Targeting pervasive infectious agents

Histoplasma capsulatum and Blastomyces dermatitidis are among the most prevalent fungal pathogens in the United States. Present in moist or fecund soils, these organisms release spores that can cause respiratory infection when inhaled. Among individuals infected with Histoplasma or Blastomyces, about half will develop symptoms. These can include fever, cough, chest pain, fatigue, headache, and body ache, but can progress to more severe illness and even death, particularly in patients who are immunocompromised.

While Histoplasma or Blastomyces have historically inhabited the Mississippi and Ohio river valleys, climate change has enabled an expansion of these organisms into a broader geographic range, putting more individuals at risk for infection.

A detection dilemma

Direct detection methods, such as culture and molecular testing, remain the gold standard for diagnostic confirmation of infection with Histoplasma and Blastomyces species. However, these methods often require invasive specimen collection that may not be suitable for all patients, and sensitivity can vary. Additionally, these organisms can take weeks to grow in culture, limiting their utility in acute diagnosis.

Detection of released antigens from these organisms is an effective alternative direct detection approach, which can quickly identify the presence of Histoplasma or Blastomyces infection. However, because of similar symptom presentation it’s nearly impossible to clinically distinguish which pathogen is causative, requiring physicians to often order two separate antigen tests. Additionally, the antigens released from Histoplasma and Blastomyces are very similar, leading to cross-reactivity between the individual assays. This frequently leads to Histoplasma antigens triggering positive results on Blastomyces testing and vice versa.

HIBAG | Histoplasma/Blastomyces Antigen, Enzyme Immunoassay, Serum

• Detects for antigens from both Histoplasma and Blastomyces species.
• Positively identifies infection and facilitates treatment initiation.
• Saves time and money through combined testing approach.

Note: This evaluation does not differentiate between Histoplasma and Blastomyces species. For species-specific identification, culture, molecular testing, and serologic assessment are recommended.

FGEN | Fungal Culture, Routine

HSTQU | Histoplasma capsulatum/Blastomyces species, Molecular Detection, PCR, Varies

UBLAS | Blastomyces Antigen, Quantitative, Enzyme Immunoassay, Random, Urine

HBRP | Histoplasma Antigen, Quantitative Enzyme Immunoassay, Random