The most under diagnosed health problem in the West, parasites may be responsible for a multitude of conditions from joint pain and chronic fatigue to many general disorders of the gut and immune system
Few of our doctors in civilized Western nations are trained to recognize the signs of parasitic infestation. Yet parasites do live among us. According to a number of experts, they may be the single most under diagnosed and under appreciated health threat in the West.
Parasites, which can be broadly classified as either protozoa (such as Giardia and Cryptosporidium), worms (including roundworms, or nematodes and tapeworms, or cestodes), or flukes (also called trematodes, which attack various body tissues with powerful suckers), have been associated with a wide range of diseases. Eminent doctors, such as WDDTY panellist Dr Leo Galland, have spent many years researching the effects of human parasites on health. Indeed Dr Galland has gone on record suggesting that "every patient with disorders of immune function, including multiple allergies (especially food allergies), and patients with unexplained fatigue or with chronic bowel symptoms, should be evaluated for the presence of intestinal parasites".
As recently as 1987, a group of American researchers from the Centers for Disease Control and Prevention analyzed the results of 216,275 stool specimens, examined by state laboratories across the US. They found parasites in 20 per cent of the samples (Am J Trop Med Hyg, 1994; 50: 705-13).
The most common were Giardia intestinalis, Entamoeba coli, Endolimax nana, Blastocystis hominus and Entamoeba histolytica, but nematodes were also found. Their conclusion was that parasites were being overlooked as an important cause of gastrointestinal (GI) illness in the US.
Other reviews clearly illustrate the extent of the problem. According to the report Parasitic Diseases (Despommier, et al, New York: Springer Verlag, 1995), the number of people worldwide who are infested with the different classes of parasites is: nematodes, 1 billion individuals; cestodes, 300 million; trematodes, 300 million; and protozoa, 1 billion. This gives some credence to the oft quoted statistic that at least 50 per cent of the world's population is infested with at least one parasite.
Although parasites, when they do occur in the West, have been considered largely a problem of rural areas, this is also untrue. Recent outbreaks of Crypto-sporidia, Cyclospora and Giardia in metropolitan and relatively affluent areas, such as New York City, Las Vegas and London, suggest that no area and no social class is exempt. Indeed, the largest outbreak in US history, affecting over 400,000 people and killing 100, occurred in Milwaukee, Wisconsin.
Parasites latch on to those whose immune systems are functioning poorly. Generally, individuals whose immune systems are already compromised from chemotherapy for cancer or from immune suppressing drugs for AIDS are especially vulnerable to parasitic infections. But because we are all bombarded daily with substances which overstimulate and exhaust our immune systems, we are all vulnerable
Misdiagnosis
Most doctors have no training in tropical medicine or parasitology, and simply would not recognize the signs of parasitic infestation. Many common symptoms, such as nausea, gastrointestinal upset, insomnia and constipation, can easily be attributed to other diseases. Consequently, doctors rely on routine tests to provide a diagnosis. Such tests will commonly yield false results, leaving the real cause of the illness uncovered.
Should a patient undergo a stool test, this may also prove to be misleading. Single stool tests are unlikely to be conclusive. To be reliable, it may be necessary to test three or more samples since the shedding of eggs in human feces tends to be cyclical. A single test would only be reliable if the sample was taken around the time that the adult parasite lays its eggs. Also, those parasites which inhabit muscles and other tissues will not show up in a stool test. To detect these parasites, tissue samples must be obtained.
The standard stool test is also unlikely to be helpful in detecting those parasites which inhabit the upper GI tract. This is why some physicians believe that the purged stool test, involving the use of a powerful laxative, may be a more conclusive tool, particularly when searching for Giardia, amoeba, roundworm, threadworm, tapeworm, flukes, Cryptosporidium and hookworm. This test should not, however, be administered in cases of intestinal obstruction, pregnancy, appendicitis, high blood pressure or debilitation.
