What is Giardiasis?

Please note: Alinia® is not approved to treat other possible symptoms of cryptosporidiosis and/or giardiasis (such as cramps, dehydration, nausea, fever, vomiting). It also is not approved to prevent the spread of infection.

What Is Giardiasis?

Giardiasis is an infection caused by Giardia lamblia (also known as Giardia). Giardia is a parasite found in water, food, soil, or on surfaces contaminated with feces from an infected person or animal. Giardia can survive outside the body for weeks or even months, and has been found in every region of the US and around the world.2

In the United States, giardiasis tends to peak in summer and decline in winter. When more individuals participate in outdoor recreational activities7 there is a higher incidence of infection—sometimes even twofold.

Giardiasis Symptoms

Once ingested, the parasite lives in the human intestines and commonly causes diarrhea. Gas, stomach cramps or pain, upset stomach, greasy stool, and nausea are also symptoms of Giardia infection. However, some individuals become infected but are asymptomatic – that is, they show no symptoms.2

Symptoms typically begin to show one to three weeks after infection and can last up to six weeks or longer.2

How Is Giardiasis Diagnosed?

A confirmed diagnosis is generally made by examining a prepared stool sample under a microscope in a laboratory. Individuals can expect to submit a series of samples over several days.2

How Does Giardiasis Spread?

Giardia can be contracted by2:

  • Swallowing Giardia picked up from surfaces (such as bathroom fixtures, changing tables, diaper pails, or toys) contaminated with stool from infected people or animals
  • Using water from water sources where Giardia may live (for example, untreated or improperly treated water from lakes, streams, or wells)
  • Accidentally swallowing water from lakes, rivers, springs, ponds and streams while swimming or playing.
  • Eating improperly prepared food that contains Giardia parasites
  • Having contact with someone who has giardiasis
  • Traveling to regions where giardiasis is more common than in the US

If you or a family member experience diarrhea and fit any of the descriptions below, you should contact your doctor to find out if you have a Giardia infection2:

  • Children in daycare or childcare settings, especially children still in diapers
  • People who have been in close contact with someone who has giardiasis or are caring for people who have giardiasis
  • People who drink water or use ice from improperly treated water sources
  • Backpackers, hikers, or campers who drink from unsafe water sources and do not practice proper hand washing while outdoors.
  • People who may have swallowed water while swimming or playing in recreational water sources like lakes, rivers, springs, ponds or streams.
  • People who have recently traveled outside the US
  • People exposed to human feces (poop) through sexual contact

For further information please refer to the Centers for Disease Control and Prevention website: http://www.cdc.gov/parasites/giardia/

Talk to your doctor to see if Alinia is right for you. Please see the Full Prescribing Information for more information.

2 Giardia – General Information. Centers for Disease Control and Prevention. www.cdc.gov/parasites/giardia/general-info.html. Accessed May 11, 2017.
7 Painter JE, Gargano JW, Collier SA, Yoder JS. Giardiasis surveillance — United States, 2011-2012. Centers for Disease Control and Prevention. MMWR 2015; 64(SSO3): 15-25.


ALINIA® for Oral Suspension (patients 1 year of age and older) and ALINIA Tablets (patients 12 years and older) are indicated for the treatment of diarrhea caused by Giardia lamblia or Cryptosporidium parvum.
Limitations of Use: ALINIA for Oral Suspension and ALINIA Tablets have not been shown to be effective for the treatment of diarrhea caused by Cryptosporidium parvum in HIV-infected or immunodeficient patients.

Important Safety Information regarding ALINIA:

  • Do NOT take ALINIA Tablets or ALINIA for Oral Suspension if you are allergic to nitazoxanide or any other ingredient in the formulations.
  • ALINIA Tablets or ALINIA for Oral Suspension should be taken with food.
  • ALINIA Tablets should NOT be taken by children 11 years or younger.
  • ALINIA tablets and ALINIA for Oral Suspension should be taken with food.
  • Please discuss with your doctor if you:
    • have hepatic, biliary, or renal disease.
    • are taking any other medications (for example, warfarin).
    • are a pregnant or a nursing woman.
    • are 65 years of age and older.
    • are HIV infected or have an immune disease (such as AIDS).
  • The most common side effects reported for ALINIA Tablets and ALINIA for Oral Suspension during clinical trials were abdominal pain, headache, chromaturia and nausea.

*For more information, please read the Full Prescribing Information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088, or contact Romark at 1-813-282-8544.

Alinia is a registered trademark of Romark, L.C.

Intended only for residents of the United States of America. ©2021 Romark, L.C., Tampa, Florida 33607-8416

The information contained in this website is provided for educational purposes only and is not intended to replace discussions with a healthcare provider. Alinia is not right for everyone. Decisions regarding healthcare must be made with a healthcare provider, considering the unique characteristics of the patient.