Kolkata, Jan. 14 -- Samples of both suspected Nipah virus cases in West Bengal have tested positive, the National Institute of Virology (NIV) in Pune confirmed on Tuesday, with officials familiar with the matter saying that the two patients, both nurses, are critical and on ventilator. The two nurses - a male and a female - who worked in the same private hospital at Barasat in North 24 Parganas and are currently admitted there. While one is a resident of Nadia, another is a resident of East Burdwan. On Tuesday, a senior official of the state health department informed that the samples have tested positive. Nipah virus is commonly found in fruit bats, and the mortality rate for the disease is 70%. All the state-run hospitals and medical colleges were asked to gear up their facilities to tackle any form of outbreak of the virus....