On 17 January 2004, a 9-year-old child from Kazipara village was brought to the emergency room of Goalanda health complex in Rajbari district, Bangladesh. The patient had a three-day history of fever and worsening neurological signs: he died within 15 minutes of admission. Between 17 and 21 January, 6 additional children (aged between 2 and 15 years) and a 28 year-old woman (mother of the youngest child) also died with the same symptoms. All patients came from the neighbouring Kazipara and Juran Molla Para villages and lived in two groups of houses located within 1 km of each other.

On 21 January, Goalanda health authorities triggered the alert and sent a report to the central level. On 22 January, a joint investigation mission with the Institute of Epidemiology Disease Control and Research (IEDCR) of the Ministry of Health, the centre for health and population research (ICDDRB) and the WHO country office was dispatched to Goalanda to verify the rumours and to collect samples for laboratory diagnosis.