The study was performed to examine whether it would be reasonable to apply the POCT rapid antigen test (RAT) kits available in Japan to screen individuals for SARS-CoV-2 COVID-19 infection and assess their risk of transmitting the infection. Viral isolation and RATs using five POCT kits obtained from five different manufacturers were performed on a total of 162 nasopharyngeal swab specimens collected from patients of COVID-19 and their close contacts who were positive for SARS-CoV-2 RNA by real-time RT-PCR analysis. The results of the tests were statistically analyzed for each kit, based on the symptom status (asymptomatic/symptomatic) of the source subjects at the time of the sample collection. In addition, information on the viral copy numbers acquired from the RT-PCR test of all the specimens were integrated into the data for the analyses. The results revealed that the RATs returned positive results, overall, in more than 95% of the specimens that were positive for isolation of the active virus, irrespective of the symptom status of the subject, suggesting that the probability of the kits missing subjects with a strong potential to spread the infection was very low, if any, and that the POCT kits are applicable for assessing the risk of transmission of the infection by patients and their close contacts.

Background: Paxlovid, an oral COVID-19 drug, is a ritonavir-containing drug, and as it significantly affects the activities of various drug-metabolizing enzymes, drug-drug interactions (DDIs) are a significant concern during clinical use of the drug. However, there are few reports on the observations during actual clinical use of Paxlovid.

Methods: We developed a list of drugs that should only be used with caution along with Paxlovid and used a DDI search tool to easily check for DDIs during use of Paxlovid. We also investigated the number of inquiries about DDIs, the number of suggestions made by pharmacists, and the number of suggestions adopted by physicians in the 33 patients prescribed with Paxlovid during the 3-month period from February 15, 2022, to May 14, 2022. In addition, as part of the patient follow-up conducted after the start of Paxlovid, outpatients who were on medications that needed to be temporarily discontinued during Paxlovid use were contacted by telephone to confirm their medication adherence/medication discontinuation compliance status and the timing of resumption of the temporarily discontinued medications.

Results: There were 28 inquiries regarding DDIs, and the adoption rate of the pharmacists' suggestions by the treating physicians was 100%. One out of the seven patients who we contacted by telephone did not clearly understand the correct timing for resuming the temporarily discontinued medications. The pharmacist gave instruction again to the patient over the phone and subsequently confirmed, in a follow-up phone call, that the medication had been resumed without error.

Discussion: Pharmacists can contribute to the proper use of Paxlovid and reduce barriers to prescribing Paxlovid through management of DDIs and patient follow-up.

An 86-year-old woman with a 6-year history of bronchiectasis and recurrent pneumonia in the right lung presented to our hospital with a several weeks' history of bloody sputum. Imaging studies showed ground-glass and infiltrative opacities in the right lung, and Nocardia species were repeatedly isolated on sputum culture testing. Genetic testing identified Nocardia wallacei, which was resistant to sulfamethoxazole/trimethoprim. Therefore, the patient was treated with clavulanic acid/amoxicillin (CVA/AMPC) for a total of 6 months, and the symptoms, including the bloody sputum and cough, as well as the imaging findings, improved. Pulmonary nocardiosis can occur in patients with chronic lung disorders such as bronchiectasis, even in the absence of immunodeficiencies. Trimethoprim-sulfamethoxazole is the drug of first choice for nocardiosis, but identification of the Nocardia species and susceptibility testing are recommended for treatment, because the susceptibility varies with the species.

We encountered a case of Candida kefyr fungemia with pyelonephritis. C. kefyr was first isolated from a dairy kefir in Caucasus in 1909 and was originally named Saccharomyces fragilis. C. kefyr has been reported to be detected in the urine and blood of immunocompromised patients and patients with hematologic malignancies. The patient reported herein, an 89-year-old woman, visited our hospital with the chief complaints of abdominal pain and fever. She was treated by ureteral stent placement and started on PIPC/TAZ for calculous pyelonephritis caused by K. pneumoniae. The clinical course was satisfactory, however, on the 15th day of hospitalization, she again developed lower abdominal pain, blood examination revealed increased levels of inflammatory markers, and C. kefyr was detected in blood and urine cultures. She was treated with L-AMB and FLCZ and discharged in good general condition. In recent years, the frequency of isolation of non-albicans Candida spp. has increased, and the incidence of C. kefyr candidemia has increased worldwide. A search of the literature to the best of my ability failed to identify the number of cases reported in Japan, and many uncertainties remain as to the epidemiology and drug susceptibility; therefore, further study of a larger number of cases is necessary in the future.

Mycobacterium chelonae is a rapidly growing nontuberculous mycobacterium and a rare cause of cutaneous infection in both immunocompromised and immunocompetent patients. The skin lesions are non-specific in nature, so that the infection remains underdiagnosed and diagnosis is often delayed. Herein, we report the case of an 83-year-old immunocompromised woman with a 6-month history of persistent skin lesions. The lesions were previously misdiagnosed and treated as herpes zoster, and even as bullous pemphigoid, for which she received prednisone. Ziehl-Neelsen staining of biopsy specimens from the subcutaneous nodules on the right forearm and dorsum of the left foot revealed acid-fast bacilli. Culture on blood agar medium under low-temperature conditions yielded colonies after 6 days. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry allowed identification of M. chelonae; the results were consistent with that of 16S rRNA gene sequencing analysis. Therefore, we made the diagnosis of disseminated cutaneous M. chelonae infection and initiated the patient on combined clarithromycin, moxifloxacin, and amikacin therapy. The findings in this case indicate that clinicians should consider mycobacterium-related infections in patients with intractable skin lesions. To obtain a proper microbiological diagnosis, good collaboration between clinicians and clinical laboratory technicians is necessary, with collection of appropriate specimens and use of appropriate stains and culture conditions, bearing in mind the suspected microorganisms.