SIOUX CITY, Iowa (AP) – A Mercy Medical Center-Sioux City official says it’s treating four people for neuroinvasive disease stemming from a West Nile virus infection.  The virus is carried by mosquitoes and infects the brain and spinal cord. It can cause brain damage, paralysis and death.

Bertha Ayi is medical director of Global Infectious Disease Services at Mercy, and she told the Sioux City Journal that Mercy has seen six patients from Sioux City between the ages of 40 and 80 test positive for the virus this year. One patient died.

The Iowa Public Health Department says 26 human cases of West Nile virus have been reported in Iowa so far this year. Ayi is urging the people to protect themselves by wearing insect repellent outdoors and avoiding mosquito-infested areas though November.