​Kembara Xtra - Medicine - Giardiasis

​Kembara Xtra - Medicine - Giardiasis 
Introduction 
Giardia lamblia is a protozoan parasite that causes intestinal infection and is one of the most widespread causes of diarrhea in the world. It is also referred to by the names Giardia duodenalis and Giardia intestinalis.
The trophozoite and cyst phases make up the life cycle.
Infectious cysts are consumed, which causes excystation in the duodenum and the production of trophozoites, which causes symptoms.
– Trophozoites move to the large intestine, where they transform back into their infectious cyst form and are eliminated in the feces.
Most illnesses are transmitted through oral or fecal-oral transmission or through consumption of unfiltered surface water, such as in contaminated swimming areas.

Epidemiology Highest risk regions include South and South East Asia, North Africa, the Caribbean, and South America. Age - Most commonly children under 5 years old and adults aged 25 to 44. Gender - More common in males. Minimal seasonal variability: slight increase in cases reported in summer and early fall.

Child Safety Considerations

Chronic infection in children can cause intestinal malabsorption (which may also be linked to growth restriction/failure to thrive) and is most common in early childhood.
Incidence

Estimated to result in 280 million cases of diarrhea each year
In the United States, about 15,000 cases (or 6 cases per 100,000) were reported in 2018.

Giardiasis affects 1.2 million people in the US each year, resulting in 3,584 hospital admissions.

Due to underreporting, the actual rate of Giardiasis infection is probably substantially higher.
Prevalence

2% of adults and 6-8% of children in industrialized countries have it, whereas 33% of people in impoverished countries have it.


Pathophysiology and Etiology 

Giardia trophozoites populate the proximal small intestine's surface.
Ventral suction disc-mediated cellular attachment to host enterocytes and parasite excretion cause structural damage that compromises intestinal epithelial cells and impairs brush border enzyme activity.
Electrolyte imbalances and increased intestinal permeability are brought on by this, which results in diarrhea.

Genetics
Only assemblages A and B of the eight genotypes known for G. lamblia (also known as assemblages A–H) have been linked to human infection.


Risk factors include going to daycare centers, having anal sex, camping in the wilderness, visiting developing nations, adopting kids from those nations, drinking untreated water from lakes, streams, or wells, swimming in contaminated recreational water (lakes, rivers, pools), having pets with Giardia infection or diarrhea, and eating uncooked produce.

Prevention 

When camping and visiting impoverished nations, you should purify your water. It works best to boil.
Cook all food items as directed.
Prevent fecal pollution of the public water supply.
Barrier protection during anal sex Sanitary removal of waste

Accompanying Conditions 

Immunosuppression, hypogammaglobulinemia, common variable immunodeficiency, IgA deficiency, and a prolonged disease course are all linked to unsuccessful treatment outcomes.

Providing History: 50–75% of those with acute giardiasis have no symptoms.
Symptomatic infections affect youngsters more often than they do adults.
- In most cases, symptoms start to show up 1–2 weeks after exposure and linger for up to 4 weeks.
- Vomiting (90%)
- Depression (86%)
- Fatty and foul-smelling stools (75%)
- Bloating (75%)
- Cramps and bloating in the abdomen (71%)
- Vomiting (69%)
- Loss of weight (66%)
- Diarrhea (23%)
- Fever (15%)
- Diarrhea (13%).
-10% Urticaria
Giardiasis chronicus - loose stools
Significant weight loss, steatorrhea, malabsorption, and stunted growth
- Malaise, exhaustion, depression, cramping in the stomach, boreborygmi, flatulence, and burping

clinical assessment 

Vital signs usually appear normal.
Abdominal exam: nonspecific; possible bloating, pain, or increased bowel sounds
Check youngsters for weight loss, dehydration symptoms, malabsorption, or failure to thrive.

Multiple Diagnoses 

Strongyloidiasis, cyclosporiasis, amebiasis, dientamoeba fragilis infection, cryptosporidiosis, microsporidiosis, and strongyloidiasis
Other causes of malabsorption include lactose intolerance, celiac sprue, tropical sprue, bacterial overgrowth syndromes, and Crohn disease. Viral gastroenteritis or traveler's diarrhea caused by a variety of organisms, including Escherichia coli and Campylobacter spp.
Irritable bowel syndrome, or diarrhea without losing weight

Initial test results from the laboratory and imaging
Light microscopy for parasites and ova in stool - Three serial stool samples are obtained every two to three days; one stool sample has a sensitivity range of 50–70%, while three serial samples improve sensitivity to >90% (4).
- Cysts can be discovered in either fixed or fresh faeces, and trophozoites can occasionally be identified in fresh diarrheal stools.
- Test restrictions: time consuming; interpretation requires an experienced operator; intermittent ova shedding indicates that ova may not be present in stool sample.
Direct fluorescent antibody (DFA) assays are the gold standard test for diagnosis when they are available, detecting complete organisms with 92-100% sensitivity and 100% specificity.
ELISA, which has a sensitivity range of 85 to 100% and a specificity of 95% for finding soluble antigens in feces. Compared to stool microscopy, the turnaround time for these two techniques is longer.

