A health worker in Lagos administers child immunizations

Kenyan health officials have reported a case of polio in northeastern Kenya, the first of its kind in the East African nation in more than 20 years.

A three-year-old girl living in a camp in the Dadaab refugee settlement near the Kenya-Somali border was diagnosed with polio last week.

According to media reports, the girl had been born in the camp, had been vaccinated for polio, and had never been to neighboring Somalia, where more than 30 cases of polio have been reported this year.

An immunization manager with Kenya's Ministry of Health, Dr. Tatu Kamau, tells VOA authorities are still trying to determine the source of the disease.

"The case is in the refugee camps," said Dr. Kamau.  "We have some query about whether the child has recently traveled or the parents have recently traveled or had contact with immigrants from Somalia."

Polio is a viral disease that can cause paralysis in a small number of cases.  Children account for more than 50 percent of the cases.  It is transmitted primarily through eating food or drinking water contaminated with the virus found in feces.  A vaccination against the disease was discovered in the early 1950s.

Dr. Kamau says there is concern that the contagious disease could spread, although authorities have tried to wipe out polio in the area and the country.

"Of course we fear that it might happen, although we've been covering the areas," she said.  "We have had four campaigns of polio vaccination in the area, and we have had very good coverage.  So, to some extent we feel safe, but you never know."

Dr. Kamau says she fears that many of the huge influx of refugees coming from neighboring Somalia have not been vaccinated for polio, raising the possibility of the disease's transmission in Kenya.

She says polio has not been controlled in Somalia, whereas the last confirmed case of polio in Kenya occurred in 1984.

The Kenya Health Ministry said tests showed the girl had a polio strain that matched one isolated to Somalia's Lower Juba region, whose main city, the key southern port of Kismayo, was seized by Islamists last month.

The refugee influx has been increasing since the Union of Islamic Courts rose to prominence earlier this year in Somalia and began capturing key areas of the country, posing serious challenges to Somalia's transitional government.

About 160,000 refugees live in the Dadaab camp, and an estimated 34,000 Somalis have crossed into Kenya since January, with an average of about 1,000 people per day in the past two weeks.