Coccidioides (spherulin) skin testing in patients with pulmonary coccidioidomycosis in an endemic region†

Challenges to Implementing a Vaccine for Coccidioidomycosis

A vaccine for coccidioidomycosis is likely to undergo trials in the near future. In this paper, we raise 4 questions that should be answered before its use and offer our solutions to these questions. These include defining the goals of vaccination, determining who should be vaccinated, how to measure vaccine immunity and protection, and how to address vaccine hesitancy and denial.

The dog as a sentinel and animal model for coccidioidomycosis

Coccidioidomycosis is a potentially fatal fungal disease of humans and animals that follows inhalation of Coccidioides spp. arthroconidia in the environment. The disease in dogs resembles that in people, and because dogs may be at increased risk of exposure due to their proximity to the ground and digging behavior, they are valuable models for the disease in humans. Dogs have been sentinels for identification of new regions of endemicity in Washington and Texas. Canine serosurveillance has also been used to predict variables associated with environmental presence of Coccidioides spp. Expansion of the endemic region of coccidioidomycosis with climate change-along with predicted population increases and increased development in the southwest United States-may result in 45.4 million additional people at risk of infection by 2090. Here we provide an overview of the value of dogs as sentinels for the disease and encourage the routine reporting of coccidioidomycosis cases in dogs to public health agencies. We also highlight the value of dogs as naturally occurring models for studying novel treatment options and preventatives, such as a novel live avirulent coccidioidomycosis vaccine.

Review of Clinical and Laboratory Diagnostics for Coccidioidomycosis

Coccidioidomycosis is a fungal disease associated with soil exposure that frequently goes undiagnosed due at least in part to its nonspecific presentation and the lack of clinical suspicion by health care providers. Currently available diagnostics for coccidioidomycosis offer qualitative results that can suffer from low specificity, while semiquantitative assays are labor-intensive and complex and can require multiple days to complete. Furthermore, significant confusion exists regarding the optimal diagnostic algorithms and appropriate usage of available diagnostic tests. This review aims to inform clinical laboratorians and treating clinicians about the current diagnostic landscape, appropriate diagnostic strategies, and future diagnostic directions for coccidioidomycosis, which is expected to become more prevalent due to increased migration into areas of endemicity and climate changes.

Diagnostic Approach to Coccidioidomycosis in Solid Organ Transplant Recipients

Coccidioidomycosis is a fungal infection endemic in the southwestern United States, Mexico, and parts of Central and South America. While coccidioidomycosis is associated with mostly mild infections in the general population, it can lead to devastating infections in immunocompromised patients, including solid organ transplant (SOT) recipients. Early and accurate diagnosis is important in achieving better clinical outcomes in immunocompromised patients. However, the diagnosis of coccidioidomycosis in SOT recipients can be challenging due to the limitations of diagnostic methods including cultures, serology, and other tests in providing a timely and accurate diagnosis. In this review, we will discuss the available diagnostic modalities and approaches when evaluating SOT recipients with coccidioidomycosis, from the use of conventional culture methods to serologic and molecular testing. Additionally, we will discuss the role of early diagnosis in assisting with the administration of effective antifungal therapy to reduce infectious complications. Finally, we will discuss ways to improve the performance of coccidioidomycosis diagnostic methods in SOT recipients with an option for a combined testing approach.

Δcps1 vaccine protects dogs against experimentally induced coccidioidomycosis

Coccidioidomycosis is a significant health problem of dogs and humans in endemic regions, especially California and Arizona in the U.S. Both species would greatly benefit from a vaccine to prevent this disease. A live avirulent vaccine candidate, Δcps1, was tested for tolerability and efficacy to prevent pulmonary coccidioidomycosis in a canine challenge model. Vaccine injection-site reactions were transient and there were no systemic effects observed. Six of seven vaccine sites tested and all draining lymph nodes were sterile post-vaccination. Following infection with Coccidioides posadasii, strain Silveira, arthroconidia into the lungs, dogs given primary and booster vaccinations had significantly reduced lung fungal burdens (P = 0.0003) and composite disease scores (P = 0.0002) compared to unvaccinated dogs. Dogs vaccinated once had fungal burdens intermediate between those given two doses or none, but disease scores were not significantly different from unvaccinated (P = 0.675). Δcps1 was well-tolerated in the dogs and it afforded a high level of protection when given as prime and boost. These results drive the Δcps1 vaccine toward a licensed veterinary vaccine and support continued development of this vaccine to prevent coccidioidomycosis in humans.

Treatment for Early, Uncomplicated Coccidioidomycosis: What Is Success?

The care of primary pulmonary coccidioidomycosis remains challenging. Such infections produce a variety of signs, symptoms, and serologic responses that cause morbidity in patients and concern in treating clinicians for the possibility of extrapulmonary dissemination. Illness may be due to ongoing fungal growth that produces acute inflammatory responses, resulting in tissue damage and necrosis, and for this, administering an antifungal drug may be of benefit. In contrast, convalescence may be prolonged by other immunologic reactions to infection, even after fungal replication has been arrested, and in those situations, antifungal therapy is unlikely to yield clinical improvement. In this presentation, we discuss what findings are clinical indicators of fungal growth and what other sequelae are not. Understanding these differences provides a rational management strategy for deciding when to continue, discontinue, or reinstitute antifungal treatments.

Coccidioidomycosis: Changing Concepts and Knowledge Gaps

Although first described more than 120 years ago, much remains unknown about coccidioidomycosis. In this review, new information that has led to changing concepts will be reviewed and remaining gaps in our knowledge will be discussed. In particular, new ideas regarding ecology and epidemiology, problems and promises of diagnosis, controversies over management, and the possibility of a vaccine will be covered.