Ginger L. Chew

Dustborne and airborne fungal propagules represent a different spectrum of fungi with differing relations to home characteristics

Background: Exposure to fungi is often assessed by culturing floor dust or air samples. Our objective was to evaluate the relationships between dustborne and airborne fungi and to identify factors that modify these relationships.

Characterization of Airborne Molds, Endotoxins, and Glucans in Homes in New Orleans after Hurricanes Katrina and Rita

ABSTRACT In August and September 2005, Hurricanes Katrina and Rita caused breeches in the New Orleans, LA, levee system, resulting in catastrophic flooding. The city remained flooded for several weeks, leading to extraordinary mold growth in homes. To characterize the potential risks of mold exposures, we measured airborne molds and markers of molds and bacteria in New Orleans area homes. In October 2005, we collected air samples from 5 mildly water-damaged houses, 15 moderately to heavily water-damaged houses, and 11 outdoor locations. The air filters were analyzed for culturable fungi, spores, (1→3,1→6)-β-d-glucans, and endotoxins. Culturable fungi were significantly higher in the moderately/heavily water-damaged houses (geometric mean = 67,000 CFU/m3) than in the mildly water-damaged houses (geometric mean = 3,700 CFU/m3) (P = 0.02). The predominant molds found were Aspergillus niger, Penicillium spp., Trichoderma, and Paecilomyces. The indoor and outdoor geometric means for endotoxins were 22.3 endotoxin units (EU)/m3 and 10.5 EU/m3, respectively, and for (1→3,1→6)-β-d-glucans were 1.7 μg/m3 and 0.9 μg/m3, respectively. In the moderately/heavily water-damaged houses, the geometric means were 31.3 EU/m3 for endotoxins and 1.8 μg/m3 for (1→3,1→6)-β-d-glucans. Molds, endotoxins, and fungal glucans were detected in the environment after Hurricanes Katrina and Rita in New Orleans at concentrations that have been associated with health effects. The species and concentrations were different from those previously reported for non-water-damaged buildings in the southeastern United States.

Housing Interventions and Control of Asthma-Related Indoor Biologic Agents: A Review of the Evidence

Subject matter experts systematically reviewed evidence on the effectiveness of housing interventions that affect health outcomes, primarily asthma, associated with exposure to moisture, mold, and allergens. Three of the 11 interventions reviewed had sufficient evidence for implementation: multifaceted, in-home, tailored interventions for reducing asthma morbidity; integrated pest management to reduce cockroach allergen; and combined elimination of moisture intrusion and leaks and removal of moldy items to reduce mold and respiratory symptoms. Four interventions needed more field evaluation, 1 needed formative research, and 3 either had no evidence of effectiveness or were ineffective. The 3 interventions with sufficient evidence all applied multiple, integrated strategies. This evidence review shows that selected interventions that improve housing conditions will reduce morbidity from asthma and respiratory allergies.

Fungal Levels in the Home and Allergic Rhinitis by 5 Years of Age

Studies have repeatedly demonstrated that sensitization to fungi, such as Alternaria, is strongly associated with allergic rhinitis and asthma in children. However, the role of exposure to fungi in the development of childhood allergic rhinitis is poorly understood. In a prospective birth cohort of 405 children of asthmatic/allergic parents from metropolitan Boston, Massachusetts, we examined in-home high fungal concentrations (> 90th percentile) measured once within the first 3 months of life as predictors of doctor-diagnosed allergic rhinitis in the first 5 years of life. In multivariate Cox regression analyses, predictors of allergic rhinitis included high levels of dust-borne Aspergillus [hazard ratio (HR) = 3.27; 95% confidence interval (CI), 1.50–7.14], Aureobasidium (HR = 3.04; 95% CI, 1.33–6.93), and yeasts (HR = 2.67; 95% CI, 1.26–5.66). The factors controlled for in these analyses included water damage or mild or mildew in the building during the first year of the child’s life, any lower respiratory tract infection in the first year, male sex, African-American race, fall date of birth, and maternal IgE to Alternaria > 0.35 U/mL. Dust-borne Alternaria and non-sporulating and total fungi were also predictors of allergic rhinitis in models excluding other fungi but adjusting for all of the potential confounders listed above. High measured fungal concentrations and reports of water damage, mold, or mildew in homes may predispose children with a family history of asthma or allergy to the development of allergic rhinitis.

