Clinical manifestation of Giardia lamblia:
- Acute giardiasis: It is characterized by acute watery diarrhea, abdominal cramp, bloating and flatulence. Occasionally nausea, vomiting, fever, rashes or constipation in some.
- Chronic giardiasis: Protuberance of abdomen, spindly extremities and stunted growth are most common sign in children.
- Complication: Giardiasis is self-limited disease and progression to chronic state is only 5% of infected people and death is rare.
What microorganism causes Giardia?
GIARDIA OVERVIEW. Giardia (also called giardiasis or Giardia infection) is an infection of the gastrointestinal tract caused by a microscopic organism called Giardia lamblia.This parasite, which also goes by the names Giardia duodenalis or Giardia intestinalis, resides in the gut and can cause diarrhea and stomach discomfort (nausea, stomachache).It is one of the most common gastrointestinal ...
What illness does Giardia lamblia cause?
It is the most common cause of parasitic gastrointestinal disease; it is estimated that 20,000 cases of giardiasis occur each year in the U.S., and there is a 20% to 40% prevalence in the world's population. Giardia lamblia exists in two forms, an active form called a trophozoite, and an inactive form called a cyst.
How to recognize the symptoms of giardiasis?
Symptoms of giardiasis generally begin by having 2 to 5 loose stools per day, with progressively increasing fatigue. Other, less common symptoms include fever, itchy skin, hives, and swelling of the eyes and joints. Over time, giardiasis can also cause weight loss and keep the body from absorbing nutrients it needs, like fat, lactose, vitamin A ...
How do humans get Giardia?
You get giardia from:
- drinking contaminated water or eating contaminated food
- being in contact with infected animals that are carrying the parasite
- being in close contact with someone who has giardia – eg, people living in the same house or if you’re looking after someone who has giardia
What is the characteristic motility of Giardia lamblia?
Flagellar motility is a key factor in Giardia's pathogenesis and colonization of the host small intestine. Specifically, the beating of the ventral flagella, one of four pairs of motile flagella, has been proposed to generate a hydrodynamic force that results in suction-based attachment via the adjacent ventral disc.
What is the classification of Giardia lamblia?
Data Quality Indicators:ClassZoomastigophoraOrderDiplomonadidaFamilyHexamitidaeGenusGiardia Kunstler, 1882SpeciesGiardia lamblia Kofoid and Christiansen, 19155 more rows
What is the characteristic feature of the trophozoite stage for the intestinal flagellate Giardia duodenalis?
Giardia duodenalis trophozoites are pear-shaped and measure 10-20 micrometers in length. In permanent, stained specimens, 2 large nuclei are usually visible. The sucking disks (used for attaching to the host's mucosal epithelium), median bodies, and flagella (8) may also be seen.
What is the structure of Giardia?
Giardia lamblia has a characteristic tear-drop shape and measures 10-15 µm in length. It has twin nuclei and an adhesive disk which is a rigid structure reinforced by supelicular microtubules. There are two median bodies of unknown function, but their shape is important for differentiating between species.
What is the common name of Giardia lamblia?
The flagellate protozoan Giardia intestinalis (previously known as G lamblia or G duodenalis), its causative agent, is the most commonly identified intestinal parasite in the United States [1, 2] and the most common protozoal intestinal parasite isolated worldwide. Infection is more common in children than in adults.
Where is Giardia most common?
Giardia infection (giardiasis) is one of the most common causes of waterborne disease in the United States. The parasites are found in backcountry streams and lakes but also in public water supplies, swimming pools, whirlpool spas and wells.
What are the stages of Giardia lamblia?
Giardia has one of the simplest life cycles of all human parasites. The life cycle is composed of 2 stages: (1) the trophozoite (see the first image below), which exists freely in the human small intestine; and (2) the cyst, which is passed into the environment. No intermediate hosts are required.
What is the difference between the trophozoite and cyst of Giardia lamblia?
