Diarrhoea and Vomiting (D&V) – Some Common Causative Agents and Their Management (Part 3)

Diarrhoea and Vomiting (D&V) – Some Common Causative Agents and Their Management (Part 3)

Antibiotic Associated Diarrhoea (Clostridium difficile Infection):

A history of any antibiotic therapy in the 6weeks prior to the onset of diarrhoea can be related to the finding of Clostridium difficile or its toxins in the stool.

This is a potent cause of diarrhoea and can produce life threatening pseudomembranous colitis.

This diagnosis is common in the elderly and treated often with metronidazole (Flagyl) for 10days.

Vancomycin may be used where the organism is unresponsive to metronidazole.

Cholera:

Aetiology & Epidemiology:

Cholera is caused by Vibrio cholera, a bacterium. Serotype 01 causes acute watery diarrhoea plus vomiting.

Following its origin in the Gangs valley, devastating epidemics have occurred, especially during large religious festivals.

Pandemics have spread worldwide.

The 7^th pandemic due to the El Tor biotype began in 1961 and spread via the Middle East to become endemic in Africa.

In 1990 it surfaced in Peru and spread throughout South and Central America.

Since August 2000, there has been a massive outbreak in South Africa.

The El Tor biotype is more resistant than the classical vibrio and can cause prolonged carriage in about 5% of infections.

A new classical toxigenic strain, serotype 0139, established itself in Bangladesh in 1992 and started a new pandemic.

Mode of Infection/Transmission:

The infection spreads via the stools and vomitus of symptomatic individuals or through the much larger number of subclinical cases (asymptomatic carriers).

Transmission is through infected drinking water, foods contaminated by flies or through the hands of carriers.

The vibrio microorganism survives for up to 2weeks in fresh water and 8weeks in salt water.

Signs and Symptoms (Clinical Features):

Severe diarrhoea starts all of a sudden without abdominal pain or colic and is soon followed by torrential vomiting.

After evacuation of normal gut faecal contents typical “rice water” stools follow consisting of clear fluid with flecks of mucous.

Classical cholera produces enormous loss of body fluids and electrolytes leading to intense dehydration with muscular cramps. Shock and oliguria develop but mental alertness remains.

Death from acute circulatory failure may occur rapidly unless fluids and electrolytes are replaced quickly. This is why the disease is more dangerous in children.

Improvement however is rapid with proper treatment.

It is to be noted however, that majority of infections cause mild illness, with slight diarrhoea and vomiting.

Occasionally, a very intense illness “cholera sicca” occurs, with massive loss of fluids into dilated bowel, killing the patient before typical gastrointestinal symptoms appear.

Diagnosis:

Clinical diagnosis is easy during an epidemic.

At other times, diagnosis is confirmed bacteriologically from rectal or stool swab cultures.

*Cholera is a notifiable disease under international health regulations.

Treatment/Management:

Quick, early restoration of the circulation by replacement of water and electrolytes is very important and is the key to survival.

Early intervention improves the prognosis.

Oral rehydration solution (ORS) is effective and safe where vomiting has been controlled by initial intravenous fluid therapy.

The addition of resistant starch to ORS reduces faecal fluid loss and shortens the duration of diarrhoea in adolescents and adults.

Total fluid requirements may exceed 50litres over a period of 2–5days. Ringer lactate is the best fluid for intravenous replacement.

Careful attention to fluid balance is especially important in children and they are prone to low blood sugar (hypoglycaemia) during the illness.

3-5days treatment with Tetracycline, or Doxycycline or Ciprofloxacin in adults and children helps to reduce the duration of excretion of vibrio and the total volume of fluids needed for replacement.

*Children should not be given Tetracycline because of discolouration of their dentition.

Prevention:

-         Strict personal hygiene

-         Clean drinking water (pipe borne or boiled)

-         Proper food hygiene to deny flies access.

-         Parental and oral vaccines provide limited protection (6months at most)

-         In epidemics, mass single dose vaccination and treatment with Tetracycline are valuable.

-         Public education, control of water sources and population movement are very important.

-         Disinfection of discharges and soiled clothing.

-         Meticulous hand washing by medical personnel reduces danger of spread.

Author: Ola Suyee

Diarrhoea and Vomiting (D&V) – Some Common Causative Agents and Their Management (Part 2)

Diarrhoea and Vomiting (D&V) – Some Common Causative Agents and Their Management (Part 2)

Travellers Diarrhoea (TD): 

This is classically defined as passage of three or more unformed stools within a 24 hour period during or shortly after a period of foreign travel.

It is frequently encountered by individuals travelling to developing countries.

Aetiology:

Most common cause of TD is the ingestion of faecally contaminated food or water.

A number of bacterial, viral, and parasitic organisms can cause TD, but the majority of cases are associated with bacteria, particularly the pathogen enterotoxigenic Escherichia coli (ETEC).

Here is a list of the most common causes of TD:

(1)  Enterotoxigenic E.coli

(2)  Shigellosis spp.

(3)  Camphylobacter jejuni

(4)  Salmonella spp.

(5)  Pleisonias Shigelloides

(6)  Non-Cholera Vibrio spp.

(7)  Aeromonas spp.

Pathogenesis: 

The organisms produce either a heat-labile or a heat-stable enterotoxin, causing marked secretory diarrhea and vomiting after 1- 2 days incubation.

Treatment: 

(a) If diarrhea is associated with severe dehydration, intravenous fluid and electrolyte replacement is indicated.

This is of particular importance in the case of diarrhea associated with Vibrio.

(b) Antibiotics: These can be used to limit the duration of symptoms and prophylaxis may help to prevent the disease.

(c) In most cases the illness is usually mild and self-limiting after 3 – 4days. Most important supportive treatment is fluid and electrolyte replacement; either orally (if there is no vomiting) or intravenously if there is.

Campylobacter jejuni:

Aetiology and Pathogenesis:

This infection is basically a zoonosis (a disease of animals that may secondarily be transmitted to man). The organism inhabits the gut of cattle and poultry, the commonest source of infection being chicken or contaminated milk.

There is also an association with pet puppies.

Campylobacter infection is now the most common cause of bacterial gastroenteritis in the U.K., even though most of the cases are sporadic.

The incubation period is 2–5days.

Clinical Features & Treatment:

Severe colicky abdominal pain which mimics surgical pathology at times ensues and is followed by nausea, vomiting and quite significant diarrhoea which may become blood stained as the illness progresses.

Majority of Campylobacter infections affect fit, young adults and are self-limiting after 4-7 days.

10-20% will have prolonged symptomatology warranting treatment with antibiotics such as ciprofloxacin or a macrolide, while another 1% of cases will develop bacteraemia and distant foci of infection.

Author: Ola Suyee