Acute infectious diarrhea in children

Ievtushenko V.

O.O.Bogomolets National Medical UniversityChair of Children Infectious Diseases

Acute infectious diarrhea = acute intestinal infection

Acute infectious diarrhea – group of infections of different etiology (viruses, bacteria, fungi, protozoa), with fecal-oral transmission and predominantly impairment of gastrointestinal tract.

Infectious diarrhea accounts for more than 2 million deaths annually and is associated with impaired physical and cognitive development in resource-limited countries (WHO)

Infectious diarrhea takes third place in mortality structure in children younger 5 years (WHO)

DefinitionDiarrhea – an increased frequency of

defecation or stool form changes (mushy or watery stool).

Acute diarrhea – an episode that has an acute onset and lasts no longer than 14 days; chronic or persistent diarrhea is defined as an episode that lasts longer than 14 days (WHO).

Acute diarrhea1. Noninfectious2. Infectious

1) Invasive2) Secretory

Noninfectious diarrhea• Pancreatic exocrine function failure• Endocrine dysfunctions (thyroid, suprarenal

glands diseases)• Bile acids insufficiency (cholestasia,

postoperative)• Intestinal enzymes deficiency (acquired or

congenital)• Noninfectious inflammation of intestine (allergic

diseases, ulcerative colitis, Crohne disease, rheumatic diseases, tumor)

Noninfectious diarrhea(continuation)

• Intestinal motor dysfunction (irritable bowel syndrome, diet disorders)

• Autoimmune diseases• Immunodeficiency (congenital or acquired)• Malabsorption• Medication intake (laxatives, antibiotics,

antihistamines)

Infectious diarrhea1. Secretory – diarrhea predominantly

caused by functional disorders of small intestine (syn. watery diarrhea, noninflammatory diarrhea)

2. Invasive – caused by inflammation of small and/or large intestine (syn. bloody diarrhea, inflammatory diarrhea)

DiarrhoeaPresense of inflammatory impurities in

faeces (pus, pus-like mucus, blood)

Yes No

Invasive doarrhoea Secretory diarrhoea

EtiologySecretory ←Diarrhea→ Invasive

• Viruses– Rotavirus– Adenovirus– Norovirus

• Bacteria– V. cholerae– EPEC– ETEC– EAgEC

• Protozoa– Cryptosporidium– Isospora– Cyclospora– Giardia lamblia

• Bacteria– Shigella– Salmonella– EIEC– EHEC– Campylobacter– Y. enterocolitica

• Protozoa– Entamoeba

histolytica

Etiology(immunocompromised patients)

• Cytomegalovirus• HSV• Mycobacterium avium• Criptosporidium• Isospora• Coccidia• Candida

Etiologic structure of acute diarrhea in children <5 y.o. (Europa)

Rotavirus 10-35 %Norovirus 2-20Campylobacter 4-13Adenovirus 2-10Salmonella 5-8Escherichia coli enteropathogenic (EPEC) 1-4,5Yersinia enterocolitica 0,4-3Lamblia Giardia 0,9-3Cryptosporidium 0-3Shigella 0,3-1,4Escherichia coli enterotoxigenic (ETEC) 0-0,5Entamoeba histolytica 0-4

Common causes of infectious diarrhea in children (Europa)

< 1 yr 1-4 yrs > 5 yrs

Rotavirus Rotavirus Campylobacter

Norovirus Norovirus Salmonella

Adenovirus Adenovirus Rotavirus

Salmonella Salmonella

Campylobacter

Yersinia

Clinical picture• Local symptomatic

• Gastritis (stomach lining inflammation)• Enteritis (small intestinum lining inflammation)• Colitis (large intestinum lining inflammation)

• Symptoms of dehydration• Toxic symptoms

• toxic encephalopathy

Local symptomaticGastritis – nausea, repeated vomiting, pain

in upper abdomenEnteritis – nonlocalized pain, flatulence,

watery large-volume stoolColitis - urgency, painful defecation,

frequent small-volume stool, blood and pus-like mucus in feces

Pathophysiology of Diarrhoea

WHY DOES IT OCCUR?

