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Acute Gastroenteritis

Definition

• characterized by changes in the character and frequency of stool.

• defined as the passage of a greater number of stools of decreased form from the normal lasting less than 14 days.

• Generally associated with other symptoms including nausea, vomiting, abdominal pain and cramps, increase in intestinal, fever, passage of bloody stools, tenesmus, and fecal urgency.

EPIDEMIOLOGY

According to WHO and UNICEF • 2 billion cases of diarrheal disease worldwide every year• 1.9 million children <5 years old die from diarrhea each year• 78% of child deaths occur in the African and South –East Asian

regions• Globally it is the 2nd leading cause of death

EPIDEMIOLOGY

ORS, improved rates of breastfeeding,

improved nutrition, better sanitation and

hygiene have contributed to a decline in the

mortality rates in the past three decades

ETIOLOGY

Bacterial agents• Escherichia coli – most common

1. ETEC – causes traveler’s diarrhea

2. EPEC – rarely causes disease in adults but is common in children

<2 years old and persistent diarrhea3. EIEC – causes bloody mucoid (dysentery) diarrhea, fever is

common

Bacterial agents

4. EHEC –produces the Shiga toxin causes bloody diarrhea, severe

hemorrhagic colitis, HUS (6-8%), cattles are the predominant

reservoir, O157:H7 from undercooked hamburger

5. EAEC – causes watery diarrhea in young children and persistent

diarrhea in children with HIV

Bacterial agents

Campylobacter – Asymptomatic infection is common– Associated with watery diarrhea sometimes dysentery– Develops Guillain-Barre syndrome in about 1 in 1000

patients with colitis– Poultry is a common source– Should ask abut recent picnic or banquets– Common among children <2 years

Bacterial agents

Shigella species– More common in toddlers and older children– S. sonnei is common in developed countries and

causes mild illness and may cause institutional outbreaks

– S. flexneri is endemic and causes dysentery and persisitent illness

Bacterial agents

– S. dysenteriae type 1- only one that produces the Shiga

toxin; is the epidemic serotype

– Commonly acquired from eating chicken

– Definitive dx: isolation of the organism from fecal material

Bacterial agents

Vibrio cholerae

– >2000 serotypes and all are pathogenic for humans

– Serogroups O1 & O139 only two types that causes

severe cholera and outbreaks

– Severe dehydartion can lead to hypovolemic shock

and death can occur w/in 12-18h after onset

Bacterial agents

– Stools are watery, colorless, eith mucus – “rice watery

stools”

– Vomiting is common, fever is typically absent

– Potential for epidemic spread and should be reported

promptly

Bacterial agents

– Commonly from seafood, especially if raw

– Laboratory isolation of the organism requires a special

medium – taurocholate-tellurite gelatin agar or

thiosulfate-citrate-bile salts-sucrose (TCBS)

Bacterial agents

Salmonella– Infants, children and the elderly who are immune-

compromised are of greatest risk– Animals are major reservoir– Enteric fever – S. enterica serovar Typhi and Paratyphi A,

B, C (typhoid fever) causes prolonged fever that lasts > 3 weeks; normal bowel habits, constipation or diarrhea

Bacterial agents

– Nontyphoidal salmonellosis- acute onset of nausea, vomiting and diarrhea that may be watery or dyseteric

– Fever develops in 70% of children– Bacteremia occurs in 1-5%, mostly in infants– Commonly acquired from mayonnais, creams or raw eggs

Bacterial agents

• Definitive dx: isolation of the organism from blood(40-80 %sensitive), BM or other sterile sites

• 1st week – blood

• 2nd week – urine

• 3rd week - stool

Viral agents

Predominant cause of acute diarrhea in both industrialized and developing countries

Rotavirus– Leading cause of severe, dehydrating gastroenteritis

among children– Neonatal infections are common but often asymptomatic– Peaks between 4-23 months of age

Viral agents

Norovirus– Belongs to the family Caliciviridae– Most common cause of outbreaks affecting in all age

group Sapovirus– Also from the family of Caliciviridae– Primarily affects children– 2nd most common viral agent after rotavirus

Parasitic agents

Cryptosporidium parvum, Giardia intestinalis, Entamoeba histolytica Usually causes traveler’s diarrhea Relatively small portion of cases

PATHOGENESIS

Pathogens have a variety of tactics to overcome host defenses

Mechanisms:1. Inoculum size- varies

Shigella, EHEC, G. lamblia, Entamoeba as few as 10 -100 bacteria or cysts

Vibrio cholerae - 105 – 108 organisms Salmonella – varies on the specie, host and food

vehicle

PATHOGENESIS

2. Adherence Adheres to the GI mucosa Specific cell surface proteins involved in attachment of

the bacteria to intestinal cells Ex. V. cholerae adheres to the brush border of the SI

enterocytes via specific surface adhesins ETEC produces an adherence protein called

colonization factor antigen

PATHOGENSIS EPEC and EHEC produce virulence that allow these

organisms to attach to and efface the brush border of the intestinal epithelium

3. Toxin production Enterotoxin – ex. Cholera toxin, Heat labile

enterotoxin, heat stable Cytotoxins – ex. Shigella dysenteriae type 1 Neurotoxins – ex. Bacillus cereus toxins

