Neonatal Candidiasis
Introduction to Neonatal Candidiasis
Neonatal Candidiasis is a fungal infection affecting newborns, typically caused by species of the genus Candida. It is a significant cause of morbidity and mortality in neonatal intensive care units (NICUs), particularly among premature and very low birth weight infants.
Key points:
- Most common fungal infection in neonates
- Primarily caused by Candida albicans, but other species are increasingly prevalent
- Can manifest as mucocutaneous or invasive disease
- Risk factors include prematurity, low birth weight, and prolonged hospitalization
Pathophysiology of Neonatal Candidiasis
The pathophysiology of neonatal candidiasis involves several factors:
- Colonization:
- Vertical transmission from mother during delivery
- Horizontal transmission in hospital settings
- Colonization of skin, gastrointestinal tract, and respiratory tract
- Host factors:
- Immature immune system in neonates, especially premature infants
- Underdeveloped skin barrier function
- Reduced gastric acidity
- Altered gut microbiome
- Virulence factors of Candida:
- Adherence to host cells
- Production of hydrolytic enzymes
- Biofilm formation
- Morphological switching (yeast to hyphal forms)
- Invasion:
- Penetration of mucosal barriers
- Dissemination through bloodstream
- Organ-specific infection (e.g., central nervous system, kidneys)
The interplay of these factors determines the progression from colonization to invasive disease.
Clinical Manifestations of Neonatal Candidiasis
Neonatal candidiasis can present in two main forms:
- Mucocutaneous Candidiasis:
- Oral thrush: white, adherent plaques on oral mucosa
- Diaper dermatitis: erythematous rash with satellite lesions
- Skin infections: erythematous, scaly patches or pustules
- Invasive Candidiasis:
- Non-specific signs: temperature instability, lethargy, feeding intolerance
- Sepsis-like syndrome: hypotension, respiratory distress, metabolic acidosis
- Organ-specific manifestations:
- Central nervous system: seizures, increased intracranial pressure
- Cardiovascular: endocarditis, mycotic aneurysms
- Renal: hematuria, renal failure
- Hepatic: hepatomegaly, elevated liver enzymes
- Ocular: endophthalmitis
- Skeletal: osteomyelitis
The clinical presentation can be subtle, especially in premature infants, making early diagnosis challenging.
Diagnosis of Neonatal Candidiasis
Diagnosing neonatal candidiasis requires a combination of clinical suspicion and laboratory investigations:
- Clinical assessment:
- Evaluation of risk factors
- Physical examination for signs of localized or systemic infection
- Laboratory studies:
- Blood cultures (gold standard for invasive candidiasis)
- Urine cultures
- Cerebrospinal fluid (CSF) analysis and culture
- Complete blood count: may show thrombocytopenia or leukocytosis
- Liver function tests
- Renal function tests
- Microbiological tests:
- Direct microscopy of clinical samples (e.g., skin scrapings, oral swabs)
- Culture on Sabouraud's dextrose agar or chromogenic media
- Species identification: biochemical tests, MALDI-TOF, molecular methods
- Non-culture diagnostics:
- PCR-based assays for Candida DNA
- β-D-glucan assay (serum biomarker of fungal infection)
- Candida mannan antigen and anti-mannan antibodies
- Imaging studies:
- Echocardiography to evaluate for endocarditis
- Cranial ultrasound or MRI for CNS involvement
- Abdominal ultrasound for hepatosplenic candidiasis
- Ophthalmoscopy to assess for endophthalmitis
Early and accurate diagnosis is crucial for timely initiation of appropriate antifungal therapy.
Management of Neonatal Candidiasis
Management of neonatal candidiasis involves a multifaceted approach:
- Antifungal therapy:
- Mucocutaneous candidiasis:
- Topical antifungals (e.g., nystatin, miconazole)
- Oral fluconazole for persistent cases
- Invasive candidiasis:
- First-line: Amphotericin B deoxycholate or liposomal amphotericin B
- Alternative: Fluconazole (if Candida species is susceptible)
- Echinocandins (e.g., micafungin) for refractory cases or azole-resistant strains
- Mucocutaneous candidiasis:
- Duration of therapy:
- Mucocutaneous: 7-14 days
- Invasive candidiasis: minimum 14 days after last positive blood culture
- CNS involvement: 4-6 weeks or longer
- Supportive care:
- Hemodynamic support
- Respiratory support
- Correction of metabolic derangements
- Nutritional support
- Source control:
- Removal or replacement of central venous catheters
- Drainage of abscesses if present
- Monitoring:
- Serial blood cultures to document clearance
- Follow-up imaging studies to assess resolution of focal infections
- Monitoring for drug toxicities
- Long-term follow-up:
- Neurodevelopmental assessment
- Hearing and vision screening
Management should be individualized based on the extent of infection, causative species, and patient factors.
