Have the prevalence and incidence of occupational asthma and rhinitis because of laboratory animals declined in the last 25 years?

From workplace to home environment: spreading of mouse allergens by laboratory animal workers

PURPOSE

Laboratory animal workers (LAW) working with laboratory mice are exposed to mouse allergens (MA). If MA are spread to home environments, this might increase the risk for allergies in LAW and their families. This study aimed to assess 1. whether spreading of MA from workplace to home environment takes place; 2. which factors increase spreading of MA.

METHODS

In a cross-sectional study, dust samples were taken on the mattress and seating in homes of LAW (n = 105) and an unexposed comparison group (n = 13). From 89 LAW, additional dust samples were taken from their workplaces. Samples were analysed using Mus m1 ELISA kits [detection limit (DL) 0.2 ng mus m1/ml]. Sociodemographic data, personal history of allergies and cleaning habits, as well as work-related characteristics (LAW only) were assessed by questionnaire. Latent factors were assessed via factor analysis. Tobit models were fitted to analyse the latent factors' contribution to MA spreading.

RESULTS

MA concentration on the seating was significantly higher in home environments of LAW (median = 1.28 ng mus m1/m²) than in the comparison group (median < DL, p = 0.019). The highest workplace MA concentration was found on the floor of the scullery (median = 140,000.00 ng mus m1/m²), followed by hair-covering caps (median = 76.02 ng mus m1/m²). Cage and mouse facility cleaning tasks and infrequent changing of bed linen at home were statistically significantly associated with higher MA concentrations at home.

CONCLUSIONS

Spreading of MA from LAW's workplace to their home environment takes place, especially among LAWs involved in cleaning tasks.

Occupational Rhinitis

There is convincing evidence that tight relationships between the upper and lower airways also apply to the workplace context. Most patients with occupational asthma (OA) also suffer from occupational rhinitis (OR), although OR is 2 to 3 times more common than OA. OR most often precedes the development of OA, especially when high-molecular-weight protein agents are involved, and longitudinal cohort studies have confirmed that OR is associated with an increased risk for the development of OA. The level of exposure to sensitizing agents at the workplace is the most important determinant for the development of IgE-mediated sensitization and OR. Atopy is a risk factor for the development of IgE-mediated sensitization only to high-molecular-weight agents. In workers with work-related rhinitis symptoms, documentation of IgE-mediated sensitization to a workplace agent via skin prick testing or serum specific IgE confirms a diagnosis of probable OR, whereas specific nasal provocation testing in the laboratory remains the reference method to establish a definite diagnosis of OR. Complete avoidance of exposure to the causal agent is the most effective therapeutic option for controlling work-related nasal symptoms and preventing the development of OA. If complete elimination of exposure is expected to induce meaningful adverse socioeconomic consequences, reduction of exposure can be considered as an alternative approach, but it is important to consider the individual risk factors for the development of OA to implement a more personalized management of OR.

How Working Tasks Influence Biocontamination in an Animal Facility

The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and characterization of airborne fungi, bacteria, endotoxin, (1,3)-β-d-glucan and animal allergens. Airborne microorganisms were collected with an air sampler and identified by microscopic and biochemical methods. Endotoxin, (1,3)-β-d-glucan, Mus m 1, Rat n 1, Can f 1, Fel d 1, Equ c 4 allergens were detected on inhalable dust samples by Kinetic LAL, Glucatell, and ELISA assays, respectively. Our data evidenced that changing cages is a determinant factor in increasing the concentration of the airborne biocontaminants; the preparation of bedding and distribution of feed, performed in the storage area, is another critical working task in terms of exposure to endotoxins (210.7 EU/m3) and (1,3)-β-d-glucans (4.3 ng/m3). The highest concentration of Mus m 1 allergen (61.5 ng/m3) was observed in the dirty washing area. The detection of expositive peaks at risk of sensitization (>2 μg/g) by Fel d 1 in animal rooms shows passive transport by operators themselves, highlighting their role as vehicle between occupational and living environments.

Association of Endotoxin and Allergens with Respiratory and Skin Symptoms: A Descriptive Study in Laboratory Animal Workers

Background

In laboratory animal work, allergens are classically considered to play a prominent role in generation of respiratory and skin symptoms. However, recent development may have changed working conditions and require an updating of preventive measures.

Objective

In workers exposed to a range of animals besides laboratory mice and rats the relative role of endotoxin, irritants, and allergens in symptom generation was assessed for updating preventative measures and health surveillance.

