Giardiasis - Clinicals, Diagnosis, and Management

Infectious diseases

Clinicals - History

Fact Explanation
Steatorrhoea Diarrhea is the most common symptom in acute giardiasis. It is more specifically, a steatorrhoea which contains pale, bulky, frothy, foul smelling stools which are floating in the lavatory pan due to fat content.
Giardiasis is caused by Giardia intestinalis, a flagellate protozoan which decreases expression of brush-border enzymes namely disaccharidases and lipase. It causes impairment of carbohydrate and lipid digestion resulting osmotic diarrhea.

Travelers to countries where giardiasis is common, People in child care settings, those who are in close contacts with patients, people who swallow contaminated or untreated water,men who have sex with men have a greater risk of becoming infected.
Steatorrhoea
Diarrhea is the most common symptom in acute giardiasis. It is more specifically, a steatorrhoea which contains pale, bulky, frothy, foul smelling stools which are floating in the lavatory pan due to fat content.
Giardiasis is caused by Giardia intestinalis, a flagellate protozoan which decreases expression of brush-border enzymes namely disaccharidases and lipase. It causes impairment of carbohydrate and lipid digestion resulting osmotic diarrhea.

Travelers to countries where giardiasis is common, People in child care settings, those who are in close contacts with patients, people who swallow contaminated or untreated water,men who have sex with men have a greater risk of becoming infected.
loose or watery stool Sometimes acute giardiasis can be presented as an abrupt onset of explosive, watery diarrhea. loose or watery stool
Sometimes acute giardiasis can be presented as an abrupt onset of explosive, watery diarrhea.
Abdominal cramps Due to intestinal peristalsis. This is associated with marked
abdominal gurgling, distention and passage
of foul gas.
Abdominal cramps
Due to intestinal peristalsis. This is associated with marked
abdominal gurgling, distention and passage
of foul gas.
Weight loss Constitutional symptoms such as weight loss,anorexia, fatigue and malaise are common.Weight loss is due to malabsorption. [1,2.3] Weight loss
Constitutional symptoms such as weight loss,anorexia, fatigue and malaise are common.Weight loss is due to malabsorption. [1,2.3]
Asymptomatic Asymptomatic carriage is very common. Only
20% becomes symptomatic .
Asymptomatic
Asymptomatic carriage is very common. Only
20% becomes symptomatic .
Recurrent diarrhea Chronic giardiasis may involve 2 or more years of intermittent
diarrhea. Chronic infection in children may
present as failure to thrive.Urticaria, cholecystitis, and pancreatitis have been reported with Giardia infections.
During this chronic phase, lassitude, headache, and myalgia may occur with continued weight loss, anorexia,
and malabsorption.
Recurrent diarrhea
Chronic giardiasis may involve 2 or more years of intermittent
diarrhea. Chronic infection in children may
present as failure to thrive.Urticaria, cholecystitis, and pancreatitis have been reported with Giardia infections.
During this chronic phase, lassitude, headache, and myalgia may occur with continued weight loss, anorexia,
and malabsorption.

Clinicals - Examination

Fact Explanation
Weight loss Rarely,malabsorption causes loss of weight. Weight loss
Rarely,malabsorption causes loss of weight.

Investigations - Diagnosis

Fact Explanation
Microscopic examination of stool Visualization of giardia for cysts & trophozoites in saline (trophozoites) & iodine (cysts) smears. 2-3 stool specimens are examined before excluding giardiasis as cyst excretion is irregular. Microscopic examination of stool
Visualization of giardia for cysts & trophozoites in saline (trophozoites) & iodine (cysts) smears. 2-3 stool specimens are examined before excluding giardiasis as cyst excretion is irregular.
Entero test (string test) A gelatin capsule containing a nylon string is swallowed while one end of the string is attached to his or her cheek
The string is left in place for several hours while the patient is fasting. The mucus from the string is examined microscopically for trophozoites.
Entero test (string test)
A gelatin capsule containing a nylon string is swallowed while one end of the string is attached to his or her cheek
The string is left in place for several hours while the patient is fasting. The mucus from the string is examined microscopically for trophozoites.
Enzyme-linked immunosorbent assay (ELISA) This immunological test has a higher specificity and sensitivity (90%).
The combined tests of microscopy and ELISA together serve as a 'gold standard' for the diagnosis of Giardiasis.
Enzyme-linked immunosorbent assay (ELISA)
This immunological test has a higher specificity and sensitivity (90%).
The combined tests of microscopy and ELISA together serve as a 'gold standard' for the diagnosis of Giardiasis.