Prevention of Neonatal Candidiasis
Prevention strategies for neonatal candidiasis focus on reducing risk factors and implementing infection control measures:
- Hand hygiene:
- Strict adherence to hand washing protocols
- Use of alcohol-based hand sanitizers
- Minimizing invasive procedures:
- Judicious use of central venous catheters
- Early removal of unnecessary lines and catheters
- Nutritional strategies:
- Promotion of breast milk feeding
- Proper handling and storage of expressed breast milk
- Antibiotic stewardship:
- Rational use of broad-spectrum antibiotics
- Timely discontinuation of empiric antibiotics when appropriate
- Antifungal prophylaxis:
- Fluconazole prophylaxis for very low birth weight infants in high-risk settings
- Nystatin prophylaxis as an alternative in resource-limited settings
- Environmental control:
- Regular cleaning and disinfection of NICU surfaces
- Proper sterilization of medical equipment
- Staff education:
- Training on infection control practices
- Awareness of risk factors and early signs of neonatal candidiasis
- Skin care:
- Gentle skin care practices to maintain skin integrity
- Use of emollients in extremely premature infants
Implementation of comprehensive prevention strategies can significantly reduce the incidence of neonatal candidiasis in high-risk populations.
Neonatal Candidiasis
- What is the most common causative agent of neonatal candidiasis?
Answer: Candida albicans - Which of the following is NOT a risk factor for neonatal candidiasis?
Answer: Cesarean section delivery - What percentage of very low birth weight infants develop invasive candidiasis?
Answer: 2-8% - Which antifungal medication is commonly used as first-line treatment for systemic neonatal candidiasis?
Answer: Amphotericin B - What is the most common clinical presentation of mucocutaneous candidiasis in neonates?
Answer: Oral thrush - How long after birth do symptoms of congenital cutaneous candidiasis typically appear?
Answer: Within the first 6 days of life - Which laboratory test is most useful for diagnosing invasive candidiasis in neonates?
Answer: Blood culture - What is the recommended duration of antifungal therapy for invasive candidiasis in neonates?
Answer: 14-21 days after the last positive blood culture - Which of the following is a common complication of untreated systemic neonatal candidiasis?
Answer: Meningitis - What is the mortality rate associated with invasive candidiasis in very low birth weight infants?
Answer: 20-30% - Which body system is most commonly affected in neonatal invasive candidiasis?
Answer: Cardiovascular system - What is the recommended prophylactic antifungal for high-risk preterm infants?
Answer: Fluconazole - How often should prophylactic fluconazole be administered to high-risk preterm infants?
Answer: Every 72 hours - What is the most common non-albicans Candida species causing invasive disease in neonates?
Answer: Candida parapsilosis - Which of the following is a characteristic sign of congenital cutaneous candidiasis?
Answer: Erythematous macules that progress to papules and pustules - What is the recommended first-line treatment for oral thrush in neonates?
Answer: Nystatin oral suspension - How long should topical antifungal treatment be continued after the resolution of oral thrush?
Answer: 2-3 days - Which of the following is a contraindication for fluconazole prophylaxis in neonates?
Answer: Severe cholestasis - What is the recommended dose of amphotericin B for treating invasive candidiasis in neonates?
Answer: 1 mg/kg/day - Which of the following is a potential long-term complication of neonatal invasive candidiasis?
Answer: Neurodevelopmental impairment - What is the most common site of Candida colonization in neonates?
Answer: Gastrointestinal tract - Which of the following increases the risk of candidemia in neonates?
Answer: Central venous catheter use - What is the recommended duration of fluconazole prophylaxis in high-risk preterm infants?
Answer: Until central lines are removed and full enteral feeds are established - Which of the following is a sign of disseminated candidiasis in neonates?
Answer: Hepatosplenomegaly - What is the most sensitive imaging modality for detecting hepatosplenic candidiasis in neonates?
Answer: Magnetic Resonance Imaging (MRI) - Which of the following maternal factors increases the risk of neonatal candidiasis?
Answer: Intrauterine device use during pregnancy - What is the recommended treatment for neonatal candiduria?
Answer: Systemic antifungal therapy - Which of the following is a potential ocular complication of invasive candidiasis in neonates?
Answer: Endophthalmitis - What is the most common clinical presentation of invasive candidiasis in extremely low birth weight infants?
Answer: Sepsis-like syndrome - Which antifungal agent is preferred for treating fluconazole-resistant Candida species in neonates?
Answer: Micafungin
