Acute infectious diarrheal disease - Cholera - DONE

Question 1

Cholera:

Answer 1

• Cholera is an acute diarrheal disease that can within hours result in profound, rapidly progressive dehydration and death.
• Cholera is a toxin-mediated disease.

Question 2

What causes Cholera?

Answer 2

The illness is caused by infection of the intestine with the bacterium Vibrio cholerae.

Question 3

All Vibrio spp are:

Answer 3

• highly motile
• facultatively anaerobic
• curved gram-negative rods with one or more flagella.

Question 4

What is the most common way of infection with Vibrio?

Answer 4

The most common way of infection is ingestion of water or food contaminated by human feces.

Question 5

Can an infected person act as a reservoir for Vibrio? How does Vibrio spread?

Answer 5

• 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

Question 6

How many deaths occur each year because of Cholera?

Answer 6

An estimated 3-5 million cases and over 100,000 deaths occur each year around the world.

Question 7

Where is Cholera most likely to be found and spread?

Answer 7

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.

Question 8

When does symptoms of Cholera usually occur?

Answer 8

Symptoms typically appear in 2-3 days (few hours-5 days)

Question 9

How severe are Cholera infections?

Answer 9

Cholera infection is often mild or without symptoms.

Question 10

• What is the percentage of infected people that will have severe disease?
• What happens to those who have severe Cholera?

Answer 10

• 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.

Question 11

Profuse diarrhea produced by cholera patients….

Answer 11

contains large amounts of infectious Vibrio cholerae bacteria

Question 12

IMPORTANT IMAGE

Answer 12

SLIDE 7

Question 13

Severe cholera - symptoms (complications derive exclusively from the effects of volume and electrolyte depletion):

Answer 13

• 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

Question 14

What causes “rice-water stools”?

Answer 14

Cholera

Question 15

What are the clinical findings of Cholera?

Answer 15

• rapid heart rate
• loss of skin elasticity
• dry mucous membranes
• low blood pressure
• restlessness or irritability
• renal failure
• somnolence
• coma

Question 16

IMPORTANT - IMAGE ON SLIDE

Answer 16

10

Question 17

What are the laboratory findings of Cholera?

Answer 17

• 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

Question 18

Cholera - diagnosis:

Answer 18

• 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.

Question 19

What is the gold standard for the laboratory diagnosis of cholera?

Answer 19

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.

Question 20

Cary Blair media

Answer 20

Cary Blair media is ideal for transport of Vibrio

Question 21

TCBS

Answer 21

the selective thiosulfate–citrate–bile salts agar (TCBS) is ideal for isolation and identification of Vibrio

Question 22

What can be detected in stool directly by dark field microscopy?

Answer 22

Vibrio cholerae can be detected in stool directly by dark field microscopy by EXPERIENCED staff.

Question 23

What is crucial in the treatment of Cholera?

Answer 23

Fluid resuscitation and management is crucial

Question 24

Treatment of patients with no to moderate dehydration:

Answer 24

• 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.

Question 25

Treatment of patients with severe dehydration:

Answer 25

• patients with severe dehydration, stupor, coma, uncontrollable vomiting, or extreme fatigue that prevents drinking should be rehydrated intravenously (IV).
• start intravenous fluids immediately; if the patient can drink, give ORS solution by mouth while the IV drip is set up
• reassess the patient every 1-2 hours and continue hydrating
• if hydration is not improving, give fluids more rapidly - 200ml/kg or more of intravenous fluids may be needed during the first 24 hours of treatment.

Question 26

Cholera treatment in general:

Answer 26

• Intravenous and oral hydration are both associated with greatly decreased mortality and remain the mainstay of treatment for cholera.
• Still antibiotics reduce volume of stool output by 8-92%, duration of diarrhea by 50-56%, and duration of positive bacterial culture by 26- 83%
• By decreasing duration of diarrhea and stool volume, antibiotics result in more rapid recovery and shorter lengths of inpatient stay.
• Although not necessary for cure antibiotics are recommended to be used in infected patients with moderate or severe illness and who have begun IV hydration.

Question 27

Cholera - antimicrobial treatment:

Answer 27

• doxycycline is recommended as first-line treatment for adults
• azithromycin or erythromycin is recommended as first line treatment for children and pregnant women

Question 28

Prevention of cholera is dependent on…..

Answer 28

access to safe water, adequate sanitation, and basic hygiene needs.

Question 29

Are there any vaccines against Cholera?

Answer 29

Oral cholera vaccines of demonstrated safety and effectiveness have recently become available for use by individuals

• Since 2010, the WHO recommendation is to use these vaccines in conjunction with other prevention and control strategies in areas where the disease is endemic and in areas at risk for outbreaks.

Question 30

IMPORTANT IMAGE

Answer 30

SLIDE 19 YALL!

Question 31

There are 3 oral cholera vaccines that are currently pre qualified by WHO:

Answer 31

• Dukoral
• Shanchol
• Euvichol