Fourteen children with acute flaccid paralysis (AFP) found during a routine surveillance in the state this month are considered "highly suspected polio cases" on the basis of their clinical characteristics and epidemiological data.

The state health department has found 1,043 AFP cases during their routine surveillance so far this year. Acute flaccid paralysis is a term which applies to the exact clinical symptoms doctors see in polio virus infection. But this may not necessarily be caused by polio viruses.

Nationwide AFP surveillance is the gold standard for detecting cases of poliomyelitis popularly, known as polio.

"The 14 children with AFP are classified as ‘hot cases’ based on clinical characteristics and the epidemiological data available about them. This is the routine process of AFP surveillance. We have to keep our suspicion of index very sharp to detect and examine every AFP case to rule out polio and vaccine derived polio virus (VDPV)," V KRokade, in charge of the vaccination programme at the directorate of state health services, told TOI. Elaborating, Rokade said, "Classifying highly suspected AFP cases as ‘hot cases’ enables us to focus minutely on the treatment outcome and get their stool sample reports done within a week whereas normal AFP stool sample report takes 28 days."

The 14 children classified as ‘hot cases’ are less than five years old, had fever at the onset of paralysis and have an incomplete vaccination history. Paralysis, in their case, has progressed rapidly. The state health department is currently awaiting reports of the children’s stool samples which were sent to the Mumbaibased designated laboratory.

Among the 14 cases, seven are from Thane and one case each has been found in Ahmednagar, Akola, Beed, Gondia and Raigad. The remaining two highly suspected cases are from Pune district, states the latest report of the health department.

As per the surveillance report, 1,043 AFP cases have so far been identified. Among them, the highest number of cases are found in Thane (188) followed by Greater Mumbai (135). Pune district has reported 69 AFP cases so far.

"Among these 1,043 AFP cases, polio has been ruled out in 820 cases so far. Reports of the remaining cases are still awaited," Rokade said.

Stool samples of contacts of hot cases are also recommended to be collected and examined. Contact is defined as a child less than 15 years old who had been in direct contact with the index AFP case, one week prior to the onset of paralysis and/or within two weeks after the onset of paralysis.

Earlier this month, an 11–month–old boy from Beed district was found infected with the vaccine–derived poliovirus (VDPV). That was the first such case in the state and the third in the country since March 2012. The baby died on June 22. However,the incident is not going to affect the country’s march toward being certified polio-free as VDPV cases are not counted as polio.

The World Health Organization says for a country to be declared polio-free, it must complete three years without asingle case of polio caused by the wild polio virus.

AFP case is classified as ‘hot case’ when

• The age of the patient is less than 5 years
• Has incomplete vaccination history
• Shows signs of fever at onset of paralysis
• Has asymmetric paralysis
• Has rapid progression of paralysis (within 3 days)

Or there is epidemiological evidence that the case has been in contact with or living in an area with possible or recent viral circulation. This includes being from a high risk group or high risk area

Objective of surveillance

• The objective of AFP surveillance is to detect the exact geographic locations where wild polioviruses are circulating in the human population. All cases of acute flaccid paralysis in children aged below 15 years are rigorously investigated by a trained medical officer, with collection of stool specimens to determine if poliovirus is the cause of the paralysis.
• Analysis of the location of polioviruses isolated from AFP cases allows programme managers to plan immunisation campaigns (pulse polio immunisation) to prevent continuing circulation of virus in such areas.

In the Global Polio Eradication Initiative, acute flaccid paralysis is defined as

• Any case of AFP in a child less than 15 years, or any case of paralytic illness in a person of any age when polio is suspected.
• Acute: rapid progression of paralysis from onset to maximum paralysis
• Flaccid: loss of muscle tone, "floppy" – as opposed to spastic or rigid
• Paralysis: weakness, loss of voluntary movement
• Any case meeting this definition undergoes a thorough investigation to determine if the paralysis is caused by polio.

(Source: National Polio Surveillance Project – A government of India and WHO Initiative)