Transplacental transmission of Cryptococcus neoformans to an HIV-exposed premature neonate

Cryptococcus: History, Epidemiology and Immune Evasion

Cryptococcosis is a disease caused by the pathogenic fungi Cryptococcus neoformans and Cryptococcus gattii, both environmental fungi that cause severe pneumonia and may even lead to cryptococcal meningoencephalitis. Although C. neoformans affects more fragile individuals, such as immunocompromised hosts through opportunistic infections, C. gattii causes a serious indiscriminate primary infection in immunocompetent individuals. Typically seen in tropical and subtropical environments, C. gattii has increased its endemic area over recent years, largely due to climatic factors that favor contagion in warmer climates. It is important to point out that not only C. gattii, but the Cryptococcus species complex produces a polysaccharidic capsule with immunomodulatory properties, enabling the pathogenic species of Cryptococccus to subvert the host immune response during the establishment of cryptococcosis, facilitating its dissemination in the infected organism. C. gattii causes a more severe and difficult-to-treat infection, with few antifungals eliciting an effective response during chronic treatment. Much of the immunopathology of this cryptococcosis is still poorly understood, with most studies focusing on cryptococcosis caused by the species C. neoformans. C. gattii became more important in the epidemiological scenario with the outbreaks in the Pacific Northwest of the United States, which resulted in phylogenetic studies of the virulent variant responsible for the severe infection in the region. Since then, the study of cryptococcosis caused by C. gattii has helped researchers understand the immunopathological aspects of different variants of this pathogen.

Invasive fungal infections in neonates: a review

Invasive fungal infections remain the leading causes of morbidity and mortality in neonates, especially preterm and very low birth weight infants. Most invasive fungal infections are due to Candida or Aspergillus species, and other fungi are increasingly reported and described. Appropriate identification and treatment are required to augment activity and reduce the toxicity of antifungal drugs. Successful use of antifungals in the vulnerable neonatal population is important for both prevention and treatment of infection. Strategies for prevention, including prophylactic antifungal therapy as well as reducing exposure to modifiable risk factors, like limiting antibiotic exposure, discontinuation of central catheters, and hand hygiene are key techniques to prevent and decrease rates of invasive fungal infections. In conclusion, this is a review of the most common causes, prevention strategies, prophylaxis, and treatment of invasive fungal infections in neonates.

Consensus guidelines for the diagnosis and management of cryptococcosis and rare yeast infections in the haematology/oncology setting, 2021

Cryptococcosis caused by the Cryptococcus neoformans-Cryptococcus gattii complex is an important opportunistic infection in people with immunodeficiency, including in the haematology/oncology setting. This may manifest clinically as cryptococcal meningitis or pulmonary cryptococcosis, or be detected incidentally by cryptococcal antigenemia, a positive sputum culture or radiological imaging. Non-Candida, non-Cryptococcus spp. rare yeast fungaemia are increasingly common in this population. These consensus guidelines aim to provide clinicians working in the Australian and New Zealand haematology/oncology setting with clear guiding principles and practical recommendations for the management of cryptococcosis, while also highlighting important and emerging rare yeast infections and their recommended management.

Cryptococcal Meningitis in an HIV-Negative Puerperal Woman

Cryptococcal meningitis is a common opportunistic infection in HIV-infected patients and other immunocompromised people. Pregnancy, which is a state of relative immunosuppression, can also be a risk factor for the development of cryptococcal meningitis. We report a clinical case of a 41-year-old woman who developed a severe meningeal syndrome after an otherwise normal pregnancy. Cerebrospinal fluid (CSF) cytochemical analysis presented hypoglycorrhachia, high protein levels, and pleocytosis. Cryptococcal antigen tested positive in serum and CSF, and Cryptococcus neoformans was identified in the CSF culture. The diagnosis of cryptococcal meningitis was confirmed, and antifungal induction therapy was started with liposomal amphotericin B and flucytosine. After clinical improvement, induction therapy was discontinued, and the patient was discharged under maintenance therapy with fluconazole. While under antifungal maintenance therapy, the patient presented worsening of symptoms and a new brain magnetic resonance showed the development of multiple cryptococcoma. Despite sterile CSF cultures, there was a deterioration of the cytochemical parameters. The diagnosis of immune reconstitution inflammatory syndrome was assumed, and after initiation of corticotherapy, the patient improved considerably. This is a rare case of cryptococcal meningitis in a puerperal woman with a challenging management.