Methods

Eligible workers were recruited from university units in which exposure to rats and/or mice, occurrence of respiratory and/or skin symptoms, and/or a history of animal bites had been reported. Exposure to endotoxin and rat and mouse allergen was assessed (71 half-day personal samples). 'Symptomatic' was defined by work-related ocular, nasal, respiratory, or skin symptoms. A concentration of specific IgE against rat or mouse (e87 and e88) ≥0.35 kU/l defined sensitization. Sensitivity analyses examined the effect of alternative exposure indicators and definitions of 'sensitized' and 'symptomatic'.

Results

From 302 eligible workers, 177 participated. There were 121 and 41 workers in the asymptomatic and non-sensitized and symptomatic but non-sensitized group, respectively. Eight subjects were symptomatic and sensitized. Six sensitized subjects were asymptomatic. One participant could not be assigned to a subgroup. Airborne endotoxin and allergen concentrations were mostly below 20 EU m-3 or the detection limit, respectively. Clinical history showed that irritants and sensitizers other than mouse/rat allergen or endotoxin were a major cause of symptoms. Results were sensitive to the selected exposure indicator and the definition of 'symptomatic'.

Conclusions

Health surveillance programs need to be adapted to include a larger range of allergens and pay more attention to irritants.

Occupational rhinitis and occupational asthma: Association or progression?

BACKGROUND

Occupational asthma is the most frequently reported occupational respiratory disease in registries, and is often co-diagnosed with occupational rhinitis. We undertook a systematic review of the English-language epidemiologic literature linking these two conditions, with emphasis on progression from occupational rhinitis to occupational asthma.

METHODS

PubMed and Embase were queried in a series of structured searches designed to identify studies comparing occupational asthma and occupational rhinitis incidence or prevalence in occupationally exposed individuals.

RESULTS

The searches yielded a total of 109 unique citations, 15 of which yielded inferential data on the occupational rhinitis-asthma relationship. Nine of fifteen studies showed statistically significant associations between the occurrence of occupational rhinitis and occupational asthma among individual workers.

CONCLUSIONS

Limited data support the notion that occupational rhinitis precedes the development of occupational asthma, particularly when high-molecular-weight (HMW) agents are involved. The relationship between the two conditions could not be evaluated in many relevant studies due to a lack of cross-tabulation of individual cases.

Laboratory animal allergy reduction from 2001 to 2016: An intervention study

Exposure to laboratory animals (LA) can cause allergic sensitization and symptoms as rhinitis, conjunctivitis, asthma, anaphylaxis and dermatitis. In 2000, a program was instituted at Trieste Universities to decrease LA allergy among scientists and technicians working with animals. The aim of our study was to investigate LA allergy in workers exposed to LA from 2001 to 2016, and to verify the effects of a preventive program. Four hundred sixty seven people underwent pre-employment screening for a job with laboratory animals at Universities of Trieste consisting in a medical examination, a full respiratory and allergy anamnesis, using a standardized questionnaire, skin prick test with common and occupational allergens, and spirometry. Every year, each worker repeated the medical examination and underwent again tests and questionnaire. Each worker can ask for a medical examination and skin prick test, in case of unset of symptoms. Logistic multivariate analysis and generalized equation estimation were use, to verify factors associated to LA allergy. Sensitization to LA decreased in years, going from 25.6% in 2001-2004 to 8.2% in 2013-2016 (p < 0.001). Multivariate logistic regression analysis confirmed the role of atopy by prick test (OR = 6; IC95% 2.2-16.6), of common allergic symptoms (OR = 2.9; IC95% 1.4-6.39) and of calendar periods. No association was found between LA allergy, years, and hours of exposure. Our study demonstrated a significant reduction of LA allergy after the application of a preventive program.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Can serum cytokine profile discriminate irritant-induced and allergen-induced symptoms? A cross-sectional study in workers mostly exposed to laboratory animals

BACKGROUND

In workers exposed mostly to laboratory animals (LA), symptoms may be due to irritants or allergens. Correct aetiological diagnosis is important for health surveillance.

OBJECTIVES

This study aims to test whether work-related (WR) allergen-induced symptoms are associated with a cytokine profile distinct from that due to irritants.

METHODS

In a cross-sectional study (n=114), WR respiratory and/or skin symptoms were assessed through a standardised clinical examination and sensitisation to rat and/or mouse allergen determined by serum immunoglobulin E. Serum cytokine concentrations were measured by multiplex assays. The predefined cytokine profiles 'sensitiser' (interleukin (IL)-4, IL-5, IL-13, eotaxin-1) and 'irritation' (IL-8, IL-17A, IL-17F, IL-22) were considered positive, when ≥3 concentrations exceeded the 95th percentile of the asymptomatic non-sensitised group. Results were examined by hierarchical clustering analyses (HCA) and multiple linear regression. Explorative analyses were carried out for nine additional cytokines. Exposure to allergens and endotoxin was assessed in a subpopulation.