In several affluent nations, regular microscopy has been supplanted by PCR assays, which have a sensitivity of 98% and a specificity of 100%.

It is not recommended to use serologic testing for circulating IgG and IgM antibodies to Giardia for clinical diagnosis.


Tests in the Future & Special Considerations
A gelatin capsule attached to a string is ingested and left in the duodenum for several hours or overnight during the string test (entero-test). The thread is taken off and examined under a microscope to check for trophozoites.
Esophagogastroduodenoscopy (EGD), which includes a biopsy and a sample of small intestine fluid Interpretation of Tests
An intestinal sample reveals trophozoites on the surface with flattened, light lymphocytic infiltrate.

Management 
If the symptoms are severe enough to result in dehydration and require parenteral fluid replacement, the patient will be hospitalized even in mild situations.


General Measures Fluid replacement is the primary line of treatment for dehydration Prophylactic therapy is advised for asymptomatic patients in close proximity to immunocompromised or pregnant people.

First Line of Medicine

preferred drugs
Nitazoxanide: 500 mg PO BID for three days. Tinidazole: 2 g PO single dose.

Agents of Second Line Alternative
Paromomycin: 10 mg/kg PO TID for 5–10 days Furazolidone: 100 mg PO QID for 7–10 days Metronidazole: 250 mg PO TID for 5–7 days Albendazole: 400 mg PO daily for 5 days Mebendazole: 200 mg PO TID for 5 days Quinacrine: 100 mg PO TID for 5 days

Precautions
Alcohol consumption has been linked to a disulfiram-like effect while receiving tinidazole or metronidazole medication.

If monotherapy is unsuccessful for a patient with resistant giardiasis, combination therapy, high-dose therapy, and/or prolonged treatment courses may be necessary.
– The best method for confirming therapy failure is PCR. Treatment failure may be brought on by host factors or by real medication resistance, which is becoming more prevalent, especially in visitors leaving South and South East Asia.


pregnant women's issues
To prevent harmful pharmacological side effects on the fetus, it may be prudent to postpone therapy for patients with mild giardiasis until the second trimester.

Giardiasis medications are generally not advised for use during pregnancy.
Paromomycin is a nonaminoglycoside that is advised for use during pregnancy due to its lower teratogenic risk due to its low systemic absorption; nonetheless, its cure rate is only about 60%, which is lower than that of most other medicines.


Child Safety Considerations
The medicine of choice for infants under 12 months old is metronidazole.
For infants between the ages of 12 and 36 months, nitazoxanide is recommended.
Tinidazole is recommended for children under the age of 36 months.

Referral 
Patients who experience treatment failure should speak with or be referred to a specialist who can rule out underlying conditions such celiac disease, hereditary disaccharidase deficiency, and immunodeficiency diseases, especially those that affect the production of total and IgA antibodies.


Further Therapies 
Water to avoid dehydration


Alternative Medicine 
Children who have giardiasis have been shown to benefit from the preventive effects of zinc and vitamin A.


Patient Follow-Up Monitoring
Keep an eye on the patient's symptoms, weight, and stool tests, especially if they don't get better.
Low-lactose/lactose-free diet for at least one month; generally beneficial low-fat diet



To minimize transmission in outdoor enthusiasts, hand washing is more crucial than water filtration. Lactose intolerance may occur after Giardia infection and result in recurrent diarrhea after therapy. Encourage patients to follow a low-lactose or lactose-free diet in order to lessen discomfort.
When you have diarrhea, avoid swimming.
– After changing diapers, wash your hands with soap before going back into the water. Never drink water from a lake, river, or pool.
– Chlorine can be used to eradicate Giardia in recreational water.


The majority of infections cure within a few weeks; occasionally, they may remain for months and persist as chronic infections. Patients with underlying immunodeficiency may experience more severe and extended sickness. However, in general, the prognosis is excellent and the majority of patients are asymptomatic.
Mortality is uncommon, especially in situations of severe dehydration that are neglected or treated insufficiently, which primarily affects newborns and children who are malnourished.


Complications 
lactose intolerance, malabsorption, poor growth and development, hypersensitivity reactions, weight loss. Cholangitis, granulomatous hepatitis, cholecystitis, and decreased exocrine pancreatic function are more infrequent conditions.

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