The main difference between cyst and trophozoite is that cyst is the dormant stage that helps to survive in unfavorable environmental conditions whereas trophozoite is a growing stage that absorbs nutrients from the host. Cysts can be found in both bacteria and nematodes.
How is Giardia lamblia diagnosed?
Microscopy with direct fluorescent antibody testing (DFA) is considered the test of choice for diagnosis of giardiasis since it provides increased sensitivity over non-fluorescent microscopy techniques.
What are the different types of Giardia?
Giardia duodenalisGiardia murisGiardia psittaciGiardia microtiGiardia agilisGiardia ardeaeGiardia/Lower classifications
Is Giardia Gram positive or negative?
It has a broad spectrum of antimicrobial activity, including gram positive and gram negative aerobic bacteria.
How does Giardia lamblia cause disease?
Giardiasis is a diarrheal disease caused by the microscopic parasite Giardia duodenalis (or “Giardia” for short). Once a person or animal has been infected with Giardia, the parasite lives in the intestines and is passed in stool (poop). Once outside the body, Giardia can sometimes survive for weeks or even months.
Is Giardia a virus or bacteria?
"Giardia is not a "worm", bacteria or virus." Giardia is a simple one-celled parasitic species; it is not a "worm", bacteria or virus. There are seven genotypes, A through G, with dogs being most commonly infected by C and D, cats with F, and humans most commonly infected with A and B.
Is Giardia a protozoan?
Causal Agent. Giardia duodenalis is a protozoan flagellate (Diplomonadida). This protozoan was initially named Cercomonas intestinalis by Lambl in 1859. It was renamed Giardia lamblia by Stiles in 1915 in honor of Professor A.
How does giardia spread?
Giardia spreads easily and can spread from person to person or through contaminated water, food, surfaces, or objects. The most common way people get sick is by swallowing contaminated drinking water or recreational water (for example, lakes, rivers, or pools).
What is the parasite that causes diarrhea?
Giardia is a tiny parasite (germ) that causes the diarrheal disease giardiasis. Giardia is found on surfaces or in soil, food, or water that has been contaminated with feces (poop) from infected people or animals. You can get giardiasis if you swallow Giardia germs.
Can a giardia infection cause long term symptoms?
Find answers to frequently asked questions about Giardia. Giardia infection can cause no symptoms, short-term symptoms, or long-term symptoms. Follow some simple steps to prevent getting sick or spreading Giardia. Talk to your doctor if you think you may be sick from Giardia.
What is the micrograph technique for Giardia lamblia cyst?
Micrograph of Giardia lamblia cyst using an iodine staining technique.
How many species of Giardia are there?
The genus Giardia has been isolated from more than 40 species. The species G. lamblia is known to infect human, mammals, reptiles, and birds, cows, sheeps and pigs, depending on the strain (Adam 2001).
How many open reading frames are there in the G. lamblia genome?
Complete mapping of the G. lamblia genome (WB strain) is in progress (95% complete, as of 2007 August), using shotgun sequencing. So far 6488 open reading frames (ORF) are predicted, of which 4746 are transcribed.
What is the AT-rich region of G. lamblia?
Studies by comparing upstream sequence to cytoskeletal protein-coding genes have found several consensus sequence, for example, an AT-rich region 5’AATTAAAAA3’ found between –30 and –70 upstream. These sequences have been proposed as promoter regions for G. lamblia, although they are relatively shorter than that of other eukaryotes. The AT-rich region shown above has been found to be essential for transcription. In addition, recent studies have shown that G. lamblia promoters, in particular, the AT-rich, “TATA”-like regions, cause the production of sterile anti-sense transcripts (Teodorvic et al, 2007).
Why is G. lamblia important?
G. lamblia is also significant in evolutionary biology. Due to its lack of mitochondria, G. lamblia is believed to be diverged from one of the earliest lineages of eukaryotes before the endosymbiotic relationship of mitochondria began (the kingdom name “Archezoa” has been proposed).
How many base pairs are there in G. lamblia?
