<prompt> Answer this question truthfullyWhat is the meaning of Sandbox: ammu save?  <response>: <reason> Birds are the main reservoir of West Nile virus WNV. Transmission of the virus is by a mosquito bite of an infected bird with high-level viremia, such as birds of the family Passeriformes. Thus, transmission is frequently denoted as bird-mosquito-bird transmission. Other forms of transmission have been speculated, such as direct bird-to-bird transmission, but further validation is still required. Other species may also be infected, such as horses, cats, and dogs. Humans are considered dead-end hosts because the disease rarely progresses to viremia in humans, making transmission of the virus from a human unlikely except in some reported cases of transmission by blood transfusion, breastfeeding, or organ transplantation. Mosquitoes responsible for viral transmission belong to different families, varying based on geographical location: Culex pipiens: Northern half and West of USA Culex quinquefasciatus: Southeast and West of USA Culex tarsalis: West of USAOther transmission routes, not involving vectors, have also been described: Blood transfusions Breast milk Organ transplants patients with organ transplants also carry an increased risk of neuroinvasive disease Intrauterine transmission Exposure in a laboratory setting 