Introduction: Post-COVID-19 condition (PCC) observed in some patients have emerged as a significant health concern. While knowledge regarding the characteristics of post-COVID-19 conditions and their impact on the quality of life is accumulating, the state of post-COVID-19 conditions management in Japan remains inadequately understood. We conducted a survey targeting medical institutions with infectious disease specialists to elucidate the current situation and challenges in post-COVID-19 conditions management.

Materials and Methods: A web-based survey was administered from January 18 to March 9, 2024, targeting 880 infectious disease specialists nationwide regarding their respective medical institutions. The survey consisted of up to 24 questions covering respondents' attributes and backgrounds, experience in managing post-COVID-19 conditions, characteristics of post-COVID-19 conditions patients, post-COVID-19 conditions treatment status, and post-COVID-19 conditions among medical institution staff.

Results: Responses were obtained from 465 specialists across 47 prefectures (response rate: 52.8%). The majority of respondents (324) were affiliated with hospitals. Among these, 69.7% had experience in managing post-COVID-19 conditions at their institutions, but only 11.2% reported having specialized outpatient clinics dedicated to these symptoms. Most respondents reported that PCC was more common in the 18-64 age group. 80.5% and 51.9% of respondents reported having patients with symptoms lasting over 3 months and 12 months, respectively. For patients with symptoms persisting over 3 months, many respondents noted neuropsychiatric symptoms such as depression and forgetfulness. Treatment approaches included not only pharmacotherapy but also rehabilitation and counseling. 27.4% of respondents reported PCC cases among staff at their medical institutions, with two-thirds of these cases requiring staff to take leave from work.

Conclusion: While many medical institutions with infectious disease specialists are addressing COVID-19 treatment, the establishment of specialized outpatient clinics for PCC is limited, highlighting the need for long-term follow-up and support systems. Additionally, PCC among healthcare workers is a significant issue, necessitating the development of support systems for their return to work.

Amebic dysentery, caused by the protozoan Entamoeba histolytica, is a serious intestinal parasitic disease associated with a high mortality, second only to that associated with malaria among parasitic infections globally. This disease is marked by severe intestinal symptoms, including bloody diarrhea, which can lead to fatal dehydration, particularly in young children in under-resourced areas. Japan has reported a rise in the number of cases of amebic dysentery, partly due to transmission via sexual contact, changing the traditional perception that amoebiasis is a travel-related infection. Despite its inclusion in mandatory infectious disease reporting, the level of awareness among medical practitioners and limitations of the diagnostic methods available remain challenges, and fatalities are still reported. This paper reviews the diverse pathogenetic mechanisms, including internal (pathogen-related) and external (microbiota-related) pathogenic factors, that contribute to disease progression and persistence of E. histolytica. The cyst-trophozoite lifecycle is described, alongside modes of transmission and resistance mechanisms that enable the parasite to survive passage through the gastric environment and establish itself in the colon. In addition, recent insights into the complex interactions between E. histolytica and the gut microbiota have revealed a modulation of the pathogenesis, suggesting that alterations in the microbiota composition can have an impact on the response of the parasite to oxidative stress. Further research into the relationship between E. histolytica and gut microbiota could pave the way for innovative therapeutic strategies, offering potential advancements in infection control and sustained prevention efforts.

Mpox (formerly known as monkeypox) is caused by monkeypox virus (MPXV), a member of the orthopoxvirus genus of viruses. Historically, it is endemic to Central and West Africa. Since 2022, however, a sharp rise in the number of mpox cases has been reported from non-endemic regions such as Europe and the United States. As compared with the traditional cases of mpox reported from the endemic regions, the majority of the patients in the new cases of mpox from non-endemic regions are gay, bisexual, and/or people living with HIV (PLWH), and anogenital skin lesions are a predominant clinical feature. Herein, we report two cases of mpox in PLWH. While case 1 had typical anogenital skin rashes with hemorrhagic proctitis, case 2 manifested proctitis without a skin rash. MPXV was detected by polymerase-chain reaction of scrapings from the skin rash in case 1, and from an anal swab in case 2. Our cases highlight the fact that in the recent outbreak of mpox, proctitis could be the sole presenting feature. Clinicians should consider the possibility of mpox in patients presenting with proctitis, irrespective of the presence/absence of skin lesions.

A 52-year-old Chinese man who was a cook by occupation visited our emergency department complaining of left-sided chest pain, and was diagnosed as having left-sided hydropneumothorax by chest computed tomography. The hydropneumothorax resolved with chest drainage, but subsequently, he presented twice within a month with recurrent right hydropneumothorax. We suspected paragonimiasis, but failed to detect any parasite ova in either the feces or the pleural fluid, and finally confirmed the diagnosis of paragonimiasis by serology. On further history-taking, the patient admitted to having eaten raw mitten crabs. Paragonimiasis is often difficult to diagnose, and detailed history-taking and proactive testing are important.