Giardiasis (Jee-aar-dai-uh-suhs) is a diarrheal illness caused by the parasite, Giardia (Jee-aar-dee-uh). Giardia is found in soil, food or water that has been contaminated with the stool (feces) from an infected person or animal. If a person or animal becomes infected with Giardia, the parasite lives in the intestines and can be passed in feces. Giardia is shown to have a protective outer shell that contributes to its survival for weeks or even months. With Giardia having a high survival rate, it can spread very easily since this parasite can contaminate anything.
- How do people get infected with giardiasis?
Animals or people infected with Giardia can pass the parasite in their stool.Since Giardia can survive for a long time outside the body, it is easy for the contamination of food, water, or surfaces to occur. Infection with Giardia occurs after ingestion of something contaminated with stool. Giardia is most spread through water, after someone swallows contaminated drinking water or recreational water (pools, lakes, or rivers). However, person-to-person transmission is also very common, which occurs after having close contact with a sick individual.
Other modes of transmission include:
- Animal contact: Having close contact with a sick animal
- Foodborne: Eating contaminated food
- Travel: Traveling to areas that have poor sanitation
- Sexual contact: Exposure to feces from a sick person through sexual contact
- Contaminated surfaces: Transferring Giardia from contaminated surfaces to your mouth
- What are the symptoms of giardiasis?
Common symptoms include:
- Diarrhea
- Stomach or abdominal cramps
- Gas or flatulence
- Greasy/fatty stools
There are some other symptoms associated with Giardiasis infection, but it may not be as common. These symptoms include:
- Nausea
- Upset stomach
- Dehydration
- Weight loss (normally caused by gastrointestinal symptoms)
A person can become sick from three to 25 days after consuming the Giardia parasite, but symptoms normally begin around seven to 10 days. Though some people who become infected with Giardia may not have symptoms, there are some common symptoms that are associated with this illness.
These symptoms usually last for two to six weeks and the infection will normally resolve on its own. In some cases, individuals may experience symptoms for up to several months. It is important to note that with Giardia it is possible to experience a cycle of symptoms. Symptoms can often go away for a while but come back if they are not treated. A person having diarrhea that lasts more than 24 hours should consult a health care provider.
- How is giardiasis diagnosed?
Diagnosis
Giardiasis infections are normally diagnosed through laboratory testing of stool, intestinal fluid, or intestinal biopsy specimens. Multiple stool specimens may be required, as it can be difficult to detect Giardia.
Treatment
Though Giardia symptoms can go away on their own without treatment, there are times when antibiotic treatment is needed for persistent infections or those who are at high risk (infants and those with weakened immune systems). Over-the-counter drugs may relieve symptoms but will not get rid of the parasite.
If symptoms are persistent, it is important to seek medical care for proper treatment to reduce any further issues.
- How can giardiasis prevented?
Practice good hand hygiene and use good handwashing techniques
- Wash your hands after using the restroom or changing diapers
- Before and after preparing food or eating
- After contact with animals or their environments
Avoid eating food or drinking water that is potentially contaminated with Giardia
- Always treat water from lakes, springs, and rivers while backpacking or camping
- Avoid swallowing water from swimming pools, hot tubs, lakes, rivers, or splash pads while swimming
- Always remember to store, clean, and prepare fruits and vegetables properly
- Separate raw and cooked foods
Practice safe sex
- Reduce contact with stool during sex
- Avoid having sex for several weeks while recovering from a Giardia infection
- What should I do if I get giardiasis?
Once you or your child start having symptoms of the illness, such as diarrhea, do not attend work (specifically for food handlers, healthcare workers, daycare workers) or attend daycare or school until a healthcare provider or someone from your local health department says you are clear to go back.
If you believe you have giardiasis and have not yet been treated or spoken to a doctor, please be sure to do so. You should be evaluated by a doctor to confirm that you have giardiasis, and that you get the correct treatment. You should also respond to requests for interview by your local or state public health department. An investigation will take place for every confirmed case of giardiasis. It is important that you answer the call from your local or state health department so that other people in your home or near you are not at risk of getting giardiasis as well. An investigation may also look into your exposures to check if other people are at risk.
If your doctor tells you that have a Giardia infection try to stay home from work or school until you feel better for at least 24 hours. This is especially important if you work in healthcare or handle food. To make sure that you don’t spread Giardia, make sure to wash your hands regularly, especially after using the bathroom. If you are sick with Giardia, avoid going swimming in recreational water, such as pools.
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Page last updated/reviewed: December 2024