Prenatal acetaminophen exposure and risk of wheeze at age 5 years in an urban, low-income cohort

Background Acetaminophen has been associated with asthma and is in part metabolised via the glutathione pathway. Inner-city minority children have high asthma morbidity and a relatively high frequency of a minor allele variant in the glutathione S transferase Pi gene (GSTP1). We hypothesised that prenatal acetaminophen exposure would predict wheeze at age 5 years in an inner-city minority cohort and examined whether this association was modified by common polymorphisms in genes related to the glutathione pathway. Methods An ongoing population-based birth cohort study of Dominican Republic and African-American children in New York prospectively assessed the use of analgesics during pregnancy and current wheeze at age 5 years in 301 children. Genotyping was conducted for GST polymorphisms. Binomial regression was used to adjust for potential confounders including postnatal acetaminophen use. Results 34% of mothers reported acetaminophen use during pregnancy and 27% of children had current wheeze at 5 years. Prenatal exposure to acetaminophen predicted current wheeze (multivariate relative risk 1.71; 95% CI 1.20 to 2.42; p=0.003), and the risk increased monotonically with increasing number of days of prenatal acetaminophen exposure (p trend <0.001). 68% of children had at least one copy of the GSTP1 minor allele (Val). The risk of wheeze was modified by GSTP1 (additive interaction p=0.009) and was observed only among children with the GSTP1 minor allele. Conclusions Prenatal exposure to acetaminophen predicted wheeze at age 5 years in an inner-city minority cohort. The risk was modified by a functional polymorphism in GSTP1, suggesting a mechanism involving the glutathione pathway.

Monthly measurements of indoor allergens and the influence of housing type in a northeastern US city

Background: We examined seasonal variation of dust‐mite (Der f 1 and Der p 1), cat (Fel d 1), and cockroach (Bla g 1) allergens in Boston, while adjusting for other covariates. Limited data are available on seasonal patterns of indoor allergen concentrations for different geographic regions in the USA. Understanding within‐home seasonal variation of allergens is important epidemiologically and clinically.

Mold and Endotoxin Levels in the Aftermath of Hurricane Katrina: A Pilot Project of Homes in New Orleans Undergoing Renovation

Background After Hurricane Katrina, many New Orleans homes remained flooded for weeks, promoting heavy microbial growth. Objectives A small demonstration project was conducted November 2005–January 2006 aiming to recommend safe remediation techniques and safe levels of worker protection, and to characterize airborne mold and endotoxin throughout cleanup. Methods Three houses with floodwater lines between 0.3 and 2 m underwent intervention, including disposal of damaged furnishings and drywall, cleaning surfaces, drying remaining structure, and treatment with a biostatic agent. We measured indoor and outdoor bioaerosols before, during, and after intervention. Samples were analyzed for fungi [culture, spore analysis, polymerase chain reaction (PCR)] and endotoxin. In one house, real-time particle counts were also assessed, and respirator-efficiency testing was performed to establish workplace protection factors (WPF). Results At baseline, culturable mold ranged from 22,000 to 515,000 colony-forming units/m3, spore counts ranged from 82,000 to 630,000 spores/m3, and endotoxin ranged from 17 to 139 endotoxin units/m3. Culture, spore analysis, and PCR indicated that Penicillium, Aspergillus, and Paecilomyces predominated. After intervention, levels of mold and endotoxin were generally lower (sometimes, orders of magnitude). The average WPF against fungal spores for elastomeric respirators was higher than for the N-95 respirators. Conclusions During baseline and intervention, mold and endotoxin levels were similar to those found in agricultural environments. We strongly recommend that those entering, cleaning, and repairing flood-damaged homes wear respirators at least as protective as elastomeric respirators. Recommendations based on this demonstration will benefit those involved in the current cleanup activities and will inform efforts to respond to future disasters.

