Three individuals in southwest Georgia have died from West Nile virus, state officials said Friday.

The state Department of Public Health (DPH) also has identified 18 other confirmed cases of the disease in Georgia.

Two people died in Dougherty County, and one died in Early County, the state said. The 21 Georgia cases join more than 1,200 recent West Nile cases nationally during the current outbreak.

DPH urged Georgians to take steps to guard against mosquitoes, including  emptying any containers holding standing water because they can be breeding grounds for the insects.

Public Health also said mosquitoes from 54 West Nile virus monitoring sites in metro Atlanta and another 20 in coastal and south Georgia have tested positive for the virus, which can lead to brain or spinal cord swelling, or even death. DPH has determined that  these areas are at high risk for West Nile virus transmission. 

“The problem of mosquitoes and West Nile virus appears to be escalating in Georgia and across the country,” said Dr. J. Patrick O’Neal, DPH’s director of health protection. “More West Nile virus cases have been confirmed by the third week in August than at any time in the last 10 years.”

Nationally, the number of West Nile virus cases in the U.S. jumped dramatically in one week, increasing to 1,221, with 43 deaths, USA Today reported Wednesday.

The report marked a big increase from last week’s tally of 693 cases and 26 deaths.

About 75 percent of the cases have been in five states: Texas, Mississippi, Louisiana, South Dakota and Oklahoma, according to the USA Today article.

Texas accounts for almost half of all cases.

“The number of West Nile cases in people has risen dramatically in the last few weeks and indicates that we are in one of the biggest West Nile virus outbreaks we have ever seen in this country,” said Lyle Petersen, director of the CDC’s Division of Vector-borne Infectious Diseases, said in the article.

The 1,221 cases are the highest number of West Nile virus disease cases reported to the CDC through the third week in August since the virus was first detected in the United States in 1999, the CDC said.

Symptoms of West Nile virus include headache, fever, neck discomfort, muscle and joint aches, swollen lymph nodes and a rash that usually develop three to 15 days after being bitten by an infected mosquito.

The elderly, those with compromised immune systems, or those with other underlying health conditions are at greater risk for complications from the disease, Georgia officials said.

Up to 20 percent of people who contract West Nile virus develop symptoms, while the remainder have no symptoms.

Here is a New York Times Q and A with a CDC medical epidemiologist about the West Nile virus and the factors fueling the current outbreak, along with some prevention tips.