HOUSTON, Texas - The health department of Houston, the largest city of the US state of Texas, confirmed on Tuesday two more deaths of the West Nile virus, bringing the death toll in the Houston area to three.

According to local TV channel ABC13 reports, the health department did not give further details of the two deaths, only saying that a man lived in southwest Houston and died after contracting the virus on Aug 17.  Another victim of the virus was a female, who was the first person to contract the virus back on Jun 27. She came from northeast Houston.

Houston reported its first death of the West Nile virus. A man from southwest Houston got the virus on August 1 and subsequently died.

Currently, Houston has reported 13 cases of the West Nile virus, which is first identified in Uganda in 1937.

In a related development, Harris County, which is located in the US state of Texas within the Houston area, on Tuesday announced a plan to use aerial spraying to control mosquitoes later Wednesday.  The plan is to spray about 63,000 acres by air.

So far, Dallas County, the worst virus-hit area in the lone star state, has reported more than 200 cases of the West Nile virus, and at least 10 people have died.

In Texas, the state has reported 586 cases of such virus and 21 deaths related to the virus.

Meanwhile, reports reaching here from the US state of Oklahoma said on Tuesday that the number of new West Nile virus cases in the state has increased by just four in the past week, and there have been 65 cases of the virus and three deaths due to the virus this year.

Since the beginning of this year, the United States has about 700 cases -- both confirmed and probable -- of the West Nile virus, including about 28 deaths.

The West Nile virus is a mosquito-borne illness that can lead to serious neurological disease in some cases, and its symptoms include sudden onset of fever, headache, nausea, dizziness and muscle weakness.

Commonly seen in temperate and tropical regions, the West Nile virus mainly infects birds, but is also known to infect human bodies mainly through mosquito biting. Scientists say about 80 percent of infections are symptomless.

The World Health Organization said that treatment of this virus often involves hospitalization, intravenous fluids, respiratory support and prevention of secondary infections.