The Changing Face of Medical Care

The aging of the population has dramatically changed the nature of medical practice in developed countries. We have moved from the former model of isolated medical care for acute illnesses to a model that is starting to address the needs of those with chronic illness. What does this mean to the medical practitioner? Firstly, it alters the relationship between the medical practitioner and her patient; the relationship becomes a cooperative one. Unlike an acute episode of pneumonia in a previously healthy young person, the long-term nature of chronic disease means that patients have to take greater responsibility for their own care. A physician will see a patient with diabetes only intermittently; successful management requires the patient to carefully monitor their own sugar levels and follow the appropriate dietary and exercise regimes. To be successful, a patient must be extensively educated about his/her condition. This is the cornerstone of successful management of most chronic diseases. Although some patients can educate themselves via texts and the Internet, this approach will not work for everybody. The enormous amount of information available (some of it garbage) means that some judgement in the selection of appropriate materials is essential. As well, the patient and doctor have to agree on appropriate goals of therapy. The goals for a 90-year-old man with diabetes might be significantly different from those of a 19-year-old man with identical blood sugar levels. The complexity of this approach means that care is often better delivered via a team of health care practitioners, rather than by a solo practitioner. As an academic physician in geriatric medicine, I would be lost without the dedicated multidisciplinary geriatric team that includes nurses, occupational therapists, social workers, and physiotherapists. One of the challenges our health care system now faces is how to ensure that primary care in the community can also be delivered in a multidisciplinary fashion.

As well as this general change in the nature of medical care in modern societies, the very diseases we are treating are changing their faces. Fifty years ago it would have been considered lunacy to have clinics devoted to cystic fibrosis in adults, or adult congenital cardiac clinics. Our success in treating certain diseases in early life, means that we are seeing for the first time, substantial numbers of patients who are aging with diseases such as cystic fibrosis or cardiac malformations. This is particularly evident in the population with end-stage renal failure. This cohort is expanding at an incredible rate for two reasons. Patients survive longer with better dialysis techniques and supportive care, and we are starting older patients on dialysis more frequently as the benefits become more evident. I am proud of the fact that a Canadian, Professor Dimitrios G. Oreopoulos, has been one of the most prominent individuals in the field of geriatric nephrology.

The article on HIV in the elderly, by Dr. Brian Conway, appearing in this issue of Geriatrics & Aging, is another fascinating example of this trend. Why are there elderly people living with HIV infection? I think there are two reasons. Modern drug regimes for HIV have been incredibly effective, so we will see more and more people infected with HIV living into old age. However, the statistics Dr. Conway quotes preceded the common use of highly active antiretroviral therapy. Simply put, this means that older people are quite sexually active and run the same type of risks as younger sexually active people do! And this series was compiled before the introduction of Viagra. It reminds us that we do not evolve into a different species simply because we grow older. The aging of the population might have increased the number of frail elderly, but it has also resulted in an even larger absolute increase in the number of fit and vigorous elderly who are as prone to various maladies as younger adults--from sexually transmitted diseases to trauma. So please read the article carefully, and promise to caution your patients to practice safe sex.

We have a wonderful selection of articles in this issue, but because of space limitations I will just mention a few here. To highlight the newly published 6th edition of the Canadian Medical Association's guide, 'Determining Medical Fitness to Drive', we have an article emphasizing the physician's legal responsibilities. For CMA members, a free copy of the guide can be obtained by calling the CMA at 888-855-2555 or 613-731-8610 extension 2307. We have a broad selection of articles on virology: influenza vaccination for patients and healthcare workers, antiviral therapy for influenza, and an article by Dr. John Conly on Herpes Zoster. We have two articles on another important infection, tuberculosis. We also have highlights from the recent World's Alzheimer Conference in Washington D.C., and hope to have more in our next edition.

Enjoy this issue.

The Pros and Cons of Vaccinating Healthcare Workers

Vaccination Curtails Influenza Outbreaks, but Side Effects are Still Possible

Dr. Allison McGeer MSc, MD FRCPC
Director,
Infectious Control,
Mount Sinai Hospital,
Toronto, ON

Every year, approximately one in six Canadians are infected with influenza. Healthy adults infected with influenza miss, on average, 2-7 days of work, and have a 10-30% chance of being prescribed a course of antibiotics. Influenza causes approximately 20% of all cases of acute otitis media in children,¹ and is the most common single infectious cause of hospital admission in young children.^2-4 However, the greatest impact of influenza is seen in the elderly. Every year, nearly 1% of older adults with any chronic underlying illness require hospital admission due to influenza, and about 4000 die from influenza and its complications.⁵

Vaccination is the only effective method for the prevention of influenza. Annual vaccination is required because influenza viruses are able to mutate their antigenic coat continuously in order to evade the human immune system (see "Chasing Away the Flu Bug" on page 20 for a more detailed description of this process).

