Acute pulmonary aspergillosis in immunocompetent subjects after exposure to bark chippings

Citizen Science Surveillance of Triazole-Resistant Aspergillus fumigatus in United Kingdom Residential Garden Soils

Compost is an ecological niche for Aspergillus fumigatus due to its role as a decomposer of organic matter and its ability to survive the high temperatures associated with the composting process. Subsequently, composting facilities are associated with high levels of A. fumigatus spores that are aerosolized from compost and cause respiratory illness in workers. In the UK, gardening is an activity enjoyed by individuals of all ages, and it is likely that they are being exposed to A. fumigatus spores when handling commercial compost or compost they have produced themselves. In the present study, 246 citizen scientists collected 509 soil samples from locations in their gardens in the UK, from which were cultured 5,174 A. fumigatus isolates. Of these isolates, 736 (14%) were resistant to tebuconazole: the third most-sprayed triazole fungicide in the UK, which confers cross-resistance to the medical triazoles used to treat A. fumigatus lung infections in humans. These isolates were found to contain the common resistance mechanisms in the A. fumigatus cyp51A gene TR34/L98H or TR46/Y121F/T289A, as well as the less common resistance mechanisms TR34, TR53, TR46/Y121F/T289A/S363P/I364V/G448S, and (TR46)2/Y121F/M172I/T289A/G448S. Regression analyses found that soil samples containing compost were significantly more likely to grow tebuconazole-susceptible and tebuconazole-resistant A. fumigatus strains than those that did not and that compost samples grew significantly higher numbers of A. fumigatus than other samples. IMPORTANCE The findings presented here highlight compost as a potential health hazard to individuals with predisposing factors to A. fumigatus lung infections and as a potential health hazard to immunocompetent individuals who could be exposed to sufficiently high numbers of spores to develop infection. Furthermore, we found that 14% of A. fumigatus isolates in garden soils were resistant to an agricultural triazole, which confers cross-resistance to medical triazoles used to treat A. fumigatus lung infections. This raises the question of whether compost bags should carry additional health warnings regarding inhalation of A. fumigatus spores, whether individuals should be advised to wear facemasks while handling compost, or whether commercial producers should be responsible for sterilizing compost before shipping. The findings support increasing public awareness of the hazard posed by compost and investigating measures that can be taken to reduce the exposure risk.

A prospective longitudinal study of chronic pulmonary aspergillosis in pulmonary tuberculosis in Indonesia (APICAL)

Objectives

Chronic pulmonary aspergillosis (CPA) can complicate recovery from pulmonary TB. CPA may also be misdiagnosed as bacteriologically negative TB. This study aimed to determine the incidence of CPA in patients treated for TB in Indonesia, a country with a high incidence of TB.

Methods

In this prospective, longitudinal cohort study in patients treated for pulmonary TB, clinical, radiological and laboratory findings were analysed. Sputum was collected for fungal culture and TB PCR. Patients were assessed at baseline (0–8 weeks) and at the end (5–6 months) of TB therapy. CPA diagnosis was based on symptoms (≥3 months), characteristic radiological features and positive Aspergillus serology, and categorised as proven, probable and possible.

Results

Of the 216 patients recruited, 128 (59%) were followed up until end of TB therapy. At baseline, 91 (42%) had microbiological evidence for TB. Aspergillus-specific IgG was positive in 64 (30%) patients and went from negative to positive in 16 (13%) patients during TB therapy. The incidence rates of proven and probable CPA at baseline were 6% (n=12) and 2% (n=5) and end of TB therapy 8% (n=10) and 5% (n=7), respectively. Six patients (two with confirmed TB) developed an aspergilloma. Diabetes mellitus was a significant risk factor for CPA (p=0.040). Persistent cough (n=5, 50%; p=0.005) and fatigue (n=6, 60%; p=0.001) were the most common symptoms in CPA.

