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DIARRHEA IN CHILDREN. Maria Naval C. Rivas Department of Pediatrics The Medical City. SOURCES. Nelson’s Textbook of Pediatrics 18 th edition World Health Organization: A Manual for Physicians and Other Senior Health Workers, 2005. DEFINITION.
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DIARRHEA IN CHILDREN Maria Naval C. Rivas Department of Pediatrics The Medical City
SOURCES • Nelson’s Textbook of Pediatrics 18th edition • World Health Organization: A Manual for Physicians and Other Senior Health Workers, 2005
DEFINITION • passage of unusually loose or watery stools • at least 3 times in a 24 hour period • Acute diarrhea: < 2 weeks • Chronic diarrhea: > 2 weeks
EPIDEMIOLOGY • 2nd leading cause of morbidity • 1,135 cases per 100,000 population • 6th leading cause of mortality • 5.3 deaths per 100,000 population • 1000M episodes of diarrhea/year in children <5y • 5M deaths in <5y • 80% deaths in 1st 2y of life (1/3 of all deaths) Sources: Carlos M.D., C. & Saniel M.D., M. Etiology and Epidemiology of Diarrhea. Research Institute for Tropical Medicine : Philippine Health Statistics, 2000
APPROACH TO A CHILD WITH ACUTE DIARRHEA Main Objectives 1. assess degree of dehydration and provide fluid and electrolyte replacement 2. prevent spread of enteropathogen 3. in select episodes, determine etiologic agent and provide specific therapy if indicated
APPROACH TO A CHILD WITH ACUTE DIARRHEA Pertinent Data oral intake frequency of stools volume of stools presence of blood or mucus in stool general appearance & activity of child frequency of urination
APPROACH TO A CHILD WITH ACUTE DIARRHEA others: day care attendance recent travel to a diarrhea endemic area use of antibiotics exposure to contacts with similar symptoms intake of seafood, uncooked meat, unpasteurized milk, unwashed vegetables, contaminated water systemic sx: fever, vomiting, seizure
APPROACH TO A CHILD WITH ACUTE DIARRHEA Degree of Dehydration MILD DEHYDRATION (3-5%) - normal or increased pulse, decreased urine output, thirsty, normal physical examination MODERATE DEHYDRATION (7-10%) - tachycardia, little or no urine output, irritable/ lethargic, dry mucous membranes, mild tenting of skin, delayed capillary refill, cool and pale
APPROACH TO A CHILD WITH ACUTE DIARRHEA Degree of Dehydration SEVERE DEHYDRATION (10-15%) - rapid and weak pulse, decreased blood pressure, no urine output, very sunken eyes and fontanel, no tears, dry mucous membranes tenting of the skin, very delayed capillary refill, cold and mottled
APPROACH TO A CHILD WITH ACUTE DIARRHEA Treatment Plan A - home therapy to prevent dehydration and malnutrition • Give the child more fluids than usual • ORS solution • salted drinks (e.g. salted water, salted yoghurt drink) • vegetable or chicken soup with salt • Give supplemental zinc (10-20mg) for 10-14 days • Continue to feed the child
APPROACH TO A CHILD WITH ACUTE DIARRHEA • Take child back to health worker if there are signs of dehydration or other problems • starts to pass many stools • repeated vomiting • becomes very thirsty • eating or drinking poorly • develops a fever • has blood in the stool • child does not get better in 3 days
APPROACH TO A CHILD WITH ACUTE DIARRHEA Treatment Plan B • oral rehydration therapy with ORS in a health facility • monitoring progress of oral rehydration • supplemental zinc (10-20mg) for 10-14 days • food should not be given during initial 4-hour rehydration period • breastmilk may be given continuously
Treatment Plan B: Approximate amount of ORS to give in the initial 4 hours
APPROACH TO A CHILD WITH ACUTE DIARRHEA Reduced osmalarity ORS mmol/liter Sodium 75 Chloride 65 Glucose 75 Potassium 20 Citrate 10 TOTAL OSMOLARITY 245
APPROACH TO A CHILD WITH ACUTE DIARRHEA Treatment Plan C • rapid intravenous rehydration • may give oral ORS if child can already drink - usually after 1-4 hours • monitoring progress of IV hydration • if IV therapy not available, give ORS by NGT at 20cc/kg/hr x 6 hrs. • manage electrolyte disturbance
