posted on August 12, 2008

A Medical Response To Pandemic Flu

By: Avram L. Nemetz, M.D.

A flu pandemic is a potential disaster that will directly affect the health and well-being of a company's most valuable asset, its employees. As such, planning for a flu pandemic must include a medical response.

After all, a company may have a terrific business continuity plan, but without healthy employees to implement it, the plan will be useless.

Goal of a Medical Response

An effective medical response will mitigate the effects that a pandemic will have within any individual company. It will be possible to reduce the number of people who will become ill, help those who are afflicted with the flu to get better and return to work faster, and most importantly reduce the number of employees who would die from influenza.

There are four main areas of focus when implementing a medical response to Pandemic Flu:

• Reducing/Avoiding Exposure
• Seasonal Flu Vaccine
• Pandemic Vaccines
• Antiviral Medicines

An effective medical response, in coordination with a business continuity plan, must address all four focus areas.

1. Ways to Reduce and Avoid Exposure

Immunity is not an all-or-nothing phenomenon. It is estimated that 30-50% of people exposed to a new influenza virus strain have antibody evidence of having been exposed, yet never develop clinical illness. What can account for that? One factor is the quality of an individual's immune response to a particular virus, but also important is the quantity of active virus particles to which one initially is exposed.

Viruses do not live and reproduce independently, in the way of more complex bacteria. An influenza virus particle must attach to and then penetrate the wall of a cell which is lining the respiratory tract. Once inside the cell, a single influenza virus particle takes over the cell's machinery and produces thousands of new virus copies, causing the cell to rupture, releasing the viruses which attach to other cells, where they then repeat the process.

To mitigate the effects of influenza, you can either reduce the number of virus particles that initially begin their attack, or, using antiviral medications, you can block the virus particles from being able to penetrate the cell wall. I will address antiviral medications later.

Reduce the level of exposure to the influenza virus with:

Education. You have to learn the facts about influenza--what it is, and how you get it--in order to protect yourself. It's not difficult to become an expert.

Personal Hygiene. Wash or sanitize your hands frequently, and learn not to touch your face. Touching your face is an easy way to introduce the virus into your respiratory tract.

Occupational Hygiene. Hard surfaces must be kept clean, and workspaces not shared too closely. Telephones, computer keyboards, and doorknobs are virus sources.

Personal Protective Equipment (PPE). Masks significantly reduce virus exposure. N-95 masks are the standard, but they are difficult to breathe through for an 8-hour workday, and require individual fitting to meet efficacy standards. Paper surgical masks have surprising effectiveness, due to their ability to block the microscopic exhaled droplets which carry the influenza virus.

Social Distancing. This refers to the voluntary isolation of the sick, voluntary quarantine of household contacts, school closings, restriction of public gatherings, etc.

2. Seasonal flu shots

This is part of every health authority's recommendations for overall pandemic planning. You cannot tell the difference between the initial physical symptoms of seasonal flu versus those of a more serious pandemic virus. If a new pandemic is developing and an employee has seasonal flu symptoms, it will be impossible to determine if the illness is from a pandemic strain.

Public health officials have other reasons for this recommendation: a pandemic virus mixing in an individual who is carrying the seasonal flu simultaneously presents a perfect medium for recombination, and the development of another novel virus strain. The fewer people who get the flu, the fewer are spreading it to others.

3. Triggering an Immune Response - Pandemic Vaccines

A vaccine works by stimulating one's body to produce antibodies, which in turn recognize and fight off the virus. A vaccine created from a specific pandemic virus will ultimately be the best medical protection. While a vaccine based on the current virus that is affecting birds has recently been approved by the FDA, it is not highly effective, may not be effective against the pandemic virus strain, and will not be available to the general public.

If a new flu virus gains the ability to be spread easily from person to person, it will take at least 6 months from the time the strain emerges before a vaccine will become available. It will take months longer than that before it is widely distributed. However, computer models estimate that within 3 months of the first pandemic case in the United States, the influenza virus will have swept from coast to coast.

There is a large window of vulnerability between the emergence of a flu pandemic and the availability of a vaccine. This window can be closed with antiviral medications.

