The cities of Atlanta and Sandy Springs together saw 159 new COVID-19 diagnoses between Sept. 15 and Sept. 18 update reports from the Fulton County Board of Health.

The number of cases increased in all of the main local ZIP codes. The 14-day trend declined in both cities, but varied among local ZIP codes.

A chart of COVID-19 diagnoses by city in Fulton County as shown in a Sept. 18 Board of Health report.

As of Sept. 18, the part of Atlanta within Fulton County had 11,260 COVID-19 diagnoses, up from 11,132 on Sept. 15. Sandy Springs had 2,319 diagnoses, up from 2,288.

Atlanta remains the number one city in the county for COVID-19 diagnoses at 42.2% of the total, and Sandy Springs remained third with 8.7% of the total.

The 14-day trend in new COVID-19 in each city is charted in the report, calculated by comparing the 14 days preceding the previous seven days with the 14-day period before that. In Atlanta, the 14-day trend was down by 21.6% and in Sandy Springs the 14-day trend was down by 14.9%.

To view the full reports, see the county website here.

The report does not state whether the numbers reflect the coronavirus’s spread, the state of testing, or both.

The statistics, which are based on patients’ home addresses, are not completely accurate due to such factors as a large number of patients whose cities or ZIP codes are unknown. Of those diagnosed, their ZIP code was unknown in 755 cases and their home city was unknown in 2,849 cases. All numbers are preliminary and may be adjusted later, including through “data cleaning” — the reassignment of some cases to a different ZIP code or city after further analysis.

The total number of confirmed COVID-19 diagnoses in the county as of Sept. 18 was 26,670, up from 26,351 on Sept. 15. Of those, 560 are reported as having died. About 6.6% of patients were hospitalized and about 1.7% died.

The number of total diagnosed cases and the 14-day trend in the main ZIP codes in Buckhead and Sandy Springs between the Sept. 15 and Sept. 18 reports were as follows.

Buckhead ZIP codes

30305: 725 (up from 715); down 5.6%

30326: 210 (up from 209); no change

Sandy Springs ZIP codes

30328: 766 (up from 753); down 6.5%

30350: 561 (up from 548); up 2.4%

Buckhead and Sandy Springs combined ZIP codes

30327: 512 (up from 502); up 24.1%

30342: Total: 1,132 (up from 1,123); down 28.6%

John Ruch is an Atlanta-based journalist. Previously, he was Managing Editor of Reporter Newspapers.