Cryptococcus gattii genotype VGIIb infection in Japan

Autochthonous Cryptococcus gattii genotype VGIIb infection in a Japanese patient with anti-granulocyte-macrophage colony-stimulating factor antibodies

A 31-year-old Japanese man presented with cerebral and pulmonary cryptococcosis. Cryptococcus gattii (C. gattii) genotype VGIIb was detected in the patient's sputum and cerebrospinal fluid specimens. The serum levels of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies were elevated in this patient, which has been associated with pulmonary alveolar proteinosis and is considered a risk factor for C. gattii infection. After undergoing >12 months of antifungal treatments, the patient showed improvements in symptoms and findings on brain and lung imaging. Several Japanese patients who develop C. gattii infection have also been reported; however, most of these patients have been infected outside Japan, as C. gattii infection is rare in Japan. Only one patient with C. gattii genotype VGIIb infection has been reported in Japan, and it is believed that this patient contracted the infection in China. In the present case, our patient has never been outside Japan, indicating that the infection originated in Japan. Our findings suggest that C. gattii might be spreading in Japan. Therefore, patients with positive serum anti-GM-CSF antibodies should be thoroughly monitored for C. gattii infection, even those living in Japan.

Clinical Characteristics of Patients with Cryptococcal Meningitis in Hokkaido: A Case Series

We retrospectively reviewed the medical histories, examination results, treatments, and prognoses of nine patients with cryptococcal meningitis who were diagnosed and treated at Hokkaido University Hospital and its affiliated hospitals over the past 10 years. Cryptococcal meningitis can develop even in immunocompetent hosts, and its prognosis is poor owing to diagnostic difficulties and delayed treatment. Although liposomal amphotericin B and oral 5-fluorocytosine are standard therapies, voriconazole or intraventricular administration of amphotericin B may also be considered treatment options for refractory patients. Some patients develop delayed exacerbations owing to immunological mechanisms that require steroid therapy.

Molecular epidemiological investigation of Cryptococcus spp. carried by captive koalas (Phascolarctos cinereus) in Japan

Cryptococcus neoformans and Cryptococcus gattii cause cryptococcosis, a systemic mycosis that infects a wide range of species. Recent molecular biological investigations have allowed for the genotyping of these species, providing more detailed information on their pathogenicity and infection routes. Koalas (Phascolarctos cinereus) are frequently colonized by Cryptococcus spp., but molecular epidemiological studies have yet to be conducted in Japan. Here, we conducted multi-locus sequence typing (MLST) analysis on Cryptococcus spp. colonization isolates obtained from all koalas kept in seven parks across Japan. Out of 46 koalas examined, 10 (22%) were positive for C. gattii and 3 (6.5%) were positive for C. neoformans. All C. gattii isolates belonged to molecular type VGI and were either sequence type (ST) 51 or a novel ST, and all C. neoformans isolates belonged to molecular type VNI and ST23. Despite the frequent movement of koalas between parks, the STs were relatively park-specific, suggesting that the floor of the rearing barns is a source of infection and may act as a reservoir. MLST analysis confirmed that C. gattii was transported, established, and spread by koalas in areas where C. gattii was not originally present. MLST analysis is considered useful in assessing the pathogenicity and tracing the transmission routes of Cryptococcus spp. carried by koalas.IMPORTANCEThis is the first study to conduct a multi-locus sequence typing analysis on Cryptococcus spp. carried by captive koalas in Japan. Cryptococcosis remains a globally high-fatality fungal infection in humans, and captive koalas are known to carry a high percentage of Cryptococcus spp. Through this research, the molecular types and transmission routes of Cryptococcus spp. carried by koalas have been elucidated, revealing the potential role of enclosure flooring as a reservoir. It has been confirmed that Cryptococcus gattii, which is not endemic in Japan, has become established through koalas and is spreading to new individuals in Japan. This study is believed to provide valuable insights into koala conservation and contribute to the One Health approach for Cryptococcosis, a zoonotic infection.

Cryptococcal Meningitis in Young, Immunocompetent Patients: A Single-Center Retrospective Case Series and Review of the Literature

Background

Cryptococcal meningitis is an uncommon but serious infection with high mortality and morbidity. Classically described in immunocompromised patients, including those with solid organ transplants or HIV/AIDS, cryptococcosis has also been reported in young and otherwise healthy patients, albeit rarely.

Methods

We retrospectively searched for all cases of cryptococcal meningitis in young (≤50 years) and previously healthy patients with no known immunocompromising conditions from January 2015 to January 2022 at Indiana University Health (IU Health). Additionally, a PubMed literature review was performed with the keywords "cryptococcal meningitis" and "immunocompetent" from January 1988 to January 2022. Clinical courses, including outcomes and treatment regimens, were evaluated.

