Risk Factors

The following groups are at high risk for influenza-related complications or hospitalization

All children less than 59 months of age.

• Note, children who are 2 through 4 years of age have a higher rate of complications compared with older children. However, the risk for these children is lower than the risk for children less than 2 years old.

All children, adolescents and adults with chronic health conditions severe enough to require regular medical followup or hospital care, specifically:

• Cardiac or pulmonary disorders, including bronchopulmonary dysplasia, cystic fibrosis, asthma or conditions associated with an increased risk for aspiration

• Diabetes mellitus and other metabolic diseases

• Renal disease

• Anemia or hemoglobinopathy

• Cancer or other immune-compromising conditions (due to disease or therapy)

• Obesity, with a body mass index (BMI greater than or equal to 40 kg/m OR a BMI z-scores greater than 3 SD above the mean for age and gender

• Neurological or neurodevelopmental conditions

• Children and adolescents ( less than 18 years of age) currently undergoing prolonged treatment with acetylsalicylic acid for a chronic condition

All Indigenous persons

All residents of chronic care facilities

All pregnant women, including adolescents, in all trimesters

All adults ≥65 years of age