4. Blocking the Virus from Replicating - Antiviral Medications

Antiviral medications are different from vaccines. Tamiflu and Relenza, the two most popular and effective antivirals, are "neuraminidase inhibitors." Neuraminidase inhibitors physically block the lock-and-key mechanism between the influenza virus and the cell that is lining the respiratory tract, which when keyed activates the virus' enzyme neuraminidase, which is used to penetrate the cell. This must happen in order for it to replicate.

This is the critical point. To use antiviral medications successfully, the timing is very important. Unlike conventional antibiotics, antiviral medications have to be taken early in the course of the illness to have the desired effect. For example, Tamiflu must be taken within 1-2 days of the onset of influenza symptoms to have any effect on the course of the illness.

Will Antiviral Medications work in a Pandemic?

While nothing is guaranteed, the April 2007 Summary of the second WHO consultation on clinical aspects of human infection with avian influenza A(H5N1) virus, finds that "experiences with early oseltamivir (Tamiflu) treatment suggest its usefulness in reducing H5N1-associated mortality. In addition, evidence of prolonged H5N1 virus replication indicates that treatment is warranted even with late presentation."

Japan is the country with the most experience using Tamiflu for seasonal influenza. Each year, 10-15% of people in Japan get seasonal influenza, which adds up to 16 million people. Six million of them receive Tamiflu. It is the elderly and the very young who are most susceptible to dying from seasonal influenza, but the mortality rate in children who receive Tamiflu is reduced by a factor of 60-90% compared to children who do not receive Tamiflu.

From the standpoint of a practicing physician, when properly used antiviral medications can result in a reduction in mortality from seasonal influenza by 60-90%, there is no choice in an individual who has influenza--you have to use antiviral medications. In the context of a corporate medical response to a pandemic, the question becomes broader: How do you do it safely and effectively, in a medically responsible manner, on a large scale?

Antivirals for Your Employees

Because of their previous scarcity, this aspect of the medical response has not received the public attention it merits. The era of scarcity of antiviral medications is now over.

An effective antiviral distribution program for your employees must include education, a medical assessment, a prescription, and distribution before an employee becomes ill.

Education. It makes no sense, as a medical pandemic strategy, to throw an antiviral medication at individuals. People have to understand what it is for, how to recognize flu symptoms, when to take it, and when not to take it.

Medical Screening. Antiviral medications are available only by prescription. A face-to-face encounter with a physician licensed in the state where the interaction occurs is a legal requirement. Fortunately, there are very few medical contraindications to using antiviral medications under emergency circumstances. The majority of employees will be able to receive antiviral medications after a brief physician encounter. Companies who initially purchased stockpiles of antiviral medications when they were scarce are now implementing health screening programs for the purposes of writing prescriptions for their employees (and oftentimes their employees' families).

Distribution. Companies can choose to distribute the antiviral medications to their employees (and oftentimes their families too) now or they can wait until a pandemic seems imminent. Distribution is most often coordinated through a mail order pharmacy, outside of a company's health insurance.

The shelf life of Tamiflu is excellent, currently five years from the date of manufacture, and may be extended. It is stored at room temperature so it can go on the top shelf of the medicine cabinet and be left there. If no pandemic develops, it's never used. If a pandemic develops and you don't get sick, you don't take it. If a pandemic develops, you have a temperature of 104F, and you're laid out in bed for 24 hours with terrible body aches and a racking cough that hurts your chest--it's not going to be subtle. This is when you reach for your Tamiflu.

Conclusion

Never before have we been able to track the virus in animals, detect early evidence of human-to-human spread, educate and communicate so effectively with large numbers of people, and interrupt the natural course of influenza's development with vaccines, personal protective equipment, and antiviral medicines.

We have effective tools with which we can protect large swaths of the population. Business continuity planners must use them all to mitigate the effects of a pandemic. Employees will feel protected and safe to come to work if they are educated, have received their flu shot, have Tamiflu or Relenza in their cabinet, know how and when to use them, and comprehend how to protect themselves from the virus' transmission.

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About the Author

Avram L. Nemetz, M.D. has been Medical Director at Affiliated Physicians for 16 years. A graduate of Cornell University and the Albert Einstein College of Medicine, he has significant experience managing corporate medical emergencies--most of which are related to infectious diseases. He has been actively involved since 2003 in creating Affiliated Physicians' program to assist companies with their Pandemic Flu planning. You can contact him directly at anemetz@affiliatedphysicians.net.