Aging and Pandemics

Populations change.  Not only do people change--people die and babies are born each day--but the structure of a population changes.  These sequential changes that every population goes through, predicts that we are entering a scary stage.

The theory goes something like this. A hundred and more years ago women gave birth to a lot of children only to see most of them die of infections and famine. Then we saw improved access to clean water, better sanitation and a better diet, which led to fewer diseases and a decline in deaths from infections and famine.  Women started having fewer children and most survived through adulthood. With fewer children being born and increasing survival, we reach a stage in our population where we are today in most developed countries--a very low incidence of infectious diseases and women continue having smaller families. In most developed countries today, women are having so few children that, without immigration, our populations will start to decline.

As a result we have entered the age of gerontology, were we have an aging population and a shrinking younger population.

With an aging population come a wave of chronic diseases--stroke, cancer, diabetes, heart disease, and neurological diseases such as Alzheimer's disease. Medicine,  in the face of such chronic diseases, starts focussing more on monitoring and maintaining health rather than battling infectious diseases. Because of this stability, from now on, populations fluctuate only as a result of wars and epidemics. We cannot predict wars, but we can predict pandemics.

We are at present going through one of the most lethal pandemics in our history. HIV/AIDS has now already claimed over 22 million people. More than 42 million are currently living with the disease and even if a vaccine for HIV were discovered today, over 40 million people would still die prematurely as a result of AIDS.

Despite this threat,  the two pandemics that clinicians seem more worried about--because of their unpredictability--are influenza and antibiotic resistant infections.

After five main pandemics of influenza, history has taught us that there will be emerging influenza pandemics every thirty to fifty years. Studies are showing how dangerous the last avian flu could have been if it became airborne. This type of airborne influenza--or its 144 variants--can devastate populations as the Spanish Flu did at the turn of the century with over 50 million people killed.

The second emerging concern is drug resistant infections. The spread of bacteria, virus or cancer cells that is resistance to drugs is man-made. Although Joshua and Esther Lederberg while at the University of Wisconsin-Madison showed that resistant bacteria has always been present, their increase is brought about by inappropriate and ineffective use of antibiotics. We are carelessly engineering super bacteria. The World Health Organization reports that, as an example, there are 50 million people with multi-drug-resistant tuberculosis, which exist in 49 countries, including the United States.

Although we have entered a tranquil and stable stage in our population--with an aging population where we are mainly dealing with long-term diseases--we do have the threat of pandemics that will dramatically affect this equilibrium. The question is not how, but when.


Mario Garrett, Ph.D., is a professor of gerontology at San Diego State University and can be reached at mariusgarrett@yahoo.com