{'fraction_non_alphanumeric': 0.02505446623093682, 'fraction_numerical': 0.030501089324618737, 'mean_word_length': 4.502994011976048, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Past trends in hepatitis C virus infection and route of transmission in Japan].

In Japan, it is known that the prevalence of hepatitis C virus(HCV) is high among the older people over 60 years of age in sharp contrast to the low prevalence among those under 30. The annual incidence rate of HCV carriers in general population remains quite low to be 1.8-3.4 per 100,000 person-year. On the other hand, HCV prevalence among intravenous drug users(IVDU) is still greater than 60%. Taking into account this epidemiological pattern together with the historical fact that Japan experienced an explosion of drug abuse among young generation of 15 to 25 years old in the period of post World War II turmoil together with the poor sanitary and medical conditions, it is suggested that a great wave of HCV spread in Japan occurred most likely in 1960's to 1970's. The spread then may have gradually fallen to the range today.