Table 1. Surveillance case definitions of human NiV infection.

Case definition	Criteria
Nipah like illness (Screening case definition)	Fever (axillary temperature >38.5°C) or history of raised temperature prior to hospitalization AND any sign/symptom of brain pathology OR Fever (axillary temperature >38.5°C) or history of raised temperature prior to hospitalization AND any sign/symptom of lung pathology
Suspected Nipah encephalitis	Fever or history of fever (axillary temperature >38.5°C) AND evidence of acute brain pathology (e.g., altered mental status, new-onset seizures, or new neurological deficit either diffuse or localized to the brain)
Suspected Nipah pneumonitis	Onset of illness within the last seven days AND fever or history of fever (axillary temperature >38.5°C) AND severe shortness of breath (i.e., dyspnea that prevents the patient from walking unassisted for not more than ten steps) AND chest radiograph consistent with diffuse acute respiratory distress syndrome
Probable Nipah infection	History of Nipah encephalitis or pneumonitis AND established epidemiological link with at least one confirmed Nipah case but the absence of laboratory confirmation due to the patient’s death
Confirmed Nipah infection	Laboratory confirmation of the infection; either by identification of anti-Nipah IgM via ELISA (Enzyme-linked immunosorbent assay) OR through identification of viral particles by qRT-PCR (quantitative reverse transcription polymerase chain reaction) with or without a history of Nipah encephalitis/pneumonitis