Forecasting the Flu
Influenza - a Category 5 killer virus
Sniffling noses and hacking coughs are respiratory distress sounds more common as fall turns to winter. On the sickness scale, common colds, bronchitis and sinusitis are the least serious respiratory woes. Various pneumonias strike like summer thunderstorms with the occasional wallop of a tornado. The granddaddy of all the respiratory infections is influenza, potentially deadlier than a Category 5 hurricane.
Parallels with hurricanes and influenza are common. Meteorologists predict the number of named storms and the likelihood for direct hits on our coast beginning each spring. Usually the predictions are ominous. True to form, University of Colorado hurricane experts predict above average activity for the 2017 season. If we take a hit, the experts take a bow. If we escape seasonal hurricanes, those wrong predictions are easily forgotten.
Just like the hurricane centers, influenza experts predict the worse, emphasize preparation, revise predictions as fall marches into winter, and hope that serially inflated concerns do not lull the public into complacency.
Influenza and hurricane comparisons date back to 1918 when “evil bearing microorganisms” invaded New Orleans with “whirlwind onset, cyclonic progress, and hurricanic destruction” during the Spanish influenza pandemic that swept the globe. In New Orleans, the death toll quadrupled during the three peak months beginning in October 1918. Extrapolated to today’s population, the count for lost lives would be the equivalent of 9,000 deaths just in Orleans Parish today.
The Asian flu pandemic beginning in 1957 was our second most serious outbreak in the past 100 years. During this pandemic, Tulane was the south’s epicenter for respiratory virus research.
“The medicine wards at Charity were overflowing. Pregnant women, who then were never vaccinated, had especially severe disease. Some died,” said Dr. William Mogabgab, a now deceased physician and virologist describing the 1957 epidemic. Dr. George Pankey, a trailblazing infectious disease specialist at Ochsner, was an intern at the University of Minnesota during the 1957 epidemic. More than half of the patients in the heart unit died.
Mogabgab lobbied the U.S. Surgeon General in 1957 to establish a national commission to standardise and improve vaccine efficacy. Since 1957, we have weathered lesser Hong Kong, Russian, and H1N1/09 outbreaks in part due to improved and better vaccines. But thanks to air travel, newer outbreaks move faster than in the old days when the virus depended on just migratory birds and ships for international travel.
Today a successor to the commision first proposed by Dr. Mogabgab decides what influenza strains to include in each year’s vaccine to cover the constantly evolving and mutating strains. This year the basic trivalent vaccine targets flu strains first isolated in Michigan, Hong Kong and Australia.
As September turns into October, various influenza predictions increase in the print and airwaves especially during slow news weeks. Will this be a bad year for influenza? What’s in the vaccine this year? Who needs the flu shot? National and local physicians usually weigh in.
There is one major difference between predicting hurricanes and influenza. Years can pass without a hurricane making landfall near our piece of semitropical paradise, but there is no such thing as a year in New Orleans without influenza. Influenza, not hurricanes, remains our most dangerous recurrent seasonal hazard.
The Louisiana Department of Health issues weekly updates on influenza-like illnesses with an eye towards early detection of any changes in viral strains or upticks in cases. Our influenza season trails our hurricane season and can even conflict with Mardi Gras. But influenza is much less predictable than Mardi Gras.
Usually influenza diagnoses gradually increase before peaking in later winter months.For southern Louisiana, January and February are classic peak periods, but influenza watchers always expect the unexpected. For example, early October spikes occurred in 2009 and 2011.
Unlike minor respiratory infections, influenza is a systemic disease. It hits with the impact of a freight train and respiratory symptoms often take a second seat to disabling fever, chills, and body aches and pains. Children less than 5 years old, pregnant women, and senior citizens are at high risk for serious complications including secondary bacterial infections and even post-viral depression months later. Folks with underlying heart, lung, and immune system disorders are most vulnerable to deadly exacerbations of their underlying chronic illnesses.
Influenza is highly contagious. Hospitalized patients are especially vulnerable, and outbreaks caused by unvaccinated healthcare employees are well documented. All local hospitals encourage employee immunization; at least one local hospital mandates immunization. Employees who refuse immunization, are mandated to wear masks for all patient contacts during outbreaks.
When prevention fails, rest, fluid and prayer are all in order. The prescription drug Tamiflu sometimes lessens symptoms. But, in a move hailed as a victory for evidence based medicine, the World Health Organization recently demoted Tamiflu to its non-essential category of drugs after non-drug company testing showed promised benefits were less than originally hyped.
The bottom line – a flu shot is good disease insurance and it is that time again.
Tips: Preventing the Flu*
1. Why should you get vaccinated? Getting an annual flu vaccine is the best way to protect yourself and your family from the flu. Flu vaccination can reduce flu illnesses, doctors’ visits, and missed work and school. Increasing the number of people who get vaccinated each year helps to protect more people.
2. When and how often should I get vaccinated? Everyone six months and older should get a flu vaccine every year by the end of October, if possible. However, getting vaccinated later is OK. Vaccination should continue throughout the flu season, even in January or later.
3. What should I do to protect myself from flu this season? In addition to getting a seasonal flu vaccine, you can take everyday preventive actions like staying away from sick people and washing your hands to reduce the spread of germs. If you are sick with flu, stay home from work or school to prevent spreading flu to others.
4. Can I get vaccinated and still get the flu? Yes. You may be exposed to a flu virus shortly before getting vaccinated or during the period that it takes the body to gain protection, or you may be exposed to a flu virus that is not included in the seasonal flu vaccine. Flu vaccination is not a perfect tool, but it is the best way to protect against flu infection.
5. What should I do if I get sick with the flu? Treatment with antivirals works best when begun within 48 hours of getting sick, but can still be beneficial when given later in the course of illness. Antiviral drugs are effective across all age and risk groups.
*Source CDC.gov (Centers for Disease Control and Prevention)