RESULTS

The prevalence of the profile 'irritation' was comparable in 28 symptomatic non-sensitised workers and 71 asymptomatic non-sensitised workers. HCA showed that nearly all symptomatic non-sensitised workers were gathered in two subclusters, characterised by high IL-17A levels, but different IL-8 levels. Multiple linear regression identified drug consumption and current complaints as confounders. Sensitised subjects were too few (n=14) for testing the profile 'sensitiser'.

CONCLUSIONS

In this unselected population of LA workers, the profile 'irritation' did not prove to be a valuable health surveillance tool. Low power precluded assessment of the profile 'sensitiser'. The increased IL-17A concentration may originate from irritative constituents of organic dust.

Occupational Rhinitis

Occupational rhinitis (OR) involves nasal congestion, rhinorrhea, nasal itching, and/or sneezing resulting from workplace exposures. OR can have a significant negative effect on quality of life and productivity. OR can be divided into allergic or nonallergic subgroups based on the underlying pathogenesis. Certain occupational exposures place employees at greater risk for developing disease. Primary treatment is avoidance of implicated exposures. Antihistamines, saline rinses, and nasal steroids may be useful. OR can coexist with occupational asthma, and rhinitis symptoms have been reported to precede those of the lower respiratory tract. OR is has both medical and socioeconomic implications.

A risk-based approach to reducing exposure of staff to laboratory animal allergens

Within the biomedical research industry, people who work with laboratory animals may be at risk of developing laboratory animal allergy, which can lead to occupational asthma. Under UK and EU laws, employers must prevent or adequately control exposure to any hazardous substance, which includes animal allergens, so far as reasonably practicable, for the protection of all people on the premises. This can be achieved in part by reviewing the risk of allergen exposure in specific areas of a facility and implementing appropriate infrastructure, environmental and performance controls to minimize that risk. The authors describe the approach used at their institution to stratify risk of allergen exposure in various areas of the animal facility and to implement appropriate controls. They also discuss their use of a monitoring program to evaluate allergen concentrations in low- and high-risk areas of the animal facility and explain how the monitoring results can be applied to determine which controls are needed to minimize risk of exposure and to provide a safe working environment.

Specific immunotherapy and biological treatments for occupational allergy

PURPOSE OF REVIEW

Occupational allergy represents a substantial health, social, and financial burden for the society. Its management is a complex task that, in selected cases, may also include allergen-specific immunotherapy. The purpose of this article is to review clinical data on allergen immunotherapy and biological treatments applied to occupational allergy in 2013.

RECENT FINDINGS

Immunotherapy in occupational allergic diseases has been scarcely used, and only for a few sensitizers, such as latex, flour, and Hymenoptera venom, partly due to the lack of standardized extracts. The recent use of the molecular diagnosis can improve the indication and selection of suitable allergens for preparing new standardized and powerful extracts for immunotherapy. Some recent reports suggest a beneficial role of treatment with omalizumab in workers with occupational asthma who continue to be exposed to the causal agent.

SUMMARY

Although scarce, available data suggest that immunotherapy and biological treatments may allow allergic workers to continue their work activity, but further studies are needed to standardize extracts and to evaluate the cost-effectiveness of these treatments, when exposure at the workplace cannot be avoided.

Occupational rhinitis: an update

Occupational rhinitis is characterized by nasal congestion, rhinorrhea, nasal itching, and/or sneezing that occur secondary to exposures in the workplace. This disease can be classified into allergic or nonallergic subgroups based upon the underlying disease pathogenesis as well as the type of causative agent. While the true prevalence of occupational rhinitis is unknown, there are certain professions and occupational exposures that place workers at a higher risk for developing the disease. Additionally, occupational rhinitis can be associated with occupational asthma and upper airway symptoms may precede those of the lower respiratory tract. Taken together, occupational rhinitis is an important disease for study given its medical as well as socioeconomic implications. This review will focus on the classification of occupational rhinitis as well the prevalence, diagnosis, and treatment strategies.

Asthma and rhinitis in cleaning workers: a systematic review of epidemiological studies

OBJECTIVE

This article presents a systematic review of epidemiological studies linking cleaning work and risk of asthma and rhinitis.

METHODS

Published reports were identified from PubMed covering the years from 1976 through June 30, 2012. In total, we identified 24 papers for inclusion in the review. The quality of studies was evaluated using the Strengthening of the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist of 22 items for cross-sectional, cohort and case-control studies.

RESULTS

Increased risk of asthma or rhinitis has been shown in 79% of included epidemiological studies. In four studies the increased risk of asthma in cleaning workers was confirmed by objective tests, such as bronchial hyper-reactivity or airflow obstruction. Level of exposure to cleaning products, cleaning sprays, bleach, ammonia, mixing products and specific job tasks has been identified as specific causes of asthma and rhinitis.

