PAEDIATRIC
GASTROINTESTINAL INFECTIONS
1. GASTROENTERITIS
Acute gastroenteritis
Most common causes are viruses. E.g.: rotavirus
Antibiotics not recommended. Antibiotic therapy may prolong carriage state of salmonellosis.
Oral rehydration is the cornerstone of treatment.
2. DYSENTERY
2.1 Bacterial Infection
Common organisms:
Shigella
E. coli
Campylobacter
Preferred
Most are mild infections which resolve spontaneously without antibiotics.
Mild or uncomplicated
Adequate fluid replacement. No antibiotics required.
Severe illness
(hospitalisation, invasive/other complications or immunocompromised patients*)
Ceftriaxone 75-100 mg/kg/day IV q24h (max. 2g/day) for 5 days (origin of infections: Asia)
Alternative
Mild or uncomplicated
Ampicillin 100mg/kg/day PO in 4 divided doses (max. 2g/day) for 5-7 days for hospitalized children
Severe illness
**Ciprofloxacin 20-30mg/kg/day IV in 2 divided doses (max. 1.5g/day) for 3 days
OR
Azithromycin 10mg/kg/dose IV q24h (max. 500mg/dose).
Total course: 3 days
Comments
Resistance patterns towards amoxicillin, trimethoprim sulfamethoxazole, ciprofloxacin & azithromycin are on the rise. Adjust antibiotic once culture & sensitivity (C&S) results are available.
*For immunocompromised host - treat longer (7-10 days).
**Reserve fluoroquinolone only for isolate where there is no other antibiotic option available due to its many side effects.
2.2 Parasitic Infection
2.2.1 Amoebiasis
Preferred
Metronidazole 30-50mg/kg/day PO in 3 divided doses (max. 750mg/dose) for 7-10 days
Alternative
--
Comments
Similar dosage for extraintestinal disease.
2.2.2 Giardiasis
Preferred
Metronidazole 15mg/kg/day PO (max. 250mg) in 3 divided dose (max. 250mg/dose) for 5-7 days
Alternative
--
Comments
Similar dosage for extraintestinal disease.
3. TYPHOID FEVER
Common organisms:
Salmonella typhi
S. paratyphi A & B
Preferred
Empirical treatment
Ceftriaxone 75-100mg/kg/day IV q24h (max. 2g/day) for 7-14 days
Mild or uncomplicated
*Ciprofloxacin 30-40mg/kg/day PO in 2 divided doses (max. 1.5g/day) for 5-7 days
Severe infection or suspected resistant organism
Ceftriaxone 80-100mg/kg/day IV q24h (max. 2g/day) for 7-14 days
Chronic carrier state (> 1 year)
Ampicillin 100mg/kg/day PO in 4 divided doses (max. 2g/day) for 6 weeks
OR
Amoxicillin 100mg/kg/day PO in 2 divided doses (max. 4g/day) for 6 weeks
OR
Trimethoprim/sulfamethoxazole
8mg (TMP)/kg/day PO in two divided doses (max. 320mg TMP/day) for 6 weeks.
Alternative
Mild or uncomplicated
Azithromycin 20mg/kg/dose PO q24h (max. 1g/dose)
OR
Ampicillin 100mg/kg/day PO in 4 divided doses (max. 2g/day)
Severe infection or suspected resistant organism
*Ciprofloxacin 30-40mg/kg/day IV in 2 divided doses (max. 0.8-1.2g/day) for 7-10 days
Chronic carrier state (> 1 year)
*Ciprofloxacin 20-30mg/kg/day PO in 2 divided doses (max. 1.5g/day) for 4 weeks
OR
Ampicillin 200-300mg/kg/day IV maximum in 4-6 divided doses (max. 12g/day).
(If oral therapy not tolerated & strain is susceptible)
Comments
Adjust antibiotic once C&S results are known.
Duration of antibiotics: 7 days (uncomplicated) to 10 days (for severe disease) or 14 days (if using ampicillin) if patient is clinically improving and without a fever for 48 hours.
Choice of antibiotics & duration depends on disease, C&S results & whether oral route is preferred.
*Fluoroquinolones need to be used with caution in children due to possible arthropathy & rapid development of resistance. There is now increasing data of other side effects e.g: hypoglycaemia & neuropsychiatric d/o.
Ampicillin & trimethoprim/ sulfamethaxazole may be considered for susceptible strain. More strains now becoming sensitive to these agents except for certain countries
4. CHOLERA
Preferred
Azithromycin 20mg/kg/day PO in a single dose (max. 1g)
OR
Erythromycin ethylsuccinate 12.5mg/kg/dose PO q6h (max. 250mg/dose) for 3 days
OR
*Doxycycline 4.4mg/kg/day PO in a single dose (max. 200mg) for children > 8 years old
Alternative
--
Comments
Oral or IV rehydration is the cornerstone of treatment. Prompt initiation of antibiotic therapy reduces the volume and duration of diarrhoea. Antibiotics should be considered for people who are moderately to severely ill. Antibiotic choice depends on age and pattern of resistance.
Monitor antibiotic sensitivity pattern at the beginning of and during the outbreak as it can change.
*Avoid using doxycycline for young children as they can cause staining of the teeth. Use of doxycycline should be considered in an epidemic caused by susceptible isolate.
Fluoroquinolones are not approved for children younger than 18 years old for this indication.
