Last week, county data showed positive COVID-19 test results were more concentrated in the ZIP codes 78703 (Tarrytown), 78704 (Central-South Austin), 78705 (West Campus), 78731 (Northwest Hills) and 78746 (West Lake Hills and Rollingwood) than in other areas of Austin.

The latest data shows cases remain concentrated in those areas, but other ZIP codes—particularly in Southeast Austin—now shade darker on the accompanying heat map.

What's going on here?

The April 6 map, above, shows the distribution starting to shift. (Travis County COVID-19 Public Dashboard)Travis County COVID-19 Public Dashboard

"We don't know for sure," Dell Medical School Dean Clay Johnston wrote in an April 3 email. "It is definitely true that travelers and big wigs (who shake a lot of hands and attend many events) were at higher risk. We expect this to change because those now with the most contacts are in lower-paying positions."

The 78705 ZIP code has the highest number of cases: 50. Last week, The University of Texas at Austin announced a large cluster of COVID-19 instances stemming from a group of students who traveled to Cabo San Lucas in March. As of Friday, 49 UT students had tested positive for the virus, and the university said it was aware of 211 students who traveled to Cabo San Lucas March 14-19.

The median household income in the city of Austin is $67,462, according to the U.S. Census Bureau. In comparison, the median household income in 78703 is $105,207; in 78704, it's $70,511; in 78731, it's $94,048; and in 78746, it's $139,951.