The number of new monkeypox infections has been steadily declining for three weeks in San Francisco, leading the city's health officer to say she's "cautiously optimistic" that the city has turned a corner on the outbreak.

A little under three months since the first reported cases of monkeypox appeared in San Francisco, and about three weeks after the city declared the virus outbreak a local health emergency, things are looking up.

SF Health Officer Dr. Susan Philip tells the Chronicle this week not to jump the gun and she's only "cautiously optimistic," because there's only one week of complete data and two weeks of preliminary data to go on. "Sometimes we believe a curve is going down and see it going back up again," Philip tells the paper, comparing the data-tracking to COVID.

But the city only recorded, so far, under five new monkeypox cases last week, and the numbers declined the previous weeks from 87 new cases to 54. This was down from over 140 new cases in the last week of July.

There have now been 672 confirmed and probably cases of the virus in the city proper as of August 21. Given that we only had 40 confirmed cases on July 5, that's an average of 90 new cases per week. So if last week's case count remains under 5, that's significant, but we'll refrain from celebrating just yet.

Chart via SF DPH

Dr. Philip suggests we need three to four weeks of a solid, confirmed trend line before we can say anything definitive on the outbreak.

Meanwhile, the city just got an influx of new vaccine doses, with 1,600 vials capable of providing 8,000 new doses — via the newly approved method of intradermal administration.

SF's health department is still officially only prioritizing first doses, but the day may soon come when those with initial doses are welcomed back for their second, at the four-week mark or later.

At one point, San Francisco represented one-third of all California cases of the virus. That share has dropped to 25 percent, with the state's total count standing at 2,660 cases as of this week. Across the country, there have been over 15,400 confirmed cases, predominantly among men and trans women who have sex with men.