During the rainy season, all of us have noticed that if bread is left unused for a few days, a green fibrous growth appears on it; this happens also if a pair of shoes is left unused for a few days in the same weather. These fibrous growths, which appear in humid weather, are moulds or fungi.
Fungi are simple plants, very small in size. They have no chlorophyll, hence they cannot synthesize their own food. They have a growing, vegetative part, made up of long branches called mycelia. They generally reproduce by means of spores.
Most of the fungi perform a useful function in nature. They act as scavengers, converting live and dead material into basic chemicals, which in turn nurture into new life. Antibiotics like penicillin and streptomycin, have been made from them. Alcohol, wine, cheese and certain bakery products are made by using fungi.
Fungi grow best between 20°C to 32°C, though some of them can grow at colder termperatures, like those inside a refrigerator. They survive freezing for months and lie dormant. Temperatures approaching the boiling point of water, kill most of them. For rapid growth, they need humidity to be above 70 per cent. The warm and humid environment inside rooms, or storage places, even shoes, is ideal for their growth.
In the house, furniture dust and mattress dust are particularly good harbourers of fungi. Fungi also attack paper, paint wood, etc. They have been found on rubber gaskets around refrigerator doors. Damp places, like basements are fertile grounds for their growth.
Home gardens breed fungal spores constantly. They grow abundantly on rotting leaves and foliage. The become infected with fungi. Cut flowers and leaves may be contaminated even before they are brought into the house.
Fields and areas where grain is grown, processed or stored also have an immense number of spores of the fungi. In the case of many fungi, cow or buffalo dung is the exclusive source of origin. In India, cow and buffalo thing are still used as domestic fuel in rural areas and those form one of the principal source materials of fungi.
Fungi are present in many foods, some are put in intentionally while others enter as contaminants. Mature cheese depends on fungi for its distinctive taste. Yeasts are used in the manufacture of beer and wine and in the preparation of bread and certain cakes. Baked foods often become mouldy, especially in humid weather, even though they are sterile after taken out of the oven. Potatoes and onions are common sources of contamination when brough in the home.
Because of their light weight and minute size, the spores of the fungi are readily carried about by wind. Spores of the fungi are readily carried in the air for hundreds of miles. They are very resistant to killing.
Not all the viable fungal spores in the air are allergenic. Important allergenic fungi include phoma, mucor, aspergillus tamarii and Candida.
Next to pollens, spores of different fungi present in the air are the commonest cause of allergy leading to asthma.
In order to treat fungus-sensitive patients, the physician must be familiar with the fungi in the air. He must know the seasons when the common fungi are at their heaviest concentration in the atmosphere of the area. Identification of the fungi and making of their calendar is similar to that of pollens, though it is more tedious.
Delhi, for which a fungal survey has been done, has a high percentage of fungal spores throughout the year. The peak periods of fungal spore concentration are the month of September to November, and February to April i.e., autumn and spring respectively. In the rainy season the spore concentration is low as the fungal spore, as well as other contaminants of the air, have been settled down by the rain.
The most frequent fungal spores trapped and identified on slides from the Delhi atmosphere are those of alteranria, cladosporium, small round spores, curvularia and heminthosporium; these from 82 per cent of the total fungal flora trapped by exposed slides.
CHARACTERISTICS OF FUNGUS-SENSITIVE PATIENTS
Patients having the following symptoms can be suspected of being allergic to fungi :
□ Those having perennial symptoms.
□ Those with perennial symptoms which become severe between September and November, and between February and April.
□ Those allergic to house dust or pollens and who do not do well under specific treatment.
□ Those who show symptoms after ingestion of mould— containing foods and beverages.
□ Those who develop symptoms on exposure to hay, straw, compost, dead leaves while harvesting, ploughing, harrowing and doing other outdoor activities.
Only a small percentage of mould-sensitive patients are sensitive to moulds alone; most of them are allergic to pollens as well.
Among mould-sensitive patients, bronchial asthma is the most frequent predominant symptom. Precautions ought to be taken to make the environments of mould-sensitive patients as free from moulds as possible. Some of these precautions are as follows:
□ Avoid basements.
□ Walls should not absorb moisture; therefore, plastered and painted walls are to be preferred.
□ All rooms and spaces inside the house should have effective ventilation.
□ Potted plants should not be kept indoors.