After a few years with relatively few West Nile Virus infections in the United States and Georgia, public health officials are warning that the virus is again on the rise.

Federal health officials report four times the usual number of cases for this time of year, with more than 1,100 infections and 41 deaths nationwide, according to the Centers for Disease Control and Infection. About 400 of the cases were reported in the past two weeks.

Three Georgians have died this year from the virus, which is typically transmitted to humans by mosquitoes. Georgia has seen 21 confirmed cases so far — almost as many as the 22 cases reported in all of 2011, and more than the 13 cases reported in 2010.

"I would expect we will have considerably more [confirmed cases] this year than last year," said Dr. J. Patrick O'Neal, director of health protection for the Georgia Department of Public Health.

Still, he noted, other states have it far worse. "Although the numbers may be a little bit greater in Georgia, I'm hopeful it won't be as horrendous as what Texas has had," O'Neal said. Nearly half of this year's reported West Nile illnesses have occurred in Texas.

Metro Atlanta has only a handful of confirmed cases so far this summer, with three in Cobb County, one in Fulton County and one in Forsyth County, according to state officials. But because mosquitoes from 54 monitoring sites in metro Atlanta have tested positive for the virus, officials declared the region at high risk for infection.

"This year is more serious because we have more cases earlier in the year," said Elmer Gray, an entomologist with the University of Georgia Cooperative Extension service. Conditions are ripe for mosquitoes to spread the virus for weeks to come, with activity typically peaking in mid-to-late September, he said.

Gray attributes the spike to a mild spring. Because it was and remains drier than usual, mosquitoes and birds had fewer water sources and thus were found in more concentrated numbers at the same places. Mosquitoes contract the virus from infected birds.

Georgia is home to 63 species of mosquitoes, but Gray said the Southern House mosquito is the primary culprit in this year's West Nile activity. That species breeds in storm drains and polluted water. (The Southern House mosquito is most active at night, thus health officials advise using extra caution during those hours.)

Luckily, O'Neal said, Georgia is not home to the species of mosquito wreaking havoc in Texas.

The Associated Press contributed to this report.

ABOUT WEST NILE VIRUS

Symptoms of a West Nile infection: Most people exposed to the virus experience no symptoms. One in five may develop mild symptoms such as fever, headache, nausea, swollen lymph glands or skin rash. About one in 150 will become severely ill with high fever, headache, neck stiffness, disorientation, vision loss and other serious symptoms, according to the CDC. The elderly and the immuno-compromised are most at risk and should take special precautions against mosquitoes.

What you can do: Wear insect repellents with EPA-registered ingredients, including DEET, picaridin or oil of lemon eucalyptus. (DEET is the most effective, officials say.) Wear loose, long clothing to minimize exposure. Empty all forms of standing water, including flower pot saucers, bird baths or puddles. Meke sure window screens are intact.

Counties with confirmed cases: Bartow - 1; Cobb - 3; Columbia - 1; Dougherty - 7 (including 2 deaths); Fulton - 1; Forsyth - 1; Early - 1 (and 1 death); Lee - 1; Mitchell - 1; Muscogee - 2; Richmond - 1; Worth - 1.