Results

We identified 4 local cases of cryptococcal meningitis in otherwise healthy patients age ≤50 years. Three cases were due to Cryptococcus neoformans, with 1 experiencing a postinfectious inflammatory response syndrome (PIIRS). The PubMed search identified 51 additional cases, with 32 (63%) being caused by Cryptococcus neoformans and 8 (17%) by Cryptococcus gattii. Of the 51 cases, only 2 resulted in death directly due to cryptococcosis. Fifteen (29%) had PIIRS, with steroid treatment documented in 11 of 15. Antifungal induction regimens and duration were varied but predominately consisted of amphotericin and flucytosine, with a mean induction duration of 5.0 weeks.

Conclusions

Cryptococcal meningitis in young, previously healthy patients is likely under-recognized. PIIRS (akin to immune reconstitution inflammatory syndrome observed in HIV/AIDS) with prolonged recovery should be of concern. Determining risk factors for cryptococcosis in these patients remains elusive.

Middle cerebral artery infarction, A rare complication of intracranial cryptococcoma in an immunocompetent patient: A case report and literature review

Background

This report presents the first case of intracranial cryptococcoma arising from the right frontal lobe causing right middle cerebral artery infarction. Intracranial cryptococcomas usually occur in the cerebral parenchyma, basal ganglia, cerebellum, pons, thalamus, and choroid plexus; they may mimic intracranial tumors, but seldom cause infarction. Of the 15 cases of pathology-confirmed intracranial cryptococcomas in the literature, no case has been complicated by middle cerebral artery (MCA) infarction. Here, we discuss a case of intracranial cryptococcoma with an ipsilateral middle cerebral artery infarction.

Case Description

A 40-year-old man was referred to our emergency room due to progressive headaches and acute left hemiplegia. The patient was a construction worker with no history of avian contact, recent travel, or human immunodeficiency virus (HIV) infection. Brain computed tomography (CT) showed an intra-axial mass, and subsequent magnetic resonance imaging (MRI) delineated a large mass of 53 mm in the right middle frontal lobe and a small lesion of 18 mm in the right caudate head, with marginal enhancement and central necrosis. A neurosurgeon was consulted in view of the intracranial lesion, and the patient underwent en-bloc excision of the solid mass. The pathology report later identified a Cryptococcus infection rather than malignancy. The patient underwent 4 weeks of postoperative treatment with amphotericin B plus flucytosine; he then received subsequent oral antifungal treatment for 6 months, and had neurologic sequelae that manifested as left side hemiplegia.

Conclusion

Diagnosis of fungal infections in the CNS remains challenging. This is especially true of Cryptococcus CNS infections that present as a space-occupying lesion in an immunocompetent patient. A Cryptococcus infection should be considered in the differential diagnoses in patients with brain mass lesions, as this infection can be misdiagnosed as a brain tumor.

Treatment of Cryptococcus gattii Infection Using Voriconazole

We previously reported a 39-year-old man who presented with pulmonary and cerebral Cryptococcus gattii (genotype VGIIa) infection and was successfully treated with liposomal amphotericin B and flucytosine induction therapy. Following induction therapy, oral fluconazole treatment was initiated as consolidation therapy. However, the patient complained of progressively worsening headache, presenting an elevated cerebrospinal fluid (CSF) cell count. The minimum inhibitory concentrations of the CSF isolate were 8 and 0.12 μg/mL for fluconazole and voriconazole, respectively. The oral administration of voriconazole for more than 18 months alleviated his symptoms. Voriconazole might be useful for controlling refractory cases of C. gattii infection.

Cryptococcus gattii genotype VGIIa infection imported from Vancouver Island to Japan

A 71-year-old Japanese man with travel history to the Vancouver Island, Canada was diagnosed the pulmonary and central nervous system infections caused by Cryptococcus gattii genotype VGIIa. This is the first imported case of Cryptococcus gattii genotype VGIIa infection from endemic area of North America to Japan. He was recovery with no residual neurological dysfunction by early resection of brain mass and antifungal therapy. Early surgical resection of cerebellar cryptococcoma may shorten the length of induction therapy with antifungal drugs.

Cryptococcus gattii Genotype VGIIa Infection in an Immunocompetent Japanese Patient: A Case Report and Mini-review

A 39-year-old man presented to our hospital with a four-week history of headache and a two-week history of low-grade fever. Chest X-rays showed a tumor of approximately 50 mm in size in the right lower field. A histopathological examination of a transbronchial lung biopsy specimen from the right S9/10 revealed numerous fungal elements that appeared as encapsulated yeast with clear halos. Gadolinium-enhanced brain magnetic resonance images showed multiple cerebral nodules. Cryptococcus gattii (Genotype VGIIa) was isolated from the bronchial lavage and cerebrospinal fluid specimens. The patient was an immunocompetent Japanese man who had not recently traveled to a C. gattii-endemic area.