Immunological Shield Wavers with Age

The Elderly Display a Weaker Vaccine-Triggered Immune Response

Janet E. McElhaney, MD
Associate Professor, Division of Geriatrics,
Glennan Center for Geriatrics and Gerontology

Introduction
Pneumonia and influenza together have been identified as a leading cause of catastrophic disability and the fourth leading cause of death in the age 65 and over population. The fact that older people have an increased risk of contracting influenza and/or pneumococcal disease is to a large extent due to the combination of immuno-senescence and chronic diseases affecting 80 to 90% of the over 65 population. The aging process results in a decline in immunity that largely affects T-cell-mediated defense mechanisms. In older people, this decline is associated with an increased risk of viral infections, particularly influenza. Humoral immunity may also diminish with aging but to a lesser degree, perhaps due to the T-cell function that regulates the production of antibodies. Due to their ability to stimulate the aging immune system, influenza and pneumococcal vaccinations are by far the most cost-effective medical interventions when it comes to older adults.

Impact of Influenza and Pneumococcal Infections
The association between advanced age and the risk of serious influenza infections is one of the most well-documented examples of the potential effects of immunosenescence.

HIV Moves Around the World and Up the Age Ladder

Brian Conway, MD, FRCPC
Staff Physician,
Centre for Excellence HIV/AIDS,
Assistant Professor, Pharmacology & Therapeutics,
University of British Columbia

Recently, the bulk of media attention has fallen on the global HIV pandemic, and on the impact it is having in Africa. In North America, although AIDS is still predominantly a disease of young adults, an aging but relatively healthy population of HIV positive individuals is slowly becoming a cohort of HIV positive elderly. A review of recent medical literature reveals few, if any, articles that deal with AIDS in elderly patients. The absence of research in this field will mean a medical community that is unprepared to treat and diagnose HIV in an older population. Consequently, elderly patients may not receive the degree of care and attention that they deserve. At Geriatrics & Aging, we strive to cover the latest medical developments and issues, even those that may be somewhat controversial. This month we are proud to present an article contributed by Dr. Brian Conway, an international leader in the field of HIV research, on how HIV is 'moving up the age ladder'.

Introduction
Although it may be assumed that the HIV epidemic is waning, it must be remembered that by the end of 1999 there were still over 33 million adults and children living with HIV/AIDS throughout the world.¹ Of these, the vast majority (32.4 million or so) are adults. In the United States, there are over 400,000 adults/adolescents living with this disease.

Breaking the Silence

The world's most distinguished scientists, community leaders and policy specialists convened in Durban, South Africa in July for the XIII International AIDS Conference. In 1998, AIDS replaced tuberculosis as being the world's deadliest infectious disease. AIDS has been particularly devastating in Africa, with nearly 85% of all of the world's AIDS-related deaths occurring in this region. In the closing session of the conference, Nelson Mandela stated that HIV/AIDS is having a devastating impact on families, communities, societies and economies: "Decades have been chopped from life expectancy and young child mortality is expected to double in the most severely affected countries of Africa. AIDS is clearly a disaster, effectively wiping out the development gains of the past decades and sabotaging the future."

AIDS is becoming an issue in the elderly population. People age 50 and older currently represent more than 10% of AIDS cases in the United States alone. In the upcoming September issue of Geriatrics & Aging, Dr. Brian Conway, one of the first Canadians to work in the field of retrovirology, and a reviewer for the Medical Research Council of Canada and the National Institutes of Health in virology, will bring you up to date on the latest medical information on HIV in the elderly.

Hepatitis B and C Incidence Among Elderly: Diagnosis and Treatment

Neil Fam, BSc, MSc

Hepatitis refers to acute or chronic inflammation of the liver, with the majority of cases resulting from either viral infection or drugs. In Canada, hepatitis B and C infections are the most common cause of viral hepatitis, and may be associated with considerable morbidity and mortality. Globally, chronic viral hepatitis is the leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma and is the most common indication for liver transplantation. This article provides an outline of the natural history of hepatitis B and C infections, and describes current approachs to diagnosis, treatment, and prevention. Unique aspects of hepatitis in the elderly are highlighted.

Epidemiology and Risk Factors
Hepatitis B virus (HBV) is a DNA virus that infects over 350 million people worldwide. Although HBV infection is extremely common in parts of Asia and Africa, Canada has a relatively low level of endemicity. In North America, HBV infection occurs mainly in sexually active young adults. Important risk factors for HBV include sexual activity, IV drug use, occupational exposure, travel or residence in an endemic area and previous blood transfusion. The route of transmission may be sexual, parenteral, or vertical, with an incubation period of 6 weeks to 6 months.