Coccidioidomycosis in Biopsies with Presumptive Diagnosis of Malignancy in Dogs: Report of Three Cases and Comparative Discussion of Published Reports

Two lateral flow assays for detection of anti-coccidioidal antibodies show similar performance to immunodiffusion in dogs with coccidioidomycosis

OBJECTIVE

To compare 2 point-of-care lateral flow assays (LFAs) with immunodiffusion (ID) IgG results for anti-coccidioidal antibody detection in dogs with coccidioidomycosis. A further aim was to compare the quantifiable output of 1 of the LFAs to ID antibody titers.

SAMPLE

Serum banked from 73 client-owned dogs diagnosed with pulmonary or disseminated coccidioidomycosis.

METHODS

ID was used to determine antibody presence and titer against a coccidioidal antigen preparation. All sera were subsequently tested on an LFA based on recombinant chitinase 1 (CTS1) and the commercially available sōna LFA. LFA results were analyzed and compared to ID IgG results and clinical diagnosis.

RESULTS

All assays showed similar sensitivities in detecting anti-coccidioidal antibodies (83.6% to 89.0%). When compared with ID IgG, the CTS1 LFA had a positive percent agreement of 100%, while the sōna LFA had a positive percent agreement of 91.4%. Since the CTS1 LFA is semiquantitative, we were able to compare test line densities with ID titers and found a strong correlation between the 2 assays (Spearman ρ = 0.82).

CLINICAL RELEVANCE

This is the first side-by-side evaluation of a commercially available LFA (sōna) and a newer more rapid anti-CTS1 antibody LFA using serum from dogs with coccidioidomycosis. Both LFAs tested have similar sensitivity to ID IgG results. The CTS1 LFA can be read after 10 minutes and is semiquantitative, while the sōna LFA is read after 30 minutes, and the results are subject to interpretation. Accurate and fast detection of anti-coccidioidal antibodies allows clinicians to initiate appropriate treatment without diagnostic delay.

A multicentre external quality assessment: A first step to standardise PCR protocols for the diagnosis of histoplasmosis and coccidioidomycosis

BACKGROUND

In-house real-time PCR (qPCR) is increasingly used to diagnose the so-called endemic mycoses as commercial assays are not widely available.

OBJECTIVES

To compare the performance of different molecular diagnostic assays for detecting Histoplasma capsulatum and Coccidioides spp. in five European reference laboratories.

METHODS

Two blinded external quality assessment (EQA) panels were sent to each laboratory that performed the analysis with their in-house assays. Both panels included a range of concentrations of H. capsulatum (n = 7) and Coccidioides spp. (n = 6), negative control and DNA from other fungi. Four laboratories used specific qPCRs, and one laboratory a broad-range fungal conventional PCR (cPCR) and a specific cPCR for H. capsulatum with subsequent sequencing.

RESULTS

qPCR assays were the most sensitive for the detection of H. capsulatum DNA. The lowest amount of H. capsulatum DNA detected was 1-4 fg, 0.1 pg and 10 pg for qPCRs, specific cPCR and broad-range cPCR, respectively. False positive results occurred with high concentrations of Blastomyces dermatitidis DNA in two laboratories and with Emergomyces spp. in one laboratory. For the Coccidioides panel, the lowest amount of DNA detected was 1-16 fg by qPCRs and 10 pg with the broad-range cPCR. One laboratory reported a false positive result by qPCR with high load of Uncinocarpus DNA.

CONCLUSION

All five laboratories were able to correctly detect H. capsulatum and Coccidioides spp. DNA and qPCRs had a better performance than specific cPCR and broad-range cPCR. EQAs may help standardise in-house molecular tests for the so-called endemic mycoses improving patient management.

Coccidioidomycosis in Latin America

Coccidioidomycosis is a highly prevalent systemic mycosis in Latin America and has been reported (human and zoonotic cases) in México, Guatemala, Honduras, Colombia, Venezuela, Brazil, Paraguay, Bolivia, and Argentina. The incidence of coccidioidomycosis in Latin America is unknown due to lack of clinical awareness and limited access to laboratory diagnosis. Coccidioidomycosis is as prevalent in Mexico as in the endemic regions of the United States. The number of cases reported in Brazil and Argentina has progressively increased during the last decade, including areas that were not considered as endemic. Genetic studies have shown that the prevalent species in Latin America is Coccidioides posadasii. Coccidioides immitis has been reported sporadically in indigenous cases from Mexico and Colombia. Coccidioidomycosis and tuberculosis share some risk factors such as immunosuppression and residing in areas endemic for these conditions, so their coexistence in the same patient is not uncommon in Latin America. In most regions, clinical diagnosis of coccidioidomycosis is based on direct sputum examination and histopathology results from biopsies or autopsies. This would explain why primary coccidioidomycosis is rarely diagnosed, and most cases published are about chronic pulmonary or disseminated disease.

The Curious Case of "Case Report" of Infections Caused by Human and Animal Fungal Pathogens: An Educational Tool, an Online Archive, or a Format in Need of Retooling

Case reports describe the unusual occurrence and complications of diseases, diagnostic challenges, and notable therapeutic successes. Some journals have discontinued the case reports, while new case report journals have appeared in recent years. During the eightieth anniversary of Mycopathologia, it is fitting to examine the relevance of the case report since the journal continues to traverse the boundaries of basic and clinical sciences. A random sample of recent case reports and other articles were selected from Mycopathologia. Springer Nature individual article download statistics, and Google Scholar and Scopus citations numbers were compared to assess the reader access and bibliometric impact of case reports. Our analysis indicated that the case report format continues to be a vital element of publication in a cross-disciplinary journal such as Mycopathologia. Medical and veterinary case reports covering fungal pathogens are widely read as evident from their download numbers. The download numbers have a positive correlation with the completeness of the report, the topics and geographic origin of reports have a neutral influence, and the recency leads to lower downloads. There is no discernible trend between the download numbers and the citations of case reports as measured by Google Scholar and Scopus. A specially designed checklist for Mycopathologia case reports and new format MycopathologiaIMAGES are being introduced to improve the quality and relevance of case reports further.

Fungal Infections of the Central Nervous System in Small Animals: Clinical Features, Diagnosis, and Management

Small animal mycoses vary geographically. Different clinical presentations are seen in animals with infection of the central nervous system (CNS), including multifocal meningoencephalomyelitis, intracranial lesions that accompany sinonasal lesions, rapidly progressive ventriculitis, or solitary granuloma of the brain or spinal cord. Systemic, nasal, or extraneural clinical signs are common but, especially in granuloma cases, do not always occur. Surgery may have a diagnostic and therapeutic role in CNS granuloma. There have been recent advancements in serology. Fluconazole, voriconazole, and posaconazole cross the blood-brain barrier, but voriconazole is neurotoxic to cats. Liposomal and lipid-encapsulated formulations of amphotericin B are preferred.