IV Treatment of Children & Adults with Severe Dehydration 1. Restore intravascular volume • normal saline: 20ml/kg over 20 mins • repeat until intravascular volume is restored 2. Calculate 24-hr water needs • calculate maintenance water • 0-10kg 100ml/kg • 11-20kg 1000ml + 50ml/kg for each kg > 10kg • > 20kg 1500ml + 20ml/kg for each kg > 20kg • calculate deficit water • Percent dehydration x weight
IV Treatment of Children & Adults with Severe Dehydration 3. Calculate 24-hour electrolyte needs • calculate maintenance sodium and potassium • calculate deficit sodium and potassium • Na deficit = water deficit x 80 mEq/L • K deficit = water deficit x 30 mEq/L 4. Select an appropriate fluid • nornal saline or Ringer lactate 5. Replace any ongoing losses as they occur
APPROACH TO A CHILD WITH ACUTE DIARRHEA Electrolyte Disturbances • Hypernatremic Dehydration (serum Na > 150 mmol/L) - due to drinks with excessive sugar or salt - e.g. soft drinks, commercial fruit drinks, concentrated infant formula - s/sx: extreme thirst convulsions
APPROACH TO A CHILD WITH ACUTE DIARRHEA Electrolyte Disturbances • Hyponatremic Dehydration (serum Na < 130 mmol/L) - due to drinking mostly water or drinks with little salt - common in Shigellosis and in severe malnutrition with edema - s/sx: lethargy
APPROACH TO A CHILD WITH ACUTE DIARRHEA Electrolyte Disturbances • Hypokalemia (serum K+ < 3 mmol/L) - s/sx: muscle weakness, paralytic ileus, cardiac arrhythmia, impaired kidney function
CLINICAL TYPES OF DIARRHEA • Acute Watery Diarrhea • Acute Bloody Diarrhea • Persistent Diarrhea
ACUTE WATERY DIARRHEA Viruses Rotavirus Astrovirus Adenovirus Calcivirus ( e.g. Norwalk agent )
ACUTE WATERY DIARRHEA Pathogenesis - destroy villus tip cells in the SI • imbalance in ratio of intestinal absorption and secretion • malabsorption of complex carbohydrates, sp. lactose - gastric mucosa is not affected - greatly enhances intestinal permeability to macromolecules increase risk of food allergies
ACUTE WATERY DIARRHEA Pathogenesis - increased vulnerability of infants • decreased intestinal reserve function • lack of specific immunity • decreased non-specific host defense mechanisms (e.g. gastric acid, mucus)
ACUTE WATERY DIARRHEA Rotavirus - most common viral cause; RNA virus - > 125 M of cases / yr in < 5 y/o - 600,000 deaths per year - most severe in ages 3mos – 24mos - transmission: fecal-oral route days before and after the clinical illness
Rotavirus in the Philippines - based on 2005 data of PPS - most common viral cause - 3,700 deaths from total of 14,500 deaths related to childhood diarrhea - most severe in ages 3mos – 24mos - 65% of diarrhea-related hospital admissions
Clinical Manifestations incubation: < 48 hours mild to moderate vomiting & fever onset of frequent, watery diarrhea Complications: dehydration, severe and prolonged symptoms in malnourished and immunocompromised children
Diagnosis - clinical and epidemiological features - enzyme immunoassays : 90% specificity/ sensitivity - stool exam : free of blood and leukocytes Treatment - rehydration - probiotics (Lactobacillus species) , zinc - no role for antiviral nor antibacterial drugs - no role for antiemetics nor antidiarrheal drugs
Prognosis - after initial infection, 38% protection against subsequent infection 77% against diarrhea 87% against severe diarrhea Prevention - good hygiene and isolation - breastfeeding - vaccine: > 80% protection against severe disease
Differential Diagnosis 1. Astrovirus – RNA virus - milder with less significant dehydration 2. Norwalk virus – RNA virus - short incubation period (<12 hrs) - vomiting and nausea tend to predominate - clinical picture resembles “food poisoning” by S. aureus
Differential Diagnosis 3. Adenovirus – DNA virus - 5-9% of diarrhea in children - mainly a respiratory virus that grows well in the epithelium of SI - diarrhea is watery but of longer duration ( 10-14 days )
Differential Diagnosis 3. Adenovirus - may be assoc with conjunctivitis, myocarditis, hemorrhagic cystitis, intussusception, encephalomyelitis - transmission: respiratory fecal-oral routes - diagnosis: virus detection by culture or PCR increase in antibody titers
