Polio virus resurfaces in Hyderabad after 5 years

The Polio virus is believed to have resurfaced in Hyderabad, India, after a strain of the virus was found in the city's sewage system. Despite the city's lack of cases of Polio in the last five years, the government has stressed the importance of vigilance and is launching a large-scale vaccination programme in response.

HYDERABAD: The dreaded wild polio (type 2) vaccine-derived virus strain, which has been traced in the city, might be more dangerous than projected, say experts.It has been two months since Telangana and Andhra Pradesh switched to the bivalent form of polio vaccine, believing that the type 2 strain has been eradicated. The bivalent vaccine tackles only type 1 and 3 strains of the virus.. This means that children up to three years of age, who were vaccinated after the switch, are at some risk for type 2 polio.While the massive drive to re-vaccinate 3 lakh children is being called 'just a precautionary measure', doctors are not ruling out the possibility of the virus already existing in a mild form, especially since the strain found is estimated to be nearly a year old."Mostly polio viruses cause very mild illnesses, which are aparalytic, and hence the virus could easily go unnoticed. It can be present like a minor viral infection or diarrhoea and settle down on its own. Since the virus is spread through the feco-oral route and given the extremely poor socio-economic and hygiene conditions, there is every chance that the virus is already existing in a mild form in the community," said Dr K Sashikiran, senior general physician, Yashoda Hospital.Dr. P Suresh Kumar, superintendent, Niloufer Hospital, explained that in extremely rare cases, the virus can even remain potent and lead to the disease. "It is to avoid even that faint chance that re-vaccination is being taken up. It is being treated as a 'global emergency' because it has been found after the switch of the vaccine," he said."The strategy is to mop up the immediate area to prevent the spread of the virus," said Lalitha Kumari, director of public health and family welfare, government of Telangana.Meanwhile, since environmental samples are being tested only in large cities, there is a chance that the virus exists in smaller cities too, where the floating population is more. In fact, many states have asked the health authorities whether they need to go for a similar drive, said sources in the Unicef office in Delhi.What has sparked fears is that between January 2015 and May 2016, 14 sewage samples collected from different parts of the country have tested positive for vaccine-derived polio virus.However, a statement from the Union ministry of health and family welfare said the chances of transmission are less even as the strain found in the city is 'genetically mutated' from the oral vaccine. "A rapid surveillance review of the area revealed that the population immunity against polio type 2 is high as trivalent oral polio vaccine (TOPV) and two mass vaccination campaigns were conducted in January and February, 2016. As per recent sample survey in the area, 94% of children were found to have received 3 doses of OPV," read the statement.