West Nile virus cases spike after 7 Harris County resident infected, 520 mosquito samples test positive KPRC Click2Houston7 Harris Co. residents infected with West Nile Virus, county health officials say KTRK-TVSeven people test positive for West Nile, officials warn of spike after Beryl Houston Chronicle West Nile Virus found in Baytown mosquitoes KPRC Click2Houston7 cases of West Nile virus confirmed in Harris County residents; over 500 positive mosquito samples KHOU.com