Fungal asthma among Ugandan adult asthmatics

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

Background

It is of utmost importance to monitor any change in the epidemiology of fungal diseases that may arise from a change in the number of the at-risk population or the availability of local data.

Objective

We sought to update the 2015 publication on the incidence and prevalence of serious fungal diseases in Uganda.

Methods

Using the Leading International Fungal Education methodology, we reviewed published data on fungal diseases and drivers of fungal diseases in Uganda. Regional or global data were used where there were no Ugandan data.

Results

With a population of ~45 million, we estimate the annual burden of serious fungal diseases at 4,099,357 cases (about 9%). We estimated the burden of candidiasis as follows: recurrent Candida vaginitis (656,340 cases), oral candidiasis (29,057 cases), and esophageal candidiasis (74,686 cases) in HIV-infected people. Cryptococcal meningitis annual incidence is estimated at 5553 cases, Pneumocystis pneumonia at 4604 cases in adults and 2100 cases in children. For aspergillosis syndromes, invasive aspergillosis annual incidence (3607 cases), chronic pulmonary aspergillosis (26,765 annual cases and 63,574 5-year-period prevalent cases), and prevalence of allergic bronchopulmonary aspergillosis at 75,931 cases, and severe asthma with fungal sensitization at 100,228 cases. Tinea capitis is common with 3,047,989 prevalent cases. For other mycoses, we estimate the annual incidence of histoplasmosis to be 646 cases and mucormycosis at 9 cases.

Conclusion

Serious fungal diseases affect nearly 9% of Ugandans every year. Tuberculosis and HIV remain the most important predisposition to acute fungal infection necessitating accelerated preventive, diagnostic, and therapeutic interventions for the management of these diseases.

Poorly controlled asthma - Easy wins and future prospects for addressing fungal allergy

Poorly controlled asthma is especially common in low resource countries. Aside from lack of access to, or poor technique with, inhaled beta-2 agonists and corticosteroids, the most problematic forms of asthma are frequently associated with both fungal allergy and exposure, especially in adults leading to more asthma exacerbations and worse asthma. The umbrella term 'fungal asthma' describes many disorders linked to fungal exposure and/or allergy to fungi. One fungal asthma endotype, ABPA, is usually marked by a very high IgE and its differential diagnosis is reviewed. Both ABPA and fungal bronchitis in bronchiectasis are marked by thick excess airway mucus production. Dermatophyte skin infection can worsen asthma and eradication of the skin infection improves asthma. Exposure to fungi in the workplace, home and schools, often in damp or water-damaged buildings worsens asthma, and remediation improves symptom control and reduces exacerbations. Antifungal therapy is beneficial for fungal asthma as demonstrated in nine of 13 randomised controlled studies, reducing symptoms, corticosteroid need and exacerbations while improving lung function. Other useful therapies include azithromycin and some biologics approved for the treatment of severe asthma. If all individuals with poorly controlled and severe asthma could be 'relieved' of their fungal allergy and infection through antifungal therapy without systemic corticosteroids, the health benefits would be enormous and relatively inexpensive, improving the long term health of over 20 million adults and many children. Antifungal therapy carries some toxicity, drug interactions and triazole resistance risks, and data are incomplete. Here we summarise what is known and what remains uncertain about this complex topic.

