Book Contents

ANTIMICROBIALS USE
IN PAEDIATRIC INFECTIONS

DR. M QUAMRUL HASSAN, MBBS, FCPS
EVERCARE HOSPITAL DHAKA
April 2026

Preface

Welcome to the Paediatric Antimicrobial Guide. This interactive e-book has been compiled to assist clinicians, registrars, and medical officers in the fast-paced hospital environment. It distills complex infectious disease guidelines into actionable, weight-based treatment regimens covering bacterial, fungal, and viral infections in neonates and children.

Disclaimer:

This document is intended as a clinical reference only and does not replace acute clinical judgment. Always review patient-specific factors such as allergies, renal function, and local resistance patterns prior to prescribing.

PART 1 — NEONATAL INFECTIONS (0–28 days)

1.1 Early-Onset Neonatal Sepsis (EOS)

Definition: Infection presenting within 72 hours of birth. Organisms acquired from maternal genital tract.

Common organisms: Group B Streptococcus (GBS), E. coli, Listeria monocytogenes, Klebsiella spp., Enterococcus spp.

First-line:
Benzylpenicillin + Gentamicin
Second-line (meningitis suspected or confirmed):
Ampicillin + Cefotaxime (avoid ceftriaxone in neonates — bilirubin displacement)
Important Notes:

Start empirically within 1 hour of suspicion

Do not wait for culture results

Add cefotaxime if meningitis suspected — better CNS penetration

GBS remains the most common cause in term infants

Duration: 7–10 days bacteraemia; 14–21 days meningitis

1.2 Late-Onset Neonatal Sepsis (LOS)

Definition: Infection presenting after 72 hours. Organisms often nosocomial (NICU-acquired).

Common organisms: Coagulase-negative Staphylococci (CONS), Staphylococcus aureus (MSSA/MRSA), Gram-negative bacilli (Klebsiella, Pseudomonas, Enterobacter), Candida spp.

First-line:
Flucloxacillin + Gentamicin (community/MSSA-predominant setting)
Alternative first-line (NICU, line-associated):
Vancomycin + Gentamicin
Second-line (Gram-negative resistant organisms suspected):
Piperacillin-tazobactam or Meropenem (if ESBL suspected)
Add antifungal if:
Candida risk factors present (prolonged antibiotics, TPN, VLBW, abdominal surgery) → Micafungin or Fluconazole
Important Notes:

CONS is the most common NICU pathogen — often line-related

Remove or replace central line if CONS or S. aureus bacteraemia

Duration guided by organism, focus, and clinical response

1.3 Neonatal Meningitis

Common organisms: GBS, E. coli (K1 strain), Listeria monocytogenes, S. pneumoniae (rare in neonates)

First-line:
Ampicillin + Cefotaxime IV
Second-line / resistant organisms:
Meropenem ± Vancomycin (if pneumococcal or resistant Gram-negative)
Important Notes:

Always LP before antibiotics if clinically safe

Minimum 14 days for GBS; 21 days for Gram-negative meningitis

Repeat LP at 48–72h to confirm CSF sterilisation in Gram-negative meningitis

Dexamethasone NOT routinely recommended in neonatal meningitis

1.4 Neonatal HSV Infection

Organisms: HSV-1, HSV-2

First-line:
IV Aciclovir 20 mg/kg TDS x 14 days (skin/eye/mouth disease) or x 21 days (CNS/disseminated)
Important Notes:

Start empirically in any unwell neonate — do not wait for PCR

Vesicular rash, seizures, hepatitis, or fever in first month = consider HSV

Follow with oral suppressive aciclovir for 6 months after CNS disease

1.5 Neonatal Conjunctivitis (Ophthalmia Neonatorum)

Common organisms: Neisseria gonorrhoeae (within 5 days), Chlamydia trachomatis (5–14 days), Chemical (day 1)

First-line (gonococcal):
Ceftriaxone 50 mg/kg IM single dose (max 150 mg) + saline eye irrigation
First-line (chlamydial):
Oral Azithromycin 20 mg/kg OD x 3 days (preferred) OR Erythromycin x 14 days
Important Notes:

Gonococcal conjunctivitis is a medical emergency — corneal perforation risk

Treat mother and partner simultaneously

Chlamydial: systemic treatment essential (topical alone insufficient)

