Module 5

• Amoebiasis


  A protozoal infection that involves the colon but may spread to soft tissues, most commonly to the liver or lungs by lymphatic dissemination
• Etiologic Agent

  Entamoeba histolytica
• Entamoeba histolytica

  • Prevalent in unsanitary areas
  • Common in warm climate
  • Acquired by swallowing Cyst
  • Cyst survives a few days outside of the body
  • Cyst passes to the large intestine and hatch into trophozoites
  • Passes into the mesenteric veins, to the portal veins, to the liver, thereby forming amoebic liver abscess
• Developmental Stages of Entamoeba Histolytica

  • Trophozoite/Vegetative form
  • Cyst
• Trophozoite/Vegetative form


  Facultative parasites that may invade the tissues or may be found in parasitized tissues and liquid colonic contents
• Cyst


  The cyst is passed out with formed or semi-formed stools and is resistant to environmental conditions<|>The cyst is considered as the infective stage in the life cycle of E. histolytica
• Pathology

  1. Cyst is swallowed

  2. Passes through the stomach unharmed

  3. Shows no activity while in an acidic environment

  4. Reaches the alkaline medium of the intestine

  5. Metacyst begins to move within the cyst wall
• This is the 1st opportunity of the organism to colonize
• Mature cyst in the large intestines leaves the host in great numbers (the host remains asymptomatic)
• The cyst is rapidly killed by putrefaction (process of decaying) desiccation (drying up) and temperatures below 40 degrees
• Source of Infection


  Human excreta
• Period of communicability


  Communicable for the entire duration of illness
• Incubation Period

  • Severe infection 3 days
  • Sub-acute and Chronic infection 3 to 4 weeks
  • Several months
• Mode of transmission

  • Person-to-person through fecal-oral transmission
  • Direct contact/through sexual contact (by orogenital, oroanal, and proctogenital sexual activity)
  • Indirect contact through ingestion of food especially uncooked leafy vegetables or foods contaminated w/ fecal material containing E. histolytica cysts
  • Foods or drinks may be contaminated by cysts through pollution of water supply, exposure to flies, use of night soil for Fertilizing vegetables, and through unhygienic practices of food handlers
• Pathogenesis


  1. Ingestion of Bacteria

  2. Multiplication in mucosa

  3. Endotoxin production affecting the lining of the small intestines, colon, and capillary

  4. Necrosis of the mucosal layer

  5. Ulceration

  6. Gangrene

  7. TOXEMIA
• Clinical manifestations: Acute amoebic dysentery


  • Slight diarrhea, w/ periods of constipations and tenesmus (distressing urge to defecate)
  • Watery diarrhea, foul-smelling stools often containing blood-streaked mucus
  • Colic (sharp sudden pain in the stomach) and gaseous distension of the lower abdomen
  • Nausea, flatulence, tenderness in the Riliac region over the colon
• Clinical manifestations: Chronic amoebic dysentery

  • Attack of dysentery that lasts for several days, usually succeeded by constipation
  • Tenesmus accompanied by the desire to defecate
  • Anorexia, weight loss, and weakness
  • Hepatomegaly (enlarged liver)
  • Semifluid to watery, bloody, and mucoid
  • Vague abdominal distress, flatulence, constipation, or irregularity of bowel
  • Mild toxemia, constant fatigue, and lassitude
  • Abdomen loses its elasticity when picked up between fingers
• The gangrenous type (fatal cases) is characterized by the appearance of large sloughs of intestinal tissues in the stool accompanied by hemorrhage
• Extraintestinal Forms: Hepatic


  • Pain in the RUQ
  • Tenderness of the liver
  • Jaundice
  • Intermittent fever
  • Loss of weight or anorexia
  • Abscess may break through the lungs; patient coughs "anchovy-sauce" sputum
• Clinical Features

  Onset is gradual<|>Diarrhea increases and stools becomes bloody and mucoid
• Untreated uncases

  • Fluid stool
  • Severe bloody-mucoid stool
  • Peritonitis
  • Hemorrhage
  • Intestinal perforation
• Untreated uncases: DEATH
• Diagnostic Exam


  • Stool exam/cyst; white and yellow pus w/ plenty of amoeba
  • Guaiac tests a test to detect the presence of blood in the stool
  • Blood exam (leukocytosis)
  • Proctosigmoidoscopy/Sigmoidoscopys
• Proctosigmoidoscopy (Proctoscopy, Sigmoidoscopy)


  An internal examination of the lower large bowel (colon), using an instrument called a sigmoidoscope
• Treatment modalities