Fungal infections in Sudan: An underestimated health problem

Fungal diseases are associated with high morbidity and mortality, yet their epidemiology and burden are not well addressed. While deaths probably exceed 1.5 million per year, many cases remain undiagnosed and underreported. Estimating the burden of these diseases is needed for prioritization and implementation of effective control programs. Here we used a model based on population at risk to estimate the burden of serious fungal infections in Sudan. The prevalence of the susceptible population including HIV, TB, cancer, asthma, and COPD was obtained from the literature. Incidence and prevalence of fungal infections were calculated using local data when applicable and if not available then regional or international figures were used. In total, the estimated number of Sudanese suffering from fungal disease is 5 M (10% of the total population). Tinea capitis, recurrent vulvovaginitis and keratitis are estimated to affect 4,127,760, 631,261, and 6,552 patients, respectively. HIV-related mycosis is estimated to affect 5,945 oral candidiasis, 1,921 esophageal candidiasis, 571 Pneumocystis pneumonia, and 462 cryptococcal meningitis cases. Aspergillus infections are estimated as follow: 3,438 invasive aspergillosis, 14,950 chronic pulmonary aspergillosis, 67,860 allergic bronchopulmonary aspergillosis cases, while the prevalence of severe asthma with fungal sensitization and fungal rhinosinusitis was 86,860 and 93,600 cases, respectively. The neglected tropical disease eumycetoma was estimated to affect 16,837 cases with a rate of 36/100,000. Serious fungal infections are quite common in Sudan and require urgent attention to improve diagnosis, promote treatment, and develop surveillance programs.

Prevalence and predictors of Aspergillus seropositivity and chronic pulmonary aspergillosis in an urban tertiary hospital in Sierra Leone: A cross-sectional study

BACKGROUND

In the World Health Organization Global Tuberculosis (TB) Report 2022, 37% of pulmonary TB patients were clinically diagnosed and thus many people were treated for TB without evidence of the disease. Probably the most common TB misdiagnosis is chronic pulmonary aspergillosis (CPA). In this study, we aimed to assess the prevalence and predictors of Aspergillus seropositivity and CPA in patients with chronic respiratory symptoms in an urban tertiary hospital in Sierra Leone.

METHODOLOGY/PRINCIPAL FINDINGS

We used a cross-sectional study design to recruit adults (≥18 years) from the Chest Clinic of Connaught Hospital, Freetown between November 2021 and July 2022. Aspergillus antibody was detected using LDBio Aspergillus IgM/IgG. Logistic regression was performed to assess the independent predictors of Aspergillus seropositivity and CPA. Of the 197 patients with chronic respiratory symptoms, 147 (74.6%) were male. Mean age was 47.1 ± 16.4 years. More than half (104, 52.8%) had been diagnosed with TB in the past, while 53 (26.9%) were on TB treatment at the time of recruitment. Fifty-two (26.4%) patients were HIV positive, 41 (20.8%) were seropositive for Aspergillus and 23 (11.6%) had CPA, 2 (3.8%) with current TB and 18 (17.3%) with past TB. Common radiologic abnormalities reported were localized fibrotic changes 62 (31.5%), consolidation 54 (27.4%), infiltrates 46 (23.4%), hilar adenopathy 40 (20.3%) and pleural effusion 35 (17.85) and thickening 23 (11.7%). Common symptoms were weight loss 144 (73.1%), cough 135 (68.5%), fever 117 (59.4%) and dyspnea 90 (45.7%). Current or past TB infection {aOR 3.52, 95% CI (1.46, 8.97); p = 0.005} was an independent predictor of Aspergillus seropositivity and CPA.

CONCLUSIONS/SIGNIFICANCE

We report a high prevalence of Aspergillus antibody seropositivity and CPA, underscoring the need to integrate the prevention and management of pulmonary fungal infections with TB services and asthma care in order to reduce unnecessary morbidity and mortality.

Prevalence of Aspergillus Sensitization and Allergic Bronchopulmonary Aspergillosis in Adults With Bronchial Asthma: A Systematic Review of Global Data

BACKGROUND

The prevalence of allergic bronchopulmonary aspergillosis (ABPA) in asthmatic patients remains unclear and is likely different across geographic locales.

OBJECTIVE

To systematically review the literature for estimating the prevalence of Aspergillus sensitization (AS) and ABPA in adults with bronchial asthma.

METHODS

We searched the PubMed and Embase databases for studies reporting the prevalence of AS or ABPA in at least 50 asthmatic subjects. The primary outcome was to assess the prevalence of ABPA. The secondary outcome was to evaluate the prevalence of AS in asthma and that of ABPA in asthma with AS. We pooled the prevalence estimates using a random-effects model and examined the factors influencing the prevalence using multivariate meta-regression.