Anti-cockroach and anti-mouse IgE are associated with early wheeze and atopy in an inner-city birth cohort

BACKGROUND The relationships between cockroach and mouse allergen exposure, anti-cockroach and anti-mouse IgE, and wheeze, rhinitis, and atopic dermatitis in children as young as age 3 years are of public health importance but have not been thoroughly evaluated. OBJECTIVE We hypothesized that inner-city children might have anti-cockroach and anti-mouse IgE by age 3 years, and their presence would be associated with respiratory and atopic symptoms. METHODS Children were followed prospectively from birth through age 3 years (n = 404). Residential levels of cockroach and mouse allergens, sera levels of anti-cockroach and anti-mouse IgE, and parental report of wheeze, rhinitis, and atopic dermatitis were measured. RESULTS The odds of early wheeze were significantly higher among children who had IgE to cockroach (odds ratio [OR], 3.3; 95% CI, 1.8-6.2), mouse (OR, 4.6; 95% CI, 2.3-9.0), or both (OR, 9.7; 95% CI, 3.4-27.3). The odds of rhinitis or atopic dermatitis were also higher among children with IgE to cockroach, mouse, or both. Higher IgE class to cockroach and mouse was associated with wheeze and atopic dermatitis (tests for trend, P < .002). CONCLUSIONS Children age 2 to 3 years who have anti-cockroach and anti-mouse IgE are at increased risk of wheeze and atopy. Moreover, a dose-response relationship was found between higher IgE class and increased prevalence of wheeze, rhinitis, or atopic dermatitis. These findings indicate the importance of reducing exposure to cockroach and mouse allergens for susceptible children.

The prevalence of mouse allergen in inner‐city homes

Mouse allergen has not been studied in detail in the general population. It is common for patients from inner‐city environments to report significant mouse infestation in their homes and neighborhoods. The aim of this study was to determine the prevalence of mouse allergen in the homes of inner‐city children with asthma in relation to the demographic features of these children and their specific housing characteristics. Seventy‐eight dust samples from 39 inner‐city homes of Lodz, Poland, were analyzed for mouse allergen. Skin‐prick tests (SPTs) to mouse allergen were performed in all patients. In addition, data regarding the demographics and housing of the subjects were related to the mouse allergen levels. Mouse allergen was detected in 22 of 78 dust samples (28%), and in 18 of 39 homes (46%), including 13 kitchen (33%) and nine bedroom (23%) samples. Mouse allergen levels did not correlate between different rooms in the same home. The levels detected ranged from 0.09 to 2.34 µg/g of dust. The highest levels were found in kitchens, with median levels of 0.2 µg/g, 95% confidence interval (CI): 0.12–0.85 (range: 0.1–2.34 µg/g); in bedrooms the mean levels were 0.23 µg/g, 95% CI: 0.1–0.97 (range: 0.09–1.62 µg/g). Eleven of 18 children with detectable mouse allergen in house dust, and three of 21 without detectable mouse allergen in house dust, had a positive SPT to mouse allergen. On home inspection, 18% of the homes had evidence of mice in one or two rooms and had higher levels of mouse allergen (p < 0.01). None of the other subject or housing variables evaluated were associated with higher mouse allergen levels. In Polish children, mouse allergen is an important factor of sensitivity and should be recognized in the diagnosis of allergic diseases as well as in allergen‐reduction programmes.

Pest and allergen exposure and abatement in inner-city asthma: A Work Group Report of the American Academy of Allergy, Asthma & Immunology Indoor Allergy/Air Pollution Committee

Our work group report details the importance of pest allergen exposure in inner-city asthma. We will focus specifically on mouse and cockroach exposure. We will discuss how exposure to these pests is common in the inner city and what conditions exist in urban areas that might lead to increased exposure. We will discuss how exposure is associated with allergen sensitization and asthma morbidity. Finally, we will discuss different methods of intervention and the effectiveness of these tactics.