1.6 Neonatal Omphalitis

Common organisms: S. aureus, GBS, E. coli, anaerobes (polymicrobial)

First-line (mild — erythema only):
Flucloxacillin + Gentamicin IV
Second-line / necrotising omphalitis:
Piperacillin-tazobactam + Metronidazole IV (surgical referral urgent)
Important Notes:

Necrotising omphalitis requires urgent surgical debridement

Spreads rapidly — reassess every few hours

PART 2 — RESPIRATORY TRACT INFECTIONS

2.1 Community-Acquired Pneumonia (CAP)

Age-based organism variation:

Age

Common organisms

<1 month

GBS, E. coli, Listeria, Chlamydia trachomatis

1–3 months

C. trachomatis, RSV, S. pneumoniae

3 months–5 years

S. pneumoniae, viral (RSV, parainfluenza), H. influenzae

>5 years

S. pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae

First-line (mild–moderate, outpatient):

<5 years: Amoxicillin 40–90 mg/kg/day in 3 divided doses x 5 days

5 years: Amoxicillin + Clarithromycin (atypical cover)

Penicillin allergy: Clarithromycin or Doxycycline (>8 years)

Second-line (severe, hospitalised):

IV Amoxicillin or Co-amoxiclav

Add Clarithromycin if atypical pneumonia suspected (school-age child)

Ceftriaxone if very severe or no response to amoxicillin

Important Notes:

Viral aetiology is commonest in <3 years — antibiotics often not needed

Mycoplasma is the classic "walking pneumonia" in school-age children

Do not routinely use broad-spectrum antibiotics for mild community CAP

2.2 Pertussis (Whooping Cough)

Organism: Bordetella pertussis

First-line:
Azithromycin 10 mg/kg OD x 5 days (all ages; preferred in infants)
Second-line:
Clarithromycin 7.5 mg/kg BD x 7 days
Alternative (>2 months):
Co-trimoxazole (if macrolide intolerant)
Important Notes:

Antibiotics reduce infectivity, not necessarily illness duration

Treatment most effective if started in catarrhal phase

Admit infants <3 months — risk of apnoea and death

Notify public health

2.3 Acute Otitis Media (AOM)

Common organisms: S. pneumoniae, H. influenzae, Moraxella catarrhalis, viral

First-line:
Amoxicillin 40–90 mg/kg/day x 5–7 days
Second-line (treatment failure, recurrent, or penicillin allergy):
Co-amoxiclav OR Cefuroxime OR Clarithromycin (if pen allergy)
Important Notes:

Many cases resolve without antibiotics — watchful waiting acceptable in >2 years with mild symptoms

High-dose amoxicillin for suspected resistant S. pneumoniae

Bilateral AOM in <2 years: treat with antibiotics

Refer if recurrent (>3 episodes in 6 months)

2.4 Acute Tonsillitis / Pharyngitis

Common organisms: Group A Streptococcus (GAS), viral (most cases in children)

First-line (confirmed or suspected GAS):
Phenoxymethylpenicillin (Pen V) 12.5 mg/kg QDS x 10 days
Second-line / penicillin allergy:
Clarithromycin 7.5 mg/kg BD x 5 days OR Azithromycin x 3 days
Important Notes:

Use FeverPAIN or Centor score to guide antibiotic decision

FeverPAIN score ≥4 = likely bacterial, treat

Do not use amoxicillin — risk of widespread rash if EBV

Rheumatic fever prevention: complete full 10-day course

Peritonsillar abscess (quinsy): Co-amoxiclav IV + surgical drainage

2.5 Acute Sinusitis

Common organisms: S. pneumoniae, H. influenzae, Moraxella catarrhalis

First-line:
Amoxicillin 40 mg/kg/day x 10–14 days
Second-line:
Co-amoxiclav (if no response at 48–72h or recurrent)
Important Notes:

Viral sinusitis is far more common — do not treat unless symptoms >10 days or worsening

Complications (orbital cellulitis, intracranial extension) require IV ceftriaxone urgently

2.6 Epiglottitis

Common organism: H. influenzae type b (Hib), GAS

First-line:
Ceftriaxone 80–100 mg/kg/day IV
Important Notes:

Airway emergency — do not examine throat, do not distress child

Anaesthetics/ENT present at assessment

Unimmunised children at highest risk

Rifampicin prophylaxis for close contacts

PART 3 — URINARY TRACT INFECTIONS

3.1 Lower UTI (Cystitis)

Common organisms: E. coli (>80%), Klebsiella, Proteus, Enterococcus

First-line:
Trimethoprim 4 mg/kg BD x 3–7 days OR Nitrofurantoin 1 mg/kg QDS x 3–7 days
Second-line:
Cefalexin OR Co-amoxiclav (guided by sensitivity)
Important Notes:

Send MSU before starting treatment

Nitrofurantoin: avoid if <3 months, avoid if upper tract infection suspected

Boys with UTI always warrants investigation (USS ± MCUG)

3.2 Upper UTI / Pyelonephritis / Febrile UTI

Common organisms: E. coli, Klebsiella, Pseudomonas (if structural anomaly)

First-line (oral, if tolerating):
Co-amoxiclav OR Cefalexin x 7–10 days
First-line (IV, if unwell/vomiting):
Ceftriaxone 50 mg/kg OD IV OR Gentamicin + Ampicillin (neonates)
Second-line (resistant organisms / no response):
Meropenem (ESBL) or Ciprofloxacin (guided by sensitivity)
Important Notes:

All children <3 months with febrile UTI: IV treatment

Imaging: renal USS within 6 weeks; DMSA scan if recurrent

NICE: all children <6 months with first febrile UTI need imaging

PART 4 — CNS INFECTIONS

4.1 Bacterial Meningitis (beyond neonatal period)

Age-based organisms:

Age

Common organisms

1–3 months

GBS, E. coli, S. pneumoniae, N. meningitidis

3 months–5 years

N. meningitidis, S. pneumoniae, H. influenzae

>5 years

N. meningitidis, S. pneumoniae

First-line:
Ceftriaxone 80–100 mg/kg/day IV OD (max 4g)
Add Ampicillin if:
Age <3 months or immunocompromised (Listeria cover)
Second-line (resistant pneumococcus):
Add Vancomycin 15 mg/kg QDS IV

Adjunctive: Dexamethasone 0.15 mg/kg QDS x 4 days — start with or before first antibiotic dose in children >3 months. Reduces hearing loss in pneumococcal meningitis.

Important Notes:

Do LP before antibiotics only if no contraindication (raised ICP, coagulopathy, haemodynamic instability)

If LP delayed — give antibiotics first, do not wait

Meningococcal disease: notify public health immediately

Rifampicin prophylaxis for household contacts

Duration: 7 days (meningococcal), 10–14 days (pneumococcal), 21 days (Gram-negative)

4.2 Viral Encephalitis

Common organisms: HSV (most important), Enterovirus, EBV, CMV, VZV

First-line (empiric — always cover HSV):
IV Aciclovir 10–15 mg/kg TDS (start immediately, before MRI or LP result)
Add:
Ceftriaxone until bacterial meningitis excluded
Important Notes:

HSV encephalitis is treatable — delay is catastrophic

MRI: temporal lobe involvement suggests HSV

CSF HSV PCR may be negative early — do not stop aciclovir on negative PCR if clinical suspicion remains

Duration: 14–21 days IV aciclovir

4.3 Brain Abscess

Common organisms: Streptococcus milleri group, anaerobes, S. aureus, Gram-negatives (post-trauma/surgery)

First-line:
Ceftriaxone + Metronidazole IV
Add Flucloxacillin if:
Post-traumatic or post-neurosurgical (S. aureus risk)
Second-line:
Meropenem + Vancomycin (nosocomial, MRSA risk, no response)
Important Notes:

Neurosurgical drainage often required — medical management alone for small (<2.5cm) abscesses

Prolonged treatment: 6–8 weeks total

Serial MRI to monitor response

PART 5 — SKIN & SOFT TISSUE INFECTIONS

5.1 Impetigo

Common organisms: S. aureus, GAS

First-line (localised):
Topical Fusidic acid 3 x daily x 5 days OR Mupirocin (if fusidic acid resistance)
First-line (widespread/systemic):
Flucloxacillin 12.5–25 mg/kg QDS oral x 5–7 days
Second-line / MRSA:
Co-trimoxazole OR Clindamycin
Important Notes:

School exclusion until lesions crusted or 48h of treatment

Do not use topical fusidic acid for >7 days — resistance

5.2 Cellulitis

Common organisms: S. aureus (MSSA), GAS (most common), occasionally Gram-negatives (immunocompromised, water-related)

First-line (mild, oral):
Flucloxacillin 12.5–25 mg/kg QDS x 5–7 days
Second-line (penicillin allergy or MRSA suspected):
Clindamycin OR Co-trimoxazole

Severe/hospitalised (IV): Flucloxacillin IV ± Benzylpenicillin (GAS cover)

MRSA cellulitis: Vancomycin IV or Clindamycin or Co-trimoxazole

Important Notes:

Mark the border of erythema with a pen at presentation — monitor spread

Elevate affected limb

Water/marine exposure: add Doxycycline (Vibrio, Aeromonas)

Periorbital (preseptal) cellulitis: Co-amoxiclav IV; always exclude orbital cellulitis

5.3 Orbital Cellulitis (Postseptal)

Common organisms: S. pneumoniae, S. aureus, GAS, anaerobes (from sinusitis extension)

First-line:
Ceftriaxone + Metronidazole IV
Add Vancomycin if:
MRSA suspected or no response
Important Notes:

CT orbits urgently to distinguish preseptal vs orbital

Ophthalmology and ENT involvement mandatory

Surgical drainage if subperiosteal abscess, vision threatened, no improvement at 24–48h

5.4 Necrotising Fasciitis

Common organisms: Type I (polymicrobial): GAS + anaerobes + Gram-negatives Type II (monomicrobial): GAS or S. aureus

First-line:
Piperacillin-tazobactam + Clindamycin + Vancomycin IV
Important Notes:

Surgical emergency — antibiotics alone are insufficient

Clindamycin essential for anti-toxin effect

Mortality high without early surgical debridement

IVIG may be considered in severe GAS disease

PART 6 — BONE & JOINT INFECTIONS

6.1 Acute Osteomyelitis

Common organisms (age-based):

Age

Organisms

Neonates

GBS, S. aureus, Gram-negatives

<5 years

S. aureus, GAS, S. pneumoniae

>5 years

S. aureus (dominant), GAS

Sickle cell

Salmonella, S. aureus

Puncture wound

Pseudomonas aeruginosa

First-line (MSSA, most common):
Flucloxacillin 50 mg/kg QDS IV → oral step-down when CRP falling and clinically improving
Second-line / MRSA suspected:
Vancomycin IV OR Clindamycin (if clindamycin-sensitive MRSA)

Sickle cell disease: Ceftriaxone + Flucloxacillin (covers both Salmonella and S. aureus)

Important Notes:

MRI is investigation of choice

IV-to-oral switch: safe once CRP falling, afebrile, tolerating oral — usually 3–5 days IV

Total duration: 3–6 weeks depending on organism and response

Surgical drainage if subperiosteal abscess, no response, or neonatal osteomyelitis

6.2 Septic Arthritis

Common organisms: S. aureus (most common at all ages), GBS (neonates), N. gonorrhoeae (sexually active adolescents), Kingella kingae (toddlers)

First-line:
Flucloxacillin 50 mg/kg QDS IV

Neonates: Flucloxacillin + Cefotaxime (broad cover for GBS and Gram-negatives)

MRSA suspected: Vancomycin IV

Adolescents (gonococcal): Ceftriaxone 50 mg/kg OD IV

Important Notes:

Orthopedic emergency — joint washout usually required

Kocher criteria help assess probability (fever, non-weight-bearing, raised CRP/ESR, raised WBC)

Kingella kingae: oral amoxicillin sufficient once identified

Duration: 2–3 weeks total (shorter if good surgical drainage)

PART 7 — GASTROINTESTINAL INFECTIONS

7.1 Gastroenteritis

Common organisms: Rotavirus, Norovirus, Adenovirus (viral — majority), Salmonella, Campylobacter, E. coli (STEC), Shigella (bacterial)

