Giardiasis lamblia is a very common infectious disease that can cause diarrhea, stomach pains, and other uncomfortable digestive symptoms in humans. Infection occurs when a person ingests Giardia lamblia parasites, which are single-celled organisms that thrive in waters and soils contaminated with human feces. Symptoms of giardiasis lamblia typically last about two weeks in otherwise healthy people, though they can be more persistent and severe in young children and individuals with weak immune systems. Rest and sufficient fluid intake is usually enough to recover from an active infection.
The parasite responsible for giardiasis lamblia is found worldwide. Immature organisms survive in untreated water and soil that has been exposed to human waste. Once they are ingested, they mature in the stomach and cling to the walls of the large intestine, forming cysts. A person may acquire an infection if he or she drinks water from a contaminated source; eats unwashed food grown in dirty soil; or handles diapers, toys, or other objects that have been used by an infected infant. Public swimming pools and recreational rivers and lakes also can be sources of giardiasis lamblia epidemics when people accidentally swallow water.
About half of people who are exposed to the parasites never develop active symptoms. When symptoms do develop, they usually present about seven days after ingesting parasites. Common symptoms include frequent bouts of diarrhea, abdominal cramps, bloating, gas, and nausea. Chronic diarrhea can lead to dehydration symptoms such as fatigue, weakness, and headaches. A person may also lose a significant amount of weight due to loss of appetite and dehydration.
Most cases of giardiasis lamblia do not require medical treatment. Otherwise healthy people are usually able to overcome their illnesses by getting plenty of rest and staying properly hydrated. Parasites typically run their course and exit the body through feces in two to four weeks. If problems persist or become serious, a doctor may be able to prescribe antibiotics or anti-parasitic medications that help speed up recovery time.
It is not always possible to prevent giardiasis lamblia, but people can take steps to limit their risks of becoming infected. Hikers should pack water bottles instead of relying on natural springs and lakes for water. If spring water must be used, it should first be boiled. It also is important to wash raw vegetables before consuming them to ensure they are free of parasites. In addition, parents and caretakers of infected individuals should regularly wash their hands to limit the chances of accidental exposure.