Virus Math and Interconnectedness

How do you get a growing number of cases when new infections are tapering off in New York and New Jersey?

How is New Jersey a statistical model for the country?

Last week, Governor Murphy released charts for New Jersey showing a decline in the number of new cases of Covid-19. However, he went further, to show that the decline was occurring in the densely populated Northern and Central parts of the state. In the rural, largely agricultural south, infections are growing. Basically, the parts of the state furthest from New York City are catching up.

That’s the same thing that’s happening in the US as a whole. New York and New Jersey were hard hit. The peak in the New York Metro area has passed, but the number of cases nationally is growing at a steady pace.

The off-setting growth areas for the virus are in the parts of the country that were “late to the party.” According to charts published this morning, the states with high growth rates of infection include Illinois, Texas, Maryland, Indiana, Virginia, Tenessee, North Carolina and Iowa.

Note that Louisiana and Michigan aren’t in this high growth group either.

While Iowa only has slightly more than 9,000 confirmed infections, the growth curve shown below is astounding. So are the charts for Minnesota, Nebraska and Kansas.

https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html?campaign_id=9&emc=edit_nn_20200504&instance_id=18202&nl=the-morning&regi_id=122337929&segment_id=26556&te=1&user_id=40f6968d95f9bcbacd72add9433713f9

Some of the states show a pause and then a renewal in growth. We can hypothesize that the initial urban infection centers got the virus under control, and then the rural areas started to contribute cases. In Illinois, for example, while Chicago was the initial center of infection, most counties in the state now have cases and deaths.

How do farming areas get infected? One mechanism is truck drivers, and given the number of asymptomatic carriers of the virus, transmission is relatively easy. Drivers have to work to get paid and are considered essential to the economy. If they don’t know they’re sick, they’ll just spread the virus far and wide. We haven’t done much virus testing at truck stops, but I suspect the results would be a shock. In turn, infected staff bring the virus into their towns. That’s how AIDS spread in the Midwest originally. The drivers took the virus from the initial metropolitan infection centers and inserted it into every town touching the Interstate Highway system.

Of course, some of the states with high growth rates are also among the ones choosing to re-open at this time — Texas and Tennessee, for example.

Since these areas haven’t had priority access to test kits, the extent of infection is likely to be much greater than the current number of confirmed cases. Even if there is a local hospital, it may not be equipped to handle Covid-19.

This should get interesting.