Follow-up: Why does the South do better with norovirus?

I picked on the Southeast yesterday for our high HIV rates. But now, why does the Southeast do better than the Midwest with norovirus?

From Wikipedia:

quote:

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The virus is usually spread by the fecal–oral route.[3] This may be through contaminated food or water or person-to-person contact.[3] It may also spread via contaminated surfaces or through air from the vomit of an infected person.[3] Risk factors include unsanitary food preparation and sharing close quarters.[3] Diagnosis is generally based on symptoms.[3] Confirmatory testing is not usually available but may be performed by public health agencies during outbreaks.[3]

Prevention involves proper hand washing and disinfection of contaminated surfaces.[4] Alcohol-based hand sanitizers are not effective against the Norovirus, according to the NHS information page on the subject,[8] this is due to Norovirus being a non-enveloped virus. There is no vaccine or specific treatment for norovirus.[4][5] Management involves supportive care such as drinking sufficient fluids or intravenous fluids.[5] Oral rehydration solutions are the preferred fluids to drink, although other drinks without caffeine or alcohol can help.[5

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Maps of outbreaks:

2001-2008




2009-2012