Dr. Jonas Salk, an American virologist and medical researcher who developed one of the first successful polio vaccines. Photo: WIkimedia Commons.

JNS.org – Remnants of poliovirus were discovered in sewage samples in Tiberias, adding to the growing list of hot spots in the country, Israel’s Health Ministry said in a statement.

A four-year-old girl from Jerusalem tested positive for the virus earlier this month, marking the country’s first case in more than 30 years. Since then, another child has tested positive and five others, suspected of carrying the virus, are being tested.

In all of the above cases, the children were not vaccinated against polio.

Last week, the Health Ministry said it thought it had found early traces polio in two other cities—Beit Shemesh and Modi’in Ilit—via its sewage-surveillance program, but on Sunday, it said that those samples turned out to be negative.

“We are not talking about rampant polio,” head of public health services Dr. Sharon Alroy-Preis stressed in a briefing shortly after the discovery of the first case of the virus. “This is polio from the weakened live vaccine that changed over time.”