Acute infectious diarrheal disease - Cholera - DONE Flashcards
(31 cards)
Cholera:
- Cholera is an acute diarrheal disease that can within hours result in profound, rapidly progressive dehydration and death.
- Cholera is a toxin-mediated disease.
What causes Cholera?
The illness is caused by infection of the intestine with the bacterium Vibrio cholerae.
All Vibrio spp are:
- highly motile
- facultatively anaerobic
- curved gram-negative rods with one or more flagella.
What is the most common way of infection with Vibrio?
The most common way of infection is ingestion of water or food contaminated by human feces.
Can an infected person act as a reservoir for Vibrio? How does Vibrio spread?
- Infected person as a reservoir can act as vehicle for spread.
- However disease is not likely to spread directly from one person to another;
therefore, casual contact with an infected person is not a risk for becoming ill
How many deaths occur each year because of Cholera?
An estimated 3-5 million cases and over 100,000 deaths occur each year around the world.
Where is Cholera most likely to be found and spread?
Cholera is most likely to be found and spread in places with inadequate water treatment, poor sanitation, and inadequate hygiene.
- The cholera bacterium may also live in the environment in brackish rivers and coastal waters.
When does symptoms of Cholera usually occur?
Symptoms typically appear in 2-3 days (few hours-5 days)
How severe are Cholera infections?
Cholera infection is often mild or without symptoms.
- What is the percentage of infected people that will have severe disease?
- What happens to those who have severe Cholera?
- Approximately 5-10% infected persons will have severe disease
- in these people, rapid loss of body fluids leads to dehydration and shock.
Without treatment, death can occur within hours.
Profuse diarrhea produced by cholera patients….
contains large amounts of infectious Vibrio cholerae bacteria
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Severe cholera - symptoms (complications derive exclusively from the effects of volume and electrolyte depletion):
- sudden, profuse, painless watery diarrhea, sometimes described as “rice-water stools” with no blood
- vomiting
- muscle cramps due to electrolyte disturbances
- thirst
- fever is usually absent
What causes “rice-water stools”?
Cholera
What are the clinical findings of Cholera?
- rapid heart rate
- loss of skin elasticity
- dry mucous membranes
- low blood pressure
- restlessness or irritability
- renal failure
- somnolence
- coma
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What are the laboratory findings of Cholera?
- Elevated hematocrit
- Mild neutrophilic leukocytosis
- Elevated levels of urea and creatinine up to renal failure
- Normal sodium, potasium and chloride levels
- Markedly reduced bicarbonate level (<15 mmol/l)
- Increased serum lactate level
- Low arterial pH
Cholera - diagnosis:
- Isolation and identification of Vibrio cholerae serogroup O1 or O139 by culture of a stool specimen remains the gold standard for the laboratory diagnosis of cholera.
- Cary Blair media is ideal for transport,
and the selective thiosulfate–citrate–bile salts agar (TCBS) is ideal for isolation and identification. - Vibrio cholerae can be detected in stool directly by dark field microscopy by expirienced staff.
- In areas with limited to no laboratory testing dipstick rapid test can provide an early warning to public health officials that an outbreak of cholera is occurring.
What is the gold standard for the laboratory diagnosis of cholera?
Isolation and identification of Vibrio cholerae serogroup O1 or O139 by culture of a stool specimen remains the gold standard for the laboratory diagnosis of cholera.
Cary Blair media
Cary Blair media is ideal for transport of Vibrio
TCBS
the selective thiosulfate–citrate–bile salts agar (TCBS) is ideal for isolation and identification of Vibrio
What can be detected in stool directly by dark field microscopy?
Vibrio cholerae can be detected in stool directly by dark field microscopy by EXPERIENCED staff.
What is crucial in the treatment of Cholera?
Fluid resuscitation and management is crucial
Treatment of patients with no to moderate dehydration:
- patients who can sit up and drink - oral rehydration salts (ORS) solution immediately
- other types of fluids, such as juice, soft drinks, and sports drinks should be AVOIDED.
- reassess the patient after 1 hour of therapy and then every 1 to 2 hours until rehydration is complete
- during the initial stages of therapy, while still dehydrated, adults can consume as much as 1000 ml of ORS solution per hour, if necessary, and children as much as 20 ml/kg body weight per hour.
