At least two polio cases from Peshawar, one each from North Karachi, Sindh and Chakwal, Punjab have been genotyped and linked to the poliovirus from Karachi, health officials told The Express Tribune.
Closely associated with the polio programme in Khyber-Pakhtunkhwa, one official, requesting anonymity, said the number of reported cases in the country is “expected” to cross 200. At the moment, Pakistan has 108 reported cases.
Cases linked to Karachi
The poliovirus in a 10-month-old girl and a 12-month-old girl—both from Peshawar—has been traced back to a virus, said to have originated in Karachi. The same virus has also been linked to the child diagnosed in Chakwal, Punjab. The 35-month-old girl is said to be the first reported diagnosis from the province since the late 90s.
Some of K-P’s health experts and officials have said these cases linked to the virus in Karachi were the last ones to have surfaced in Peshawar. They cited negative environmental sampling in Larama and Shaheen Muslim Town for the first time in two years as evidence of the success of Sehat ka Insaf.
Peshawar’s own virus has ended, one of the experts claimed, requesting anonymity. The last polio victim’s virus originated in Karachi, they reiterated. However, it has not been confirmed if the children in Peshawar had travelled to Karachi or if someone from the city by the sea had carried the poliovirus to Peshawar.
While talking to The Express Tribune, K-P Chief Minister’s Polio Cell Focal Person Dr Imtiyaz Khan said after Sehat Ka Insaf, Peshawar’s poliovirus has been largely eradicated. Khan was hopeful the 241,000 children of North Waziristan Agency (NWA), deprived of polio vaccinations since 2012, could now be reached. Close to 50,000 families were displaced from NWA in the wake of Operation Zarb-e-Azb. “The government hopes Pakistan would be polio free soon,” said Khan.
From 108 to 200?
There were only 38 reported cases in the first eight months of 2013; by November 2014, Pakistan will have around 200 reported cases, asserted health officials.
High-transmission months do fall between April and November, but some of K-P’s health experts claimed the increase in cases can also be blamed on the inefficacy of the polio vaccine in hot weather.
However, UNICEF’s K-P and Fata polio team leader Dr Bilal Ahmed disagreed with this assessment. “Yes, winter is low-transmission. Right now, we are in a high-transmission season and more cases will be reported as the environment is more favourable for the virus,” said Ahmed. “The vaccine is effective in all weather conditions.” Others associated with polio campaigns in the country confirmed the vaccine is indeed effective throughout the year.
As with many other vaccines, maintaining the cold-chain is key, but polio workers across Pakistan are provided with refrigerated units to carry the vials as they go door to door. In fact, the vaccine vials carry a sticker which changes colour to indicate the efficacy of the vaccine—light pink means it’s still effective but any darker or turning red means the polio vaccine is now rendered useless but it still would have no adverse reaction if administered at that point.
Referring to the “200 cases”, Ahmed said, “One cannot make exact estimates.” The UNICEF team leader admitted the situation was pretty bad, looking at the flip side of access to NWA children.
“Now the NWA cases are also moving to the southern districts like Lakki Marwat, Tank and Bannu, so those places are at greater risk.”
Ahmed said, “You can assume there will be more cases but you absolutely cannot make exact estimates. This is all situational; no one can guess how many cases.”
Number of doses needed
There is often confusion surrounding how the vaccine protects a person from the crippling virus; especially when children who have received doses contract the disease.
Ahmed explained each person has a different biology and one dose is never enough. Drawing parallels to how doctors prescribe a basic dose in any ailment and alter it according to progress made, Dr Ahmed said, “There is no exact number of doses [especially in high-risk areas] which will provide foolproof coverage.”
This is why repeated polio campaigns are conducted during outbreaks, said the doctor. Even at the airport, he said, a traveller is required to have had a dose of the vaccine within a month of their journey as the vaccine blocks the poliovirus for roughly 30 days.
“You can give as many doses, there are no side effects. The more the number of campaigns, the safer the area.”
Explaining why some children are safe with fewer doses, Dr Ahmed said, “Everyone has different levels of immunity.” The polio vaccine will be rendered less effective if the child has diarrhoea or vomiting. The nutritional intake of the child also counts, said Ahmed.
“That is why we have repeated campaigns,” reiterated the doctor.
Published in The Express Tribune, August 12th,2014.