The G. lamblia genome consists of 1.2 million base pairs, distributed among five linear chromosomes, each flanked by the telomere sequence (5’TAGGG3’) comparable to other eukaryotes (Le Blancq et al, 1991). Chromosome packing is done by core histones, but the mechanism is slightly different from other eukayotes (Yee et al, 2007). [See also #Current Research ].
Is G. lamblia a waterborne disease?
G. lamblia is one of the major cause of waterborne diseases worldwide (CDC, 2004), and infection results in giardiasis (characterized by malabsorption and severe diarrhea). Giardia-induced intestinal infection is particularly severe in developing world, where giardiasis occurrence relates heavily to water source contamination. In the united states, G. lamblia has been found in both drinking and recreational water. Due to the high prevalence of giardiasis, G. lamblia is of significant interest in the clinical research community. However the pathogenic mechanisms are not completely understood. [See also #Pathology ].
What is Giardia Lamblia?
Giardia lamblia is also known as intestinilis or G.duodenalis. It was first observed by Antony von Leewenhoek (1681) while examining his own stool and Lambi (1859) describe the parasite and named it as Giardia labmlia. Giardia is the only intestinal flagellate known to cause endemic and epidemic diarrhea in human.
What are the virulence factors of Giardia?
Virulence factors: Cytoskeleton: Giardia contains microtubules (MT) cytoskeletion which is essential for motility, attachment, intracellular transport, cell division and encystation/excystation. Cysts: Cysts are resistant and responsible for transmission of parasite.
What is the only intestinal flagellate known to cause endemic and epidemic diarrhea in human?
Giardia is the only intestinal flagellate known to cause endemic and epidemic diarrhea in human.
What is the function of lectins on the surface of Giardia?
Lectins present on the surface of Giardia binds to receptor present on surface of enterocytes. This attachment process damage microvilli, which interfere with nutrition absorption by villi.
What is the shape of a trophozoite?
The shape of trophozoite is pear shape or tennis racket shape with broad round anterior end and a tapering posterior end.
What is the main reservoir of Giardia?
Man is the main reservoir of Giardia.
What is the nucleus of a parasite?
Each nucleus consists of large central karyosome giving a characteristic face like appearance to the parasite in stained preparation.
Is giardiasis a travel related disease?
In developed countries, giardiasis is considered a travel related disease. However, routine surveillance data from Germany indicate that >50% of infections were acquired indigenously. We studied the epidemiological characteristics of symptomatic Giardia infections acquired in Germany and abroad, and verified the proportion of cases acquired in Germany in order to investigate risk factors for sporadic autochthonous Giardia infections.
Is Giardia lamblia a protozoan?
Giardia lamblia is an enteric protozoan pathogen found in a variety of mammalian hosts, including humans. Giardia lamblia isolates exhibit wide genetic diversity. Strains isolated from humans can be grouped into the major assemblages A and B [ 1 ]. Attempts to associate symptoms with genotype in human infections have not provided a definitive answer to date [ 2 – 4 ].
How long does it take for giardia to show symptoms?
For those who do get sick, signs and symptoms usually appear one to three weeks after exposure and may include:
Where do Giardia parasites live?
Giardia parasites live in the intestines of people and animals. Before the microscopic parasites are passed in stool, they become encased within hard shells called cysts, which allows them to survive outside the intestines for months. Once inside a host, the cysts dissolve and the parasites are released.
How long does it take for giardia to clear up?
Giardia infection can be spread through food and person-to-person contact. Giardia infections usually clear up within a few weeks. But you may have intestinal problems long after the parasites are gone. Several drugs are generally effective against giardia parasites, but not everyone responds to them.
How to get rid of giardia cysts?
Purify wilderness water. Avoid drinking untreated water from shallow wells, lakes, rivers, springs, ponds and streams unless you filter it or boil it for at least 10 minutes at 158 F (70 C) first.
What happens when you have diarrhea?
