In a recent sixteen-year span (2004-2020), nine human cases in France, all whom were of sub-Saharan west Africa origin, were identified with an invasive fungal infection called Nannizziopaia obscura species complex [1]. The patients were previously T-cell immunocompromised, which caused a range of complex clinical manifestations, contributing to the misidentification of these infections.
Cases of this infection are likely underestimated because only something called "sequencing", which is a complex clinic analysis, can enable proper identification of this disease. It is highlighted that the onset of this infection is likely to occur when immunity fails. Most of the cases presented with subcutaneous and/or lung nodules, and upon direct examination at a microbiologic laboratory, nonspecific hyphae (a filament within fungi) was also present; while on culture there were no specific features.
Exactly how the people were infected , meaning which portal the infection passed through, was found to be unclear. For example, skin and inhalation were investigated, but the results were inconclusive. The first line of treatment consisted of antifungal therapy, but two of seven patients with known outcomes died. The low number of patients makes it challenging for the researchers to recommend an effective antifungal treatment. Researchers found, however, a decrease in immunosuppressive therapy can result in improvements while surgery can address abscesses, and that prognosis outcome was driven by underlying diseases.
After reading this article, this infectious disease and several species of Nannizziopsis is an area needing further investigation, which can explain the rarity of the cases reported and the challenges in treating the disease.
Reference:
[1] Garcia-Hermoso D, Hamane S, Fekkar A, et al. Invasive Infections with Nannizziopsis obscura Species Complex in 9 Patients from West Africa, France, 2004–2020. Emerging Infectious Diseases. 2020;26(9):2022-2030. doi:10.3201/eid2609.200276.