There is no threat to the polio-free status of any South Asian country including India, the World Health Organisation said on Saturday. The organisation’s South Asia Regional Office said that the countries in the region have maintained a “high vigil” for detection of polio and that detecting a rare strain of the disease was “not unusual”, PTI reported.

The WHO’s statement comes days after a sewage sample in Hyderabad tested positive for the virus. Health officials were also reportedly investigating a second case, where a six-year-old in Uttar Pradesh showed symptoms of the disease.

“Such viruses have been detected from environmental samples only – no children have been affected nor cases of paralysis associated,” it said, adding that, “The South-East Asia Region was certified polio-free on 27 March 2014 and there is no threat to the Region’s polio-free status from the VDPV isolates in the sewage samples.”