What is the recommended approach for managing an infectious disease referral?

Managing Infectious Disease Referrals

Patients with highly infectious diseases (group 3 or 4 agents) or unknown human-to-human transmissible febrile illnesses must be referred immediately to a High-Level Isolation Unit (HLIU) for specialized management. 1

Immediate Referral Criteria to HLIU

Refer immediately when:

• Unknown human-to-human transmissible or potentially transmissible epidemic febrile illness (native or imported from abroad) 1
• Known infection caused by group 3 or 4 agents, including:
  • Multidrug-resistant or extensively drug-resistant tuberculosis 1
  • Yersinia pestis (plague) 1
  • Viral hemorrhagic fevers 1
  • Other highly pathogenic agents with human-to-human transmission capability 1

Emergency Department Management Pending Transfer

While awaiting HLIU admission:

• Apply standard precautions immediately plus cough and respiratory etiquette 1
• Isolate in a single room with dedicated route and direct access 1
• Upgrade to airborne precautions whenever highly infectious disease is suspected, as transmission modes are often underestimated 1
• Use appropriate PPE: N95/FFP2 respirators for airborne precautions, surgical masks for droplet precautions 1
• Maintain close communication with the HLIU team at the referral hospital 1

Laboratory Sampling Protocols

Critical infection control measures:

• Perform all sampling in the isolation room or HLIU, never in general laboratory areas 1
• Use point-of-care bedside tests whenever possible to minimize specimen transport 1
• Send samples to biosafety level 3/4 laboratory if point-of-care testing unavailable 1
• Inactivate samples with formalin before routine laboratory testing 1

Hospital Referral for Community-Acquired Infections

For less severe infectious diseases, refer to hospital (not necessarily HLIU) when:

Clinical Severity Indicators:

• Temperature <35°C or ≥40°C 1
• Heart rate ≥125 beats/min 1
• Respiratory rate ≥30 breaths/min 1
• Blood pressure <90/60 mmHg 1
• Cyanosis, confusion, drowsiness, or altered mental status 1

Risk Factors:

• Age >65 years 1
• Significant comorbidities: COPD, cardiovascular disease, diabetes, chronic liver/renal failure 1
• Recent hospitalization (within previous year) or recent antibiotic use 1
• Institutionalized patients 1

Laboratory Abnormalities:

• Leukopenia (<4,000 WBC/mL) or severe leukocytosis (>20,000 WBC/mL) 1
• Anemia (hemoglobin <9 g/100 mL) 1
• Renal impairment (serum urea >7 mM or creatinine >1.2 mg/dL) 1
• Hypoxemia (PaO₂ <60 mmHg) or hypercapnia (PaCO₂ >50 mmHg) on room air 1
• Acidosis (pH <7.3) 1

Social/Practical Factors:

• Home management impossible: vomiting, social exclusion, extreme poverty, dependency, poor compliance likelihood 1
• Failure of first-line antibiotic therapy 1
• Suspected complications: pleural effusion, cavitation, metastatic infection 1

Special Populations

Pediatric patients:

• All children with suspected highly infectious disease must be admitted to HLIU 1
• Minimize family participation during acute infectious period 1
• Ensure HLIU has pediatric-appropriate nursing capabilities 1

Critical Pitfalls to Avoid

• Never delay referral while awaiting confirmatory testing for highly infectious diseases 1
• Do not underestimate transmission modes—upgrade to airborne precautions when uncertain 1
• Avoid transporting specimens through general hospital areas without proper biosafety protocols 1
• Do not assume standard isolation is sufficient for group 3/4 agents—HLIU admission is mandatory 1
• Never perform aerosol-generating procedures without appropriate PPE and negative-pressure environment 1

Mandatory Reporting

Prompt reporting to national public health authorities is mandatory for all suspected or confirmed highly infectious diseases 1