Osmotic diarrhoeaIf excessive amounts of solutes are retained

in the intestinal lumen, water will not be absorbed and diarrhoea will result.

May be caused by • Ingestion of a poorly absorbed substrate

(mannitol, sorbitol, MgSO4 and some antacids)

• Inability to absorb certain substances (malabsorption)

Secretory diarrheaOccurs when secretion of water into the intestinal

lumen exceeds absorption.Caused by• Exposure to toxins from several types of bacteria

(e.g. E. coli, Vibrio cholerae)• Action of certain substances (some laxatives,

some types of asthma medications, antidepressants, cardiac drugs, certain metals, organic toxins, arsenic, insecticides, mushroom toxins, caffeine)

Inflammatory diarrheaOccurs when microbial or viral pathogens disrupt

the epithelium of the intestine that results in exudation of serum and blood into the intestinal lumen and inefficiency of digestion and absorbtion.

Examples of pathogens frequently associated with infectious diarrhea include: Bacteria (Salmonella, E. coli, Campylobacter), Viruses (rotaviruses, coronaviruses, parvoviruses, norovirus), Protozoa (coccidia species, Cryptosporium, Giardia)

DehydrationWeight loss

Age <5 yo >5 yo

Mild ≤5% <3%Moderate 6-9% 4-6%Severe ≥10% >6%

Clinical symptoms of dehydrationMild (3-5%) Moderate (5-10%) Severe

(>10%)General Alert Restless, Irritable LethargicBlood Pressure Normal Normal Normal/

decreasedQuality of Pulse Normal Normal, Moderately

slightly decreased decreasedHeart Rate Normal Increased IncreasedSkin Turgor Normal Decreased DecreasedFontanelle Normal Sunken SunkenMucus membranes Slightly dry Dry DryEyes Normal Sunken Deeply sunkenExtremities Warm, normal Delayed Cool, mottled

cap refill cap refill Urine Output Slightly < 1 ml/kg/hr << 1 ml/kg/hr

decreasedThirst Slightly Moderately Increased/

increased increased decreased

EncephalopathyCNS symptoms associated with brain

edema and may include:Severe headacheLethargyMeningismusDeliriumConvulsionsComa

ShigellosisGenus Shigella is grouped into 4 species:Shigella dysenteriae (group A)Shigella flexneri (group B)Shigella boydii (group C)Shigella sonnei (group D)

ShigellosisSymptoms include the following:• Sudden onset• High-grade fever• Emesis• Anorexia• Abdominal pain (commonly left lower quadrant)• Tenesmus• Seizures (may be an early manifestation)• Large-volume watery diarrhea quickly becomes

small-volume with purulent mucus and blood (colitis)

SalmonellosisGastrointestinal diseases in humans

(Nontyphoidal Salmonella infections) mostly caused by two serotypes:

• S. Enteritidis (S. enterica serotype Enteritidis)

• S. Typhimurium (S. enterica serotype Typhimurium)

SalmonellosisCommon symptoms:• Abrupt onset• Nausea and vomiting• Crampy abdominal pain (primarily in the

periumbilical area and right lower quadrant)

• Liver enlargement• Large-volume watery diarrhea (sometimes

with blood and dark-green mucus)

Yersinia enterocolitica Symptoms• Fever • Abdominal pain (commonly right lower quadrant)• Mesenteric lymphadenitis (may mimic appendicitis)• Diarrhea (enterocolitis). Stools may be watery and/or

contain leukocytes and sometimes frank blood and mucus

• Liver enlargement• Rash (may be scarlet fever-like), socks and gloves

symptom• Arthralgia

Escherichia coli 5 major groups of diarrheagenic E. coli have been

characterized on the basis of clinical, biochemical, and molecular-genetic criteria:

