How many people does Giardia affect each year?

Giardiasis is the most commonly reported intestinal protozoan infection worldwide; an estimated 200 million people are infected each year.

What are the statistics of Giardia?

During 2018, 508 cases of Giardia infection (9.1 per 100,000) were reported. This represents a 22% decrease from the median number of cases reported annually from 2008 through 2017 (median, 654 cases; range, 620 to 846). Recent immigrants and refugees accounted for 8% of cases.

How common is Giardia in USA?

In the United States, only 1 or 2 out of every 10,000 people have Giardia in a typical year, but the infection is found in about 1 out of 3 people who have prolonged diarrhea symptoms if they have recently traveled to a developing country. As one part of their life cycle, G. lamblia parasites change into cysts.

Is Giardia an epidemic?

During 2012–2017, public health officials from 26 states reported 111 giardiasis outbreaks involving 760 cases. Leading causes of outbreaks were waterborne and person-to-person exposures. Private residences and child care facilities were the most common settings of giardiasis outbreaks across all transmission modes.

Can you see Giardia in stool?

Results. If a giardia infection is present, the parasite or its cysts can be seen when the stool is looked at under a microscope. Evaluating 3 stool samples detects up to 90% of Giardia lamblia infections.

How many illnesses are caused by Giardia each year?

Each year in the United States, it is estimated that Giardia causes more than 1.2 million illnesses ( 3 ). Giardiasis is a nationally notifiable disease; the first full year of reporting was 1993. National data are collected through passive surveillance.

Where do you report a case of giardiasis?

Healthcare providers and laboratories that diagnose confirmed giardiasis cases report to the local or state health departments. State and territorial health departments, the District of Columbia (DC), and the New York City health departments, in turn, voluntarily notify CDC of cases via the National Notifiable Disease Surveillance System (NNDSS).

How long is the incubation period for Giardia?

Giardia cysts are highly infective. As few as ten human-source Giardia cysts produced infection in a clinical study of male volunteers. The incubation period (time interval between ingestion and the first appearance of symptoms) can range from 3 to 25 days.

What are the symptoms of Giardia duodenalis in humans?

Giardiasis is an illness caused by the protozoan parasite Giardia duodenalis (formerly called G. lamblia or G. intestinalis ), which causes gastrointestinal symptoms such as diarrhea, abdominal cramps, bloating, weight loss, or malabsorption ( 1, 2 ).