Investigations - Management

Fact Explanation
Blood urea and serum electrolytes Paromomycin can cause ototoxicity and nephrotoxicity.Toxicity should not be a concern in persons with normal kidneys. However, it should be used with caution in those with impaired renal function.
Apart from that diarrhea can cause fluid loss and electrolyte imbalance which can lead to renal dysfunction.
Blood urea and serum electrolytes
Paromomycin can cause ototoxicity and nephrotoxicity.Toxicity should not be a concern in persons with normal kidneys. However, it should be used with caution in those with impaired renal function.
Apart from that diarrhea can cause fluid loss and electrolyte imbalance which can lead to renal dysfunction.

Management - Supportive

Fact Explanation
Proper personal hygiene Proper personal hygiene has an utmost importance as a Preventive measure.
Drinking boiled cool water, Hand washing (before preparing & eating meals & after toilet),washing fruits & vegetables with clean running water,protecting food from flies & other insects,safe disposal of excreta etc. are important.
Proper personal hygiene
Proper personal hygiene has an utmost importance as a Preventive measure.
Drinking boiled cool water, Hand washing (before preparing & eating meals & after toilet),washing fruits & vegetables with clean running water,protecting food from flies & other insects,safe disposal of excreta etc. are important.
Community measures Community measures such as provision of purified drinking water, sanitary disposal of excreta,screening of food handlers and health education are paramount preventive strategies. Community measures
Community measures such as provision of purified drinking water, sanitary disposal of excreta,screening of food handlers and health education are paramount preventive strategies.
Nutritional Management Nutritional management of giardiasis consists of foods and supplements that inhibit Giardia growth, replication, and/or attachment to enterocytes; and promote host defense mechanisms against Giardia.
These aims can best be achieved by consuming a whole-foods, high fiber,low-fat, low simple-carbohydrate diet. Additionally, ingestion of wheat germ and probiotics can aid in parasite clearance.
Nutritional Management
Nutritional management of giardiasis consists of foods and supplements that inhibit Giardia growth, replication, and/or attachment to enterocytes; and promote host defense mechanisms against Giardia.
These aims can best be achieved by consuming a whole-foods, high fiber,low-fat, low simple-carbohydrate diet. Additionally, ingestion of wheat germ and probiotics can aid in parasite clearance.

Management - Specific

Fact Explanation
Nitroimidazole derivatives Metronidazole and Tinidazole are the most commonly used antiprotozoal drugs. Metronidazole utilizes the anaerobic metabolic pathways present in Giardia.
500–750 mg/day for 5–10 days is recommended.
The most effective agents for therapy of giardiasis are single doses of tinidazole or ornidazole or 5 to 7 days of metronidazole.
Combination treatment based on a nitroimidazole with one or two second-line drugs, in a 7–10 day short course, in persistent giardiasis after conventional
treatment is also recommended. eg: metronidazole or tinidazole + paromomycin + albendazole.

In pregnancy, if treatment is required, paromomycin should be tried in the first trimester and paromomycin or metronidazole should be used in the second and third trimesters.
Nitroimidazole derivatives
Metronidazole and Tinidazole are the most commonly used antiprotozoal drugs. Metronidazole utilizes the anaerobic metabolic pathways present in Giardia.
500–750 mg/day for 5–10 days is recommended.
The most effective agents for therapy of giardiasis are single doses of tinidazole or ornidazole or 5 to 7 days of metronidazole.
Combination treatment based on a nitroimidazole with one or two second-line drugs, in a 7–10 day short course, in persistent giardiasis after conventional
treatment is also recommended. eg: metronidazole or tinidazole + paromomycin + albendazole.

In pregnancy, if treatment is required, paromomycin should be tried in the first trimester and paromomycin or metronidazole should be used in the second and third trimesters.
Management of dehydration Oral Rehydration Solution (ORS) can be used to prevent mild to moderate dehydration.In severe dehydration Intravenous lactated Ringer solution or normal saline should be used. Management of dehydration
Oral Rehydration Solution (ORS) can be used to prevent mild to moderate dehydration.In severe dehydration Intravenous lactated Ringer solution or normal saline should be used.

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