1) enterotoxigenic E. coli (ETEC); 2) enteroinvasive E. coli (EIEC);3) enteropathogenic E. coli (EPEC); 4) Shiga toxin–producing E. coli (STEC), also

known as enterohemorrhagic E. coli (EHEC) or verotoxin producing E. coli (VTEC);

5) enteroaggregative E. coli (EAEC)

Escherichia coliSecretory diarrhea Invasive diarrhea

EPEC EIECETEC EHECEAEC

Viral diarrheaCommon enteropathogenic viruses:• Rotaviruses• Noroviruses (Norwalk virus)• Adenoviruses• Caliciviruses• Astroviruses

Viral diarrheaClinical picture• Abrupt onset• Nausea, repeat vomiting• Large-volume watery diarrhea• Catarrhal symptoms may be presence

Laboratory Studies• Stool culture (urine, blood, bile culture if

generalized course suspected)• Serologic tests (revealing of specific antibody in

blood)• Antigen detection (used for detection of viral

antigen in stool)• Blood chemistry (if dehydration or toxic

symptoms expressed)• Fecal leukocytes and erythrocytes (microscopy)

Methods of therapy1. Rehydration therapy2. Antibacterial treatment3. Additional therapy4. Diet

Rehydration therapyRehydration used in all patients with

infectious diarrhea.Rehydration• Oral rehydration therapy (ORT)• Parenteral (intravenous, IV) rehydration

therapy

Rehydration therapyOral rehydration therapy (ORT) is appropriate for

patients with mild and moderate dehydration.Compared to IV rehydration, ORT is safer, less

costly, and able to be administered in various clinical settings.

Oral rehydration solutions (ORS) should contain 45-90 mmol/L of sodium and 74-140 mmol/L of glucose.

Acceptable, commercially available ORS include: Rehydron, Naturalyte, Pedialyte, Infalyte, Rehydralyte, WHO Oral Rehydration Salts, and Pediatric Electrolytes.

Rehydration therapyChildren with severe dehydration should

receive fluids IV. Those unable or unwilling to drink or who have repetitive vomiting can receive fluid replacement IV, through an NGT, or sometimes orally through frequently repeated small amounts.

For IV therapy used 0.9% or 0.45% Saline, 5% Glucose solutions, Ringer’s solution.

Rehydration therapy

Volume (daily amount) = Maintenance (base) + Deficit + Ongoing losses

Rehydration therapyMaintenance volume

Body weight Fluid per day0–10 kg 100 mL/kg 11–20 kg 1,000 mL + 50 mL/kg for

each kg > 10 kg >20 kg 1,500 mL + 20 mL/kg for

each kg > 20 kg

Rehydration therapyOngoing losses:

Diarrhoea – 25-75ml/kg/dayVomiting – 20 ml/kg/dayFever – 10ml/kg Tachipnea – 30 ml/kg/day

Rehydration therapyExample:11-months-old boy (weight – 10 kg) with moderate

dehydration. Diarrhea – up to 8 times/day, vomiting – 4 times/day.

Deficit: 10kg x 10% = 1kg (1000ml)Base: 100ml/kg x 10kg = 1000mlOngoing losses: 50ml/kg x 10kg = 500ml

20ml/kg x 10kg = 200mlVolume = 1000ml+1000ml+500ml+200ml=2700ml

Antibacterial treatmentIndications:• Moderate or severe course of invasive diarrhea• Moderate or severe course of secretory diarrhea

in children under 6 mnth• Children under 3 months, immunocompromised

children independently of severity of diarrhea• Stool with frank blood• Bacterial complications

Antibacterial treatmentDrug of choice for treatment of invasive

diarrhea:Azithromycin 10 mg/kg/day (orally)

or Ceftriaxone 50-100 mg/kg/day (IV)

Additional therapy• Zinc (20 mg/day for 14 days) – especially

for Shigellosis (not available in Ukraine)• Probiotics (lacto-, bifidumbacteria,

saccharomyces)• Prebiotics (e.g. lactulose)• Antidiarrheal drugs (e.g. diosmectite)