A multicenter survey of asymptomatic cryptococcal antigenemia among patients with advanced HIV disease in Nigeria

Correlation Between Cryptococcus Infection and the Nasal Mycobiota in a Population of Free-Ranging Koalas (Phascolarctos cinereus) in New South Wales, Australia

Cryptococcosis is a fungal disease in humans and animals, caused by the Cryptococcus neoformans and Cryptococcus gattii species complexes. Clinical cryptococcosis primarily manifests as upper respiratory tract disease; however, dissemination to other organs, particularly the brain, can occur. Nasal colonisation and subclinical cryptococcosis are common in koalas (Phascolarctos cinereus) due to their shared environmental niche with Cryptococcus: Eucalyptus trees. However, for reasons that remain unclear, the prevalence of clinical disease is low in koalas. Interactions between respiratory pathogens and the nasal mycobiome are thought to play a role in the development and progression of numerous respiratory diseases. As such, this study aimed to characterise the mycobiome of the nasal vestibule in koalas with and without evidence of cryptococcal colonisation and subclinical disease via the next-generation sequencing (NGS) of the ITS1 region of the fungal internal transcribed spacer (ITS) gene. Samples were collected from 47 koalas from a population of free-ranging koalas in the Liverpool Plains, NSW, Australia, with a known history of Cryptococcus exposure and nasal colonisation. Of the 47 animals tested, 6.4% were culture-positive only, 4.3% were seropositive only, and 2.1% were culture- and seropositive. C. gattii was detected in four samples via NGS. C. neoformans was not detected via NGS. There were no significant differences in the nasal mycobiomes of Cryptococcus-positive and -negative animals; thus, we could not establish a definitive association between the mycobiome and infection outcomes. We identified a number of fungal genera that were significantly more abundant in samples from Cryptococcus-positive animals, but there was no apparent relationship between these genera and the development of cryptococcosis. This study represents the first investigation of the nasal mycobiota of wild koalas. Further studies involving koalas with clinical disease are necessary to determine the role of the nasal mycobiota in the development of cryptococcosis.

Implementation of the advanced HIV disease package of care using a public health approach: lessons from Nigeria

BACKGROUND

Nigeria adapted the WHO package of care for Advanced HIV Disease (AHD) in 2020. The package includes CD4 + cell count testing to identify People Living with HIV (PLHIV) with AHD, screening and treatment of opportunistic infections, rapid antiretrovirals (ART) initiation, and intensive adherence follow-up. The national program adopted a phased approach in the rollout of the AHD package of care to learn lessons from a few representative health facilities before scaling up across the country. This study describes the process and lessons learned from the first phase of implementation.

METHODS

This was a prospective observational study, and participants were enrolled between February and September 2021. Healthcare-worker (HCW) capacity was built to implement the AHD package of care. The study population included newly diagnosed PLHIV ≥ 10 years presenting to care in 28 selected facilities across 4 states in Nigeria. Eligible participants received CD4 + cell testing at baseline. Those with CD4 + cell count < 200 cells/mm3 were subjected to a blood cryptococcal antigen (CrAg) test and urine TB lateral flow lipoarabinomannan (LF-LAM). Those with positive CrAg tests had a cerebrospinal fluid (CSF) test to confirm cryptococcal meningitis. Those negative for both blood CrAg and TB LF-LAM were rapidly initiated on ART and underwent intensive follow-up. Participants were followed up for 12 months.

RESULTS

A total of 6,781 patients were enrolled; 71% (4,812) received CD4 + cell count test, of which 41% (1,969 of 4812) had a CD4 + count < 200 cells/mm3. Approximately 81% (1,492 of 1,850) of those with CD4 + count < 200 cells/mm3 had TB LF-LAM test results documented; 25% were positive, of which 47% started TB treatment. Blood CrAg screening coverage among those with CD4 + count < 200 cells/mm3 was 88% (1,634 of 1,850), of which 5% (85 of 1,634) were positive. Cotrimoxazole preventive therapy was initiated for 65% (1,198 of 1,850) of the participants with CD4 + count < 200 cells/mm3, and 70% (966 of 1,375) of AHD patients with a negative TB LF-LAM and blood CrAg results were initiated on ART on the day of enrolment. Approximately 91% (421 of 461) of those who received viral load results at month 12 post-enrollment were virally suppressed. The retention rate and the Kaplan Meier survival probability estimate at month 12 were 65% (1,204 of 1,850) and 0.93 (CI, 0.91-0.94), respectively, for the enrolled participants.

