New Orleans officials said Friday that they have detected West Nile virus in mosquitoes on the city’s West Bank.

While about 90 percent of people who test positive for the virus after being bitten by infected mosquitoes do not show symptoms, the city urged residents and visitors to protect themselves against being bitten. That’s because a small number of people infected with West Nile show serious symptoms associated with neuroinvasive disease, which can be deadly.

Here are some steps people can take to protect themselves from mosquito bites:

W ear bug repellent containing DEET.

Wear long-sleeved shirts and pants when outdoors for long periods.

Routinely clear roof gutters.

Clean and chlorinate swimming pools.

Eliminate standing water around households.

Mosquitoes breed in standing water, which can collect in containers such as flower pots, tires or cans.

New Orleans officials said the city’s Mosquito and Termite Control Board will continue spraying insecticides by truck and airplane after detecting the virus.

The city didn’t specify precisely where the infected insects were found, but it said the board will keep conducting residential inspections around the city.

People over the age of 65 are most vulnerable to developing complications from West Nile virus, which can cause flu-like symptoms. Yet, everyone is at risk for infection, the city said.

In 2014, officials said, Louisiana registered 62 cases of neuroinvasive disease.