Lynn Johnston

On January 30, 2001, the federal Immigration Department's headquarters in Ottawa were evacuated and shut down following a bioterrorism scare, which turned out to be a hoax. The building reopened 48 h later, after it was determined that the substance found was not anthrax (1). In the same week, a similar hoax forced the evacuation of an Ontario provincial government building in Toronto (1).

Knowledge about Whipple's disease began to emerge in 1907, when George Hoyt Whipple recognized the first case of the disease that now bears his name. He reported the case of a 36-year-old physician with "a gradual loss of weight and strength, stools consisting chiefly of neutral fat and fatty acids, indefinite abdominal signs, and a peculiar multiple arthritis" (1). Findings at autopsy consisted of poly-serositis, aortic valve vegetations and deposition of fat in the intestinal mucosa and regional lymph nodes with marked infiltration by foamy macrophages (1). It was originally thought to be a disorder of fat metabolism, and the term 'intestinal lipodystrophy' was proposed. Whipple's disease has since been recognized as a rare, multivisceral, chronic disease with a clinical presentation dominated by a symptom triad of diarrhea, weight loss and malabsorption. However, digestive symptoms are often preceded for months or years by other symptoms, the most common being arthralgia, although cardiovascular, neurological or pulmonary involvement may be more prominent at times. Once considered the ideal case report, recent characterization ofTropheryma whippeliiby means of broad range bacterial ribosomal DNA polymerase chain reaction (PCR) analysis (2,3) and its subsequent cultivation (4) has led to a veritable explosion of individual case reports, case series and hitherto unrecognized manifestations of the disease, such that it is now considered an underdiagnosed infectious disease (5). It is timely to provide an update on new developments in Whipple's disease.

In April 2000, the American Thoracic Society published guidelines for targeted tuberculin testing and the treatment of latent tuberculosis infection (LTBI) (1). These guidelines are a joint statement of the American Thoracic Society and the Centers for Disease Control and Prevention, and were endorsed by both the Infectious Diseases Society of America and the American Academy of Pediatrics. Similar recommendations were published by the Infectious Diseases Society of America in its guidelines for the treatment of tuberculosis (TB) (2). These updated guidelines were developed in recognition of the importance of treating LTBI as one component of eliminating TB in the United States ‐ a goal reiterated in 1999 by the Advisory Council for the Elimination of Tuberculosis (3) ‐ but also realizing the differing risks and benefits of treatment for patients based on their individual risks of developing active disease or drug toxicity (4). The 2000 edition of the Canadian Tuberculosis Standardsprovided similar recommendations for the treatment of LTBI (formerly known as chemoprophylaxis) and reminded us of the two major Canadian TB elimination initiatives: the National Tuberculosis Elimination Strategy (Medical Services Branch, 1992), with the aim of eliminating TB in First Nations people by 2010, and the National Consensus Conference on Tuberculosis (Health Canada, 1997), with an interim goal of a 5% reduction in the number of TB cases each year in Canada (5). Given the recent publication of the American guidelines and the updated Canadian Tuberculosis Standards (Fifth Edition), it was considered timely to remind readers of the evidence supporting the use of antituberculous chemotherapy in the treatment of latent infection.

The past decade has seen a dramatic change in Canadian health care as the treatment of many patients shifts from the hospital setting to the home or other alternative health care settings (1). Complex advances in technology and significant changes in the funding environment have also precipitated many changes in the functional capacity of our health care system. The portion of the total Canadian health care expenditures that has been allocated to hospitals and other institutions has declined steadily over the past two decades (2,3). This reduction in institutional-based funding reflects the need to develop a system that improves the use of out-of-hospital sites for delivery of health care services and decreases reliance on the specific institutional component of the health care sector. Recent data reveal that Canadian hospital discharge rates have decreased by 14% between 1994 and 1998, and there has been a reduction in the length of stay from 7.4 to 7 days (4). In conjunction with a reduction in the number of hospital beds, there has been a massive shift in the proportion of surgeries that are performed on an outpatient basis. Further developments in the delivery of care include the increased use of telehealth, which allows health care professionals to provide increasingly complex services centralized hospital sites to outlying areas.

Over the past year, several situations have occurred in Canada in which patients who had recently undergone a surgical procedure were subsequently diagnosed with confirmed or suspected Creutzfeldt-Jakob disease (CJD). This raised concerns over contamination of surgical instruments: which instruments might have been contaminated from direct exposure to tissues; can instruments become cross-contaminated by exposure to other contaminated instruments; what assessment is necessary to determine cross-contamination; and what should be done with instruments that have been contaminated. Additionally, should there be a patient traceback in the face of potential but unproven exposure? Unfortunately, there are no easy answers to most of the above questions. Australia, the United Kingdom and the World Health Organization have developed guidelines for the infection control management of patients with CJD, as well as instruments and devices that come into contact with them and their tissues (1-3). Health Canada's draft CJD infection control guidelines, withdrawn from the Health Canada Web site until safety concerns regarding sodium hydroxide can be addressed, closely mirrored recommendations made in those documents. The Centers for Disease Control and Prevention guidelines for CJD are under revision. However, a recent American publication made recommendations on what procedures should be used for reprocessing items that have been in contact with the prion protein (PrP) (4). These recommendations differ substantially from the draft Canadian guidelines. This article reviews current knowledge about CJD, and highlights some of the infection control concerns and controversies.

Pertussis or whooping cough is an acute infectious disease of the respiratory tract caused principally by Bordetella pertussis and less commonly by Bordetella parapertussis (1). Until two decades ago, pertussis in adults was a medical curiosity (2‐4), but with the purification of specific Bordetella species antigens, the development of reliable enzyme immunoassays allowing accurate serological diagnosis and better understanding of the duration of immunity from vaccination, it has been clearly demonstrated that B pertussis is a common cause of prolonged cough in adults. Indeed, its incidence has been increasing gradually over the past decade in both adults and adolescents. Given the recognition of the importance of pertussis as a cause of prolonged cough in adults and the advent of the new acellular pertussis vaccines, it is timely to review current concepts of the pathogenesis of pertussis, its epidemiology in adults and the utility of the anticipated impact of the acellular vaccine.