Patna: Bihar has launched an extensive microfilaria survey in 12 districts to track the spread of lymphatic filariasis, a parasitic disease that remains a public health challenge in many parts of India. Blood samples will be collected in three phases between 8.30 pm and midnight, with the first phase running until August 31.
According to the state’s filariasis advisor Anuj Singh Rawat, all districts have been instructed to ensure high-quality reporting during the night-time survey, which is necessary as microfilaria is detectable in the blood only at night.
The first phase covers the districts of Buxar, Bhojpur, Darbhanga, Kishanganj, Lakhisarai, Madhepura, Madhubani, Nalanda, Nawada, Rohtas, Samastipur and Patna. Subsequent phases will extend the survey to the remaining districts by December 15.
The health department is targeting areas where anti-filaria medication has previously been administered. In each selected village, blood samples will be taken from 300 residents.
Once the survey is complete, any area found to have a microfilaria rate exceeding 1% will see mass drug administration campaigns before February 10, 2026.



