CONCLUSION

Implementation of the AHD package of care in Nigeria has improved the diagnosis of TB and CM, and will potentially enhance the quality of care for PLHIV if sustained. Findings from this implementation were used to guide national scale-up.

The emerging links between immunosenescence in innate immune system and neurocryptococcosis

Immunosenescence refers to the age-related progressive decline of immune function contributing to the increased susceptibility to infectious diseases in older people. Neurocryptococcosis, an infectious disease of central nervous system (CNS) caused by Cryptococcus neoformans (C. Neoformans) and C. gattii, has been observed with increased frequency in aged people, as result of the reactivation of a latent infection or community acquisition. These opportunistic microorganisms belonging to kingdom of fungi are capable of surviving and replicating within macrophages. Typically, cryptococcus is expelled by vomocytosis, a non-lytic expulsive mechanism also promoted by interferon (IFN)-I, or by cell lysis. However, whereas in a first phase cryptococcal vomocytosis leads to a latent asymptomatic infection confined to the lung, an enhancement in vomocytosis, promoted by IFN-I overproduction, can be deleterious, leading the fungus to reach the blood stream and invade the CNS. Cryptococcus may not be easy to diagnose in older individuals and, if not timely treated, could be potentially lethal. Therefore, this review aims to elucidate the putative causes of the increased incidence of cryptococcal CNS infection in older people discussing in depth the mechanisms of immunosenscence potentially able to predispose to neurocryptococcosis, laying the foundations for future research. A deepest understanding of this relationship could provide new ways to improve the prevention and recognition of neurocryptococcosis in aged frail people, in order to quickly manage pharmacological interventions and to adopt further preventive measures able to reduce the main risk factors.

Fungal diseases in Africa: Closing the gaps in diagnosis and treatment through implementation research and advocacy

Fungal diseases impose an escalating burden on public health in Africa, exacerbated by issues such as delayed diagnosis, inadequate therapy, and limited access to healthcare resources, resulting in significant morbidity and mortality. Effectively tackling these challenges demands a comprehensive approach encompassing research, training, and advocacy initiatives. Recent clinical mycology surveys conducted by Global Action for Fungal Infection (GAFFI) and the European Confederation of Medical Mycology/International Society for Human and Animal Mycology (ECMM/ISHAM) have underscored gaps in fungal diagnostics and the availability and accessibility of antifungal therapy in Africa. The World Health Organization (WHO) Fungal Priority Pathogens List (FPPL) identifies fungi of critical or high importance to human health, providing a roadmap for action and highlighting the urgent need for prioritizing fungal diseases and developing targeted interventions within the African context. To enhance diagnosis and treatment, it is imperative to invest in comprehensive training programs for healthcare workers across all levels and disciplines. Equipping them with the necessary knowledge and skills will facilitate early detection, accurate diagnosis, and appropriate management of fungal infections. Moreover, implementation science research in medical mycology assumes a pivotal role in bridging the gap between knowledge and practice. By identifying the barriers and facilitators that influence the adoption of diagnostic techniques and public health interventions, tailored strategies can be formulated to improve their implementation within healthcare settings. Advocacy plays a critical role in raising awareness regarding the profound impact of fungal diseases on public health in Africa. Engaging policymakers, healthcare providers, researchers, industry experts and communities underscore the importance of addressing these diseases and galvanize efforts for change. Substantial investment in surveillance, research and development specifically focused on fungal diseases is indispensable for advancing our understanding of local epidemiology, developing effective interventions, and ultimately improving patient outcomes. In conclusion, closing the gaps in diagnosing and treating fungal diseases in Africa demands concerted research and advocacy initiatives to ensure better healthcare delivery, reduced mortality rates, and improved public health outcomes.