Self-study
Birds and mammals can be infected with West Nile virus only through mosquito bites. ███████████ ██ █████ ██████ ████████ ████ ███ █████ ████ ████ ████ ███████ ████████ █████ ██ ████████ ███ █████ ███ ██████████ ████████ ██ ████████ ██████ ███ ██████ ██ █████ ███████ ██ ███ ██████ ██████ █████████ █████ ████ ████ ██████ ███ ███ █████ █████ ███████ ████████ ██████ ██ █████ █████ ██ ██████ █ █████████
Summary
Birds and mammals are infected with West Nile virus only through bites from mosquitoes. Mosquitos become infected when they bite infected birds or mammals. The virus was first detected in Africa and spread to North America. Humans can catch West Nile virus, but infected humans cannot infect a mosquito.
Strongly Supported Conclusions
Mosquitos infected with West Nile virus have been present in Africa and North America.
Humans are sometimes bitten by mosquitos infected with West Nile virus.
9.
The statements above, if true, ████ ████████ ███████ █████ ███ ██ ███ ██████████
a
West Nile virus ████ █████ ██ █ ██████ ███████ █████ ███████
Unsupported. Humans can get the virus from mosquitoes, so they may be bitten by infected mosquitoes in large numbers in the future. There’s no evidence this won’t happen.
b
West Nile virus ██ ████ ██████ ██ █████ █████ ██ █████ ███████ ████ ███ ███████ ███████ ██ ███████████
Unsupported. We know that humans can get West Nile virus, but we don’t know how common the virus is among mosquito populations in North America. Perhaps it’s most common in specific parts without dense mosquito populations.
c
Some people who ██████ ████████ ████ ████ ████ █████ █████ ████ ████████ ██ ████████
Unsupported. We don’t know anything about the symptoms of West Nile virus and whether people can have the virus without exhibiting symptoms.
d
West Nile virus ███████ ████ ██████ ██ ████████ ██████ ████ ██ ████ ██ █████ ████████
Unsupported. We know that the virus was first detected in northern Africa. We don’t know whether that suggests the virus infects more people there than in North America. Maybe there are far fewer people to be infected there? Maybe the virus is more common North America?
e
West Nile virus ███ ███ ███████ ██ █████ ███████ ███ ██ ████████ ███████
Strongly supported. We know that infected humans cannot infect a mosquito. So, if the virus was found in North America, that means a mosquito must have bitten an infected bird or mammal. Either that mosquito or the infected bird or mammal carried the virus to North America.