RESULTS

Of the 11,801 records retrieved, 86 studies with 25,770 asthmatic subjects met the inclusion criteria. Most of the studies were from tertiary care centers. The pooled prevalence of ABPA in asthma (47 studies; 9822 asthmatic subjects) was 11.3% (95% CI, 8.7-14.2). The pooled prevalence of AS in asthma (73 studies; 23,003 asthmatic subjects) was 25.1% (95% CI, 20.5-30.0), whereas the prevalence of ABPA in AS (36 studies; 2954 asthmatic subjects) was 37.0% (95% CI, 27.9-46.6). Multivariate meta-regression identified studies published from India (odds ratio, 1.11; 95% CI, 1.01-1.23) as the only factor associated with higher ABPA prevalence. There was presence of significant statistical heterogeneity and publication bias.

CONCLUSIONS

We found a high prevalence of ABPA in adult asthmatic subjects, underscoring the need for screening for ABPA in all asthmatic subjects seeking tertiary care.

Burden of fungal infections in Kenya

The burden of fungal infections has been on the rise globally and remains a significant public health concern in Kenya. We estimated the incidence and prevalence of fungal infections using all mycology publications in Kenya up to January 2023, and from neighbouring countries where data lacked. We used deterministic modelling using populations at risk to calculate the disease burden. The total burden of serious fungal infections is estimated to affect 6,328,294 persons which translates to 11.57% of the Kenyan population. Those suffering from chronic infections such as chronic pulmonary aspergillosis are estimated to be 100,570 people (0.2% of the population) and probably nearly 200,000 with fungal asthma, all treatable with oral antifungal therapy. Serious acute fungal infections secondary to HIV (cryptococcal meningitis, disseminated histoplasmosis, pneumocystis pneumonia, and mucosal candidiasis) affect 196,543 adults and children (0.4% of the total population), while cancer-related invasive fungal infection cases probably exceed 2,299 and those in intensive care about 1,230 incident cases, including Candida auris bloodstream infection. The burden of fungal infections in Kenya is high; however, limited diagnostic test availability, low clinician awareness and inadequate laboratory capacity constrain the country's health system in responding to the syndemic of fungal disease in Kenya.

Mild allergic airways responses to an environmental mixture increase cardiovascular risk in rats

Recent epidemiological findings link asthma to adverse cardiovascular responses. Yet, the precise cardiovascular impacts of asthma have been challenging to disentangle from the potential cardiovascular effects caused by asthma medication. The purpose of this study was to determine the impacts of allergic airways disease alone on cardiovascular function in an experimental model. Female Wistar rats were intranasally sensitized and then challenged once per week for 5 weeks with saline vehicle or a mixture of environmental allergens (ragweed, house dust mite, and Aspergillus fumigatus). Ventilatory and cardiovascular function, measured using double-chamber plethysmography and implantable blood pressure (BP) telemetry and cardiovascular ultrasound, respectively, were assessed before sensitization and after single and final allergen challenge. Responses to a single 0.5 ppm ozone exposure and to the cardiac arrhythmogenic agent aconitine were also assessed after final challenge. A single allergen challenge in sensitized rats increased tidal volume and specific airways resistance in response to provocation with methacholine and increased bronchoalveolar lavage fluid (BALF) eosinophils, neutrophils, lymphocytes, cytokines interleukin (IL)-4, IL-5, IL-10, IL-1β, tumor necrosis factor-α, and keratinocyte chemoattract-growth-related oncogene characteristic of allergic airways responses. Lung responses after final allergen challenge in sensitized rats were diminished, although ozone exposure increased BALF IL-6, IL-13, IL-1 β, and interferon-γ and modified ventilatory responses only in the allergen group. Final allergen challenge also increased systolic and mean arterial BP, stroke volume, cardiac output, end-diastolic volume, sensitivity to aconitine-induced cardiac arrhythmia, and cardiac gene expression with lesser effects after a single challenge. These findings demonstrate that allergic airways responses may increase cardiovascular risk in part by altering BP and myocardial function and by causing cardiac electrical instability.