Richard Long, MD, Professor, Department of Medicine, University of Alberta, Edmonton, AB; Chairman, Tuberculosis Committee, Canadian Thoracic Society.

The incidence of tuberculosis increases with age in Canadians. The prevalence of latent tuberculosis infection (LTBI) may also increase with age in Canadians, though information on the age distribution of LTBI is less precise. Chronic inflammatory conditions that currently constitute the major indications for new biologic therapies (tumour necrosis factor inhibitors), such as Crohn's disease and rheumatoid arthritis, often have an older age onset. Biologic therapies have the potential to cause LTBI to progress to active tuberculosis disease. Their use in older Canadians or other populations that may have a higher than average prevalence of LTBI poses a challenge to tuberculosis control.
Key words: tuberculosis, tumour necrosis factor inhibitors, age, rheumatoid arthritis, Crohn's disease.

Alexander I. Aspinall, MD, PhD and Jon B. Meddings, MD, FRCPC, Division of Gastroenterology, Faculty of Medicine, University of Calgary, Calgary, AB.

The inflammatory bowel diseases (IBD)--Crohn's disease (CD) and ulcerative colitis (UC)--have a second peak of onset after the age of 60. Discerning IBD from alternate diagnoses is a great challenge in the geriatric population, as other diseases commonly encountered in the elderly can mimic IBD. The possibilities include ischemic colitis, diverticulitis and infectious colitis. Diagnosing and treating IBD should involve consultation with a gastroenterologist, but the approaches do not vary significantly from the strategies used in younger patients. Therapeutic modalities used in younger age groups are also applicable to the geriatric population, but great attention needs to be given to side effects and drug interactions.
Key words: inflammatory bowel, crohn's disease, ulcerative colitis, differential diagnosis

Epidemiology and Pathophysiology
The inflammatory bowel diseases--Crohn's disease (CD) and ulcerative colitis (UC)--are illnesses of unknown cause.

Leora Horn, MSc

Inflammatory bowel disease (IBD) is the general term used to describe idiopathic chronic disorders that cause inflammation or ulceration of the gastrointestinal system. Canada is believed to have one of the highest incidences of IBD in the world with an estimated one hundred thousand people suffering from the disease (Crohn's and Colitis Foundation of Canada). The majority of IBD cases are characterized by periods of remission and exacerbation of symptoms often requiring long-term drug therapy, hospitalization, and recurrent surgery. IBD may develop at any age in the geriatric population, but the peak incidence falls between ages 60 and 80. IBD is a chronic disease; people who develop IBD when they are young will carry the disease into old age. Within the elderly population, two-thirds of IBD patients develop the disease in their sixties, a quarter of patients develop IBD in their seventies, and one tenth of patients develop IBD in their eighties.

IBD is classified as either ulcerative colitis (UC) or Crohn's disease. UC is three times more likely than Crohn's disease to occur in the elderly, with twelve percent of UC patients developing the disease when they are over sixty years of age. Approximately four percent of people with Crohn's disease develop symptoms when they are over sixty with incidence among women being higher than among men.¹