Chronic pulmonary aspergillosis is common among patients with presumed tuberculosis relapse in Ghana

Abstract

Chronic pulmonary aspergillosis (CPA) may mimic pulmonary tuberculosis (PTB). The two diseases are clinically indistinguishable and may result in CPA misdiagnosed as PTB or vice versa. Although, PTB is largely recognised as a differential diagnosis of CPA and often ruled out prior to CPA diagnosis, the converse is uncommon. The aim of this study was to determine the proportion of CPA cases among patients being assessed for PTB. A cross-sectional survey was conducted among consecutive patients referred for GeneXpert Mycobacterium tuberculosis (MTB) test for the diagnosis of PTB at the Korle-Bu Teaching Hospital, Accra, Ghana. Patients’ demographics, clinical and socioeconomic details were obtained using a structured questionnaire. Blood was collected for Aspergillus and HIV serology, and sputum samples obtained for Aspergillus culture. Chest radiograph was obtained, and computed tomography (CT) scan was also done for patients with positive Aspergillus serology or cavitation. CPA was defined using an algorithm developed by the Global Action for Fungal Infections (GAFFI) international expert panel. One hundred and fifty-four patients were included in the analysis, of whom 134 (87%) did not have a prior PTB diagnosis. There were 41 (26.6%) GeneXpert positive cases. CPA prevalence was 9.7% overall, but 50% in patients with a prior history of PTB and 3.7% in those without previous PTB. Although CPA is rarely considered as a differential diagnosis of PTB in Ghana, our findings show that CPA may affect half of patients being assessed for PTB relapse. Efforts to diagnose CPA should be prioritised in this patient group.

Importance of Aspergillus-Specific Antibody Screening for Diagnosis of Chronic Pulmonary Aspergillosis after Tuberculosis Treatment: A Prospective Follow-Up Study in Ghana

“…We prospectively followed up new bacteriologically confirmed PTB patients from a previous study [ 17 ] to evaluate the incidence of CPA from the time of PTB diagnosis to the time after completing the TB treatment, and finally, six months after the treatment regimen. A CT scan was performed in all the CPA patients in our study.…”

“…Similarly, another study in Uganda reported ~20% CPA incidence among PTB patients with persisting symptoms after 2 months of TB treatment [ 6 ]. In a recently published study, a possible PTB-CPA coinfection was reported, but there are still doubts with regard to the existence of a true PTB infection [ 17 ]. As more studies are being conducted on CPA in patients presenting with PTB, the phenomenon of co-infection may be further explored.…”

“…Clinicians thus need to consider Aspergillus -specific antibody testing in successfully treated PTB patients who return with new or persistent respiratory symptoms without radiological progression on chest radiographs. Most of these cases are usually presumed to have anti-TB treatment failure, PTB relapse or reinfection, but studies have shown that over 50% actually have CPA [ 9 , 17 , 30 ]. The current finding corroborates a recent study in Ghana, where CPA was present in 50% of the patients with presumed recurrent PTB [ 17 ].…”

“…Adult (≥18 years) patients with MTB detected in their sputum in a previous study [ 17 ] and were subsequently placed on an anti-TB treatment were enrolled for this study. The patients were receiving care for suspected PTB at the Chest Clinic of the Korle-Bu Teaching Hospital, Accra, Ghana, or they were referred from various health facilities across the country to the Chest Clinic TB laboratory for GeneXpert MTB and rifampicin (RIF) resistance testing (Xpert ® MTB/RIF, Cepheid, California, CA, USA).…”

“…Serum samples were obtained from all the patients for Aspergillus -specific antibody testing with the LDBio Aspergillus IgG & IgM LFA (LDBio Diagnostics, Lyon, France) following the manufacturer’s instructions. A sputum Aspergillus culture was performed for all of the patients using a modified version of the high-volume culture method by inoculating an aliquot (1–2 mL) of undiluted sputum on Sabouraud dextrose agar, and then, it was incubated at 37 °C for up to 8 days [ 17 ]. A chest CT scan was performed for the patients with positive Aspergillus serology or cavitation on baseline chest radiograph with new or persistent respiratory symptoms.…”