HYDERABAD: Monthly environmental sampling of poliovirus in Hyderabad has again tested positive. It was confirmed in Jacobabad and Sukkur districts also to provincial Emergency Operations Centre for Polio by the National Institute of Health (NIH).

“Genetic sequencing report about Hyderabad’s [environmental] sample confirms the virus travelled from Lahore though for the first time. [Environmental] sample of virus in Jacobabad is localised while the report of Sukkur is under process. Presence of virus in Hyderabad remains intermittent,” said Umer Farooq Bullo, centre’s provincial coordinator.

He added that “genetic sequencing result about Sukkur is to be conveyed”.

Hyderabad district’s health authorities collect monthly samples from a sewerage pumping station which is the designated site in this divisional headquarter in the middle of the city for environmental sampling. “If sample is tested positive, it alerts health authorities,” said an official. Sindh has 17 such designated sites, 11 of which are in Karachi alone given population figures of the metropolitan city.

Environmental samples in Hyderabad also tested positive in the recent past — first in 2016 and then in 2018 in the month of January which, according to officials, remained a seasonal migration period. Sampling is done by trained health staff in line with the World Health Organisation (WHO) guidelines and last month it was done on Jan 24.

Vaccination coverage among children of below five years of age in Hyderabad was said to be impressive which is 95 per cent. At times, it was over 95pc. Officials said it was high-risk mobile population (HRMP) that remained a leading cause of virus’ transmission.

Broken sewerage system

In view of fragile and broken sewerage system, the provincial and district health officials remained concerned about virus once its presence was confirmed. The fact that sewage lines get mixed with water supply lines of the Water and Sanitation Agency (Wasa) is a potential threat.

“Cross-border [Afghanis­tan] and regional movement has been a huge challenge for us in polio virus eradication,” said Fayyaz Jatoi, who served as provincial coordinator of the centre in Sindh in the last two years. He said Hyderabad’s coverage remained “ideal”.

Officials pointed out that cases of polio virus in environmental sampling were being reported in Khyber Pakhtunkhwa (KP) mainly where active transmission of virus was confirmed and then came those areas of Karachi dominated by Pashto-speaking population. In Sukkur and Jacobabad such virus was reported off and on.

According to Bullo, a child affected by poliovirus last year in Karachi hailed from Khyber Pakhtunkhwa and he was a frequent traveller between KP and Gadap, Karachi. He said it was the first time that Lahore was detected in Hyderabad’s genetic sequencing, otherwise it was KP.

“The report about genetic sequencing of sample in Sukkur was under process and its outcome is yet to be communicated to us,” he remarked.

Officials said that virus survived in human body and chances of its multiplication got increased in areas having population density like Karachi and Hyderabad, for human population movement remained uncontrolled. As compared to provincial capital, Hyderabad now has fewer number of refusal cases during polio vaccination. Karachi has thousands of such cases whereas Hyderabad recorded 480 in last round of January. Prior to that they stood at around 2,000 in Hyderabad.

But presence of revenue and police officials recently in the team had improved vaccination coverage among refusal cases significantly and that’s why their number has reduced to 480. Mobilisation campaigns among local community to clear misconception about polio drops’ administration were seen to be effective.

“Pakistan has 55 sites to determine environmental presence of virus while India has lesser number of sites which shows we have better surveillance system,” said Jatoi. He added that anyone who was not immune to virus shed it in next 28 days at least through stool with threat to affect others through mainly drinking water supply.

“During examinations a phylo-genetic tree is created which determines its nearest presence in the recent past and that’s how genetic sequencing is ascertained,” he said. So, human population’s movement remained a big challenge.

According to Bullo, presence of virus was earlier reported in Sukkur two months ago and now it was again reported.

Published in Dawn, February 21st, 2019