It usually takes several days to detect slow-growing bacteria by a blood culture system. Moreover, even if the microbial growths are detected in blood samples, they will escape our notice at a microscopic examination using Gram’s stain. Consequently, the results are often regarded as false positive.　　This paper reports case of malignant lymphoma in which bloodstream infection caused by slow-growing spirillum was observed. The patient in chemotherapy for malignant lymphoma, complained of repeated fever. Repeated blood cultures were taken and occasionally positive signals, which mean increased CO2 concentrations in the culture bottle, were detected by BACTEC 9240 (Becton Dickinson). However, routine microscopic examination with Gram’s stain did not detect any bacteria. Thus, the results of BACTEC were thought to be false positive. Thereafter, the bacterial culture period was extended. Finally, a spirillum, suspected of one of Helicobacter species, was observed microscopically. The detected spirillum was regarded as Helicobacter canadensis with 98.08% homology, using polymerase chain reaction with the 16S rRNA method and basic local alignment search tool (BLAST).　　H. canadensis is one of new species isolated from humans with diarrhea. This bacterium is considered to cause a zoonotic infection. There have been some case reports that this bacterium infected immunosuppressive patients, so we should exercise caution against such conditions. Moreover, we should keep vigilant against the spread of slow-growing bacteria when there are discrepancies in findings between blood culture system and microscopic examination. It is useful to extend the culture period to detect such slow-growing bacteria.

A 71-year-old woman underwent gastrostomy due to malnutrition resulting from impaired esophageal peristalsis due to scleroderma. However, the gastrostomy tube was removed due to worsening of difficult-to-treat dermatitis around the gastrostomy. An intractable gastrocutaneous fistula with persistent gastric juice leakage and peri-gastrostomy dermatitis was treated with fistulotomy and local negative pressure closure therapy under local anesthesia. Spontaneous closure of an intractable fistula after gastrostomy removal can be difficult due to underlying malnutrition and exposure to leaking gastric juice, among other factors. The present case suggests that fistulectomy followed by local negative pressure closure therapy for an intractable fistula after gastrostomy removal can enable oral intake in the early postoperative period and also facilitate wound management.

The establishment of enhanced surveillance systems for mass gatherings to detect infectious diseases that may be imported during an event is recommended. The World Health Organization Regional Office for the Western Pacific contributed to enhanced event-based surveillance for the Tokyo 2020 Olympic and Paralympic Games (the Games) by using Epidemic Intelligence from Open Sources (EIOS) to detect potential imported diseases and report them to the National Institute of Infectious Diseases (NIID), Japan. Daily screening of media articles on global infectious diseases was conducted using EIOS, which were systematically assessed to determine the likelihood of disease importation, spread and significant impact to Japan during the Games. Over 81 days of surveillance, 103 830 articles were screened by EIOS, of which 5441 (5.2%) met the selection criteria for initial assessment, with 587 (0.6%) assessed as signals and reported to NIID. None of the signals were considered to pose a significant risk to the Games based on three risk assessment criteria. While EIOS successfully captured media articles on infectious diseases with a likelihood of importation to and spread in Japan, a significant manual effort was required to assess the articles for duplicates and against the risk assessment criteria. Continued improvement of artificial intelligence is recommended to reduce this effort.

In 2021, the National Institute of Infectious Diseases, Japan, undertook enhanced event-based surveillance (EBS) for infectious diseases occurring overseas that have potential for importation (excluding coronavirus disease 2019 [COVID-19]) for the Tokyo 2020 Olympic and Paralympic Summer Games (the Games). The pre-existing EBS system was enhanced using the World Health Organization Epidemic Intelligence from Open Sources system and the BlueDot Epidemic Intelligence platform. The enhanced EBS before and during the Games did not detect any major public health event that would warrant action for the Games. However, information from multiple sources helped us identify events, characterize risk and improve confidence in risk assessment. The collaboration also reduced the surveillance workload of the host country, while ensuring the quality of surveillance, even during the COVID-19 pandemic.