Masashi Narita

SUMMARY: BACKGROUND: Tuberculous endocarditis (TBE) is a rare but often fatal manifestation of Mycobacterium tuberculosis . Although diagnosis is now possible with advanced techniques, the lack of standardized diagnostic criteria complicates timely recognition and management. METHODS: A 79-year-old man with a history of the Bentall procedure for annuloaortic ectasia, presented with fever and chest pain. Imaging revealed infective endocarditis with an aortic root abscess and vegetations. Histopathology identified granulation tissue with multinucleated giant cells, and M. tuberculosis was confirmed via PCR and culture. A literature review of TBE cases was performed to develop systematic diagnostic criteria. RESULTS: The diagnosis of TBE was established through histopathology and molecular methods. Based on this case and prior reports, diagnostic criteria for TBE were developed and categorized as ‘Definitive’, ‘Probable’, and ‘Possible’. These criteria incorporate clinical, microbiological, histological, and imaging findings to aid in diagnosis. The patient’s treatment included surgical intervention combined with antimicrobial therapy, aligning with strategies designed to improve outcomes. CONCLUSION: This case underscores the importance of considering TBE in infective endocarditis cases, especially those with atypical features. The proposed diagnostic criteria aim to improve the recognition and guide the management of TBE, emphasizing a multidisciplinary approach for better patient outcomes.

Background: Scrub typhus (ST) is endemic in Fukushima, with the largest number of cases reported in Japan from 2009 to 2010. Although ST is highly treatable, its atypical clinical presentation impedes diagnosis, causing delays in treatment. Methods: We review the clinical features of ST in adults from 2008 to 2017 at Ohta Nishinouchi General Hospital in Fukushima, Japan. Results: Fifty-five cases (serotype Karp 24, Irie/Kawasaki 21, Hirano/Kuroki 10) of ST were confirmed via serology based on elevated immunoglobulin (Ig)M and IgG and polymerase chain reaction positivity of eschar samples. The mean age was 69 years, and 64% were female. The case fatality rate was 1.8% (1/55). Approximately 70% of cases (38/55) were not diagnosed as ST upon the initial clinic visit. Inappropriate use of antibiotics was identified in 22% of cases (12/55). In terms of atypical clinical features, 1 or more of the manifestations, fever, rash, and eschar, was absent in 31% of cases (17/55). Approximately 11% of cases presented without eschar (6/55; Karp 1, Irie/Kawasaki 1, Hirano/Kuroki 4). Moreover, severe complications were observed with shock and disseminated intravascular coagulation in 7% of cases (4/55), Thus, while 53% of cases presented with the typical triad (29/55), unusual complications and atypical features occurred in 40% (22/55). Conclusions: Diagnosis of ST becomes clinically challenging in the absence of typical features. In Fukushima, an endemic area of ST, an atypical presentation involving multisystem disease is common.

Rationale: Diagnosing multifactorial, multidimensional symptoms unexplained by presumptive diagnosis is often challenging for infectious disease specialists. Patient concerns: We report a rare case of a 30-year-old Japanese bisexual man with a history of virally suppressed human immunodeficiency virus and syphilis infections who developed chest pain and an erosive lesion under the lower midline jaw. Diagnosis: Imaging examinations revealed erosive lesions on the sternum and left the ninth rib. Biopsy and polymerase chain reaction testing of sternal tissue specimens were noncontributory. However, due to elevated rapid plasma regain levels, a diagnosis of syphilitic osteomyelitis and gumma of the jaw was made. Interventions: The patient was treated with 5 weeks of intravenous ceftriaxone and then with 8 weeks of oral amoxicillin. Outcome: After the antibiotic treatment, bone pain disappeared. We conducted a literature review on syphilitic osteomyelitis, and all of the articles included were case reports. Approximately half of the 46 patients with syphilitic osteomyelitis had HIV coinfection, and 10 (22%) patients lacked signs of early syphilis. Given its rarity, clinical data to establish appropriate guidelines for diagnosing and treating syphilitic osteomyelitis are still lacking. Cognitive biases, such as anchoring, cognitive overload bias, and premature closure, may contribute to diagnostic delays. Lessons: In cases of idiopathic multiple bone lesions, syphilis must always be ruled out, and clinicians should guard against cognitive pitfalls when diagnosing rare diseases.

A 76-year-old man who had been bathing in a hot spring was taken to the hospital in a coma. PCR assay performed on the eschar revealed a serotype Hirano/Kuroki of Orientia tsutsugamushi. Coexisted heatstroke superimposed on multiple underlying risk factors likely led to a fatal clinical course.

Introduction: Acinetobacter species are a diverse group of gram-negative, aerobic coccobacilli. Currently, more than 50 Acinetobacter spp. are recognized, but most are not pathogenic to humans. With respect to Acinetobacter ursingii, there have been only a few reports about bacteremia, especially in immunocompetent patients. Patient concerns: A 9-month-old girl presented with complex febrile seizure. She had cough and nasal discharge for 2 weeks, and fever on the day of admission. Diagnosis: The blood culture was positive for Acinetobacter ursingii. Intervention: The patient was treated with intravenous cefotaxime for 10 days. Outcomes: The treatment was successful, and the patient was discharged with no further complications. Conclusion: Acinetobactor ursingii is a rare causative pathogen in immunocompetent patients and almost all of the cases are due to nosocomial infection. Acinetobactor ursingii is usually considered as a low virulence strain with a benign clinical course. The fatality of bacteremia depends on the host immunity. Blood cultures positive for Acinetobactor ursingii should be treated with appropriate antibiotics to minimize the risk of complications.

During August 2020, we carried out a serological survey among students and employees at the Okinawa Institute of Science and Technology Graduate University (OIST), Japan, testing for the presence of antibodies against SARS-CoV-2, the causative agent of COVID-19. We used a FDA-authorized 2-step ELISA protocol ( 1, 2 ) in combination with at-home self-collection of blood samples using a custom low-cost finger prick-based capillary blood collection kit. Although our survey did not find any COVID-19 seropositive individuals among the OIST cohort, it reliably detected all positive control samples obtained from a local hospital and excluded all negatives controls. We found that high serum antibody titers can persist for at least up to 6.5 months post infection. Among our controls, we found strong cross-reactivity of antibodies in samples from a serum pool from two MERS patients in the anti-SARS-CoV-2-S ELISA. Here we show that a centralized ELISA in combination with patient-based capillary blood collection using as little as one drop of blood can reliably assess the seroprevalence among communities. Anonymous sample tracking and an integrated website created a stream-lined procedure. Major parts of the workflow were automated on a liquid handler, demonstrating scalability. We anticipate this concept to serve as a prototype for reliable serological testing among larger populations.