Occasionally, people with giardiasis will have long-term complications such as reactive arthritis, irritable bowel syndrome, and recurring diarrhea that can last for years.
Some people develop a chronic form of Giardia that lasts even longer, although symptoms tend to become less severe over time. Nutritional problems — Giardia can also interfere with the way the body absorbs nutrients, so it can cause vitamin deficiencies and other nutritional problems.
Giardia forms spore-or egg-like cells called cysts, which can survive outside the body for long periods of time. The cysts are a resting or dormant stage that helps the organism survive in unfavorable environmental conditions.
The active form is present in the gut of an infect person or animal. The inactive cyst form can remain dormant in the environment for several months. Parasites can leave their host's body when a person or animal has a bowel movement. Outside, they form a hard, protective shell and become a Giardia cyst.
In the United States, Giardia infection is the most common intestinal parasitic disease, and it affects more than 1 million people per year.
Several drugs can be used to treat Giardia infection. Effective treatments include metronidazole, tinidazole, and nitazoxanide. Other medications include paromomycin, quinacrine, and furazolidone. Some of these drugs may not be readily available in the United States.
Thus, drug resistance in Giardia is the ability of this parasite to survive in the presence of an antimicrobial drug dose that would normally kill it or limit its growth.
How long after infection do symptoms appear? Symptoms of giardiasis normally begin 1 to 2 weeks after becoming infected.
Natural treatment methods for giardiasis are usually quite inexpensive, with most health food stores having the black walnut or a bottle of grapefruit seed extract available for just a few dollars. Medicines such as Metronidazole are also quite inexpensive.
Watery, sometimes foul-smelling diarrhea that may alternate with soft, greasy stools.
Parasites can live in the intestines for years without causing symptoms.
If it's left untreated, symptoms can last 6 weeks or more. As with any illness, complications can occur. These include: Dehydration – losing too much water and other fluids in your body.
The Giardia lifecycle has two distinct phases: a vegetative trophozoite and an infective cyst that is resistant to harsh environmental conditions.
Symptom recurrence, including abdominal symptoms and fatigue, can result from re-infection, treatment failure, disturbances in the gut mucosa or post-infection syndromes.
Low-grade fever (infrequent) Various neurologic symptoms (eg, irritability, sleep disorder, mental depression, neurasthenia)
Individuals infected with Cryptosporidium are more likely to develop symptomatic illness than those infected with Giardia. Symptoms include watery diarrhea, cramping, nausea, vomiting (particularly in children), low-grade fever, anorexia and dehydration.
Occasionally, people with giardiasis will have long-term complications such as reactive arthritis, irritable bowel syndrome, and recurring diarrhea that can last for years. Among children in particular, severe giardiasis may delay physical and mental growth, slow development, and cause malnutrition.
Eat slowly and avoid foods that are hard to digest or may irritate your stomach, such as foods with acid (like tomatoes or oranges), spicy or fatty food, meats, and raw vegetables.
Children and adults who have giardia infection without symptoms usually don't need treatment unless they're likely to spread the parasites. Many people who do have problems often get better on their own in a few weeks.
Giardiasis can cause minor to severe digestive symptoms, such as loose, runny stools and stomach cramps. The Giardia parasite can live outside the body for a long time. It can survive in water or food and on surfaces such as doorknobs.
Sometimes it can be difficult for doctors to know for sure if Giardia is making you sick. This is because people with a Giardia infection do not pass Giardia germs with every stool. Even when there are Giardia germs in their stool, there may not be enough for the laboratory to find and identify them.
Diarrhea is the most common symptom; foul-smelling stools may be accompanied by flatulence, abdominal distension, and poor appetite.
Reinfection is common; likely due to the low infectious dose of only 10 cysts required to cause disease, the high volume of excretion of cysts from infected individuals (1-10 billion cysts/day), most infected individuals are asymptomatic, and the environmental hardiness of the cysts (lasting months).
In some patients, giardiasis resolves within a few days, while in others the symptoms last for years, even in the presence of circulating antibodies in serum or secretory antibodies at mucosal sites and the cell-mediated immunity.
Life Cycle
When Giardia cysts are swallowed, they pass through the mouth, esophagus, and stomach into the small intestine where each cyst releases two trophozoites through a process called excystation. The Giardia trophozoites then feed off and absorb nutrients from the infected person.