Infectious Lung Disease: Staying Ahead of Morphing Bacteria and Viruses

The H1N1 flu is currently shining a dramatic spotlight on one of the most common infectious lung diseases – flu. This new strain highlights America's need to adhere each year to public health principals to prevent the spread of potentially deadly flu. But if we dig just a bit below the surface we can find the story-behind-the-story: the need for ongoing research that will lead us to new methods for developing vaccines and improved treatments for infections. Infectious lung diseases have affected the course of history, with each disease's story changing  with the power of a specific bacterium or virus to morph genetically, resist antibiotics and other compounds, and seemingly resurrect itself from near-eradication.

Nowhere are the scientific lessons of high-tech study and on-the-street lessons more clear than in the world of influenza. Seasonal influenza comes around each year with various strains that are captured in the annual flu vaccine. These strains themselves can be deadly. And every 10 years or so, an influenza virus strain appears that is dramatically different from the other members of its family, encountering very few people with antibodies that are effective against the new virus. The 1918 influenza epidemic, the recent avian flu outbreak, and today's H1N1 flu all resulted from a genetic exchange among viruses. Researchers' work to prevent these new strains from rapidly spreading is compounded by the current, process of vaccine development that has been used for the past 50 years. Scientists today are researching DNA-based influenza vaccines, for example, that would include dozens of strains and protect individuals for five to 10 years, similar to a tetanus shot. Studying this year's experience of seasonal flu and H1N1 could produce pivotal opportunities to change the course of science's understanding of influenza and subsequent pathways to replacing the 50 year-old vaccine development process with an efficient, long-term change.

Tuberculosis (TB) remains a major public health issue worldwide, and in America medicine is most challenged by particularly virulent forms of TB such as extensively drug-resistant TB (XDR TB) and multidrug-resistant TB (MDRTB). Scientists in Africa are testing a TB vaccine in clinical trials, while investigators also continue to search for new drug therapies that will shorten the duration of treatment to offset the proven enemy of TB treatment—patients' stopping therapy before completing the prescribed course.

Cases of difficult-to-treat nontuberculous mycobacterium (NTM) disease, on the other hand, seems to be on the rise in the United States. Physicians now are seeing NTM infections in otherwise healthy people, a distinct change from the former profile of NTM patients (those with weakened immune systems due to another primary illness or other reasons). Researchers are focused on finding safe and effective treatments that are less toxic than the current therapy for this long-term disease.

Investigators continue to work to understand the cause(s) of asthma, and one theory is focused on infections. Scientists believe that a certain amount of asthma is caused by infectious agents, based on evidence from biopsies, and some researchers are testing the use of antibiotics.

Clinicians and researchers continue to work together to find answers to the spectrum of infectious lung diseases. Certainly, the victories in our understanding of infectious lung diseases---pneumonia, influenza, TB—come from years of tenacious work by scientists who learn from one another's advances. They begin with laboratory research, impacted by physicians' experience treating patients from every walk of life, and continue to advance through a dynamic process that takes advantage of our most high-tech tools and the most basic feedback of doctors on the front lines, caring for infected patients.