Conclusion

CPA should be considered a relatively frequent differential diagnosis in patients with possible or proven TB in Indonesia. Lack of awareness and limited access to Aspergillus-specific IgG tests and CT imaging are obstacles in establishing a CPA diagnosis.

Systematic Review: Occupational illness in the waste and recycling sector

BACKGROUND

The waste and recycling sector is a growing part of industry. Whether health surveillance is indicated and how it should be undertaken is unclear.

AIMS

To undertake a review of the literature to identify hazards to health, biological effects and occupational illnesses for workers in the sector.

METHODS

A systematic review of the published literature and two UK databases.

RESULTS

Rates of fatal, non-fatal injuries and self-reported work-related illness were found to be higher in the waste and recycling sector than in UK industry as a whole. There was an increased prevalence of respiratory, gastro-intestinal and skin complaints in workers exposed to compost relative to controls. They may also be at increased risk of extrinsic allergic alveolitis, allergic bronchopulmonary aspergillosis, occupational asthma and abnormalities of lung function. Workers involved with the recycling of batteries and cables may be at risk of lead poisoning and exposure to other heavy metals. There were case reports of mercury poisoning from the recycling of fluorescent lights. Cases of occupational asthma have been reported in association with wood and paper recycling. The recycling of e-waste may cause exposure to heavy metals and organic pollutants, such as polybrominated diphenyl ethers, dioxins and polyaromatic hydrocarbons, which have been associated with damage to DNA and adverse neonatal outcomes.

CONCLUSIONS

Ill-health and adverse biological effects have been described in waste and recycling workers, but their true prevalence has probably not been captured. Targeted health surveillance may be required to assess exposure and to identify occupational illness.

Coinfection with Lichtheimia corymbifera and Aspergillus flavus in an Immune-Competent Patient Mimicking as Pulmonary-Renal Syndrome

Lichtheimia corymbifera and Aspergillus flavus pulmonary coinfection has been rarely reported in immune-competent patients. We report case of a young male who presented with clinical features of pulmonary-renal syndrome and was later diagnosed to have bilateral polymicrobial fungal lung infection.

Acute invasive pulmonary aspergillosis, shortly after occupational exposure to polluted muddy water, in a previously healthy subject

Invasive pulmonary aspergillosis (IPA) predominantly occurs in severely neutropenic immunocompromised subjects. The occurrence of acute IPA after brief but massive exposure to Aspergillus conidia in previously healthy subjects has been documented, although only six such cases have been reported. The diagnosis was delayed in all six of the affected patients, five of whom died. We report the case of a 50-year-old HIV-negative male, a water pipeline maintenance worker, who presented with acute-onset dyspnea and fever one day after working for 2 h in a deep pit containing polluted, muddy water. Over a one-month period, his general condition deteriorated markedly, despite antibiotic therapy. Imaging showed bilateral diffuse nodules with cavitation, some of which were surrounded by ground-glass opacity suggestive of a halo sign (a hallmark of IPA). Cultures (of sputum/bronchial aspirate samples) and serology were positive for Aspergillus fumigatus. After being started on itraconazole, the patient improved. We conclude that massive exposure to Aspergillus conidia can lead to acute IPA in immunocompetent subjects.

Lesson of the month 1: A cough that doesn't fit the mould

Aspergillus disease has a wide spectrum of manifestations within the lungs; however invasive Aspergillus is most commonly associated with immunocompromise or pre-existing respiratory disease. Here we present a case of Aspergillus tracheobronchitis causing right middle lobe collapse, masquerading as late-onset asthma in a patient with no pre-existing risk factors following massive inhalation of Aspergillus spores from working with compost. This case highlights the importance of having a high index of suspicion for Aspergillus-related disease even in those with no traditional risk factors.

