What is the diagnosis, treatment, and prevention of Nipah Virus?

Nipah Virus: Diagnosis, Treatment, and Prevention

Nipah virus is a highly lethal zoonotic paramyxovirus causing severe encephalitis and respiratory disease with mortality rates of 40-75%, requiring immediate isolation and intensive supportive care as no FDA-approved specific antiviral treatment currently exists. 1

Clinical Presentation and Diagnosis

Key Clinical Features

• Most common symptoms include fever (80%), myalgia (47%), headache (47%), shortness of breath/acute respiratory distress syndrome (44.1%), altered sensorium (44.1%), and vomiting (42.6%). 2
• Neurological manifestations include encephalitis, seizures (39.2%), myoclonic jerks with characteristic 1:1 relationship to EEG periodic complexes, dystonia, areflexia, and hypotonia—all indicating poor prognosis. 3
• Respiratory involvement can progress rapidly to acute respiratory distress syndrome. 2, 4
• Laboratory findings may show thrombocytopenia, leukopenia, and transaminitis. 4

Diagnostic Testing

• RT-PCR from throat swabs, respiratory specimens, CSF, or urine is the primary diagnostic test in the acute phase (used in 45.5% of cases). 1, 2
• Serology (IgM and IgG antibodies) from serum and CSF becomes positive during the convalescent phase. 1
• Contact the CDC Special Pathogens Branch for diagnostic assistance. 1
• Always perform herpes simplex PCR on all CSF specimens to rule out treatable causes of encephalitis. 3

Treatment and Management

Critical Care Approach

Early intubation and invasive mechanical ventilation for severe hypoxemia is mandatory rather than prolonged trials of non-invasive ventilation, which increase mortality and staff exposure risk during emergency intubation. 3, 1

• If non-invasive ventilation or high-flow nasal oxygen is attempted in carefully selected patients with mild respiratory distress, it must be done in an ICU setting with strict airborne precautions, proper interface fitting, and a low threshold for proceeding to intubation if no improvement occurs. 3
• Continuous monitoring with preparedness for urgent intubation is essential, as treatment failure rates with non-invasive ventilation are high in severe viral infections. 3

Supportive Care Measures

• Dynamically monitor vital signs, oxygen saturation, neurological status, water-electrolyte balance, acid-base balance, and organ function continuously. 3
• Monitor for complications including acute respiratory distress syndrome, septic shock, stress ulcers, and deep vein thrombosis. 3
• Aggressive anticonvulsant therapy is required for myoclonic seizures and status epilepticus, with continuous EEG monitoring to detect subclinical seizure activity. 3

Nutritional Support

• Provide high-protein, high-vitamin, carbohydrate-containing diets for patients who can tolerate oral intake. 3
• For critically ill patients, dynamically assess nutritional risks and provide enteral nutrition as soon as possible if compatible; if enteral nutrition is not feasible, initiate parenteral nutrition promptly to meet energy requirements. 3

Antiviral Considerations

• Ribavirin can be considered for Nipah virus encephalitis, though evidence for efficacy is limited (C-III recommendation). 3, 1, 4
• No FDA-approved specific antiviral treatment exists; management is entirely supportive. 1, 5
• M102.4 monoclonal antibody and favipiravir are the only other antivirals with some activity against Nipah virus, though not currently approved. 4

Psychological Support

• Provide psychological and humanistic care, especially for awake patients, using techniques like mindfulness-based stress reduction to relieve anxiety and panic. 3
• Positively encourage patients and address their concerns promptly to reduce fear and anxiety. 3

Infection Control and Prevention

Healthcare Worker Protection

Airborne precautions with N-95 respirators, gowns, aprons, and face shields are mandatory for all suspected or confirmed cases, as person-to-person transmission occurs in approximately 50% of cases. 3, 1

• Avoid non-invasive ventilation or high-flow nasal oxygen in uncontrolled settings due to aerosolization risk. 1
• Standard precautions, hand hygiene, and personal protective equipment are the cornerstone of comprehensive infection prevention and control strategy. 4

Transmission Routes and Prevention

• The most common route of transmission is direct human contact with infected patients. 2
• Endemic regions include South and Southeast Asia, particularly Bangladesh, India, Malaysia, Singapore, and the Philippines. 1
• The Indo-Bangladesh outbreaks were associated with consumption of raw date palm sap contaminated by fruit bats. 4, 6
• The first outbreak in Malaysia was related to contact with infected pigs. 7, 5, 4

Prognosis and Long-term Outcomes

• Case-fatality ratio ranges from 40-75%, with a systematic review reporting 73.9% mortality. 1, 2
• 30-50% of survivors develop long-term neurologic sequelae including seizures, cognitive deficits, motor weakness, and behavioral problems. 1
• Do not discharge patients without definite or suspected diagnosis and comprehensive follow-up plans, as neurological sequelae may emerge later. 3

Critical Pitfalls to Avoid

• Do not delay intubation by attempting prolonged trials of non-invasive ventilation or high-flow nasal oxygen—this increases mortality and puts staff at risk during emergency intubation. 3, 1
• Always maintain high clinical suspicion in travelers returning from South/Southeast Asia with fever and encephalitis. 1
• Do not underestimate the risk of person-to-person transmission; strict isolation and airborne precautions are non-negotiable. 3, 1