PATHOGENESIS

4. Invasion5. Host defenses – ability to combat pathogens

Normal flora Gastric acidity Intestinal motility Immunity Genetic determinants

CLASSIFICATION

Classified accordingly as:

Acute diarrhea - >3 loose watery stools in the previous 24

hours

Dysentery – presence of visible blood in stools

Persistent diarrhea – acutely starting episode of diarrhea

lasting more than 14 days

CLINICAL MANIFESTATIONS

CLINICAL MANIFESTATIONSLoose watery stoolsFeverBloody stoolsNausea and VomitingAbdominal pain

Clinical evaluation

• Assess the degree of dehydration, presence of

acidosis and provide rapid rehydration

• Obtain appropriate contact, travel or

exposure history

• Clinically determine the probable etiology for

prompt antibiotic institution if indicated

HISTORY

Initial evaluation should include the ff:Onset, frequency, type, volume+/- bloodVomitingMedicines takenComorbiditiesEpidemiologic clues24h food recall

PHYSICAL EXAM

Body weightTemperaturePR and RRBPComplete PE and assess the level of dehydaration

DHAKA METHODASSESSMENT PLAN A PLAN B PLAN C

1. General condition

N Irritable/ less active*

Lethargic /comatose *

2. Eyes N Sunken Sunken

3. Mucosa N Dry Dru

4. Thirst N Thirsty Unable to drink*

5. Radial pulse N Low volume* Absent

6. Skin turgor N Reduced* Reduced

Diagnosis No signs of dehydration

Some dehydrationAt least 2 signs;

including one key sign (*) are present

Severe dehydrationSome signs of

dehydration plus at least one key sign

present

LABORATORY EVALUATION

• Stool examination

• Stool cultures are indicated in cases of dysentery or

where the diagnosis of AGE is unclear

• CBC to look for anemia, hemoconcentration, or an

abnormal white blood cell count.

LABORATORY EVALUATION

• Serum electrolyte concentrations are used to determine

the extent of fluid and electrolyte depletion

• Blood culture for some etiologies like Salmonella

TREATMENT

TREATMENT

PLAN A PLAN B PLAN C

TREATMENT Prevent dehydration

Reassess periodically

Rehydrate with ORS solution

Reassess frequently

Rehydrate with I.V. fluids and ORS

Reassess more frequently

TREATMENT

PLAN A -Home therapy to prevent de hydration and malnutritionRule 1: give more fluids than usual• <2 y.o : 50-100 ml after each loose stool• 2-10 : 100-200ml• Older children and adults : as much as the want

PLAN A

Rule 2: give Zinc (10-20mg) daily for 10-14 days

Rule 3: Continue to feed the child to prevent

malnutrition

Rule 4: take the child to a health worker when signs f

dehydration develop

PLAN B

Oral rehydration therapy

Give also supplemental Zinc

Monitoring of the patient’s conditon

If at any time the patient develops signs of severe

dehydration, shift to plan C

PLAN C

• Intravenous rehydration- Give 100ml/kg PLR:

• Reassess patient every 1-2 hours• After 3 or 6 hrs evaluate patient then choose

appropriated treatment plan

Age First give 30ml/kg in: Then give 70ml/kg in:

Infants <12 months 1 hour 5 hours

Older 30 minutes 2.5 hours

Oral Rehydration Therapy

Oral rehydration therapy (ORT) is the administration

of appropriate solutions by mouth to prevent or

correct diarrheal dehydration.

ORT is a cost-effective method of managing acute

gastroenteritis and it reduces hospitalization

requirements in both developed and developing

countries.


The new lower-osmolarity ORS recommended by

(WHO and UNICEF) has reduced concentrations of

sodium and glucose and is associated with less

vomiting, less stool output, lesser chance of

hypernatremia, and a reduced need for intravenous

infusions in comparison with standard ORS.


This formulation is recommended irrespective of

age and the type of diarrhea including cholera.

According to the 2012 WGO guidelines ORT is

contraindicated as initial therapy in cases of

severe dehydration, children with paralytic ileus,

frequent and persisitent vomiting.


However, nasogastric administration of ORS solution

is potentially lifesaving when intravenous rehydration

is not possible.

Rice-based ORS is superior to standard ORS for adults

and children with cholera, and can be used to treat

such patients wherever its preparation is convenient.


Constituents of the new oral rehydration solution (ORS) Sodium 75 mmol/LChloride 65 mmol/LAnhydrous glucose 75 mmol/LPotassium 20 mmol/LTrisodium citrate 10 mmol/LTotal osmolarity 245 mmol/L

In comparison


Home-made oral fluid recipe Preparing 1 L of oral fluid using salt, sugar and

water at home. The ingredients to be mixed are:

One level teaspoon of salt.

