Community Airborne Mold Spore Counts and Invasive Fungal Disease Risk Among Pediatric Hematological Malignancy and Stem Cell Transplant Patients

Background Patients with hematological malignancies and hematopoietic stem cell transplantation (HSCT) recipients are at risk of developing invasive fungal infections, but the quantitative risk posed by exposure to airborne mold spores in the community has not been well characterized. Methods A single-institution, retrospective cohort study was conducted of pediatric patients treated for hematological malignancies and HSCT recipients between 2014 and 2018. Patients with invasive fungal disease (IFD) due to molds or endemic fungi were identified using published case definitions. Daily airborne mold spore counts were obtained from a local National Allergy Bureau monitoring station and tested for association with IFD cases by zero-inflated Poisson regression. Patients residing outside the region or with symptom onset more than two weeks after admission were excluded from the primary analysis. Results Sixty cases of proven or probable IFD were identified of which 47 cases had symptom onset within 2 weeks of admission and were therefore classified as possible ambulatory onset. The incidence of ambulatory-onset IFD was 1.2 cases per 10,000 patient-days (95% CI, 0.9-1.7). A small excess of ambulatory-onset IFD was seen from July through September during which period spore counts were highest, but this seasonal pattern did not reach statistical significance (P = 0.09). No significant association was found between IFD cases and community mold spore counts over intervals from one to six weeks prior to symptom onset. Conclusions There was no significant association between IFD cases and community airborne mold spore counts among pediatric hematological malignancy and HSCT patients in this region.

Bacteria and Mold Spore Heat Resistance in Guava Juice and Its Control by pH and Sodium Benzoate

Heat-resistant bacteria and molds can survive the pasteurization conditions used in high-acid fruit juices. The objective of this study was to evaluate the log reductions and thermal inactivation kinetics of spores of Bacillus subtilis bacteria and ascospores of Talaromyces flavus and Eupenicillium javanicum molds under influence of pH and sodium benzoate preservative. The spores were suspended in guava juice, processed at 90-100°C for B. subtilis and at 80-90°C for T. flavus and E. javanicum, and decimal reduction ( D ) values were estimated from the log survivor curves. Next, the effects of pH change (3.5-4.5) and 0.015% sodium benzoate addition on the D values of spores were investigated. Lower D values were obtained at higher temperatures ( D 100 ° C value of 2.32 min vs. D 90 ° C value of 15.33 min for B. subtilis, D 90 ° C value of 2.96 min vs. D 80 ° C value of 59.52 min for T. flavus, and D 90 ° C value of 1.58 min vs. D 80 ° C value of 21.32 min for E. javanicum). The D values decreased further (to 1.8 min at 100°C for B. subtilis, to 2.33 min at 90°C for T. flavus, and to 1.49 min at 90°C for E. javanicum) when the pH of guava juice was decreased from 4.1 to 3.5. Inclusion of sodium benzoate in pH 3.5 juice enhanced the thermal inactivation of spores ( D 100 ° C value decreased to 1.4 min for B. subtilis, to 1.98 min for T. flavus, and to 1.34 min for E. javanicum). To conclude, the combination of low pH and sodium benzoate provided the best method for spore inactivation, which could enhance food safety and extend food’s shelf life.

The influence of sea breeze on mold spore dispersion

Background: Many allergists consider the ocean breeze to be free of allergens and recommend visits to the coast for relief; however, the coast may perpetuate an allergenic environment. Objective: This study investigated the sea breeze's impact on spore dispersion between coastal and inland sites, and the potential implications of sea breeze on human health and coastal resources. Methods: Spore sampling occurred during 2006 by using pollen samplers. Samplers were located at the Rutgers University Institute of Marine and Coastal Sciences Marine Field Station and the Rutgers University Pinelands Field Station. Statistical analysis was performed on the spore data to compare concentrations from the various locations. The effect of sea breeze circulation on particulate matter was analyzed from meteorological data collected in 2006. Sea breeze data were collected from simulations, Doppler radar, and meteorological towers at varying heights. Results: There was no significant difference between the total spore concentration at the New Jersey coast and the New Jersey Pinelands canopy. Conclusion: Sea breeze has been shown to favor aerobiologic transfers from coastal seawater to land, but the immediate environment (floor) still remains a primary determinant of affecting an individual's allergic airway disease. Results of some studies have shown that coastal environments may favor the onset allergic airway, but in our study this seemed to be equivalent to the floor (or immediate locale) of an individual affected with allergy. However, the sea breeze effect seemed to have the ability to impact allergic airway disease (AAD) populations not only living along the coasts but of those living up to 130 km inland and potentially those living in the Philadelphia metropolitan area.