ACUTE WATERY DIARRHEA Enterotoxigenic Escherichia coli (ETEC) - major cause of infantile diarrhea - important etiologic agent of traveler’s diarrhea - 20-30% of diarrhea worldwide and in the Philippines
Pathogenesis - colonization of SI and subsequent elaboration of enterotoxins - enterotoxins: heat-labile (LT) heat- stable (ST) - require a large inoculum of organisms to induce disease - mode of transmission: food or water-borne
ACUTE WATERY DIARRHEA Enteropathogenic Escherichia coli (EPEC) - major cause of infant diarrhea and mortality in < 2 years - pathogenesis: “attaching and effacing lesion” • intimate attachment of bacteria to epithelial surface and effacement of host cell microvilli
Clinical Manifestations - explosive, watery, non-bloody, non-mucoid - abdominal pain - nausea and vomiting - +/- fever - self-limited: 3-5 days but occassionally > 1week
Diagnosis - clinical features seldom distinctive - laboratory studies not readily available: • isolation of bacteria from stool cultures • biochemical criteria (fermentation patterns) • tissue culture • identification of specific virulence factors • detection of antibodies
Treatment - rehydration - early refeeding - history of travel from developing country - DOC: Trimethoprim-Sulfamethoxazole Prevention - prolonged breastfeeding - personal hygiene - proper food and water handling - public health measures
ACUTE WATERY DIARRHEA CHOLERA (Vibrio cholerae) - 5-7M cases and > 100,000 deaths/yr. - an EMERGENCY!! - latest epidemic in 1990s in Americas death rate = 12,000 deaths/70,000 cases -V. cholerae is a gram-negative rod with a polar, flagellum - 2 strains: O1 and O139
Pathogenesis colonization of SI by > 10 viable vibrios production of cholera toxin (CT) entry of toxin into intestinal epithelial cells high cAMP level decrease absorption of Na and Cl by villous cells active secretion of Cl by crypt cells 8
Clinical Manifestations - most are asymptomatic - ¼ with mild to moderate disease - 2-5% with severe disease - hallmark: massive loss of fluids and electrolytes - incubation: 6 hours – 5 days - watery diarrhea, vomiting, low-grade fever - severe: profuse, painless, watery diarrhea with rice-water consistency and fishy odor
Diagnosis - primarily clinical - laboratory confirmation during epidemics • culture by thiosulfate-citrate-bile-sucrose(GOLD STANDARD) • appear as large, yellow colonies against bluish-green medium • culture by tellurite-taurocholate-gelatin agar • small, opaque colonies with zone of cloudiness around them
Treatment - fluid and electrolyte replacement - refeeding does not affect purging rates or duration of illness - success of ORT shown in Peru epidemic in 1991 with <1% mortality - antibiotics for moderate or severe disease DOC: tetracycline and doxycycline resistant strains: TMP-SMZ, Erythromycin, Furazolidone
Complications - dehydration: hypoglycemia acute tubular necrosis - hypokalemia: cardiac arrhythmia paralytic ileus - sodium disturbance: lethargy seizures coma
Prevention - prolonged breastfeeding - safe food and water handling - improved vaccine is priority - Cholera vaccine • 50% efficacy, highly reactogenic, does not protect against O139 vibrios • used only for very high-risk persons (e.g. achlorhydria) with high probability of exposure • not recommended for < 6 mos old
ACUTE WATERY DIARRHEA Staphylococcus aureus - most common cause of food poisoning - ingestion of pre-formed enterotoxins sudden, severe vomiting watery diarrhea - treatment: supportive - prevention: • eat/refrigerate prepared food immediately • exclude those with Staphylococcal skin infections from food handling or preparations 2-7 hours
ACUTE WATERY DIARRHEA GIARDIASIS (Giardia lamblia) - frequently identified during outbreaks assoc with drinking water - high prevalence during childhood - role of child-care centers - transmission: water and food borne low infectious dose extended periods of cyst shedding resistant to chlorination and UV light irradiation