Dehydration. Often a result of severe diarrhea, dehydration occurs when the body doesn't have enough water to carry out its normal functions. Failure to thrive. Chronic diarrhea from giardia infection can lead to malnutrition and harm children's physical and mental development. Lactose intolerance.
How to prevent giardia?
Prevention. No drug or vaccine can prevent giardia infection. But commonsense precautions can go a long way toward reducing the chances that you'll become infected or spread the infection to others. Wash your hands. This is the simplest and best way to prevent most kinds of infection.
What to do if you have giardia?
Call your doctor if you have loose stools, stomach cramping and bloating, and nausea lasting more than a week, or if you become dehydrated. Be sure to tell your doctor if you're at risk of giardia infection — that is, you have a child in child care, you've recently traveled to an area where the infection is common, or you've swallowed water from a lake or stream.
What are the side effects of Giardia intestinalis?
Giardia intestinalis infection causes enterocytes damage and loss of brush border of the epithelial cells of the intestine that leads to shortening of microvilli and altered epithelial barrier function. This pathology results in aqueous diarrhoea, steatorrhea, nausea, abdominal pain, vomiting and weight loss. However, most infections are asymptomatic. The main consequence of Giardia colonization is nutrients malabsorption. Several families of drugs with good efficacy are used for Giardia treatment, but sometime dosing regimens are suboptimal and emerging resistance begins to question their clinical value. Moreover, some of these drugs can cause side effects that result in patient discomfort and low adherence to the treatment. This paper reviews the drugs currently used for the treatment against Giardia: the mechanism of action, the efficacy, the normal dosing, side effects and in vitro and clinical studies. In addition, new therapies against Giardia such as those based on phytochemicals, Lactobacillus and nanotechnology are collected in this paper, trying to find the ideal treatment for this disease with maximum efficacy and minimum adverse effects.
Can giardia cause side effects?
Moreover, some of these drugs can cause side effects that result in patient disco mfort and low adherence to the treatment.
How big is a giardia?
They range from 12 to 15um in length and between 5 and 9um in width.
What is a giardia?
Giardia is a genus consisting of a number of flagellated species with similar morphological characteristics. Members of this genus can be found in various environments (water, soil etc) and are responsible for giardiasis (a diarrheal illness) in both human beings and other vertebrates. Given that the parasite is largely spread through ...
How are Giardia species differentiated?
While Giardia species have a number of similar morphological characteristics, they can be differentiated based on a number of structural differences and the hosts they infect.
What is the phylum of Giardia?
Giardia, which falls under this subkingdom, are parasites of human beings and various vertebrates. · Phylum: Sarcomastigophora - The term Sarcomastigophora is derived from the combination of the terms "Sarcodina" and "Mastigophora". Members of this phylum, including Giardia, are characterized as a locomotory organ (flagella in the case of giardia) ...
Which structure is the first to appear in the excyzoite body?
Based on microscopic studies, flagella are the first structures to appear followed by the excyzoite body of the organism. While the host's stomach actively promotes the excystation process, the cysteine proteases in the peripheral vesicles have also been suggested to contribute to the degradation of the hardy cyst wall from within.
What organelle does G. duodenalis lack?
duodenalis, the organism was found to lack a number of organelles commonly found in other eukaryotic cells including mitochondria, peroxisomes as well as a well organized golgi complex.
What is the classification of Giardia?
Classification of Giardia. · Kingdom: Protista - Members are neither animals, fungi or plants. A majority of these organisms are single-celled with unique and very diverse characteristics. · Subkingdom: Protozoa - falls under the kingdom Protista and consist of eukaryotic single-celled organisms that either exist as parasites or as free-living ...
Classification
Description and Significance
Genome Structure
Cell Structure
Metabolism
Ecology
Pathology
- Giardiasis is the clinical manifestation of G. lambliainfection. It is characterized by severe diarrhea, malnutrition weight loss, and slight intestinal epithelial injury. The complete pathogenesis is no well known, but several theories exist. The disruption of the small intestine epithelium is proposed to be caused by induced apoptosis (Chin et al...
Current Research
References