2020 年 37 巻 4 号 p. 644-646
In the fall of 2015, acute flaccid paralysis (AFP) occurred frequently. As a result of an active epidemiological survey based on the Infectious Diseases Control Law, 115 cases were confirmed between August and December 2015. A secondary survey found that 58 patients met the case definition for acute flaccid myelitis (AFM).
Japan was the only country in the WHO Western Pacific Region not carrying out an AFP surveillance. Due to the frequent occurrence of AFM in 2015, “Acute flaccid paralysis (excluding poliomyelitis)” has been reported as a notifiable infectious disease, by National Epidemiological Surveillance of Infectious Diseases based on the Infectious Diseases Control Law since May 2018 (week 18). Accordingly, all physicians are required to notify a Public Health Center within seven days of a diagnosis of AFP (including GBS) involving a patient under the age of 15 years.
The number of AFP cases has increased since week 39 of 2018, with 139 reported by week 52, and the number of reports peaking in October (51 cases in October). The median age was 3 years (interquartile range, 2–7 years). In 2019, 36 cases were reported by week 26 (up to June 30). The search for causative pathogens can be performed by storing clinical specimens (respiratory specimens, stool, serum, and cerebrospinal fluid) early in the onset of paralysis, subdivided into several at −70°C or lower. For more information on diagnostic treatment, see “Guidance on Surveillance, Diagnosis, Testing, and Treatment of Diseases with Acute Flaccid Paralysis” (https://www.niid.go.jp/niid/images/idsc/disease/AFP/AFP-guide.pdf). An electrophysiological examination of the peripheral nerves and an MRI of the cerebrospinal cord are important for a pathological judgment. MRI imaging requires imaging of the entire spinal cord, even for uniparalysis. The treatment is being analyzed based on a 2018 case study, but may be targeted at protecting the horn cells of the spinal cord.
This research study was conducted under the Grant–in–Aid for Scientific Research on the Ministry of Health, Labor and Welfare Research Project for Emerging and Re–emerging Infectious Diseases and Vaccination Policies, “Clinical epidemiology research to contribute to the investigation of causes and pathologies, including a comprehensive pathogen search, for neurological diseases such as acute flaccid paralysis, acute encephalitis, and encephalopathy, and the establishment of therapeutic methods (Research Representative : Dr. Keiko Tanaka-Taya),” undertaken by Dr. Ryutaro Kira, Dr. Pin Fee Chong, Dr. Hiroyuki Torisu, Dr. Akihisa Okumura, Dr. Harushi Mori, Dr. Sawa Yasumoto, and Dr. Masato Yashiro, as Joint research with Dr. Mitsuaki Hosoya, Dr. Satoshi Kamei, Dr. Makoto Hara, Dr. Hiroyuki Shimizu, Dr. Reiko Shimbashi, Dr. Satoru Arai, Dr. Takahiro Maeki, Dr. Chang–Kweng Lim, Dr. Hiroto Shinomiya, Dr. Tsuguto Fujimoto, and Dr. Nozomu Hanaoka.
