RESUMO
Histoplasmosis is endemic to the Midwestern United States, but cases have been reported nearly worldwide. A 1970 study found 3.8% skin test sensitivity to Histoplasma capsulatum in Uganda but no systemic study of histoplasmosis exposure has occurred since the onset of the human immunodeficiency virus (HIV) pandemic. This study investigated the seroprevalence of H. capsulatum and sought previously undetected cases of histoplasmosis in Kampala, Uganda. Serum, cerebrospinal fluid (CSF) and/or urine specimens were obtained from HIV-infected persons with suspected meningitis. Specimens were tested for H. capsulatum IgG and IgM by enzyme immune assay and Histoplasma antigen. 147 of the 257 subjects who were enrolled had cryptococcal meningitis. Overall, 1.3% (2/151) of subjects were serum Histoplasma IgG positive, and zero of 151 were IgM positive. Antigen was not detected in any serum (n = 57), urine (n = 37, or CSF (n = 63) samples. Both subjects with serum Histoplasma IgG positivity had cryptococcal meningitis. Histoplasma capsulatum IgG was detected at low levels in persons with HIV/AIDS in Kampala, Uganda. Histoplasmosis is not widespread in Uganda but microfoci do exist. There appears to be no cross-reactivity between Cryptococcus neoformans and Histoplasma antigen testing, and cryptococcosis appears to be at most, a rare cause of positive Histoplasma IgG.
Assuntos
Histoplasmose/epidemiologia , Adulto , Anticorpos Antifúngicos/análise , Líquido Cefalorraquidiano/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HIV/complicações , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Masculino , Estudos Prospectivos , Estudos Soroepidemiológicos , Soro/imunologia , Uganda/epidemiologia , Urina/químicaRESUMO
Having reported that pretreatment of serum samples with EDTA at 100 degrees C improved the sensitivity for the detection of Histoplasma antigenemia, we have evaluated this method for the detection of Coccidioides antigenemia. Urine and serum samples from patients with coccidioidomycosis were tested using the MVista Coccidioides enzyme immunoassay, and serum samples with and without EDTA-heat treatment were tested. Antigenemia was detected in 28.6% of patients whose samples were not EDTA-heat treated and in 73.1% of those whose samples were treated. Antigenuria was detected in 50% of patients. Specificity of 100% was obtained in healthy subjects, but cross-reactions were seen in 22.2% of patients with histoplasmosis or blastomycosis. EDTA-heat treatment improves the sensitivity for the detection of Coccidioides antigenemia.