CONCLUSIONS

Possible preventive measures encompass the substitution of cleaning sprays, bleach and ammonia, avoidance of mixing products, the use of respiratory protective devices, worker education and medical surveillance.

Occupational asthma: new low-molecular-weight causal agents, 2000-2010

Background. More than 400 agents have been documented as causing occupational asthma (OA). The list of low-molecular-weight (LMW) agents that have been identified as potential causes of OA is constantly expanding, emphasizing the need to continually update our knowledge by reviewing the literature. Objective. The objective of this paper was to identify all new LMW agents causing occupational asthma reported during the period 2000-2010. Methods. A Medline search was performed using the keywords occupational asthma, new allergens, new causes, and low-molecular-weight agents. Results. We found 39 publications describing 41 new LMW causal agents, which belonged to the following categories: drugs (n = 12), wood dust (n = 11), chemicals (n = 8), metals (n = 4), biocides (n = 3), and miscellaneous (n = 3). The diagnosis of OA was confirmed through SIC for 35 of 41 agents, peak expiratory flow monitoring for three (3) agents, and the clinical history alone for three (3) agents. Immunological tests provided evidence supporting an IgE-mediated mechanism for eight (8) (20%) of the newly described agents. Conclusion. This paper highlights the importance of being alert to the occurrence of new LMW sensitizers, which can elicit OA. The immunological mechanism is explained by a type I hypersensitivity reaction in 20% of all newly described LMW agents.

Occupational rhinitis: consensus on diagnosis and medicolegal implications

PURPOSE OF REVIEW

Work-related rhinitis is a common disease in many working groups, frequently associated with asthma. The purpose of this review is to summarize the specific literature published within the past 12 months, to discuss the diagnostic workup and to illustrate the medicolegal aspects pertaining to this disease.

RECENT FINDINGS

Recently, there has been a growing scientific interest in work-related rhinitis, which includes both occupational rhinitis and work-exacerbated rhinitis. The epidemiological relevance and the relationships to asthma have been evaluated. New etiologic agents and populations at risk have been identified. A new definition and classification, and a diagnostic algorithm, have been proposed.

SUMMARY

In consideration of the epidemiological relevance and of the medicolegal implications, occupational rhinitis should be considered in daily clinical practice by all physicians. In adults with late-onset rhinitis, occupational causes should be queried and patients in whom an occupational association is suspected should be referred for specific assessments.

Prevention of occupational asthma

Prevention of occupational asthma related to a work-sensitizing agent ideally would be achieved by avoidance of exposures that cause immunologic sensitization and subsequent asthma. There are a few examples in which a sensitizing agent has been removed from a work process and others in which exposure has been significantly changed or reduced with associated reduced rates of sensitization and disease. Additional measures include containment, use of robots, ventilation measures, exposure monitoring, and use of respiratory protective devices. Secondary prevention includes medical surveillance, which may involve periodic respiratory questionnaires, spirometry, and immunologic tests aiming to detect sensitization or disease early to allow intervention and improve outcomes. Education measures for workers to understand the meaning of work-related respiratory symptoms and appropriate workplace safety measures have not been formally evaluated but may also be expected to enhance protective measures and lead to earlier diagnosis. Tertiary prevention includes medical management and workers' compensation.

Occupational rhinitis and asthma: where do we stand, where do we go?

This review provides an overview of current and emerging issues regarding occupational rhinitis (OR) and occupational asthma (OA), focusing on studies discussing concepts and results that are relevant to both diseases. OA and OR are conditions that affect the upper and lower airways, are characterized by reduced airway caliber and hyperresponsiveness and by inflammation, and are caused by agents present in the workplace. To explain disease expression, research is moving from the T-helper type 1/type 2 cells paradigm to consider the contribution of diverse alternative pathways such as neural inflammation, a dysfunctional epithelial barrier, and autoimmune mechanisms, among others. Objective assessment of OR and OA has been improved and tested for research and, currently, clinical application. Further developments in the field of OR are expected to lead to more generalized clinical applications, following the example of what has been achieved for OA.

Occupational and environmental lung disease: occupational asthma

Occupational exposures cause 10-15% of new-onset asthma in adults, and that represents a considerable health and economic burden. Exposure to many causative agents is now well controlled but workplace practices are constantly evolving and new hazards being introduced. Overall, there is no good evidence that the incidence of occupational asthma is decreasing. Evidence-based guidelines such as those published by the British Occupational Health research Foundation and Standards of Care documents should help raise awareness of the problem and improve management. Key targets include the control of occupational exposures, a high index of suspicion in any adult with new onset asthma, and early detailed investigation.