Republished: The clinical spectrum of pulmonary aspergillosis

The clinical presentation of Aspergillus lung disease is determined by the interaction between fungus and host. Invasive aspergillosis develops in severely immunocompromised patients, including those with neutropenia, and increasingly in the non-neutropenic host, including lung transplant recipients, the critically ill patients and patients on steroids. A high index of suspicion is required in patients without the classical risk factors as early presentation is usually silent and non-specific, pyrexia uncommon and timely treatment is crucial for survival. Invasive aspergillosis has also been diagnosed in normal hosts after massive exposure to fungal spores. Chronic pulmonary aspergillosis affects patients without obvious immune compromise, but with an underlying lung condition such as COPD or sarcoidosis, prior or concurrent TB or non-tuberculous mycobacterial disease. Aspergillus bronchitis may be responsible for persistent respiratory symptoms in patients with Aspergillus detected repeatedly in sputum without evidence of parenchymal Aspergillus disease, especially in patients with bronchiectasis and cystic fibrosis. Allergic bronchopulmonary aspergillosis affects patients with asthma and cystic fibrosis, and is important to recognise as permanent lung or airways damage may accrue if untreated. Changes in the classification of Aspergillus allergic lung disease have been proposed recently. Cases of extrinsic allergic alveolitis and chronic pulmonary aspergillosis have been observed after Aspergillus exposure. Asymptomatic colonisation of the respiratory tract needs close monitoring as it can lead to clinical disease especially with ongoing immunosuppression. The various syndromes should be viewed as a semicontinuous spectrum of disease and one form may evolve into another depending on the degree of ongoing immunosuppression.

Evaluation of exposure-response relationships for health effects of microbial bioaerosols - A systematic review

Studies suggest adverse health effects following exposure to bioaerosols in the environment and in particular at workplaces. However, there is still a lack of health-related exposure limits based on toxicological or epidemiological studies from environmental health or from the working environment. The aim of this study was to derive health-based exposure limits for bioaerosols that can protect the general population as group "at risk" via environmental exposure using analysis of peer-reviewed studies related to occupational medicine, indoor air and environmental health. The derivation of exposure limits should be conducted by the members of a bioaerosol expert panel according to established toxicological criteria. A systematic review was performed in Medline (PubMed) including studies containing both data on exposure measurements and observed health outcomes. In addition, literature recommended by the experts was considered. A comprehensive search strategy was generated and resulted in a total of n=1569 studies in combination with the literature recommendations. Subsequently, abstracts were screened using defined exclusion criteria yielding a final number of n=44 studies. A standardized extraction sheet was used to combine data on health effects and exposure to different bioaerosols. After full-text screening and extraction according to the defined exclusion criteria n=20 studies were selected all related to occupational exposures comprising the working areas wood processing, farming, waste processing and others. These studies were analyzed in collaboration with the bioaerosol expert network in terms of suitability for derivation of health-related exposure limits. The bioaerosol expert network concluded that none of the analyzed studies provided suitable dose-response relationships for derivation of exposure limits. The main reasons were: (1) lack of studies with valid dose-response data; (2) diversity of employed measuring methods for microorganisms and bioaerosol-emitting facilities; (3) heterogeneity of health effects; (4) insufficient exposure assessment. However, several indicator parameters and exposure concentrations could be identified for different bioaerosol-emitting facilities. Nevertheless, health-related exposure limits are urgently needed especially in approval procedures of facilities like composting plants or livestock farms emitting bioaerosols in the neighbourhood of residents. In the regulatory toxicology framework, it is common to use animal experimental studies for derivation of general exposure limits if appropriate environmental epidemiological studies on harmful substances are lacking. This might be another possibility to obtain health-related exposure limits for specific bioaerosol parameters. Furthermore, we recommend to use suitable measurable outcome parameters related to bioaerosols; to measure bioaerosols according to a protocol representative for exposure pattern and duration at the particular work place; to develop standardized detection methods for indicator parameters; to combine different detection methods to compensate for the limitations of each method; to apply new analysis methods to identify the real risk potential.