It is believed that taking samples of rectal mucous, which the eggs adhere to, is the most reliable way of determining whether an individual is suffering from parasitic infestation, especially for those who are greatly debilitated. A recent study showed that when this method was used, almost 50 per cent of patients previously diagnosed as having irritable bowel syndrome were discovered to actually be suffering from giardiasis. The patients had been suffering with misdiagnosed bowel problems for an average of seven years (AL Gittleman, Guess What Came To Dinner, New York: Avery, 1993).
Blood tests can only be a general indicator of parasitic infection. Most parasites, except for Giardia and amoeba, will elevate levels of the white blood cell eosinophil, which is produced in response to allergens and infections, in this case the parasite. Blood tests can also be used to detect specific antibodies to such organisms as Entamoeba histolytica, Toxoplasma gondii, Leishmania, Strongyloides and flukes. However, these may not be entirely reliable in individuals who are already so immune compromised that they cannot produce antibodies.
But at the moment, diagnosis is almost a moot point since the majority of doctors simply would not consider the search for parasites as a first option in treatment. Because of this, patients can be left with damaging parasites infesting their tissues and organs, leeching essential nutrients from their system and causing extensive gut damage. But more importantly, a misdiagnosis leads physicians to prescribe powerful drugs which can further depress the immune system leaving the individual open to more prolific infestation.
Once parasites take up residence, symptoms may appear immediately, within a few days or, in some cases, not for months of even years. Infected individuals may also be asymptomatic, showing no symptoms themselves but still capable of transmitting parasites to others. In latent cases, it is usually another illness, surgery or stress, which further challenges the immune system and may, in turn, bring on symptoms of infestation.
Where do they come from?
Perhaps the most disturbing aspect of parasite infestations is that they come from many of the things which we need in order to survive: the water we drink and bathe in, the food we eat, the air we breathe. Pets, sexual practices, crowded day care centers and international travel are also implicated.
Drinking water is increasingly becoming an act of faith. Apart from being polluted with high levels of toxic chemicals, studies by American water authorities have shown that the Giardia cyst can survive for up to three months in cool or cold water, while the Cryptosporidium cyst can survive for between 12 and 18 months (Journal AWWA, Feb 1988: 14-27). Cryptosporidium is now the leading cause of water borne illness in the US, with over 80 per cent of surface water samples and 28 per cent of drinking water samples taken from hundreds of sites across the eastern and western US found to be contaminated with this parasite (Appl Environ Microbiol, 1994; 57: 2617-21).
While water is the most common source for parasites such as Cyclospora, food can also harbour this parasite. In the spring of 1996 and 1997 in the US and Canada, an outbreak of cyclosporiasis was associated with the consumption of fresh Guatemalan raspberries (Ann Intern Med, 1999; 130: 210-20). The outbreak affected more than 1000 individuals.
Cryptosporidiosis has also been associated with the consumption of school milk. In West Yorkshire in 1995, 50 children became ill with gastrointestinal symptoms after drinking school milk. Lengthy questionnaires pinpointed the source as being a small scale local producer who had an on farm pasteuriser (Lancet, 1997; 350: 1005-6). Other studies have associated Cryptosporidium with drinking unpasteurised milk (BMJ, 1990; 300: 774-7; Eur J Clin Microbiol, 1987; 6: 56-9).
What Doctors Don't Tell You Volume 10 No 3
Symptoms associated with parasitic infestation
-Constipation -Diarrhea
-Gas and bloating -Joint and muscle pain
-Anemia -Allergy
-Skin conditions -Granulomas
-Nervousness -Sleep disturbance
-Teeth Grinding -Chronic fatigue
Immune dysfunction
CLINICAL TIP
Watch the full moon. Parasites are more active around the full moon and symptoms may be more apparent around then. Your stomach is your number one line of defense for your gastrointestinal system. 80% of your immunity is though your gut. Low stomach acid is another reason many people many have problems with parasites. I have found through practice that many of my patients who eat sushi to have problems with parasites too.
Dr. J