Acute pulmonary histoplasmosis (APH) can be severe, especially following heavy exposure and is characterized by systemic and respiratory symptoms typically beginning 5 days to 3 weeks following exposure. The diagnosis of APH is often suspected when multiple individuals present with similar clinical findings following a common activity involving disturbance of a site contaminated with bird or bat guano. Rapid diagnosis is critical and often possible by detection of antigen in serum or urine. In one study, antigen was present in 83% of acute pulmonary histoplasmosis cases, but 38% would have been missed if only urine was tested. Testing for antibody could assist in the diagnosis of cases with negative antigen results, especially those with mild to moderate disease.
The MVista® Histoplasma Antibody EIA was most sensitive in the epidemiological cases (96.0% ). A statistical increase in sensitivity was seen over CF, ID and antigen detection in the epidemiological cases (P = .003, P < .001, and P < .001, respectively) and over ID within the clinical cases (P = .002). The MVista® Antigen or MVista® Antibody EIA was positive in 27 of 30 clinical (90%) and in all 50 epidemiological cases (100.0%). Combining antigen and antibody detection using the MVista EIAs increased overall sensitivity to 96%.
The MVista® Histoplasma Antibody EIA offers distinct advantages over currently available tests and may aid in the improved diagnosis of acute pulmonary histoplasmosis, which can be difficult to diagnose due to false-negative results in antigen tests, ID and CF tests. The MVista® Histoplasma Antibody EIA complements antigen detection and shows increased sensitivity compared to ID, CF, and antigen testing alone. Additionally, the MVista® Antibody EIA offers semi-quantitative detection of lgG and lgM antibodies, which may help to distinguish current from past infection. Combining antigen and antibody testing using the MVista® EIAs provides the highest sensitivity (96%) for diagnosing acute pulmonary histoplasmosis.
Richer SM, Smedema ML, Durkin MM, et al. Improved Diagnosis of Acute Pulmonary Histoplasmosis by Combining Antigen and Antibody Detection. Clin Infect Dis 2016; 62:896-902.
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