Antibiotics: Not routinely recommended for viral or uncomplicated bacterial gastroenteritis

Treat with antibiotics if:

Shigella: Azithromycin 12 mg/kg OD x 3 days (first-line UK)

Salmonella (invasive/bacteraemia): Ceftriaxone IV, then Ciprofloxacin oral

Campylobacter (severe/immunocompromised): Azithromycin 10 mg/kg OD x 3 days

Giardia: Metronidazole 7.5 mg/kg TDS x 5–7 days

C. difficile (mild–moderate): Metronidazole; (severe): Oral Vancomycin

Important Notes:

E. coli O157 (STEC): do NOT give antibiotics — risk of HUS

Rehydration is the mainstay of treatment

Rotavirus: prevent with vaccination

7.2 Intra-abdominal Sepsis / Peritonitis

Common organisms: E. coli, Bacteroides fragilis, Enterococcus, Klebsiella (polymicrobial)

First-line:
Co-amoxiclav IV OR Ceftriaxone + Metronidazole IV
Second-line (severe / hospital-acquired):
Piperacillin-tazobactam IV

Third-line (ESBL / no response): Meropenem IV

Important Notes:

Surgical source control is essential — antibiotics are adjunctive

Spontaneous bacterial peritonitis (SBP in cirrhosis): Ceftriaxone + Albumin

PART 8 — FEVER WITHOUT SOURCE & SEPSIS

8.1 Fever Without Source (FWS) — Infant <3 Months

Risk stratification: Use NICE traffic light, PECARN, or Step-by-Step criteria

High risk / unwell infant: Admit; Blood culture, LP, urine; Start Ceftriaxone + Aciclovir empirically (cover HSV)

Low risk, well infant (>28 days): Observe; LP if <21 days; guided by CRP/PCT

Important Notes:

Age <21 days: always admit and treat as sepsis

HSV must always be considered in any febrile neonate

SBI (serious bacterial infection) risk is highest in first 3 months

8.2 Paediatric Sepsis

Empiric treatment:

Setting

First-line

Second-line

Community-acquired

Ceftriaxone IV

+ Vancomycin if MRSA risk

Hospital-acquired

Piperacillin-tazobactam

Meropenem if ESBL

Febrile neutropenia

Piperacillin-tazobactam

+ Vancomycin; Meropenem 2nd line

Neonatal

Benzylpenicillin + Gentamicin

Ampicillin + Cefotaxime (meningitis)

Important Notes:

Give antibiotics within 1 hour of sepsis recognition — every hour delay increases mortality

Follow Sepsis 6 / PEWS protocol

De-escalate based on cultures — do not continue broad-spectrum unnecessarily

Consider antifungal if Candida risk factors (VLBW, prolonged antibiotics, TPN, abdominal surgery)

PART 9 — LESS COMMON BUT IMPORTANT INFECTIONS

9.1 Lyme Disease

Organism: Borrelia burgdorferi

Stage

Treatment

Early localised (EM rash)

Amoxicillin x 14–21 days (<8 yrs) or Doxycycline x 14–21 days (≥8 yrs)

Early disseminated (facial palsy, arthritis)

Same oral regimen, 21–28 days

Lyme meningitis / encephalitis

Ceftriaxone IV x 14–28 days

Lyme carditis

Ceftriaxone IV (severe) or oral (mild)

9.2 Typhoid Fever

Organism: Salmonella typhi / paratyphi

First-line (sensitive):
Azithromycin 20 mg/kg OD x 7 days (oral, uncomplicated)

Severe / complicated: Ceftriaxone 80 mg/kg OD IV x 10–14 days

Important Notes:

Ciprofloxacin resistance common in South Asia — avoid empirically

Notify public health

School exclusion until 2 negative stool cultures

9.3 Tuberculosis (TB)

Standard regimen:

2 months: Isoniazid + Rifampicin + Pyrazinamide + Ethambutol (HRZE)

4 months: Isoniazid + Rifampicin (HR)

TB Meningitis:

Same 4 drugs x 2 months, then HR x 10 months (total 12 months)

Add Dexamethasone

Important Notes:

Always notify public health / TB team

Check for HIV co-infection

Contact tracing essential

Directly observed therapy (DOT) preferred

9.4 Malaria

Organism: Plasmodium falciparum (severe), P. vivax/ovale/malariae

Uncomplicated P. falciparum: Artemether-lumefantrine (Riamet) — weight-based dosing x 3 days

Severe P. falciparum: IV Artesunate (preferred) OR IV Quinine + Doxycycline

P. vivax / ovale: Chloroquine + Primaquine (check G6PD before primaquine)

Important Notes:

Any child returning from endemic area with fever = malaria until proven otherwise

Thick and thin blood films x 3

Admit all children with P. falciparum

Notify public health

9.5 Meningococcal Disease

Organism: Neisseria meningitidis (serogroups B, C, W, Y)

Pre-hospital / GP: Benzylpenicillin IM/IV immediately if meningococcal disease suspected and transfer arranged

Hospital: Ceftriaxone 80–100 mg/kg/day IV

Prophylaxis for close contacts: Ciprofloxacin single dose (adults and children >5 years) OR Rifampicin BD x 2 days

Important Notes:

Non-blanching rash + fever = emergency

Do not delay antibiotics for LP

Notify public health within 24 hours

PART 10 — FUNGAL INFECTIONS IN CHILDREN & NEONATES

10.1 Invasive Candidiasis / Candidaemia

Risk factors:

Prematurity (VLBW), prolonged antibiotics, central venous catheter, TPN, abdominal surgery, immunocompromised, steroids

Common organisms:

Candida albicans, C. parapsilosis (neonates/lines), C. glabrata, C. krusei (azole-resistant), C. auris (emerging, resistant)

First-line (neonates):

Micafungin 10 mg/kg OD IV

First-line (infants and children):

Caspofungin 70 mg/m² loading then 50 mg/m² OD IV

OR Micafungin 2 mg/kg OD IV

Step-down (once stable, sensitive organism):

Fluconazole 6–12 mg/kg OD IV/oral (only if C. albicans/parapsilosis, NOT C. krusei/glabrata/auris)

Second-line (azole-resistant / refractory):

Liposomal Amphotericin B 3–5 mg/kg OD IV

Important Notes:

Remove or replace central venous catheter — essential for cure

Ophthalmology review — Candida endophthalmitis can cause permanent visual loss

Echocardiogram — exclude Candida endocarditis in prolonged candidaemia

Duration: minimum 14 days from last positive blood culture and resolution of symptoms

C. auris: requires specialist ID input — pan-resistant strains reported

10.2 Mucosal Candidiasis (Oral Thrush / Nappy Rash)

Common organisms:

Candida albicans

First-line (oral thrush):

Nystatin 100,000 units QDS oral x 7 days (swab around all mucosal surfaces)

Second-line / persistent / immunocompromised:

Fluconazole 3–6 mg/kg OD x 7–14 days

Oesophageal candidiasis (immunocompromised):

Fluconazole 6 mg/kg OD x 14–21 days OR Micafungin IV if fluconazole-resistant

Candida nappy rash:

Topical Clotrimazole or Miconazole cream x 7–14 days

Important Notes:

Persistent oral thrush in an otherwise well infant beyond 3 months warrants immune workup

Oesophageal candidiasis in a child = consider HIV or primary immunodeficiency

10.3 Invasive Aspergillosis (IA)

Risk factors:

Prolonged neutropenia (AML, HSCT), high-dose steroids, chronic granulomatous disease (CGD), lung transplant

Common organisms:

Aspergillus fumigatus (most common), A. flavus, A. terreus (amphotericin-resistant), A. niger

First-line:

Voriconazole IV/oral

<12 years: 9 mg/kg BD (loading x2 doses, then 8 mg/kg BD)

≥12 years: 6 mg/kg BD loading → 4 mg/kg BD

TDM essential: target trough 1–5.5 mg/L

Second-line / voriconazole intolerant:

Liposomal Amphotericin B 3–5 mg/kg OD IV

Salvage (refractory IA):

Posaconazole OR Isavuconazole OR Caspofungin (combination with voriconazole)

Prophylaxis (high-risk: AML induction, GVHD on steroids):

Posaconazole 300 mg OD delayed-release tablet (≥13 years)

Itraconazole or voriconazole for younger children (per local protocol)

Important Notes:

Galactomannan (serum and BAL) — useful diagnostic marker in neutropenic patients

CT chest: halo sign, air crescent sign suggest IA

Voriconazole does NOT cover Mucorales — distinguish from mucormycosis early

Surgical debridement may be needed for localised disease or CNS involvement

Chronic pulmonary aspergillosis: long-term oral azole therapy

10.4 Mucormycosis

Risk factors:

Haematological malignancy, DKA, iron overload (deferoxamine therapy), trauma, burns, immunosuppression

Common organisms:

Rhizopus spp., Mucor spp., Cunninghamella spp. (most lethal)

First-line:

Liposomal Amphotericin B 5–10 mg/kg OD IV (high dose — do not under-dose)

Step-down / adjunct:

Posaconazole delayed-release tablet OR Isavuconazole (once stable)

Important Notes:

Surgical debridement is mandatory and urgent — antibiotics alone will fail

Rhinosinusal mucormycosis: ENT + ophthalmology + neurosurgery involvement

Voriconazole has NO activity — if started for suspected Aspergillus and not improving, consider Mucor and switch to amphotericin

Cunninghamella species: extremely aggressive, very high mortality

Do NOT use posaconazole suspension — poor absorption; delayed-release tablet only

Combination amphotericin + echinocandin used in some centres

10.5 Pneumocystis jirovecii Pneumonia (PCP)

Risk factors:

HIV/AIDS (CD4 <200), prolonged steroids, SCID, leukaemia (especially during maintenance), organ transplant, biologic therapies

First-line (treatment):

Co-trimoxazole (TMP-SMX) 120 mg/kg/day in 4 divided doses IV/oral x 21 days

Add Prednisolone if moderate-severe (PaO2 <70 mmHg or A-a gradient >35)

Second-line (intolerant to co-trimoxazole):

IV Pentamidine 4 mg/kg OD x 21 days

OR Atovaquone (mild–moderate disease)

OR Primaquine + Clindamycin

Prophylaxis:

Co-trimoxazole 150 mg/m²/day trimethoprim component in 2 divided doses, 3 days per week

Alternative:
Dapsone or monthly nebulised Pentamidine (>5 years)
Important Notes:

PCP in a previously well child = investigate for underlying immunodeficiency

BAL with silver stain or PCR for diagnosis

HIV test in all newly diagnosed PCP

Do not stop prophylaxis prematurely in HIV — continue until immune reconstitution (CD4 >200 for >3 months)

10.6 Cryptococcal Meningitis

Risk factors:

HIV (CD4 <100), organ transplant, haematological malignancy

First-line (induction — 2 weeks):

Liposomal Amphotericin B 3–4 mg/kg OD IV + Flucytosine 25 mg/kg QDS oral/IV

Consolidation (8 weeks):

Fluconazole 12 mg/kg OD oral (max 800 mg)

Maintenance (≥12 months, HIV):

Fluconazole 6 mg/kg OD until immune reconstitution

Important Notes:

India ink stain and cryptococcal antigen (CrAg) — rapid bedside diagnosis

Serial LPs essential — raised intracranial pressure is the main cause of early death

ICP management: daily LP or lumbar drain until opening pressure <20 cmH2O

Flucytosine: monitor levels and FBC (bone marrow suppression)

Rare in immunocompetent children — always investigate immunity

10.7 Dermatophytosis (Tinea Infections)

Common organisms:

Trichophyton, Microsporum, Epidermophyton spp.

Important Notes:

Tinea capitis requires systemic treatment — topical alone is insufficient

Kerion (inflammatory tinea capitis): add short course of prednisolone to reduce scarring

Contagious — check household contacts and pets (Microsporum canis from cats/dogs)

Wood's lamp: green fluorescence with Microsporum species only

10.8 Invasive Fungal Infections in Specific Contexts

Important Notes:

Aspergillus is the leading cause of death

Lifelong Itraconazole prophylaxis 5 mg/kg OD

Treat invasive aspergillosis with Voriconazole + consider IFN-γ

Allergic Bronchopulmonary Aspergillosis (ABPA): Itraconazole + Prednisolone

Aspergillus sensitisation: monitor IgE, spirometry

Scedosporium apiospermum colonisation: increasing post-transplant — Voriconazole

Mould prophylaxis: Posaconazole (≥13 yrs) or Voriconazole

Pre-emptive therapy guided by galactomannan and CT findings

Echinocandin for suspected invasive candidiasis before species identification

PART 11 — VIRAL INFECTIONS IN CHILDREN & NEONATES

11.1 Herpes Simplex Virus (HSV)

Treatment (Neonatal):

