Fungi Associated With Lower Respiratory Infection

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Fungi Associated With Lower Respiratory Infection

From Judy Tidwell,

Your Guide to Allergies.

http://allergies.about.com/cs/molds/a/blats071703.htm

An American Thoracic Society News Release

In a prospective study of 499 infants during their first year,

researchers demonstrated a strong relationship between high levels of

fungus in the household and an increased incidence of doctor-

diagnosed lower respiratory tract illnesses, including croup,

pneumonia, bronchitis, and bronchiolitis.

Writing in the second July 2003 issue of the American Thoracic

Society's peer-reviewed American Journal of Respiratory and Critical

Care Medicine, Diane R. Gold, M.D., M.P.H., of Channing Laboratory,

Harvard Medical School, Boston, Massachusetts, along with four

associates, found that of the 492 homes surveyed 324 residences had

high levels of at least one type of fungi. According to the authors,

children in environments with more than the 90th percentile for one

or more fungi had an 86 percent increased risk of developing a lower

respiratory illness during their first year of life.

(All infants involved in the study were born of one or more parents

who suffered from asthma or allergies.)

Fungi constitute a group of simple plantlike organisms, including

yeast, some of which can cause disease.

Of the 499 infants studied, 107 (21 percent) had a report of one

doctor-diagnosed lower respiratory illness during the first year on

one questionnaire. Twenty (4 percent) had a second illness reported.

In drawing their conclusions, investigators controlled for sex,

presence of water damage or visible mold/mildew, being born in the

winter, breastfeeding, and being exposed to other children through

siblings.

Although fungal spores are known to either contain or to produce

allergens, the authors said that it was unlikely that allergy is the

dominant mechanism through which fungal spores influence the risk of

lower respiratory infection in infancy. Instead, they believe that

the effects are likely due to other fungal spore components or to

metabolites released from actively growing fungi.

To obtain the study data, a trained technician visited each child's

home to determine household and socioeconomic characteristics and to

conduct air and dust sampling. Indoor air and dust samples were

collected from the bedroom where the child usually slept. At 2 months

of age, a follow-up questionnaire was given to the child's primary

caregiver. The research team asked about respiratory symptoms and

illnesses, possible daycare attendance, and certain questions on home

characteristics. Every 2 months repeat telephone calls were made to

follow-up on these questions.

According to the authors, high levels of one fungus did not

necessarily imply that a household would have high levels of another

fungus.

In this study, the fungi that were significantly associated with

lower respiratory infection were airborne Penicillium, dust-borne

Cladosporium, dust-borne Zygomycetes, and dust-borne Alternaria.

" People are routinely exposed to more than 200 different species of

fungi, " said Dr. Gold. " Exposure occurs universally and is impossible

to avoid completely. Often, there are no adverse effects, but, at

times, exposure to fungi can directly and in-directly influence an

individual's health. "

Dr. Gold also pointed out that the independent effects of visible

mold or mildew suggested that dampness-related factors other than

common cultivable fungi are important. However, she noted that the

study demonstrated the relationship between fungal exposure and lower

respiratory illness is independent of parent-reported visible mold

and mildew.