Cryptococcosis in pregnancy and the postpartum period: Case series and systematic review with recommendations for management

Cryptococcal meningitis causes 15% of AIDS-related deaths. Optimal management and clinical outcomes of pregnant women with cryptococcosis are limited to case reports, as pregnant women are often excluded from research. Amongst pregnant women with asymptomatic cryptococcosis, no treatment guidelines exist. We prospectively identified HIV-infected women who were pregnant or recently pregnant with cryptococcosis, screened during a series of meningitis research studies in Uganda from 2012 to 2018. Among 571 women screened for cryptococcosis, 13 were pregnant, one was breastfeeding, three were within 14 days postpartum, and two had recently miscarried. Of these 19 women (3.3%), 12 had cryptococcal meningitis, six had cryptococcal antigenemia, and one had a history of cryptococcal meningitis and was receiving secondary prophylaxis. All women with meningitis received amphotericin B deoxycholate (0.7-1.0 mg/kg). Five were exposed to 200-800 mg fluconazole during pregnancy. Of these five, three delivered healthy babies with no gross physical abnormalities at birth, one succumbed to meningitis, and one outcome was unknown. Maternal meningitis survival rate at hospital discharge was 75% (9/12), and neonatal/fetal survival rate was 44% (4/9) for those mothers who survived. Miscarriages and stillbirths were common (n = 4). Of six women with cryptococcal antigenemia, two received fluconazole, one received weekly amphotericin B, and three had unknown treatment courses. All women with antigenemia survived, and none developed clinical meningitis. We report good maternal outcomes but poor fetal outcomes for cryptococcal meningitis using amphotericin B, without fluconazole in the first trimester, and weekly amphotericin B in place of fluconazole for cryptococcal antigenemia.

Cryptococcal Disease in HIV-Infected Children

Cryptococcus neoformans is an encapsulated fungal pathogen that is remarkable for its tendency to cause meningoencephalitis, especially in patients with AIDS. While disease is less common in children than adults, it remains an important cause of morbidity and mortality among HIV-infected children without access to anti-retroviral therapy. This review highlights recent insights into both the biology and treatment of cryptococcosis with a special emphasis on the pediatric literature.

Cryptococcosis in patients living with hepatitis C and B viruses

Cryptococcosis, a systemic fungal infection, has become a significant, global public health problem. Patients with liver disease have an increased predisposition to infections, such as Cryptococcosis. To report the underlying disease, the variety of etiologic agents involved and the outcomes of the Cryptococcosis in patients living with HBV and/or HCV, we reviewed 34 medical records of patients who were diagnosed with Cryptococcosis by the Mycology Laboratory of Santa Casa Hospital, Porto Alegre, Brazil. Males corresponded to 79% of the patients, and the average patient age was 46.9 years. The cultures of 26/34 patients were positive: 25 patients were infected with Cryptococcus neoformans and one with C. gattii. A total of 14 deaths (41%) occurred. As a criterion of our study, all patients had viral hepatitis infection: 27 (80%) were infected with HCV, five (15%) were infected with HBV, and two patients were infected with both viruses. Because HBV and/or HCV are transmitted among drug users through infected blood, and the end-stage cirrhotic liver must be transplanted, these two population types were well represented in this study and were analyzed in detail. Cryptococcosis patients living with HCV and/or HBV appear to have the same symptoms, mean age and gender distribution as the general Cryptococcosis population. Once Cryptococcosis affects the brain, a high mortality rate ensues; therefore, physicians must be aware of the possible occurrence of this disease in patients living with HCV and HBV.