( CNN ) -- Sixty-six people have died from West Nile virus infections this year , and the number of human cases has grown to 1,590 , the U.S. Centers for Disease Control and Prevention said Wednesday . That 's the highest case count through the last week of August since the virus was first detected in the United States in 1999 . Nearly half of all the infections have occurred in Texas , where officials said later Wednesday that 894 cases have been reported along with 34 deaths . `` Those numbers are going to go up , '' said Dr. David Lakey , commissioner for the Texas Department of State Health Services . Lakey said it looks like 2012 will be the worst year so far when it comes to West Nile virus cases . In 2003 , Texas reported 40 deaths because of the virus , and health officials believe they will surpass that number this year . All lower 48 states are now reporting West Nile activity , and 43 states have reported at least one person infected with the virus . Fast facts on West Nile virus . More than 70 % of all West Nile virus cases in the United States are found in six states : Texas , South Dakota , Mississippi , Oklahoma , Louisiana and Michigan , according to the CDC . While the CDC said these are the highest number of cases reported by the last week in August since the disease was first recorded in 1999 , it 's not the highest number the country has seen . In 2003 , the United States had 9,862 reported cases of West Nile virus , and in 2002 there were more than 4,100 cases and 284 fatalities . In more than half the current nationwide cases , West Nile has led to neuroinvasive disease -- serious illnesses like meningitis , encephalitis or virus-associated paralysis . About 10 % of these cases can be fatal , according to the CDC , and a high proportion of those who survive can be left with longstanding neurological problems . Older people are more vulnerable to severe illness from West Nile . So far , the median age among those with neuroinvasive disease this year is 58 . In Texas , nearly two-thirds of all cases are in people older than 50 . Health officials do not yet know why there are more cases this year than in recent years . Based on previous experiences with floods and hurricanes , health officials do not believe Hurricane Isaac will have a major impact on this year 's outbreak . Mosquitoes that spread the virus breed in small nutrient-rich pools of water , such as the water found in old tires , so a large rainfall event or flooding usually washes out those small pools and eliminates breeding sites , said Dr. Lyle Petersen , who heads the CDC 's Division of Vector-Borne Infections . But after the water recedes , there 's always the possibility that new small pools of water will form . Petersen urged the public to take proper precautions to prevent getting sick regardless of whether they live in a state with high or low case counts . To reduce your risk of exposure to mosquitoes and to prevent their breeding sites : . -- Drain all standing water from flower pots , old tires , clogged rain gutters , etc. , where mosquitoes breed . -- Use an insect repellant that contains DEET , picaridin or oil of lemon eucalyptus . -- Also wear long sleeves and long pants to protect your skin when you 're outside . -- Stay indoors at dusk and dawn because that 's when mosquitoes are most active . West Nile outbreak largest ever in U.S .
More than 1,590 cases of the virus are reported . The World Health Organization says that more than 10,000 people have been infected with Ebola in West Africa and nearly 4,000 died. Texas is the hardest hit , with 34 deaths reported .