Colliding Epidemics and the Rise of Cryptococcosis.

Christina Chang,Sharon Chen

doi:10.3390/jof2010001

Abstract

Discovered more than 100 years ago as a human pathogen, the Cryptococcus neoformans–Cryptococcus gattii (C. neoformans–C. gattii) complex has seen a large global resurgence in its association with clinical disease in the last 30 years. First isolated in fermenting peach juice, and identified as a human pathogen in 1894 in a patient with bone lesions, this environmental pathogen has now found niches in soil, trees, birds, and domestic pets. Cryptococcosis is well recognized as an opportunistic infection and was first noted to be associated with reticuloendothelial cancers in the 1950s. Since then, advances in transplant immunology, medical science and surgical techniques have led to increasing numbers of solid organ transplantations (SOT) and hematological stem cell transplantations being performed, and the use of biological immunotherapeutics in increasingly high-risk and older individuals, have contributed to the further rise in cryptococcosis. Globally, however, the major driver for revivification of cryptococcosis is undoubtedly the HIV epidemic, particularly in Sub-Saharan Africa where access to care and antiretroviral therapy remains limited and advanced immunodeficiency, poverty and malnutrition remains the norm. As a zoonotic disease, environmental outbreaks of both human and animal cryptococcosis have been reported, possibly driven by climate change. This is best exemplified by the resurgence of C. gattii infection in Vancouver Island, Canada, and the Pacific Northwest of the United States since 1999. Here we describe how the colliding epidemics of HIV, transplantation and immunologics, climate change and migration have contributed to the rise of cryptococcosis.

Highlights

The history and biology of Cryptococcus neoformans (C. neoformans), recognised as a species complex (the Cryptococcus neoformans–Cryptococcus gatti (C. gattii) complex), is detailed in an authoritative text by Casadavell and Perfect [1]
Prior to 1981, cryptococcosis was a relatively rare condition (500–1000 cases a year in the United States (USA)) but with the onset of the HIV epidemic, 1200 cases of cryptococcosis were observed in New York City alone in 1991 [1]
Prognosis of cryptococcosis was dismal in the early 1900s—with the exception of surgical removal of localized spinal lesions—until the antifungal agent, amphotericin B, was introduced in the late 1950s, which provided the first effective therapy against cryptococcosis. Both amphotericin B formulations and azole antifungals remain the mainstay of therapy

Summary

Introduction

The history and biology of Cryptococcus neoformans (C. neoformans), recognised as a species complex (the Cryptococcus neoformans–Cryptococcus gatti (C. gattii) complex), is detailed in an authoritative text by Casadavell and Perfect [1]. Prior to 1981, cryptococcosis was a relatively rare condition (500–1000 cases a year in the United States (USA)) but with the onset of the HIV epidemic, 1200 cases of cryptococcosis were observed in New York City alone in 1991 [1]. Prognosis of cryptococcosis was dismal in the early 1900s—with the exception of surgical removal of localized spinal lesions—until the antifungal agent, amphotericin B, was introduced in the late 1950s, which provided the first effective therapy against cryptococcosis Today, both amphotericin B formulations and azole antifungals remain the mainstay of therapy

Cryptococcosis in Association with Malignancy and Autoimmune Diseases

The Rise of Transplantation and Transplant Immunology

Cryptococcosis and HIV

Environmental Outbreaks

Findings

Conclusions