Tuesday, July 21, 2009

Pandemic Viral Illnesses Occur Every Year.

A Perspective

What interests me and other science philosophers is how nonsense routinely overwhelms reliable knowledge. Humans appear to have an endless capacity and need to generate nonsense. Nonsense is generated, in part, as nominal fog that obscures a simple truth - we do not know what will happen next. "Experts" are just as limited as the most ignorant and opinionated nonsense generator. You could, without any hesitation, award television news media with the Oscar for the best nonsense generators of the year. Their nonsense spreads worldwide with speed and penetration that would make any virulent virus envious.

There are a host of current examples of noumenal fog generators under titles such as Health Care, Economy, National Security, Terrorism and most recently, Pandemic. Whenever these key words appear, have a look, you will not be disappointed -- the ratio of nonsense to sense will be at least 9 to 1.

I have chosen today to do a brief review of the Swine Flu Scare of 2009 - a great pile of nonsense that seem to have overwhelmed even the most cautious of scientists. This is not to argue that H1A1 viruses are innocuous, but to develop a perspective on the relative threats of viruses in general and to reveal that the evidence for swine flu as a special threat is lacking.

In the Northern hemisphere, viral epidemics cause up to 80% of all respiratory illnesses. The most common infections are caused by six viral groups: rhinovirus (RVs), respiratory syncytial virus, influenza virus, parainfluenza virus, corona virus, and adenovirus. In one study of 285 children admitted to hospital with lung infection, viruses were identified in 125 - respiratory syncytial virus (107), influenza (9) and parainfluenza type 3 (9). Clinical and radiologic diagnoses included bronchiolitis (127), interstitial pneumonia (47) and lobar pneumonia (91).

Rhinoviruses often referred to as “cold viruses” cause the majority of respiratory illnesses. Other viruses contribute to waves of colds, coughs, bronchitis, asthma and pneumonia that pass through every human population in epidemic patterns. Colds are rhinovirus infections that are usually mild and self-limiting but are more serious in premature babies and children with chronic diseases or immunosuppression. The average child can expect to have four to eight rhinovirus infections per year, and adults have three to five infections.

Respiratory Syncytial Virus is spread by coughing and sneezing; by close contact with sick patients or by hand contamination. Infection develops in care -givers who touch their eyes or nose with contaminated fingers.

Adenoviruses While Influenza viruses are well-known and epidemics of more virulent influenza strains are feared, other less known viruses, especially adenoviruses, tend to be common and can produce severe illnesses. For example, adenoviruses are the second most prevalent cause of acute lower respiratory infection of viral origin in children under four years of age in Buenos Aires, Argentina. Pneumonia was observed in 71% and bronchiolitis in 29% of children admitted to hospital with adenovirus infection. Wheezing occurred in 58% of the children. Four children died (a fatality rate of 16.7%). Adenoviruses have emerged as important pathogens in immunocompromised patients, in whom disseminated disease occurs frequently and is associated with a high mortality rate. For over 25 years, the US military controlled adenoviral respiratory infections through immunization of its members. A group of Navy physicians reported a “large epidemic of respiratory illness due to adenovirus in healthy young adults” after adenovirus vaccine supplies were depleted.

The US military medical services are perhaps best equipped to diagnose and treat adenovirus infection which cause outbreaks of disease among military recruits. A National Surveillance for Emerging Adenovirus Infections system includes military and civilian laboratories at 15 sites in the USA. Fifty-one adenovirus serotypes have been identified. In 2007 the emergence of a virulent Ad14 variant spread through the United States with some deaths. Ad14 infection was described initially in 1955 and was responsible for an epidemic acute respiratory disease in military recruits in Europe in 1969. In 2001-2002, Ad14 was associated with approximately 8% of respiratory adenoviral infections in the pediatric ward of a Taiwan hospital, with approximately 40% of Ad14 cases in children aged 4-8 years manifesting as lower airway disease. During the years, 2004-2007, the US surveillance system detected 17 isolates of Ad14 from seven sites. During March-June 2007, a total of 140 additional cases of confirmed Ad14 respiratory illness were identified in Oregon, Washington, and Texas. Fifty-three (38%) of these patients were hospitalized, including 24 (17%) who were admitted to intensive care units (ICUs); nine (5%) patients died

Influenza viruses cause epidemic respiratory illness every winter in most countries on the planet. New virus strains spread globally and cause prolonged illness and some deaths. The routine death toll in the US and Canada every year has been estimated to be 32,000 people.
Since the exact cause of fatal pneumonia is seldom correctly diagnosed, the fatality rate for influenza ( and other viral infections) is not really known. Other viruses also cause illnesses that spread globally with substantial morbidity, cost and some deaths. Influenza often begins with cold symptoms and progresses to involve the lungs. Most patients develop a chronic cough that can last for weeks. Pneumonia can develop and is a common cause of death.

Much publicity has been given to the possibility of an especially virulent strain emerging that will increase the death toll from thousands per year in the US and Canada to millions. Some virologists were concerned that influenza virus epidemics in birds would produce a newly virulent human virus. The World Health Organization warned that the world was not prepared for the next pandemic ( true). As of January 2006, the strain of avian influenza, A (H5N1), has been identified in only 148 human, 79 of them fatal, from direct contact with infected birds. The strain was first detected in Hong Kong in 1997 and has spread through Southeast Asia and then in Russia and Turkey. So far, bird flu has not become a major threat to human survival.

In 2009 a H1N1 variant ("swine flu") emerged and caused another media frenzy; the WHO declared a "pandemic" and despite reports of a relatively mild illness with a low mortality rate, news anchors began to refer to a "deadly virus" (false). The positive aspect of the scare tactics was increased international cooperation in monitoring the spread of the virus and increased funding of vaccine development.

Some of the fear was generated by comparison with the 1917 flu pandemic caused by another H1A1 virus. The truth is that speculations adn predictions based on very limited knowledge of that pandemic are likely to be wrong. While you can argue that every year, influenza and many other types of viruses create pandemics and every year more virulent strains could emerge, there is no reliable knowledge that allows experts to predict what will happen next.

Airborne causes of illness are discussed in the 2009 book,
Air and Breathing by Stephen Gislason MD