Influenza and Epidemic Preparedness

By Hiba Fatima and Leah Watson

We all remember the 2009 swine flu epidemic that caused 14,000 deaths worldwide. Despite only causing cold-like symptoms, the mass panic that surrounded this epidemic was notable, and to an extent, justified. It brought attention to our health system’s ability to cope with an epidemic and shed light on other countries’ healthcare infrastructure. After the epidemic was over, many of our governmental organizations turned their attention to bolstering preparedness for such epidemics. The widespread concern was not if it would happen again, but rather when. This series of events put the spotlight on vaccinations, influenza and the health issues that surround them.

Source: http://www.who.int/csr/don/2009_08_12/en/

Influenza is the most common cause of any respiratory illness as well as the most prevalent, it accounts for 2.7% of global DALYs, 3.9% of death worldwide. The influenza vaccine is very helpful in stopping the spread of influenza in the United States and is renewed every year because the virus undergoes recombination and becomes a new subtype. The pathogenicity of influenza is usually undermined in the United States while in the developing world it is taken much more seriously. This is because the neglect of influenza can very often lead to death. Influenza A and B are the most prevalent, and Influenza A is most commonly responsible for pandemics. This is partly due to its ability to infect and stay in avian and swine species which act as reservoirs for the disease. This gives the virus many opportunities to jump to a human host. Since influenza is an airborne disease, people who work in pig and poultry farms are especially affected, just by being in close contact. Additionally, children ages 5-9 are disproportionately affected compared to the rest of the population. Other high-risk groups for influenza include the elderly living in assisted living institutions, pregnant women and healthcare workers. In many industrialized countries, influenza poses an economic burden as well, many people lose days of work or school and it causes a significant strain on the healthcare system.

Live animal markets are notorious for the spread of influenza from the animals to humans. Prolonged exposure to the hosts causes a high susceptibility to contracting influenza, especially avian and swine influenza. This is exacerbated by the fact that influenza is airborne, making it very easy to spread in a small and confined population. As Dr. Gray mentioned, pigs are the easiest mode of transportation for influenza virus to get to humans. Another point of concern is that the virus undergoes recombination within the animal host and emerges as a novel virus. So by the time it gets to a human host, it is completely new and we have no way of fighting or preventing it.

Source: http://wncn.com/2015/10/07/threat-of-avian-flu-cancels-nc-state-fair-poultry-shows/ 

North Carolina is currently anticipating a potential avian flu epidemic, as Dr. Gray described in his lecture, due to a highly pathogenic avian influenza strain, H5N2, that has already been found in 21 states. Prevention measures are already being taken, such as the cancellation of large poultry-focused events described in the WNCN news headline from October 7th this year (above). The Charlotte Observer reports an $18 billion poultry industry in North Carolina, which may be in jeopardy depending on the progress of the epidemic. Though no cases have yet been reported, a task force has already been formed to ensure effective culling of affected flocks found to be carrying the influenza strain. More than 44 million birds have been killed so far in an attempt to keep this influenza strain under control, and more are projected to be culled as the migration season approaches. This threat may initially seem irrelevant to us humans, until we consider the proximity of vulnerable animals to agricultural workers. While the species barrier between birds and humans may be harder to cross than the species barrier between pigs and humans, close contact with infected birds increases likelihood of passing on the virus from poultry to human.

There’s an additional layer to the issue. With the threat of the potential influenza A epidemic looming over North Carolina, the scientific community is faced with the challenge of promoting public health measures despite pushback from industries who may face economic damage. The balance of economic and public health issues pervades the issue of global influenza. As Dr. Gray mentioned in class, live animal markets in China have been a foundation of local economies and traditions for thousands of years, and threatening to remove these is unlikely to result in immediate compliance. Similarly, as mentioned, Dr. Gray’s article “Variant Influenza A (H3N2) Virus: Looking Through a Glass, Darkly”, farmers are unlikely to comply with studies on zoonotic influenza transmission if they perceive the success of their businesses to be at risk.

This brings us to areas of pandemic influenza that are hotly contended. How, then, do we propose to unite the efforts of these two sides of the equation? Is legislation the only option - in essence, using the power of the law to initiate compliance among economic stakeholders? Might there be areas of overlap in which both sides can cooperate? These are questions that both the scientific community and those with commercial interests will need to answer, and soon. As migration season for many bird species is rapidly approaching, united strategies will be key to effective prevention of an impending epidemic.

We cannot underestimate the importance of pandemic influenza, and the urgency with which we must handle it. Although we may have only had to deal with inconvenient symptoms like sneezing or a runny nose, this does not mean that influenza isn’t a serious illness; its strains can become deadly when left unchecked, particularly when cultivated in animal reservoirs for extended periods of time. United efforts such as OneHealth here at Duke have made huge headway in bridging the gap between different areas of study of influenza, including medicine, veterinary medicine, and environmental health, and this has greatly helped us to understand different contributors to influenza pandemics. However, true prevention of an epidemic requires further open collaboration among the government, economic stakeholders, the public, and the scientific community, and it is only when we take a multi-perspectival look at the issue that we’ll be able to deal with it this year and in years to come.