Public Health Laboratory Internship: Keeping an Eye Out for Drug-Resistant Influenza

By Nikeshan Jeyakumar, PHASE Intern, Laboratories Division of Virology and Immunology, Maryland Department of Health and Mental Hygiene

Public Health Laboratory Internship: Keeping an Eye Out for Drug-Resistant Influenza | www.aphlblog.org

Public health as a discipline derives its importance from its direct positive impact on society. Unlike some fields of study that can remain relevant while being entirely theoretical, public health is entirely dependent on the application of its fundamental principles to real-world situations. Given this reality, the Johns Hopkins Bloomberg School of Public Health (JHSPH) has been taking a forward approach in offering its students a unique opportunity to utilize their education. Now in its tenth year, Public Health Applications for Student Experience (PHASE) internships at JHSPH have enabled students to supplement their education with practical experience. Students can choose from a wide range of internships that span the breadth of public health work and help them develop connections within the greater Baltimore community as well as network with public health professionals. The PHASE internships allow students to enhance their education by taking them out of the classroom and into the field, or in my case, into the Maryland State Public Health Laboratory.

I was a PHASE intern at the Laboratories Division of Virology and Immunology at the Maryland Department of Health and Mental Hygiene in Baltimore from January to June 2013. One of our primary roles as a public health laboratory is to receive samples containing suspected microbial pathogens and conduct diagnostic and surveillance testing in order to characterize such samples. We would then report our results to the submitters, the local government, and to the Centers for Disease Control and Prevention (CDC). As an intern, I was able to participate in a study that evaluated assays for detecting influenza susceptibility to a class of antiviral drugs termed neuraminidase inhibitors. This was part of a larger effort by our laboratory to conduct a surveillance campaign of drug resistance levels in circulating influenza strains during the 2012-2013 flu season. We used an inhibition assay that detects the activity of neuraminidase (NA), a surface protein that facilitates the release of influenza viruses from host cells so that they can travel to other cells and establish new infections. The assay contains a substrate which interacts with influenza NA and quantifies its activity by emitting light in proportion to the amount of activity detected. The quantity of drug required to knock down NA activity to 50% of baseline levels (known as the inhibitory concentration or IC50 value) was then obtained using a CDC-developed computer program that converts the light output data to IC50 values. From this information, we were able to determine the susceptibility of viruses to the three NA inhibitor drugs used in hospitals and clinics worldwide. High levels of NA activity (as measured against standard control levels established by the CDC) in the presence of inhibitor drugs is a strong indicator of resistance.

Seasonal influenza strains are resistant to the entire class of drugs termed adamantanes, which were the first drugs developed against influenza. As a result, doctors really only have three options to cure influenza infections: the inhalable drugs oseltamivir (TamifluTM) and zanamivir (RelenzaTM), and the last-resort intravenous drug peramivir, which is still in investigational stages. The development of widespread resistance to any of these drugs would cripple our ability to treat influenza in clinical settings, so it is essential for us to keep an eye on these viruses and their susceptibility to our pharmaceutical arsenal. One only needs to look at the rise in MRSA and CRE-related fatalities to realize how vulnerable we are as a population to drug-resistant pathogens. Happily, with the flu season coming to a close in May our lab did not detect any phenotypically resistant strains despite only a moderately-effective vaccine and a high number of infections due to a dominant circulating H3N2 strain, which in the past has been responsible for more severe disease outbreaks.

This project has been a wonderful application of my graduate education in microbiology at JHSPH to a real-life public health issue of great importance. It really illustrates the significance of why we have to understand infectious diseases in such detail in order to curb their effects on society. In addition to exposing me to the laboratory aspect of public health, the PHASE internship has also allowed me to network with professionals in the laboratory field and develop a set of connections that will be a tremendous asset in the future. The staff at the Maryland state laboratory is composed of a highly professional group of individuals that work very effectively together in order to carry out their numerous shared responsibilities. The laboratory personnel are particularly well-experienced in clinical virology and are extremely capable and proficient workers when their services are in high demand. This was most evident during the peak of the influenza season in January 2013 when we were inundated with an enormous amount of hospital samples that all had to be confirmed or disconfirmed for influenza infection. Every sample was processed efficiently and in a reasonable timeframe due to the professionalism and hard work of the staff. Dr. Maria Paz Carlos, the chief of the Division of Virology and Immunology, is also very involved in the work of all of the laboratories she manages and is always in constant communication with the rest of the staff and us, the interns. As a result, she has established a collaborative environment in that is extremely conducive to a team-based approach to problem-solving.

I highly encourage anybody attending JHSPH to take full advantage of this unique opportunity offered by the PHASE program. Public health laboratory internships can be a greatly enriching educational experience for students who spend so much time learning concepts and skills in the classroom to actually apply them in a hands-on setting. I would also advocate that other schools of public health collaborate with local and state public health laboratory departments to develop similar programs throughout the country. Engaging public health students and professionals in real-world settings is essential to the proper design and implementation of public health practices and policies from the local to the global scale.

Leave a Reply

Your email address will not be published. Required fields are marked *