By J.D. Miles

DALLAS (CBS 11 NEWS)  -The West Nile virus has been detected dangerously close to a Dallas clinic that treats people most vulnerable to the sometimes deadly disease.

A positive test outside the Martin Luther King Clinic near Fair Park raises more concerns about the severity of the outbreak. It also reveals the limits of mosquito spraying that cities and counties say may not be enough to stop West Nile from spreading.

The Martin Luther King Clinic serves hundreds of low income residents.  Many of these residents are chronically ill or children.

CBS 11 News has learned that a mosquito trapped near a water cooling tower tested positive for West Nile even after the neighborhood was sprayed. Margaret Lopez has been a regular patient at the M-L-K clinic for three years. The Garland woman has diabetes, a heart condition and walks outside fearful of catching West Nile.

“I worry a lot about it I’ve got a compromised immune system because of the medications I’m on,” said Lopez.

Lopez and others at the clinic didn’t know that on July 18 mosquitos carrying West Nile were captured in a trap right outside the clinic. The city says the neighborhood was sprayed in mid-June and early July.

The presence of more disease transmitting mosquitos so close to the clinic even after spraying frightens those patients who are most vulnerable.

“I heard people are dying from it and I’m afraid,” said Katherine Smith, clinic patient.

The clinic’s director says they were never officially informed by the city of Dallas about the positive test on July 18. But, the city says it would be nearly impossible to inform every resident of every positive test, so that’s not city policy.

The city sprayed the area around the clinic 12 days later despite a goal to spray within seven days of a positive test. Patients and residents say places like the clinic should be priorities for spraying and the city should do more to alert them.

“We should be informed all the time about all this type of stuff,” says Lamont Henderson, a neighborhood resident.

“I’m nervous about it. I’m afraid for my children,” said Smith.

The city says signs and press releases go out 48 hours prior to spraying, but that’s the extent of its policy toward informing the public of a positive test.