Diarrhea – Part 1 – Diarrhea Lab findings

Diarrhea Lab findings

Definition of diarrhea

1. This is characterized by 3 loose stools per day and may be accompanied by:
   1. Abdominal pain.
   2. Nausea and vomiting.
   3. Fatigue.

Causes of Diarrhoea: 

1. Diarrhea may be acute or chronic.
2. This may be due to:
   1. Viral infections. The most common cause is retrovirus among children. Other viruses are Adenovirus, cytomegalovirus, and HIV.
   2. Bacterial infections are due to salmonellosis, Vibrio, Campylobacter, and Yersinia. Other causes are toxigenic bacteria like Staphylococcus and Bacillus cereus, Shigella, and E.Coli.
   3. Parasitic infestation, e.g., Giardia Lamblia and Entamoeba histolytica.
      

      Diarrheal causes

Pathophysiology

1. Most of the diarrhea is due to infections.
2. Age: Mostly, the young are susceptible due to poor health.
   1. Poor general health and nutrition will predispose to diarrhea.
3. Bacteria leading to diarrhea depends:
   1. A dose of the bacterial infection.
   2. Production of enterotoxin.
   3. Its ability to attach to the intestinal mucosa and to invade the mucosa.
4. Other factors for diarrhea are:
   1. Poor sanitation.
   2. Contaminated food and water.
   3. Personel hygiene, washing hands with soap after defecation, prevents the fecal-oral spread.
   4. Food stored at room temperature allows rapid bacterial growth and the production of toxins.
   5. Food stored at 4 °C cannot kill the bacteria; it can only prevent the multiplication of bacteria.
      1. Avoid keeping the food at room temperature, which leads to the rapid proliferation of the organism.
   6. AIDS has a prominent feature of diarrhea.

Diarrhea causes and diagnosis:

Causative agent	Source	A common source of infection	Diagnosis
Salmonella species	Animal and humans	Milk, eggs, meat, and poultry	The specimen is feces, culture on selective media.
Shigella species	Humans	Food, fomites, and feco-oral route	Stool and rectal swab on MacConkey and selective media
Escherichia coli	Humans	Food, water, fomites, and feco-oral route	Feces culture on MacConkey medium
Bacillus species	Soil	Rice	Suspected food, vomitus, and stool culture on ordinary media
Staphylococcus aureus	Septic lesion on food handlers	Dairy products and cooked meat	Suspected food, vomitus, or feces are cultures on ordinary media
Campylobacter species	Animals	Meat, milk, and poultry	Feces culture on selective medium
Clostridium perfringens	Animal	Meat pies and stews	Feces and suspected food on aminoglycoside blood agar anaerobically
Clostridium difficle	Humans	Feco-oral and overgrowth of strains in colon	Direct detection of toxin and isolation on selective media
Vibrio cholerae	Humans	Food and water	Feces on selective medium (TCBS agar).
Yersinia species	Animal	Food and water	Isolation from feces or blood or rising antibody titer

Lab. workup of the patient with diarrhea:

1. History of the patient as regards the duration of the clinical symptoms.
   1. Any history of travel to a foreign country.
   2. Food history of the other people living with the patient.
2. Take a stool sample or rectal swab.
   1. Take the sample of suspected food.
   2. Get the vomitus sample.
3. Stool examination for ova and parasites.
4. Stool cultures for pathogenic organisms.
5. Bood culture in severe cases. It is advised in very young and old patients.
6. Take the sample of the suspected food if possible.
7. Antigen tests for G.lamblia and E.Coli.
8. Antibodies tests can diagnose parasitic diseases.
9. A rapid antigen test can diagnose the retrovirus.
10. Causes of noninfectious disease are diagnosed by:
    1. Fecal fat.
    2. Lactose intolerance test.
    3. Celiac disease is diagnosed by anti-endomysial and antigliadin antibodies.
    4. Tests other than lab are colonoscopy, endoscopy, and sigmoidoscopy.
11. In case of outbreak, advise:
    1. Fecal samples from the kitchen personnel.
    2. Food handling practices by the workers in the kitchen.
       

       Diarrhea diagnosis

Electrolytes findings  are as follows:

Lab Test	Value
Serum Sodium	Decreased
Serum Potassium	Decreased
Serum Bicarbonate	Normal
Serum Chloride	Decreased
Urine volume	Decreased

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