The Japanese government implemented as of 1 April 1999 the Infectious Disease Act (Act Relating to Infectious Disease Control and Healthcare for Patients) to replace the previous Infectious Disease Prevention Act in order to cope with the rapidly changing infectious diseases, to implement various policies for preventing infectious diseases, and to implement infectious disease control in consideration of the patient’s human rights.

During November 2002 to July 2003, SARS broke out outside of Japan and began to spread worldwide from East Asia via advanced transportation and fast communications of humans and materials. In order to cope with the rapidly changing situation that healthcare institutions faced, the Japanese government amended on 16 October 2003 the Infectious Disease Act (implemented on November 5) and combined it with the Tuberculosis Prevention Act in a second amendment on 1 April 2007.
As shown above, the Japanese government has been playing an active role in coping with the ever-changing infectious diseases.

According to the Infectious Disease Act, there are 7 classes of infectious diseases, including known infectious diseases divided into 5 classes based on their severity and infectability and the statutory infectious diseases and new-type infectious diseases. Healthcare institutions have different control policies based on the risk and severity of these 7 classes of infectious diseases.

Infectious disease classification

●Class 1 infectious diseases:

Extremely risky infectious diseases based on the severity of integrated infectability at infection

Target diseases:

Ebola hemorrhagic fever, Crimean-Congo hemorrhagic fever; smallpox; bubonic plague; Marburg virus, Lassa Fever and South America hemorrhagic fever

●Class 2 infectious diseases:

Highly risky infectious diseases based on the severity of integrated infectability at infection

Target diseases:

Acute poliomyelitis, diphtheritis, SARS, TB

●Class 3 infectious diseases:

Highly risky infectious diseases based on the severity of integrated infectability at infection

Target diseases:

Enterohaemorrhagic E. Coli, cholera, bacillary dysentery, typhoid fever and typhus.

●Class 4 infectious diseases:

Health-affecting infectious diseases communicable by animals or their corpses, food and drink, clothing, bedding and other objects.

Target diseases:

Hepatitis E, West Nile virus (including West Nile meningitis or encephalitis), hepatitis A, cestodiasis, yellow fever, psittacosis, Omsk hemorrhagic fever, relapsing fever, Kyasanur Forest disease, Q fever, rabies, coccidioidomycosis, monkeypox, hemorrhagic fever with renal syndrome, Western equine encephalitis, mite-vector encephalitis, anthrax, scrub typhus, dengue fever, Eastern equine encephalitis, avian flu, Nipah virus, Japanese spotted fever, Japanese encephalitis, hantavirus pulmonary syndrome (HPS), Cercopithecine herpesvirus-1 (herpesvirus B), melioidosis, brucellosis, Venezuelan equine encephalitis, Hendra virus, epidemic typhus fever, Clostridium botulinum, malaria, tularemia or rabbit fever, Lyme disease, rabies, rift valley fever, melioidosis, legionnaires’ disease, leptospirosis, and spotted fever Rickettesiosis

●Class 5 infectious diseases:

Infectious diseases announced by the government after investigations to prevent occurrence and spread.

Notifiable Diseases:

Amoebiasis, viral hepatitis (except hepatitis E and A), acute encephalitis (except West Nile encephalitis and Japanese encephalitis), cryptosporidiosis, Creutzfeldt-Jakob disease (CJD), severe invasive streptococcal infection, AIDS, hexamitiasis, meningococcus meningitis, congenital rubella syndrome (CRS), syphilis, tetanus, vancomycin-resistant Staphylococcus aureus, and Vancomycin-resistant enterococcus

Focused infectious diseases

Respiratory syncytial virus, pharyngo-conjunctival fever, hemolytic strepococcal pharyngitis, transmittable gastroenteritis, chickenpox, hand, foot and mouth disease, erythema infectiosum, acute rash, bronchocephalitis, urticaria, herpangina, measles (except adult measles), epidemic mumps, influenza (except avian flu), acute hemorrhagic conjunctivitis, sexually transmitted Chlamydial disease, genital herpes, condylomata acuminate, gonorrhea, Chlamydial pneumonia (except psittacosis), bacterial meningitis (except meningococcus meningitis), penicillin-resistant Streptococcus pneumoniae (PRSP), Mycoplasma pneumonia, adult measles, aseptic meningitis, methicillin-resistant Staphylococcus aureus, and multidrug-resistant Pseudomonas aeruginosa

●Statutory infectious diseases

Known infectious diseases other than Classes 1-3 infectious diseases and must be treated as Classes 1-3 infectious diseases (one year by law).

●New-type infectious diseases

Infectious diseases with confirmed man-to-man infection and significant difference with known symptoms. The class of new-type infectious diseases is determined based on their infectability at infection.