Prevalence of Aspergillus fumigatus skin positivity in adults without an apparent/known atopic disease in Uganda

Abstract

Background: Skin prick testing (SPT) is an important investigation in the evaluation of allergy to fungal pathogens. However, the background sensitivity to fungal allergens among healthy people in Uganda is unknown. Our aim was to assess the background prevalence of Aspergillus fumigatus SPT positivity in apparently healthy adults without known atopic disease in Uganda. Methods: For this pilot study, we recruited 50 healthy volunteers using convenience sampling, 56% of whom were health workers. We performed the SPT for A. fumigatus according to manufacturer’s instructions. A wheal diameter of ⩾3 mm was considered positive. Results: The prevalence of A. fumigatus skin positivity was 60% (30/50). Participants with a positive A. fumigatus SPT were significantly younger than those with a negative result [median age (years): 28 versus 35; p = 0.005]. Conclusion: There is a high skin positivity against A. fumigatus among non-atopic healthy Ugandan adults. There is an urgent need to establish a normal wheal cut-off value for this population. SPT alone may be an unreliable test for the diagnosis of A. fumigatus associated allergic syndromes. More studies are needed to define the prevalence of A. fumigatus skin positivity among non-atopic healthy population in Africa.

Re-estimation of the burden of serious fungal diseases in Uganda

“…There is no documented case of cystic fibrosis in Uganda. In Uganda, ABPA occurs in about 3.2% of adult patients living with asthma, 23 , 107 and SAFS in about 33% of most poorly-controlled (10%) of adult asthmatics among African population adult patients living with asthma. 23 ABPM was also documented as a discrete group in 2.9% 17 but we have not added this group to our overall estimate of fungal asthma.…”

Fungal exposome, human health, and unmet needs: A 2022 update with special focus on allergy

“…Exposure to fungi may result in infection (e.g., mucormycoses, coccidioidomycoses, invasive or noninvasive aspergillosis, or fusariosis) or hypersensitivity in predisposed individuals (such as conjunctivitis, asthma, rhinitis, allergic bronchopulmonary aspergillosis (ABPA), and hypersensitivity pneumonitis (HSP)) 6,35–37 . In particular, fungal IgE sensitization is often present in patients with asthma, bronchiectasis, cystic fibrosis, and chronic obstructive pulmonary disease (COPD), contributing to the initiation or pathophysiology of these diseases, which rank among the most prevalent worldwide 17,19,38 . Fungal infections develop predominantly in immunocompromised hosts and may exceed 50% case‐fatality rates 17,39 .…”

“…6,[35][36][37] In particular, fungal IgE sensitization is often present in patients with asthma, bronchiectasis, cystic fibrosis, and chronic obstructive pulmonary disease (COPD), contributing to the initiation or pathophysiology of these diseases, which rank among the most prevalent worldwide. 17,19,38 Fungal infections develop predominantly in immunocompromised hosts and may exceed 50% case-fatality rates. 17,39 HSP may occur in subjects without a previous condition and relates to a non-type 2 immune response with robust cellular and antigen-specific IgG responses.…”

Fungal exposome, human health and unmet needs: a 2022 update with special focus on allergy

“…Exposure to fungi may cause a vast variety of diseases, mainly allergic (such as conjunctivitis, asthma, hypersensitivity pneumonitis, rhinitis, and allergic broncho-pulmonary aspergillosis) or infectious (e.g., mucormycoses, invasive aspergillosis, or fusariosis). Fungal hypersensitivity is often found in patients with asthma, chronic obstructive pulmonary disease, cystic fibrosis, and bronchiectasis, ranking among the most prevalent diseases worldwide (4,15). Fungal infections develop predominantly in immunocompromised hosts and may exceed 50% case-fatality rates (4,16).…”