A four-year-old girl from Jerusalem has been diagnosed with polio, Israel’s Health Ministry said Sunday – the first case in the country since 1989.

The source of the girl’s infection is vaccine-derived polio virus, according to Israel’s head of Public Services Dr Sharon Alroy-Preis, speaking to reporters on Monday evening.

“We are not talking about wild polio,” Alroy-Preis stressed. “This is polio from the weakened live vaccine that changed over time.”

Neither the child nor any of her family members – all part of an ultra-Orthodox Jewish sect in the city – had been vaccinated against the disease. The ministry believes the child could be just one of dozens of others who have been exposed to a mutant strain of the virus, Alroy-Preis said. That is a particular concern since among some communities in Jerusalem, vaccination rates are less than 50%.

Alroy-Preis said that officials are in touch with 10 family members who were in close contact with the child, another 20 children in her preschool and staff. The city is working to get the necessary permissions to screen the children for the disease.

Jerusalem health officials will notify anyone else who might have come into close contact with the four-year-old and provide specific instructions, the ministry said. Based on the findings of the investigation, further recommendations will be made.

Others could have been exposed

Routine vaccination rates tend to be lower among ultra-Orthodox Jews in Israel, partially because of ideological reasons and a lack of trust in the government and its systems, and partially for technical reasons. Ultra-Orthodox families tend to be large and parents may struggle to adhere to each child’s vaccination calendar, Alroy-Preis said.

To help immediately increase polio vaccination rates, the Health Ministry has launched a dedicated communications campaign and is working to recruit nurses to offer vaccines during off hours and in non-traditional locations.

Israel is a member of the World Health Organization’s European Region, which was declared polio-free in 2002, according to the European Centre for Disease Prevention and Control.

Israel regularly monitors for the virus through a dedicated sewage surveillance program and in health clinics. In 2013, traces of polio were detected through the sewage program but no one was diagnosed with the virus.

Israel administers four doses of the polio vaccine between the ages of two and seven: two injections of the inactivated virus vaccine and two doses of the oral polio vaccine containing live attentuated virus, given as liquid drops. The live virus protects the digestive tract where polio is contracted.

Polio is a highly infectious disease that is transmitted person-to-person, especially in children. It enters through the mouth and is excreted in the faeces. There are usually no signs of illness, though one in about a thousand unvaccinated people can develop severe symptoms, including paralysis.

“The main concern is that we have a virus that can harm children – not only children, but mostly children – with a preventable illness,” Alroy-Preis said. “Even if it harms only a small number of children, the disease can be severe and irreversible.”

Case discovered two weeks ago

The case was discovered almost two weeks ago, Alroy-Preis said.

The child was admitted to Jerusalem’s Hadassah Medical Center, the hospital said. She was suffering from severe weakness in her leg muscles as well as other polio-like symptoms. Tests with the involvement of a paediatric neurologist confirmed the polio diagnosis.

The child was treated at the hospital for a week and with an improvement in her condition she has been transferred for further rehabilitation, the hospital added.

The Jerusalem District Health Bureau has opened an epidemiological investigation.

Last month, a child in Malawi was diagnosed with wild poliovirus (WPV type-1) linked to the strain in Pakistan. Neither the three-year-old Malawian girl, diagnosed after she experienced an onset of paralysis, nor any of her family members had recently travelled to Pakistan, meaning that she became infected locally.

Alroy-Preis said authorities had no way of knowing if the vaccine-derived virus was imported or developed locally.

Image Credits: Jean-Marc Giboux/Rotary International.