-old male Yokohama high school student, who had tested positive for influenza A the day earlier. He turned out to have the Soviet strain of influenza A.
May 8 The first three cases of H1N1 in Japan were confirmed in patients who had spent time in Oakville, Canada and returned via Detroit.
May 10 A fourth case was confirmed in a student who had returned from a school trip to Canada.
May 16 Japan's first domestic case of infection was confirmed in Kobe in a male high school student without a history of traveling abroad. He was initially thought to have a seasonal flu, and therefore a Polymerase chain reaction (PCR) test had not been performed on him in a timely manner. Two other students were suspected, and 17 other students claimed flu-like symptoms, but the route of the infection was not traceable. An emergency meeting was held in Kobe, and the decision was made to close public schools and kindergartens in several wards--Higashinada, Nada, Chūō—and in a neighboring city, Ashiya, for seven days. The annual Kobe Festival, planned for that day and the next, was cancelled. The number of confirmed high school cases in Kobe reached 8 by nightfall, many were members of the same volleyball club who had recently competed in an inter-scholastic match. In Osaka prefecture, one high school student tested positive, her sample having been sent to the Infectious Disease Surveillance Center. Other 100 students at the same school and some of their family members exhibited flu-like symptoms. Based on the prefectural plan of measures against new flu, Hyōgo Prefecture declared a state of emergency. Schools in Hyogo, Kita, and Nagata wards were closed for one week.
May 17 161 people were reported to have been in close contact with the infected students in Hyōgo Prefecture only.
May 18 In Hyōgo and Osaka prefectures, elementary, junior high and senior high schools were closed for a week. By evening, confirmed cases in Japan totaled 144: 140 domestic cases from Hyōgo and Osaka Prefectures, and four other cases found during quarantine inspection. Domestic cases include employees of a railway kiosk and a bank; therefore, several railway kiosks in Kobe were closed and 70 other bank workers who had worked with an infected employee were told to stay home.
May 19 According to Osaka's educational committee, about 2400 students among 198,000 left, and 19,000 reported symptoms including sore throat, nasal congestion, and fever. Tonooka Tatsuhito, former chief of the city of Otaru's public health center, reported "Because clinical presentation of novel flu and seasonal flu show the same symptoms, there is a possibility that unaware of novel flu, patients have been treated at ordinary clinic as if they had seasonal flu," and that "this time, a doctor of Kobe submit sample (of first confirmed male high school student who never went abroad and didn't even have fever at that time) by chance, so it was recognized as novel flu. The infection is not only a problem of Kansai area." To avoid false positive reporting, the Health, Labour and Welfare Ministry added to the diagnostic criteria for the novel flu that a patient have a record of overseas travel but Tokyo metropolitan changed its policy to detect early stage novel flu and perform inspection even if no record of travel abroad existed.
May 20 Shiga Prefecture became the third prefecture to report infection: a 23-year-old man in Ōtsu. Tokyo Prefecture and Kanagawa Prefecture's Kawasaki city each announced their first confirmed cases in two 16-year-old high school girls, one living in Hachiōji in west Tokyo, and the other in Kawasaki. They went to the same Kawasaki high school and had traveled together from the United States, where they had attended a mock session of the United Nations. Although the student from Hachioji developed a fever during the flight, she tested negative to preliminary testing for influenza A and B at Narita airport, according to Tokyo officials. Confirmed cases in Japan reached 267 that day: 263 domestic cases from Hyōgo, Osaka, Shiga, Tokyo and Kanagawa prefectures, and four other cases found during quarantine inspection.
May 21 Kawasaki city apologized to national media at the Kawasaki press club for hiding their suspected case, saying the student's family hoped the case would not be made public until confirmed. The day prior, Kawasaki knew that she had tested positive in a simple test, but denied this fact in media inquiries, until they confirmed the case in a public announcement later that night. Tokyo announced its second confirmed case: a 36-year-old woman living in Meguro ward, who returned to Japan on May 19 after traveling to Florida and San Francisco, California, for about two weeks. Nara prefecture announced that of 1117 junior and senior high school students and faculty members who had fever and coughs, all had been interviewed by school doctors, seven of them visiting fever consultation clinics, and all had tested negative. Kyoto announced the first confirmed case its prefecture: a 10-year-old elementary-school boy.