Important issues of fungal sensitization: aerobiological aspects

Aim: to assess the dynamics of mold sporulation in Samara to predict the risk of allergy development and exacerbation. Patients and Methods: mold spore samples were collected from April 1 to September 30 in 2016–2019 using trap impactor and placed on slides coated with Vaseline-wax mixture. Mold spores were calculated and referred to various taxa. Allergy risks were predicted. Thresholds for evoking asthma are estimated to be 100 spores/m3 for Alternaria and 3,000 spores/m3 for Cladosporium. Results: in Samara, average mold vegetative period was 164 days. Cladosporium and Alternaria spores were identified. Their spores were estimated as 34.4% of total atmospheric spores in Samara. Cladosporium spores estimated as 15.3% of total fungal spores were identified during the whole observation period. Maximum concentration was less than 960 spores/m3 having been within the average range. Alternaria spores were estimated as 19.1%. The proportion of days exceeding the threshold value of 100 spores/m3 was 6% to 81% having been the highest in July-September. Conclusion: prerequisites for the development of fungal sensitization were revealed. Regional specificity of sporulation in Samara was illustrated. Major mold taxa were identified. Allergy risks in Alternaria and Cladosporium sensitization were assessed. The highest total average monthly amount of Alternaria spores was during Artemisia and Ambrosia pollination season. This could be challenging for the diagnosis and treatment of patients suffering from allergic symptom exacerbations during this period. Our findings will improve the diagnosis, treatment, and prevention of allergic disorders in Samara. KEYWORDS: aerobiological monitoring, allergy, mold spores, Cladosporium, Alternaria, fungal sensitization. FOR CITATION: Mazokha K.S., Manzhos M.V., Khabibulina L.R. et al. Important issues of fungal sensitization: aerobiological aspects. Russian Medical Inquiry. 2021;5(1):4–9. DOI: 10.32364/2587-6821-2021-5-1-4-9.

Research and simulation analysis of thermal performance and hygrothermal behavior of timber-framed walls with different external thermal insulation layer: Cork board and anticorrosive pine plate

In order to improve the comfort of the living environment, the thermal performance and temperature–humidity regulation of the exterior walls of two timber-framed structure buildings is theoretically calculated and experimentally studied in this study. Both of the two buildings are located in Nanjing, China, the hot-summer and cold-winter zone. Then WUFI is used to simulate and predict the changes of temperature, relative humidity, and water content of the two timber-framed structure buildings, to strengthen the theoretical analysis of the thermal and humidity coupling of the external walls, and to propose an optimal design scheme for the insulation and temperature and humidity regulation of the external walls. The main results show that the tested thermal conductivity is basically consistent with the predicted value, which prove that WUFI simulation can effectively predict the thermal insulation performance of the external wall. The two timber-framed structure buildings are both suitable for the cold areas, and the reasonable optimization of the design of the structure is the key to the insulation of the building wall. Timber-framed structure is proved to have good temperature–humidity regulation effect. The moisture content of the two timber-framed structure buildings is stable, and the annual temperature and winter humidity are within the appropriate humidity range, which indicates that the wall design is suitable for Nanjing hot-summer and cold-winter climate zone. Four types of wall structure indoor mold spore germinations are less likely, which is not easy to produce the mold. The above research aims to optimize the design of the energy-saving wall of the timber-framed structure and create a comfortable and healthy living environment.