The director of Vector-Borne Infectious Diseases for the CDC is warning that the United States could see the worst outbreak of West Nile Virus in history.

The virus is responsible for 41 deaths in the US and over 1,100 people infected. The CDC states that increase is alarming considering that only 25 cases had been reported last month. The only states that do not have cases reported are Alaska, Hawaii and Vermont.

“This will be amongst the biggest or the biggest break we’ve had in the United States,” Dr. Lyle R. Petersen said.

Texas is the hardest hit with 21 confirmed deaths although Dr. David Lakey of Texas Department of Health said another death happened yesterday. The CDC has not had time to confirm the death as being caused by West Nile.

Spraying of pesticides has begun over the city of Dallas despite concerns the chemicals could cause problems for those with breathing problems. Experts are attributing the heavy outbreak around Dallas to studies that show warmer temperatures increase the transferability of the disease in mosquitos. The heat with stagnant water enhances mosquito breeding.

Four out of five victims of the virus never feel sick. However, a small percentage of people will suffer symptoms ranging from high fever, headache, neck stiffness and disorientation to convulsion, vision loss and paralysis.