5. PERITONITIS
Common organisms:
Gram-positive
Gram-negative organisms
Anaerobes
Preferred
Primary/spontaneous bacterial peritonitis
Cefotaxime 200mg -300mg/kg IV in 4 divided doses (max. 2g/dose)
Secondary peritonitis (secondary to perforated viscus)
Cefotaxime 200mg -300mg/kg IV in 4 divided doses (max. 2g/dose)
PLUS
Metronidazole 15mg/kg/dose loading dose followed by 7.5mg/kg/dose IV q8h (max. 4g/day)
Secondary (nosocomial) peritonitis
Piperacillin/tazobactam IV 300mg/kg/day in 3-4 divided doses (max. 16g/day)
If culture proven ESBL:
Imipenem/cilastatin 60-100mg/kg/day IV in 4 divided doses (max. 4g/day)
OR
Meropenem 60-100mg/kg/day IV in 3 divided doses (max. 6g/day)
De-escalate treatment to ertapenem 30mg/kg/day IV in 2 divided doses (max. 1g/day) once patient is stable.
Alternative
Ampicillin 100mg/kg/day PO in 4 divided doses (max. 2g/day)
PLUS
Gentamicin 5mg/kg/day IV OD
PLUS
Metronidazole 7.5mg/kg/dose IV q8h max. 4g/day) for 7-14 days
OR
Amoxicillin-clavulanate
Age 3 months and above: 75mg/kg/day (amoxicillin dose) IV in 3 divided doses
Age < 3 months or < 4kg: 50mg/kg/day (amoxicillin dose) IV in 2 divided doses
Comments
May omit metronidazole in primary peritonitis.
In immunocompetent patient with mild to moderate peritonitis and source control, suggest 5 days of therapy.
Ertapenem is not licensed to be used in infants less than 3 months old.
6. LIVER ABSCESS
6.1 Liver abscess (amoebic)
Entamoeba histolytica
Preferred
Metronidazole 35-50mg/kg/day PO in 3 divided doses for 7-10 days
Alternative
--
Comments
Amoebic abscess tends to be solitary lesion. Consider surgical drainage if needed.
6.2 Liver abscess (pyogenic)
Common organisms:
Klebsiella spp.
E. coli
Streptococcus milleri
Other Gram-negative organisms
Anaerobes
S. aureus
Preferred
Cefotaxime 200mg-300mg/kg/day IV in 4 divided doses (max. 2g/dose)
OR
Ceftriaxone 100mg/kg/day IV in 1-2 divided doses (max. 2g/dose; 4 g/day)
PLUS
Metronidazole 22.5-40mg/kg/day IV in 3 divided doses (max. 4g/day)
Alternative
Piperacillin/tazobactam 300-400mg/kg/day (of piperacillin component) IV in 3-4 divided doses (max. 16g/day)
ESBL-Klebsiella:
Ertapenem 30mg/kg/day in 2 divided doses (max. 1g/day) (above 3 months of age)
Comments
Surgical drainage is needed in most cases.
Duration: 4-6 weeks.
7. CHOLANGITIS
Acute cholangitis
Gram-positive & Gram-negative organisms, anaerobes
Preferred
Cefotaxime 200mg -300mg/kg IV in 4 divided doses (max. 2g/dose)
OR
Ceftriaxone 100 mg/kg/day IV in 1-2 divided doses (max. 2g/dose; 4g/day)
PLUS
Metronidazole 22.5-40 mg/kg/day IV in 3 divided doses (max. 4g/day)
Alternative
Piperacillin/tazobactam 300-400mg/kg/day (of piperacillin component) in 3-4 divided doses IV (max. 16g/day)
OR
Ampicillin/sulbactam 200-300mg/kg/day (of ampicillin component) IV in 4-6 equally divided doses
Comments
Duration ∽ 7 days. Outcome is similar with less than 7 days to those with longer duration > 7 days in patients treated with percutaneous cholecystectomy. Source control is needed in cases of treatment failure.
8. ENTEROCOLITIS
Common organisms:
Enterobacteriaceae
Enterococci
Bacteroides
Preferred
Ampicillin 200mg/kg/day IV in 4-6 divided doses (max. 12g/day)
PLUS
Metronidazole 15mg/kg loading dose, followed by 7.5mg/kg/dose IV q8h (max. 4g/day)
Alternative
Cefotaxime 200mg/kg/day IV in 4 divided doses (max. 2g/dose)
PLUS
Metronidazole 15mg/kg loading dose, followed by 7.5mg/kg/dose IV q8h (max. 4g/day)
Comments
Antibiotics should be adjusted with results of C&S.
Duration: 5-7 days for uncomplicated enterocolitis.
References:
CDC. Antibiotics Resistance Threats in the United States 2013
Dr. Phoebe Williams, Prof James A Berkeley.Dysentery (Shigellosis) Current WHO Guidelines and the WHO Essential Medicine List for Children. November 2016
Frank Shann, Seventeenth edition, 2017
WHO/V&B/03-07 (2003) Background document: the diagnosis, treatment and prevention of typhoid fever
WHO/CDD/SER/91.15 REV.1. Management of Patient with Cholera
Christoph Lübbert, Johannes Wiegand, Thomas Karlas. Viszeralmedizin. 2014 Oct; 30(5): 334–341
Patrick Mosler. Management of Acute Cholangitis. Gasteroenterol Hepato (NY) 2011 Feb; 7(2): 121–123
Solomkin JS, Mazuski JE, Bradley JS, et al.; Surgical Infection Society; Infectious Diseases Society of America. Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(2):135
American Academy of Paediatrics. Commitee on Infectious Diseases. Red Book: Report of the Committee on Infectious Diseases (2021-2024)
The WHO AWaRe (Access, Watch, Reserve) Antibiotic Book, 2022
Manual of childhood infections-Blue Book 4th edition; Oxford University Press.