What are the symptoms, prevention strategies, and treatment options for a patient suspected of having Nipah virus infection, particularly with recent travel history to Southeast Asia or contact with infected animals?

Nipah Virus: Clinical Overview

Nipah virus is a highly lethal zoonotic paramyxovirus with mortality rates of 40-75% that requires immediate isolation with airborne precautions and intensive supportive care, as no FDA-approved antiviral treatment currently exists. 1

Clinical Presentation and Symptoms

The hallmark symptoms include fever (80% of cases), severe encephalitis, and acute respiratory distress syndrome. 2 Key clinical features to identify include:

• Neurological manifestations: Altered sensorium (44%), seizures (39%), headache (47%), and progressive encephalitis leading to coma 2
• Respiratory symptoms: Shortness of breath/ARDS (44%), severe hypoxemia requiring mechanical ventilation 2
• Constitutional symptoms: Fever (80%), myalgia (47%), vomiting (43%) 2
• Rapid progression: Symptoms evolve quickly from influenza-like illness to life-threatening encephalitis and respiratory failure within days 3

The clinical presentation mimics influenza initially, creating diagnostic challenges and delays in outbreak detection. 3

Diagnostic Approach

RT-PCR from throat swabs, respiratory specimens, CSF, or urine is the primary diagnostic test during the acute phase (used in 45.5% of cases). 1, 2

• Obtain specimens early—RT-PCR has highest yield in the first week of illness 1
• Serology (IgM and IgG) becomes positive during convalescent phase but is not useful for acute diagnosis 1
• Contact the CDC Special Pathogens Branch immediately for diagnostic assistance—do not delay isolation while awaiting test results 1
• Maintain high clinical suspicion in travelers returning from South/Southeast Asia (Bangladesh, India, Malaysia, Singapore, Philippines) with fever and encephalitis, regardless of vaccination history 1, 4

Treatment and Management

No FDA-approved specific antiviral treatment exists; management is entirely supportive with aggressive intensive care. 1

Critical Respiratory Management

Early intubation and invasive mechanical ventilation for severe hypoxemia is mandatory—avoid prolonged trials of non-invasive ventilation or high-flow nasal oxygen, which increase mortality and staff exposure risk during emergency intubation. 1 This is the single most important management decision that impacts survival.

Pharmacologic Considerations

• Ribavirin may be considered (C-III recommendation) but has limited evidence for efficacy 1
• Intensive supportive care for neurologic and respiratory complications is the mainstay of treatment 3, 5
• Symptomatic management of seizures, cerebral edema, and multi-organ dysfunction 5

Infection Control Measures (Mandatory)

Airborne precautions with N-95 respirators, gowns, aprons, and face shields are required for all suspected or confirmed cases. 1 This is non-negotiable given the 50% person-to-person transmission rate among healthcare workers. 1

• Isolate patients immediately in negative pressure rooms 1
• Do not use non-invasive ventilation or high-flow nasal oxygen in uncontrolled settings due to aerosolization risk 1
• Healthcare workers represent extremely high-risk groups with documented nosocomial transmission 1

Prevention Strategies

Primary Prevention

Avoid direct contact with fruit bats (Pteropus species), their excreta, or partially eaten fruit in endemic regions. 4, 3

• Do not consume raw date palm sap, which is frequently contaminated by bat saliva or urine 5
• Avoid contact with sick pigs in rural agricultural areas, particularly in Malaysia where pig-to-human transmission occurred 1, 4
• Implement strict biosafety level 4 containment for laboratory workers handling specimens 1

Secondary Prevention

Rapid case identification and immediate implementation of infection control measures are essential to contain outbreaks. 4

• Screen travelers from endemic regions (South/Southeast Asia) presenting with fever and neurological symptoms 1
• Trace and monitor all contacts of confirmed cases for 21 days 3
• Pig farmers and healthcare workers in endemic areas require heightened surveillance 1

Tertiary Prevention

Currently, no licensed vaccine exists for human use, though this is a priority on the WHO's research agenda. 3, 5

Prognosis and Long-Term Outcomes

The case-fatality ratio is 73.9%, with 30-50% of survivors developing permanent neurologic sequelae including seizures, cognitive deficits, motor weakness, and behavioral problems. 1, 2

• Mortality exceeds that of Japanese Encephalitis (20-30% case-fatality) 6
• Complications include persistent seizures (39%), altered mental status, and respiratory failure 2
• Long-term neuropsychiatric sequelae significantly impact quality of life in survivors 1

Critical Pitfalls to Avoid

Do not delay intubation with prolonged non-invasive ventilation trials—this single error increases mortality and creates dangerous staff exposure during emergency intubation. 1

• Do not dismiss fever and encephalitis in travelers from South/Southeast Asia as common viral illness 1
• Do not wait for confirmatory testing before implementing airborne isolation precautions 1
• Do not underestimate person-to-person transmission risk—50% of cases involve human-to-human spread 1

Human-to-human transmission associated with recurrent outbreaks represents a potential global health threat, necessitating aggressive early containment measures. 7