Allergic bronchopulmonary aspergillosis in garden waste (compost) collectors--occupational implications

The separation of rotting garden material from general domestic waste and its collection for processing in industrial composting sites is a relatively new industry in the UK. Two cases of allergic bronchopulmonary aspergillosis and the results of health surveillance are described in a team of 28 garden waste (compost) collectors. A few cases of extrinsic allergic alveolitis due to Aspergillus fumigatus have previously been reported in compost workers. In the absence of any guidance from research and to prevent similar cases of a potentially serious illness, we advise that new starters to the job of collecting or processing compost are screened for asthma and aspergillus sensitivity, cystic fibrosis, bronchiectasis and immunodeficiency if their exposure to high levels of Aspergillus sp cannot be controlled. Annual health surveillance for these workers is also recommended.

Acute Aspergillus pneumonia associated with mouldy tree bark-chippings, complicated by anti-glomerular basement membrane disease causing permanent renal failure

A non-immunocompromised man developed acute Aspergillus pneumonia after spreading mouldy tree bark mulch. Despite normal renal function at presentation, he developed rapidly progressive glomerulonephritis with acute kidney injury due to anti-glomerular basement membrane antibodies (anti-GBM) 4 weeks later. He remained dialysis dependent and died of sepsis 10 months later. We hypothesise that he contracted invasive pulmonary Aspergillosis from heavy exposure to fungal spores, leading to epitope exposure in the alveoli with subsequent development of GBM auto-antibodies.

Trypacidin, a spore-borne toxin from Aspergillus fumigatus, is cytotoxic to lung cells

Inhalation of Aspergillus fumigatus conidia can cause severe aspergillosis in immunosuppressed people. A. fumigatus produces a large number of secondary metabolites, some of which are airborne by conidia and whose toxicity to the respiratory tract has not been investigated. We found that spores of A. fumigatus contain five main compounds, tryptoquivaline F, fumiquinazoline C, questin, monomethylsulochrin and trypacidin. Fractionation of culture extracts using RP-HPLC and LC-MS showed that samples containing questin, monomethylsulochrin and trypacidin were toxic to the human A549 lung cell line. These compounds were purified and their structure verified using NMR in order to compare their toxicity against A549 cells. Trypacidin was the most toxic, decreasing cell viability and triggering cell lysis, both effects occurring at an IC₅₀ close to 7 µM. Trypacidin toxicity was also observed in the same concentration range on human bronchial epithelial cells. In the first hour of exposure, trypacidin initiates the intracellular formation of nitric oxide (NO) and hydrogen peroxide (H₂O₂). This oxidative stress triggers necrotic cell death in the following 24 h. The apoptosis pathway, moreover, was not involved in the cell death process as trypacidin did not induce apoptotic bodies or a decrease in mitochondrial membrane potential. This is the first time that the toxicity of trypacidin to lung cells has been reported.

Health effects of Aspergillus in food and air

This review summarizes the health aspects of the medically important fungal genus Aspergillus. The morphology and systematics of the genus are explained as well as its biogeography. Major mycotoxins, the aspergilli that produce them, affected crops, and symptoms of the toxicoses are summarized, as are the major mycoses caused by aspergilli. The current status of the relationship between Aspergillus in the indoor environment and health issues are discussed.

Invasive pulmonary aspergillosis 10 years post bone marrow transplantation: a case report

INTRODUCTION

Invasive pulmonary aspergillosis is a leading cause of mortality and morbidity in bone marrow transplant recipients. Establishing the diagnosis remains a challenge for clinicians working in acute care setting. However, prompt diagnosis and treatment can lead to favourable outcomes

CASE PRESENTATION

We report a case of invasive aspergillosis occurring in a 39-year-old Caucasian female 10 years after an allogeneic haematopoietic bone marrow transplant, and 5 years after stopping all immunosuppression. Possible risk factors include bronchiolitis obliterans and exposure to building dust (for example, handling her husband's dusty overalls). There are no similar case reports in the literature at this time.

CONCLUSION

High clinical suspicion, especially in the setting of failure to respond to broad-spectrum antibiotics, should alert clinicians to the possibility of invasive pulmonary aspergillosis, which, in this case, responded to antifungal therapy.