IV Aciclovir 20 mg/kg TDS

Treatment (Encephalitis):

IV Aciclovir 10–15 mg/kg TDS

Treatment (Gingivostomatitis):

Oral Aciclovir 20 mg/kg QDS

Important Notes:

Suppressive therapy: Oral Aciclovir or Valaciclovir daily for 6–12 months

Aciclovir-resistant HSV: IV Foscarnet (specialist use only)

11.2 Varicella Zoster Virus (VZV)

First-line (oral, mild–moderate):

Aciclovir 20 mg/kg QDS x 5 days (start within 24h of rash) OR Valaciclovir 20 mg/kg TDS x 5 days (max 1g TDS)

First-line (severe / immunocompromised):

IV Aciclovir 10 mg/kg TDS x 7–10 days

Post-exposure prophylaxis:

Varicella-Zoster Immunoglobulin (VZIG) within 10 days of exposure — for immunocompromised, neonates, pregnant contacts

11.3 Cytomegalovirus (CMV)

First-line (Congenital):

Oral Valganciclovir 16 mg/kg BD

First-line (treatment):

IV Ganciclovir 5 mg/kg BD

Important Notes:

Congenital CMV: test hearing before and after treatment

Monitor FBC weekly — ganciclovir causes neutropenia

CMV viraemia in transplant: pre-emptive treatment when viral load rising

Ganciclovir-resistant CMV: IV Foscarnet OR Cidofovir (specialist)

11.4 Epstein-Barr Virus (EBV) / Infectious Mononucleosis

Treatment:

Supportive — no antiviral indicated for uncomplicated infectious mononucleosis

Important Notes:

Do NOT give Amoxicillin or ampicillin — causes widespread maculopapular rash in ~95%

Avoid contact sports for minimum 4 weeks (splenic rupture risk)

11.5 Respiratory Syncytial Virus (RSV)

Treatment:

Supportive — no antiviral routinely recommended

Antiviral (specialist use only):

Inhaled Ribavirin — severely immunocompromised children

Prevention:

Palivizumab 15 mg/kg IM monthly during RSV season

11.6 Influenza

Treatment:

Oseltamivir (Tamiflu) — by weight <15 kg: 30 mg BD x 5 days

Important Notes:

Most effective if started within 48h of symptom onset

11.7 COVID-19 (SARS-CoV-2)

Treatment:

Nirmatrelvir/ritonavir (Paxlovid) — limited paediatric data

Remdesivir IV

Dexamethasone 0.15 mg/kg OD x 10 days

MIS-C (Multisystem inflammatory syndrome):

IVIG 2 g/kg + Aspirin + consider steroids

11.8 Hepatitis B Virus (HBV)

Treatment:

Tenofovir disoproxil fumarate (TDF) OR Entecavir

11.9 Hepatitis C Virus (HCV)

Treatment (≥3 years):

Sofosbuvir/Velpatasvir (EPCLUSA)

11.10 HIV in Children

Treatment:

Lopinavir/ritonavir + 2 NRTIs (ABC + 3TC)

Dolutegravir + 2 NRTIs

11.11 Viral Haemorrhagic Fevers (VHF)

Treatment:

Ebola: Atoltivimab/maftivimab/odesivimab

Lassa fever: IV Ribavirin

CCHF: IV Ribavirin

11.12 Enteroviruses (Coxsackievirus, Echovirus, EV-A71)

Treatment:

Supportive — no licensed antiviral for most enteroviral disease

Severe neonatal enteroviral sepsis: IV Immunoglobulin (IVIG)

11.13 Measles

Treatment:

Supportive — no specific antiviral licensed

Vitamin A

11.14 Mumps & Rubella

Treatment:

Supportive only — no antiviral

11.15 Adenovirus

Treatment:

Cidofovir IV (specialist use) OR Brincidofovir oral