It’s a familiar scenario: You show up at the doctor feeling miserable—sneezing, coughing, lethargic. We’ve all been there. And we’ve all been told the same answer: we’re suffering from “a virus.”
Some patients may be satisfied with that diagnosis, others may be frustrated, and still others may demand antibiotic treatment for a bacterial infection that is usually not even present. As an infectious disease doctor who specializes in pandemic preparedness, I detest using the catch-all “virus” diagnosis for a range of symptoms from common colds to life-threatening pneumonias to unexplained fevers. Failing to establish a specific microbial cause undermines the health of individual patients—and potentially the public at large.
Confirming a specific diagnosis to determine which virus is behind those nasty symptoms is not just an academic exercise. The benefits are plentiful. Patients can forego antibiotic treatment, possibly benefit from antiviral treatment, understand their illness, and be given a prognosis. Additionally, if hospitalized, patients with certain viral infections require specific types of precautions so as not to spread the virus within the hospital.
Another largely undervalued benefit of such an approach is that it allows experts to begin assembling an arsenal of tools that might stave off a global health catastrophe. With severe pandemics, such as the 1918 influenza pandemic that killed 50 to 100 million people, it can be challenging to predict which of the myriad microbial species (bacteria, viruses, fungi, parasites, prions) will be the most likely cause. Many different approaches to prediction exist, but there is a general lack of rigorous analysis about what it takes for any microorganism to reach the pantheon of pandemic pathogens. My colleagues and I at the Johns Hopkins Center for Health Security recently developed a new framework to understand the characteristics of pandemic pathogens.
One of our major conclusions is that the most likely pandemic pathogen will be viral and spread through respiratory means. Viruses rise to the top of the list because, when compared to other types of infectious agents, they have several features that confer pandemic potential: they mutate a lot, the speed of infection is rapid, and there are no broad-spectrum antivirals akin to broad-spectrum antibacterial agents. Contagion through breathing, coughing, and sneezing is likely because it is much more difficult for standard public health measures to extinguish respiratory spread agents compared to other routes of transmission like food, body fluids, or mosquitoes.
Many of the viral families that could pose a pandemic threat are very common causes of upper respiratory infections like influenza, the common cold, and bronchitis. These viruses cause a wide range of illnesses from mild coughs to serious pneumonias. Indeed, the 2009 H1N1 influenza pandemic virus was discovered in San Diego in a child with very mild illness in whom viral diagnostic testing was pursued. This event highlights the fact that such diseases are not only found in exotic locations in the developing world, but could appear anywhere.
Understanding the patterns of respiratory virus infections — how frequent they are, which strains are predominating, changes in severity of disease, expanding geographic range — may provide a glimpse into the first forays of a new human virus or an alert to changing behavior from a well-known virus. With this information, physicians and scientists can begin taking actions to prevent spread of the infection by developing vaccines, testing antiviral compounds, and making diagnostic tests for concerning viruses. Additionally, alerts to healthcare providers will provide greater situational awareness of the patterns of infection.
So, the next time you are given a wastebasket diagnosis of “viral syndrome,” push your doctor a little harder. In 2018, we have countless diagnostic tests for viral infections available, many at the point-of-care, that too few physicians use. Not only will you be more satisfied with a real diagnosis, you may be spared an unnecessary course of antibiotics. You can also rest assured that having a name for your virus will help epidemiologists doing a very important job. While we have not yet technologically achieved the famed Tricorder of Star Trek fame that diagnoses everything with a sweep of the hand, using the tools we do have could be one of the keys to detecting the next pandemic virus early enough to intervene.