Monkeypox cases are surging, testing likely plays a role
New data from CDC shows case counts continue to grow, tracking with expansion of testing to commercial providers
Today the Centers for Disease Control and Prevention published an epidemic curve (also called an epicurve) of the daily number of monkeypox cases reported to the agency. Previously, only counts for the current day were available, making it difficult to track trends over time.
The epicurve shows that the monkeypox outbreak is growing rapidly, from fewer than fifty daily reports in early July to several hundred per day now. This puts us on a diverging path from the United Kingdom, where the latest assessment from their Health Security Agency judges the outbreak there to be reaching a plateau.
Although I hope to see case counts begin to decline as we work towards containment (see my previous essay on containment here), a surge in case reports is not always a bad thing. Early in the outbreak, diagnostic testing was centralized in 69 public health laboratories belonging to the Laboratory Response Network (LRN). In the last few weeks, testing has expanded to commercial laboratories, including Quest and LabCorp. This move has increased capacity from 6,000-8,000 to 80,000 tests per week and made testing more accessible to healthcare providers who may not be as familiar with the LRN.
I expect this change is turning up more cases, which is important for enabling public health departments to break chains of transmission through post-exposure prophylaxis, contact tracing, and supported isolation. A formal diagnosis also enables patients to access supportive care and treatment for their infection.
I will be watching this newly-available epicurve closely in the coming weeks for signs that the outbreak is slowing. More data on the number of tests being run (and the demographics of people receiving them) would further aid interpretation of this important indicator.
Disclosure: I recently worked at CDC helping to start the Center for Forecasting and Outbreak Analytics.