Detection of Aspergillus Galactomannan in Blood for Early Diagnosis of Pulmonary Aspergillosis in HIV Positive Subjects with and without Tuberculosis in Calabar, Nigeria

Abstract

This study was aimed at determining the prevalence of pulmonary aspergillosis using Aspergillus galactomannan detection in human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/ AIDS) subjects with and without tuberculosis. The study was a prospective cohort study carried out at the University of Calabar Teaching Hospital and Dr. Lawrence Henshaw Memorial Hospital in Calabar. Subjects were HIV-positive patients with and without tuberculosis. Blood and sputum samples were obtained from 215 subjects who consented to the study. A structured questionnaire was administered to assess demograph¬ic data and medical history. Sputum samples were subjected to direct microscopy, culture, and Ziehl-Nel¬seen test. Aspergillus galactomannan assay and CD4 counts were performed on the blood samples. The results of Aspergillus galactomannan-positive subjects were communicated to the attending Physicians for proper patient management. Aspergillus species were recovered from 35(16.3%) sputum samples. Asper¬gillus fumigatus was the most encountered isolate 18(8.4%). The most common presenting symptoms were cough 35(100%) and fatigue 30(85.7%). Out of the 35 subjects with Aspergillus isolates, 21(60.0%) had TB, 9(25.7%) had no TB and 5(14.3%) had co-morbidity of HIV and TB. All the subjects with aspergillosis had CD4 counts less than 200 cellsμl-1 and there was a statistically significant association between pulmonary aspergillosis and CD4 levels (H=7.02; p = 0.03). Galactomannan assay could be used for early diagnosis of invasive aspergillosis and timely management of patients as it is sensitive, cost-effective, and has a turna¬round time of less than 1 hour compared to culture methods.