It seems as though every year we have a new infectious disease to worry about.
This year, Zika virus has all the media attention. Indeed its unique feature of causing microcephaly, or small brain, in a baby born to a mother who contracts this infection is a serious concern that is challenging public health experts as to how best to advise the populations at risk.
A risk for Guillian-Barre is an additional concern for others.
In general, other than these two risks, infection with this virus is otherwise a nonevent and thankfully neither problem is overwhelming in its frequency. But Zika is simply the latest in what seems to be an annual event of new and scary infections that capture the media attention and worry the population.
Ebola, Chikungunya, Middle East Respiratory Syndrome (MERS), West Nile, Chicken Flu, SARS are part of the list of infections that have been part of our news cycle over the past five years. Are we seeing more infections or are they changing in severity or character? What is the next disease we might see? These are questions infectious diseases physicians ask, study and try to anticipate to protect our communities. In this installment of our message to the community I will try to answer some of these questions.
Part of the answer comes from the greater mobility of our society. With the dramatic increases in air travel over the past 50 years, it is relatively easy for diseases to move from one region to another in the world. For example, animals, insects or humans carrying certain diseases can hop a plane and be in a different part of the world less than 24 hours. This allows diseases that previously had a limited geographic distribution to move quickly to other regions. Indeed, this is what happened with West Nile, Chikungunya and Zika, all of which had the place of origin in Africa and then spread locally and globally via readily available air travel.
Another reason for the dramatic increases that can be seen in the numbers of cases are the low levels of natural immunity for new diseases. For example, when Zika and Chikungunya were introduced to the Western Hemisphere, they were new to the population in these regions so no immunity existed in that population. As a result, once transmission began, it moved quickly to affect large numbers of people as there was no natural barrier to infection.
The severity of certain illnesses that we have seen recently increases concern and media attention. So, for example, even though Ebola is highly unlikely to be able to establish a significant chain of transmission outside certain areas of Africa, the high death rate of up to 90 percent and movies about the dramatic features of the illness, like “Outbreak,” increase the scrutiny and attention from the media.
What is the greatest concern that public health officials discuss as it relates to new infections? Most often, I hear the concern raised about novel influenza. This form of the standard flu virus implies a genetic change to the virus that would make it more aggressive and more easily passed. If this were to occur, many humans would have no immunity, and since it is easily passed from person to person, a pandemic could occur that would cause far more death and debility than we have seen from any of the previously mentioned problems. Scientists are very actively watching for this event. I hope it does not occur.
In the meantime, remember to clean your hands often, avoid undercooked food, and get all possible vaccines to keep yourself safe and protected.