Fungal Infection in Peripheral Arterial Disease-Associated Lower Extremity Ulcers and Its Impact on Wound Healing

Abstract

Background: Peripheral arterial disease (PAD) is an important cause of chronic lower-extremity ulceration and impaired wound healing. Although bacterial infection of chronic ischemic ulcers is well recognized, fungal infection remains relatively under-recognized. Diabetes mellitus, tissue ischemia, impaired host immunity and prolonged wound duration may predispose to fungal colonization or infection. Fungal communities may also interact with bacteria and form mixed biofilms, potentially contributing to delayed wound healing. [1–4] Chronic wounds have been shown to harbour diverse fungal communities, and fungal composition has been associated with healing outcomes. [1]
Aim: To determine the prevalence and microbiological profile of fungal infection among patients with PAD-associated lower-extremity ulcers and to assess its association with diabetes mellitus, bacterial co-infection and wound-healing outcomes.
Methods: A prospective observational study of 50 adults with PAD-associated lower-extremity ulcers was considered. Clinical characteristics and comorbidities were recorded. Wound specimens were evaluated for fungal and bacterial growth. The prevalence of fungal infection, fungal species, bacterial co-infection, healing time, complete healing and amputation were compared between fungal-positive and fungal-negative patients. Categorical variables were analysed using the Chi-square test or Fisher’s exact test, while continuous variables were analysed using an independent-samples t-test.
Results: Among 50 patients, 22 (44%) were fungal-positive and 28 (56%) were fungal-negative. Diabetes mellitus was present in 35 (70%) patients. Fungal infection was present in 18/35 (51.4%) diabetic patients and 4/15 (26.7%) non-diabetic patients. Candida spp. were the most frequently isolated fungi (12/22, 54.5%), followed by Aspergillus spp. (6/22, 27.3%) and Fusarium spp. (4/22, 18.2%). Bacterial co-infection was present in 15/22 (68.2%) fungal-positive patients. Mean wound-healing time was significantly longer in fungal-positive patients than fungal-negative patients (14.1 ± 3.2 vs 8.4 ± 2.3 weeks; p<0.001). Complete healing by 12 weeks occurred in 5 (22.7%) fungal-positive patients compared with 22 (78.6%) fungal-negative patients (p<0.001). Amputation occurred in 8 (36.4%) fungal-positive patients compared with 3 (10.7%) fungal-negative patients (p=0.042).
Conclusion: Fungal infection was identified in 44% of this illustrative PAD-ulcer cohort and was associated with diabetes, frequent bacterial co-infection, delayed wound healing and higher amputation rates. Fungal infection should be considered in persistent or non-healing PAD-associated ulcers, particularly in patients with diabetes or polymicrobial infection.