Fever

an ancient and beneficial response to infection


by Ruth Welburn

 

Lady with fever looking at a thermometer

For years, healthcare professionals considered fever to be undesirable and diligently sought to reduce it. This led to the ubiquitous and indiscriminate use of fever reducing medications in hospitals and at home. But is fever a bad thing? Could Nature have been right after all? Is there a benefit to be gained from the very symptoms we seek to annihilate? Fever earned its bad reputation partly because it is symptomatic of an infectious disease and partly because it causes discomfort to the patient. Reducing the fever was thought synonymous to treating the infection. It is now thought that quite the opposite is true.

Indeed, fever may be beneficial to our immune system. In a 2003 bulletin issued by the World Health Organization, Heinz F. Eichenwald points out that “fever represents a universal, ancient and beneficial response to infection.” The fact that fever, despite its enormous energy requirement, is found as a component of the immune response in all mammals strongly suggests that fever has critical evolutionary value. Eichenwald concludes that the suppression of fever “under most circumstances, has few, if any, demonstrable benefits. While, on the other hand, some harmful effects have been shown to occur as a result of suppressing fever.” He unequivocally discourages the widespread use of fever reducing medications.

In a 2007 issue of Microbiologist, Green and Hoption-Cann explain that fever is more than just an increase in temperature; it is a very complex, natural immunological reaction to infection and triggers the production of white blood cells and molecules that fight the infection. Fever increases the metabolic rate by 30 to 50 percent. In addition, the accompanying chills double or triple the metabolic rate. This higher metabolic rate supplies the substantial energy required to mount an immune response without compromising the energy supply for normal cellular activity. Fever also causes blood to circulate faster, which allows white cells to reach the site of infection quicker, and it speeds up the elimination of toxins from our system. Increased body temperature can also hinder the growth of bacteria and viruses and interferes with their ability to produce toxins.

One notable benefit of febrile infections is that they possess some hidden mechanism within the body’s immune system that can regress or cure tumours. Since the middle of the 20th century, there has been a surge in the incidence of cancer in the developed world. Before the elimination of many severe febrile diseases, fever was Nature’s defence against cancer. In the late 19th century, a surgeon by the name of Dr. William Coley discovered this fact when he realized that some inoperable tumours spontaneously regressed following acute febrile infections such as scarlet fever, rheumatic fever, diphtheria, typhoid, influenza, amoebic dysentery, smallpox and erysipelas. If the fever was high enough and of long enough duration, patients could sometimes live out the rest of their lives cancer free.

Today, some types of cancer are treated by stimulating the patient’s natural immune system to mount an attack on the tumour. One example of this treatment, known as “immunotherapy,” is the use of a weakened form of tuberculosis called BCG to treat superficial bladder cancer. BCG has become increasingly regarded as the most effective treatment for the removal of residual tumours following surgery. The bacterial suspension is administered directly into the bladder cavity via a catheter. It is not thought to have any direct anti-tumour effect, but it induces an inflammatory reaction that triggers a response by the immune system that indirectly affects tumours by attracting white blood cells and cytokines to the area. The cytokines change the environment in the bladder causing it to inhibit future tumour growth. In some cases, BCG induces flu-like symptoms with fever and chills that enhance the anti-tumour action. This treatment has resulted in complete tumour regression.

A recent report at a 2010 ASCO (American Society of Clinical Oncology) meeting suggests that fever has a beneficial side effect to immunotherapy. Researchers from Aarhus, Denmark, suspended the routine use of fever reducing dugs with patients receiving immunotherapy to treat metastatic melanoma. They found the therapy was more effective when patients were allowed temperatures up to 41°C (105.8°F).

There is a mounting body of evidence that indicates it is folly to interfere with the intricately designed mechanism of fever. Maybe we should think twice before taking fever reducing medication and just allow fever to run its course.

Ruth Welburn holds a Master of Science degree in microbiology. She has 20 years of experience in university research labs in the fields of virology, microbiology and infectious diseases. She has recently released a novel, The Devil’s Ruse, which deals with the 1918 influenza pandemic. Preview the novel at www.ruthwelburn.com

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