Eight level teaspoons of sugar.

One liter (five cupfuls) of clean drinking water, or water that has been

boiled and then cooled.

SUPPORTIVE TREATMENT

Zinc supplement Recommendation : 20mg OD for 10 days

Multivitamins and minerals Diet

normal feeding should be continued for those with

no signs of dehydration

food should be started immediately after correction

of some and severe dehydration

SUPPORTIVE TREATMENT

Breastfed infants and children should continue receiving

food

However, for non-breastfed, dehydrated children and

adults, rehydration is the first priority.

Avoid fruit juices

Probiotics are said to be beneficial

Nonspecific antidiarrheal agents

Antimicrobial agents

ORGANISM DOC DOSAGEShigella Ciprofloxacin, ampicillin,

ceftriaxone, azithromycin, or TMP-SMXMost strains are resistant now to severalantibiotics

•Ceftriaxone 50-100 mg/kg/day IV or IM, qd or bid for 7 days•Ciprofloxacin20-30 mg/kg/day PO bid for 7-10days•Ampicillin PO,IV 50-100 mg/kg/dayqid for 7 days

EPEC, ETEC, EIEC

TMP-SMX or ciprofloxacin •TMP 10 mg/kg/dayand SMX 50 mg/kg/daybid for 5 days•Ciprofloxacin PO 20-30 mg/kg/dayqid for 5-10 days

Salmonella No antibiotics for uncomplicatedgastroenteritis in normal hosts caused by nontyphoidal speciesTreatment is indicated in infants <3 mo, and patients with malignancy, chronic GI disease,severe colitis hemoglobinopathies, or HIV infection, and other immunocompromised patientsMost strains have become resistant to multiple antibiotics

See treatmentof Shigella

ORGANISM DOC DOSAGECampylobacter jejuni Erythromycin or

azithromycin•Erythromycin PO 50 mg/kg/daydivided tid for 5days•Azithromycin PO 5-10 mg/kg/day qid for 5 days

Entamoeba histolytica Metronidazole followed by iodoquinol or paromomycin

•Metronidazole PO 30-40 mg/kg/day tid for 7-10 days•Iodoquinol PO 30- 40 mg/kg/daytid for 20 days•Paromomycin PO 25-35 mg/kg/day tid for 7 days

Giardia lamblia Furazolidone or metronidazole or albendazole or quinacrine

•Furazolidone PO 25 mg/kg/day qid for 5-7 days•Metronidazole PO 30-40 mg/kg/daytid for 7 days•Albendazole PO 200 mg bid for 10 days



Approach in adults with acute diarrhea1. Perform initial assessment.

2. Manage dehydration.

3. Prevent dehydration in patients with no signs of dehydration, using

home-based fluids or ORSsolution.• Rehydration of patients with some dehydration using ORS– Correct dehydration of a severely dehydrating patient with an appropriate intravenous fluid.• Maintain hydration using ORS solution.

Approach in adults with acute diarrhea

– Treat symptoms if necessary4. Stratify subsequent management:

• Epidemiological clues: food, antibiotics, sexual activity, travel, day-care attendance, other illness, outbreaks, season.• Clinical clues: bloody diarrhea, abdominal pain, dysentery, wasting, fecalinflammation.

5. Obtain a fecal specimen for analysis6. Consider antimicrobial therapy for specific pathogens.

Indications for medical consultation or in-patient care are:

Caregiver’s report of signs consistent with dehydration Changing mental status History of premature birth, chronic medical conditions, or

concurrent illness Young age (< 6 months or < 8 kg weight) Fever 38 °C for infants < 3 months old or 39 °C for children aged 3–

36 months

Indications for medical consultation or in-patient care are:

Visible blood in stool High-output diarrhea, including frequent and substantial volumes Persistent vomiting, severe dehydration, persistent fever Suboptimal response to ORT No improvement within 48 hours—symptoms exacerbate and

overall condition gets worse No urine in the previous 12 hours

WHEN to discharge?

When to discharge?

Stable Vital signs

Normal urine output

Maintains a sufficient fluid intake

Able to eat meals adequately

Able to take medications (if still indicated)

Prevention

• Promotion of exclusive breast feedingPromotes passive immunity

• Improved complementary feeding practices Start giving complementary food at 6 mo. And continue BF up to 1

year or longer

• Rotavirus immunization• Improved case management of diarrhea• Patient education

Patient Education

• Risk factors

– Environmental contamination

– Young age, immunodeficiency state, measles, lack of exclusive

breast-feeding

– Malnutrition

• Vitamin A deficiency

• Zinc deficiency

Patient Education

• Proper personal hygiene and safe food preparation.

• Hand-washing with soap is an effective step in preventing spread of illness

• Human feces must always be considered potentially hazardous, whether or not

diarrhea or potential pathogens have been identified.

• Select populations may require additional education about food safety, and health

care providers can play an important role in providing this information.

Thank you!

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