Scott Friedman, NBC 5 Investigates
The plan for fighting West Nile virus in Sacramento, Calif., could offer lessons for Dallas and Dallas County.
In the months leading up to this year's West Nile virus epidemic, Dallas and Dallas County did not have the people, money or resources to fight the virus like cities with the most aggressive plans do, an NBC 5 investigation has found.
As of Sept. 5, Dallas County has 335 human cases of West Nile virus and 13 fatalities. There are more than 800 human cases and 23 deaths in all of North Texas.
Dallas County records obtained by the NBC 5 Investigates team show that the county health department knew on June 10 that 16 percent of trapped mosquito pools were already testing positive for West Nile virus.
Two weeks later, that number jumped to 28 percent. And by July 1, the numbers exploded -- 44 percent of the mosquito pools collected tested positive for West Nile virus.
Dr. Bill Reisen, who runs a West Nile virus-testing program at the University of California, Davis, one of the country's most respected programs, said he would have been alarmed to see the numbers Dallas County was looking at during the end of June and early July -- weeks before hundreds of people were sickened and weeks before county started talking about aerial spraying for mosquitoes.
When the Dallas numbers are put into the risk assessment worksheet he uses to advise California cities, it shows that Dallas County was likely at epidemic levels of West Nile virus as early as the end of June or beginning of July.
But it was three weeks after that point -- the end of July -- before Dallas County Judge Clay Jenkins said Dallas County Health and Human Services first alerted him the county was facing a crisis and needed more larvicide to fight mosquitoes.
By then, Dallas County already had 64 human cases, and the first two victims had died.
When asked if he was concerned that health officials didn't ask for more help sooner, Jenkins said: “Well, hindsight is 20-20. But my focus right now is what do we need to do today to protect our citizens.”
Within days of talking with the health department in late July, Jenkins declared a public health emergency and started mustering support for aerial spraying.
By mid-August, planes were flying.
Jenkins said he is happy with the health department's response but is waiting for a Centers for Disease Control and Prevention report that is expected to address whether more could have been done leading up to the crisis.
In California, Sacramento had a similar outbreak in 2005.
Today, if the number of infected mosquitoes climbs to the levels the city of Dallas saw in late June or early July, Sacramento considers aerial spraying before human cases happen and before it reaches a point where the entire city needs to be sprayed.
“I think we've learned that when you see these kinds of numbers, you really have to make that intervention early to avoid having to do as widespread an intervention as we had to do in 2005 and you're having to do in Dallas now,” said David Brown, Sacramento-Yolo Mosquito and Vector Control District general manager.
Since the outbreak in Dallas started, city and county officials have reached out to Sacramento for advice.
Its mosquito control program is widely considered one of the best. Sacramento traps and tests a lot more mosquitoes than Dallas, and it tests year round, trying to catch the first signs of the virus early in spring.
“If you want to catch the beginning of transmission in order to sort of keep the genie in the bottle, so to speak, then early is good,” Reisen said.
NBC 5 Investigates learned that Dallas didn't start testing mosquitoes this year until May, even though the city's own mosquito plan suggests testing as early as April.
And experts told NBC 5 Investigates that April might even be late in a year with such a warm spring.
Brown agreed that a city could miss an opportunity to get a handle on things early by waiting to start trapping until May.
Dallas Mayor Mike Rawlings said he's waiting for CDC recommendations on how early the city should trap and how many traps to use. He said the city plans to take a look at every aspect of its West Nile virus plan in the wake of the current crisis.
“Let me tell you, any time someone dies and is sent to the hospital -- whether it's a police situation, a traffic accident -- you say, 'How can we do better?' And that's the way it should be,” he said. “We should be thinking, 'How can we be better all the time?'"
NBC 5 Investigates discovered that the city of Dallas right now only runs 20 mosquito traps per week -- about one for every 19 square miles.
Houston, which has the most aggressive plan in Texas, runs one trap for every six square miles. And Sacramento sets up hundreds every week to pinpoint where the virus lives.
Reisen said that adding more traps helps a city be more precise in finding and treating the virus.
But money is the key difference.
Sacramento's mosquito control district has 70 employees. The city of Dallas and Dallas County each have just four people dedicated to mosquito control in the areas they cover.
West Nile virus survivor Sean Lemoine, who suffered permanent neurological damage in 2009, said there's no question that Dallas should step up the fight.
“And my hope is that they take this lesson and make sure it doesn't happen in the future,” he said.
County Health Commissioner Zach Brown told NBC 5 Investigates that Sacramento's plan might be a good example, but the question is whether people in Dallas would be willing to conduct aerial spraying when the virus only shows up in mosquitoes and not in humans.
Currently, Dallas’ plans call for aerial spraying only when there are multiple human cases. Dallas County Health and Human Services Director Zachary Thompson said after the current crisis subsides, he wants to talk about the plan going forward.