In Kerala, no Nipah-positive cases were reported yesterday in Kozhikode. Samples of 49 persons tested yesterday returned negative results. The findings of 36 more samples are yet to be received. 11 persons are in isolation. The condition of three positive Nipah patients continues to be stable, while that of a nine-year-old boy, is improving. 

State Health Minister Veena George said it is believed that mutation of the virus has not taken place so far. However, she said more studies will have to be done in this regard. Samples of 36 bats taken from a particular place were found to be negative. Experts said nothing unusual was noticed in the tests conducted on the carcasses of wild boars in the region.

Meanwhile, addressing a press conference in Thiruvananthapuram yesterday, Chief Minister Pinarayi Vijayan said the threat posed by Nipah virus in Kozhikode cannot be treated as over. He said the health authorities suspected the viral infection at the initial stages itself, and steps were taken to contain its spread.