Giardia lamblia is a protozoan flagellate that causes the disease Giardiasis. In Europe, the organism is sometimes called Lamblia intestinalis. At one time, the infection was known as “beaver fever” because it was thought that only the beaver harbored the cyst. Because of its teardrop shape and two nuclei, the organism has a distinct appearance under a microscope, resembling a human face looking back at you. It also has four flagella for locomotion, and exists in both the trophozoite and cyst stages.
Giardia is a tiny organism but only one cyst is enough to cause disease. About 8,000 trophozoites can fit on the head of a pin. They are not all killed with chlorination, but can be with iodine-based solutions. Boiling also kills them, but the water must be a rolling boil for at least ten minutes at sea level. At higher elevations, boiling requires and additional five minutes. Understandably, there is not much left of the water after that length of time. Filtering is the most reliable means, but not all filters are created equal. The filter size cannot be greater than three microns, and it must state that giardia will be filtered out. Washing vegetables and fruits must also be taken into account when using tap water.
The cyst is able to exist for long periods outside the body, remaining on such inanimate objects as toys, and regaining entrance to a human body through the oral route. Since many children do not readily show symptoms of any illness, they unwittingly spread the disease. More often than not, infection is spread when the cysts lodge under fingernails after a diaper change. In this manner, infection can easily be passed from one infant to another in day care centers, or from one person to another in homes. In some day care centers, more than 90% of the children were infected. The infection rate is increasing so rapidly that it may now be the most frequently found parasite.
Since giardia cysts are resistant to stomach acid destruction, it passes on through to the intestines. There, it reverts to the trophozoite stage and multiplies by dividing (just a little mathematical humor!). Incubation is five to twenty-five days, with most feeling sick within a week. The trophozoites adhere only to the upper small intestine, and do not spread to other parts of the body. By adhering to this part of the intestine, its numbers prevent the digestion and assimilation of foods, causing gastroenteritis. Another result of such interference is with the absorption of fats, causing them to be eliminated in the feces. This may sound like a wonderful idea for dieting, but instead, it is destructive. Fat soluble nutrients are then unable to be assimilated because the fats are unable to help carry them into the system. Therefore, deficiencies soon develop. Damage to the intestinal villi can persist long after the infection is controlled. Problems with chronic iron deficiency, anemia, vitamins A and B12 deficiencies, low serum calcium, lack of folic acid, fat malabsorption, and lactose intolerance occur with prolonged infections. Infectiousness can last a year or as long as the cysts are excreted. The expelled cysts can remain infectious in a moist environment for several months.
Signs of giardia infection include the following: gastroenteritis and diarrhea that produce dark, greasy, foul-smelling stools; bloating; nausea; weight loss; and abdominal cramping. Chills, low-grade fever, belching, and a headache may also be present, along with considerable amounts of discomfort and flatulence. After an acute episode, symptoms will diminish, leaving intermittent diarrhea and constipation, abdominal distention, and a persistent foul-smelling gas. The giardia can sometimes attach to the bile ducts of the liver, creating symptoms mimicking gall bladder disease. In addition, it is one of the many microscopic organisms that can affect behavior, as well as physical, function. Chronic fatigue and depression are symptomatic of long-standing giardiasis. In small children and the elderly, severe dehydration caused by diarrhea and vomiting can be fatal. It can also be misdiagnosed as celiac disease or failure to thrive syndrome. Symptoms can last for two to three weeks, with gradual improvement. The infection can become chronic, however, with intermittent bouts of diarrhea, accompanied by anorexia, weight loss, and nausea. With or without treatment, the organism is difficult to eliminate. Individuals most at risk are those with type A blood, who lack sufficient hydrochloric acid, or who have a history combating Candida albicans. (See Avoiding and Treating Parasites.)
Almost 50% of those infected will have a sugar intolerance, especially to lactose and sucrose. Children diagnosed with celiac disease or ADD may be infected with this parasite, and, by treating them for it, all the other symptoms disappear, in most cases. It is the most common intestinal protozoal infection in the US, with municipal water often the source of infection. Outbreaks of giardiasis are doubling every five years, having infected at least eighteen million people in the US alone. Because of the number of ignored or misdiagnosed cases (giardiasis often being diagnosed as irritable bowel or chronic fatigue syndrome), many researchers feel that the actual number of giardiasis cases is astronomical. Other estimates are that 90% of the documented cases of water-borne giardia come from surface water contaminated by animal feces. Divers often become infected with giardia as well as Entamoeba histolytica.