Fungal DNA, allergens, mycotoxins and associations with asthmatic symptoms among pupils in schools from Johor Bahru, Malaysia

Abstract

While there is a large variation of prevalence of asthma symptoms worldwide, what we do know is that it is on the rise in developing countries. However, there are few studies on allergens, moulds and mycotoxin exposure in schools in tropical countries. The aims were to measure selected fungal DNA, furry pet allergens and mycotoxins in dust samples from schools in Malaysia and to study associations with pupils' respiratory health effects. Eight secondary schools and 32 classrooms in Johor Bahru, Malaysia were randomly selected. A questionnaire with standardized questions was used for health assessment in 15 randomly selected pupils from each class. The school buildings were inspected and both indoor and outdoor climate were measured. Dust samples were collected by cotton swabs and Petri dishes for fungal DNA, mycotoxins and allergens analysis. The participation rate was 96% (462/480 invited pupils), with a mean age of 14 yr (range 14-16). The pupils mostly reported daytime breathlessness (41%), parental asthma or allergy (22%), pollen or pet allergy (21%) and doctor-diagnosed asthma (13%) but rarely reported night-time breathlessness (7%), asthma in the last 12 months (3%), medication for asthma (4%) or smoking (5%). The inspection showed that no school had any mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures. The mean building age was 16 yr (range 3-40) and the mean indoor and outdoor CO(2) levels were 492 ppm and 408 ppm, respectively. The mean values of indoor and outdoor temperature and relative humidity were the same, 29°C and 70% respectively. In cotton swab dust samples, the Geometric Mean (GM) value for total fungal DNA and Aspergillus/Penicillium (Asp/Pen) DNA in swab samples (Cell Equivalents (CE)/m(2)) was 5.7*10(8) and 0.5*10(8), respectively. The arithmetic mean (CE/m(2)) for Aspergillus versicolor DNA was 8780, Stachybotrys chartarum DNA was 26 and Streptomyces DNA was 893. The arithmetic means (pg/m(2)) for the mycotoxins sterigmatocystin and verrucarol were 2547 and 17, respectively. In Petri dish dust samples, the GM value for total fungal DNA and Asp/Pen DNA (CE/m(2) per day) was 9.2*10(6) and 1.6*10(6), respectively. The arithmetic mean (CE/m(2) per day) for A. versicolor DNA was 1478, S. chartarum DNA was 105 and Streptomyces DNA was 1271, respectively. The GM value for cat (Fel d1) allergen was 5.9 ng/m(2) per day. There were positive associations between A. versicolor DNA, wheeze and daytime breathlessness and between Streptomyces DNA and doctor-diagnosed asthma. However, the associations were inverse between S. chartarum DNA and daytime breathlessness and between verrucarol and daytime breathlessness. In conclusion, fungal DNA and cat allergen contamination were common in schools from Malaysia and there was a high prevalence of respiratory symptoms among pupils. Moreover, there were associations between levels of some fungal DNA and reported respiratory health in the pupils.

Volatile organic compounds (VOC), formaldehyde and nitrogen dioxide (NO 2 ) in schools in Johor Bahru, Malaysia: Associations with rhinitis, ocular, throat and dermal symptoms, headache and fatigue

“…The participation rate was 96%, a total of 462 pupils participated. All schools had a two shift system, one group was at school from 7 a.m. to 1 p.m. (our study group) and another afternoon shift was at school from 1 p.m.-7 p.m. (not participating in our study).We have previously published results on associations between fungal and bacterial exposure and asthmatic symptoms and airway infections among the students in these schools (Cai et al, 2011;Norbäck et al, 2014;Norbäck et al, 2016).…”

Respiratory symptoms and fractional exhaled nitric oxide (FeNO) among students in Penang, Malaysia in relation to signs of dampness at school and fungal DNA in school dust

“…We used a self-administered questionnaire from previous school studies (Smedje et al, 1997;Cai et al, 2011;Mi et al, 2006;Zhao et al, 2008;Norbäck et al, 2014) with questions on doctors' diagnosed asthma, current asthma, allergies, respiratory symptoms and airway infections obtained from the ISAAC study (Asher et al, 2006), the European Respiratory Health Survey (ECRHS) (Janson et al, 2001) and our previous school studies (Smedje et al, 1997;Cai et al, 2011;Mi et al, 2006;Zhao et al, 2008;Norbäck et al, 2014). There were (yes/ no) questions on doctors' diagnosed asthma, current asthma medication (sprays, tablets etc.)…”

Targeted Inspection of Environmental Mycological Load for Mitigation of Indoor Mold toward Improved Public Health

“…These can include EI and long-term sampling, e.g. of settled dust or pumped air, and use of total fungal analyses, such as for ergosterol, beta 1-3 glucan or total molds by the CAMERANEA method [21][22][23] or fungal DNA analysis via quantitative or qualitative polymerase chain reaction (PCR) [21][22][23][24].…”

“…In Malaysia, data on the prevalence of respiratory symptoms and infections among pupils aged 14-16 years were examined, in an attempt to associate environmental allergens, fungal DNA and mycotoxin exposure with health problems. In particular, the Malaysian team showed a positive association between levels of Aspergillus versicolor DNA and wheezing and daytime attacks of breathlessness, whereas Streptomyces DNA was positively associated with medically diagnosed asthma [21]. In a small-scale population study in Israel, including 395 members of one rural community, the rate of positive skin tests for at least one of the fungal allergens tested was reported to be 30.5% in the age range of 4-9 years [58].…”

“…Environmental inspections (EIs) of mycological load have been suggested using a range of fungal-detection techniques, e.g. open Petri dish (OPD) versus active air sampling [19,20] and qualitative identification and quantitative monitoring of diverse fungal species and their mycotoxins [21][22][23][24].…”