E. coli and other facultative anaerobes constitute about 0.1% of gut flora, and fecalâoral transmission is the major route through which pathogenic strains of the bacterium cause disease.
Asthma symptoms in children ages 5-11. Common asthma signs and symptoms in children ages 5 to 11 include: 1  Coughing, particularly at night. 2  Wheezing. 3  Difficulty breathing. 4  Chest pain, tightness or discomfort. 5  Avoiding or losing interest in sports or physical activities.
In children under three years of age, viral infections are likely to be the most common trigger. After three years, allergies also begin to play an increasing role as a trigger. After 20 years of age, occupational exposure to toxic substances and allergens also can be important triggers for asthma.