  • Metronidazole (Flagyl) 800 mg TID x 5 days
  • Tetracycline 250 mg q 6 H
  • Ampicillin, quinolone, sulfadiazines
  • Streptomycin Sulphate, chloramphenicol (contraindicated for children less than 2 years old Could lead to gray baby syndrome)
• Lost fluids and electrolytes should be replaced
• Nursing Management

  • Observe isolation and enteric precaution
  • Provide health education and instruct patient to: Boil water for drinking or use purified water; Avoid washing food from water from open drums and pails; Cover left over food; Wash hands after defecation and before eating; Avoid eating ground vegetables (lettuce, carrots, and the like)
  • Proper collection of stool specimen: Never give paraffin or any oil preparation for at least 48 hours prior to collection of specimens; Instruct the patient to avoid mixing urine w/ stools; Select stool containing blood and mucus as possible; Send the specimen as fresh as possible; Label the specimen properly
  • Skin care
  • Mouth care
  • Optimum comfort
• Diet

  • During the acute stage, fluids should be forced
  • In the beginning of the attack, cereal and strained meat broths fat should be given
  • Chicken and fish may be added when convalescence is established
  • Bland diet without cellulose or bulk-forming foods
• Nursing Diagnosis

  • Altered nutrition: Less than body requirement
  • Alteration in bowel elimination
  • High risk for infection
  • Anxiety
  • Altered body temperature
• Methods of Prevention

  • Health education
  • Sanitary disposal of feces
  • Protect, chlorinate and purify drinking water
  • Observe cleanliness in food preparation and food handling
  • Detection and treatment of carriers
  • Fly control
• Anthrax


  An infection caused by Bacillus Anthracis occurs primarily in herbivores (cattle, sheep, horses, goats)<|>Aerosolized spores of B. anthracis have a potential for use in biological warfare or bioterrorism
• Etiologic agent

  Bacillus Anthracis<|>A large, aerobic, spore-forming, Gram (+), rod shaped microorganism that is capsulated and non-motile<|>Grows in chains<|>Spores of B. anthracis can survive for years in dry soil but can be destroyed by boiling for ten minutes (treatments done by oxidizing agents such as KM04(Potassium permanganate), hydrogen peroxide or diluted formaldehyde<|>Most agents are susceptible to penicillin
• Humans are more resistant to anthrax than herbivorous animals
• Human cases

  • Agricultural cases, result from contact w/ animals that are infected (e.g., during skinning, butchering, or dissecting), from bites of contaminated or infected flies, and from consumption of contaminated meat
  • Industrial cases, associated w/ exposure to contaminated hides, goat hair, wool, or bones
• Modes of transmission

  • Direct through contact w/ infected animals or contaminated animal products
  • Indirect through animal bites and ingestion of contaminated meat
  • Airborne through inhalation of contaminated or polluted air
• Types

  • Cutaneous anthrax
  • Inhalation anthrax (Wool sorter's disease)
  • Gastrointestinal anthrax
• Cutaneous anthrax

  • Incubation period: 9 hours to two weeks
  • 2-3 days a small pimple or macule appears
  • 4th day a ring of vesicles develops around the papule. Vesicular fluid may exude
  • Marked edema starts to develop. Lymphadenitis may develop in the inguinal area. Lesion is not painful
  • 5th to 7th days the original papules ulcerate to form the characteristic eschar
  • Lesions may be located on the face, neck or chest
  • Severe forms: high fever, toxemia, regional painful lymphadenopathy, and extensive edema. Shock and death may ensue
• Inhalation anthrax (Wool sorter's disease)


  Symptoms resemble those of severe viral respiratory diseases<|>1 to 3 days acute phase; increasing fever, dyspnea, stridor, hypoxia, and hypotension occurs, usually leads to death within 24 hours<|>Organisms are directly deposited into the alveoli, producing hemorrhagic necrosis
• Gastrointestinal anthrax


  Results from the ingestion of inadequately cooked meat from animals with anthrax<|>Primary infections occur in the intestine, accompanied by hemorrhagic lymphadenitis<|>Symptoms include fever, nausea and vomiting, abdominal pain, bloody diarrhea, and sometimes rapidly developing ascites (the accumulation of fluid in the peritoneal cavity, causing abdominal swelling)
• Complications

  • Anthrax meningitis is the intense inflammation of the meninges of the brain and the spinal cord
  • Anthrax sepsis develops after lymphohematogenous (spread by lymph vessels and blood vessels) spread of B. anthracis from the primary lesion