May 22 Saitama Prefecture announced its first confirmed case: a 29-year-old man of town of Washimiya, who travelled to Osaka and Kyoto on May 17 to May 19. By the morning of May 22, confirmed cases in Japan totaled 279: 275 domestic cases from Hyōgo (146), Osaka (123), Tokyo (2), Kanagawa (1), Saitama (1), Kyoto (1) and Shiga (1) prefectures, and four other cases found during quarantine inspection. Six days after the first domestic infection case was confirmed, the government implemented a new policy, revising its guidelines on battling the novel strain of H1N1. The new policy grouped areas of Japan into two categories, depending on the number of confirmed patients. In areas already with high or sharply rising numbers of confirmed cases, more flexible measures were to be applied which focused on preventing patients from developing serious symptoms; priority would be placed on treating people with underlying health problems such as diabetes and asthma; local authorities would take initiative in dealing with outbreaks, and school lessons could be suspended on a school-by-school basis or on a class-by-class basis. In areas with few or no cases confirmed, strict measures were to remain in place to prevent the spread of infection; all infected patients would be hospitalized at medical institutions designated to treat cases of infectious diseases; Nearby schools or, those in a location at risk for spreading the virus, would be asked to suspend lessons. The government also called off blanket in-flight quarantine inspections on aircraft arriving from Mexico, the United States and Canada. Tokyo's third case was confirmed: a 25-year-old man from Mitaka who was in Osaka from May 14 to May 20. Another case was confirmed during quarantine inspection at Narita: a South Korean man who arrived from Chicago on May 21.
May 23 Nursery schools and day care facilities reopened in Hyōgo Prefecture. The number of newly confirmed domestic cases had been declining since May 20, according to a data report released on May 23 from the Ministry of Health, Labour and Welfare. In preparation for resumption of school on May 25, teachers in a Kobe municipal high school made masks of folded paper-towels, for students who couldn't bring in their own due to low supply at stores.
May 24 The sixth quarantine case was confirmed at Narita: a 41-year-old Japan Airlines ground crewman, who had been on a business trip to Seattle and then arrived at Narita Airport from Vancouver on May 24. Confirmed cases in Japan reached 343 that day: 337 domestic cases and six other cases found during quarantine inspection.
May 25 Most schools in Osaka and Hyōgo Prefectures resume. Fukuoka Prefecture announced the first confirmed case in Kyushu region: a U.S. citizen who visited his wife's parents' home.
May 26 Shizuoka announced the first confirmed case from Shizuoka Prefecture: a seven-year-old boy who returned from the Philippines on May 22. Two U.S. nationals were confirmed ill on May 26 during quarantine inspection: a man and his child who arrived at Narita on May 25. By 9:30 PM that night, there were 353 confirmed cases in Japan, including one from Shizuoka prefecture and eight cases that had been found during quarantine inspection.
May 27 First confirmed case in Wakayama Prefecture: a 28-year-old man who returned from a trip to Hawaii on May 23. Two out of four new cases in Kobe were students of high schools that had been closed until May 24; The schools suspend classes for an additional week. Shizuoka announced another confirmed case: a younger sister of the first confirmed boy. By the evening, confirmed cases in Japan numbered 364, 356 domestic cases and eight cases found during quarantine inspection.
May 28 367 confirmed cases by the evening. The Mayor of Kobe held a press conference saying "[The spread of the novel H1N1 virus] seems to have ceased in the city. I send a message that Kobe is safe in the meantime. Please visit Kobe." The chairman of the city's medical association scoffed that it was too early to make such an announcement, that the mayor should have waited for at least seven consecutive days to pass with no new cases.
May 29