Colds and influenza: a review of diagnosis and conventional, botanical, and nutritional considerations

Alternative Medicine Review, March, 2007 by Mario Roxas, Julie Jurenka

Abstract

The common cold is the leading cause of doctor visits in the United States and annually results in 189 million lost school days. In the course of one year the U.S. population contracts approximately 1 billion colds. Influenza infection is still a leading cause of morbidity and mortality, accounting for 2025 million doctor visits and 36,000 deaths per year in the United States. Conventional therapies for colds and flu focus primarily on temporary symptom relief and include over-the-counter antipyretics, anti-inflammatories, and decongestants. Treatment for influenza also includes prescription antiviral agents and vaccines for prevention. This article reviews the common cold and influenza viruses, presents the conventional treatment options, and highlights select botanicals (Echinacea spp., Sambucus nigra, larch arabinogalactan, Astragalus membranaceous, Baptisia tinctoria, Allium sativa, Panax quinquefolium, Eleutherococcus senticosus, Andrographis paniculata, olive leaf extract, and Isatis tinctoria) and nutritional considerations (vitamins A and C, zinc, high lactoferrin whey protein, N-acetylcysteine, and DHEA) that may help in the prevention and treatment of these conditions.

Introduction

The common cold, also referred to as acute viral nasopharyngitis, is a mild, self-limiting infectious disease that can be caused by more than 100 different viruses. Of these, rhinoviruses and coronaviruses are responsible for approximately 50-70 percent of all colds. (1,2) Colds were known to man even in ancient Egypt where they were depicted in hieroglyphs. The Greek physician Hippocrates described the disease as early as the 5th century BC. In 1914, Walter Kruse, a German professor, demonstrated that viruses, not bacteria, cause the common cold, (3) but the finding was not widely accepted until the 1920s when Alphonse Dochez confirmed it in chimpanzees and humans. The term "cold" was likely derived from ancient physicians who described "cold conditions" and "warm conditions" that were dependent on or caused by cold or warm environments. In modern times the misnomer has persisted, possibly due to the viruses' effect on thermogenesis. People are thought to associate the shivering from a viral-induced fever with shivering from being in a cold climate. (4)

Although generally benign in symptomology, cold viruses are the most common infectious diseases humans contract and result in significant costs to the economy in lost workdays and school attendance. Adults average 2-4 colds per year and children 6-10, depending on age and exposure. (5) A 2003 study found common colds resulted in more than 100 million physician visits annually, at a cost of $7.7 billion. At least one-third of these patients received an antibiotic, even though they have no effect on viral infections, not only adding to the cost but also contributing to the development of antibiotic resistance. The study also found Americans spend nearly $3 billion annually on over-the-counter drugs that may not provide any symptom relief. In addition, an estimated 189 million school days are missed due to colds, which consequently result in 126 million missed workdays by parents who stay home to care for sick children. (6)

Influenza is an acute respiratory illness caused primarily by the influenza virus (serotypes A and B). It occurs worldwide and is responsible for considerable morbidity and mortality. The first report of what was likely an influenza epidemic was noted in 1173-1174, (7) and the first definitive report occurred in 1694. (8) During the 18th century, data on flu epidemics increased considerably; with comprehensive reports appearing in the 19th century. (7,9,11) Influenza A viruses were first isolated in the laboratory from human specimens in 1933, (12) and in 1957 the virus was made available for laboratory analysis. (13) Subsequent studies have demonstrated the influenza virus mutates rapidly (antigenic drift), creating difficulties each year for researchers trying to develop effective vaccines. (14)

Influenza--usually more severe than the common cold--typically causes fever, headache, muscle aches, and a more significant cough; however, mild cases of influenza are similar to colds. Of the two serotypes, influenza A occurs more frequently and is more dangerous. Although most epidemics and pandemics are caused by influenza A, both A and B serotypes frequently co-circulate during yearly outbreaks. Although influenza B is usually less severe, in children the clinical presentation may be similar to that of influenza A.15 Influenza-like illness is clinically similar to true influenza but is caused by a virus other than influenza A or B (e.g., the respiratory syncytial virus). (16)

In the United States, influenza epidemics typically occur during the winter months; the influenza "seasoft" stretches from fall to spring in the Northern Hemisphere, with peak activity from December through early March. Between 1990 and 1999, 36,000 deaths per year were attributed to influenza in the United States. (17,18) In influenza epidemic years, 10 percent or more of the population is typically infected, with about 50 percent of those infected showing symptoms. (19) Although influenza viruses infect every age group, children have the highest infection rates. Serious illness and death rates are highest among the elderly, young children under age two, and those with medical conditions placing them at increased risk for influenza complications. (17)