Mpox, Rabies Diagnostic Testing Paused by CDC Amid Downsizing

The CDC announced on April 1 that they would be downsizing their operations, leading to the pause of diagnostic testing for mpox, rabies, and more than 2 dozen other infectious diseases.¹ The CDC has maintained that the pause will be only temporary and allow for a routine review of laboratories to assure they are of high quality.

The pause of diagnostic testing for these infectious diseases should be lifted within the coming weeks, according to Andrew Nixon of HHS.¹ The pause in testing comes after operations of the CDC laboratory were faulted during the COVID-19 pandemic, but the pause could also be due to staffing shortages. The CDC has experienced a reduction in staffing of approximately 20% to 25%, which could have affected laboratories.

State-level laboratories should be able to pick up some of the gap left with the pausing of the federal laboratories, but this will depend on the state. States such as New York and California should be able to continue conducting testing through their state-level diagnostic sites.

Should the pause in diagnostic testing persist for a longer period of time, it could affect how quickly patients are treated for these infectious diseases. Mpox can manifest itself as a rash and spread through symptomatic exposure, including through contaminated objects or close contact with another person.² Through March 2, the CDC has reported 370 cases of mpox, equaling approximately 100 cases per month.³ If there is a delay in diagnosis, the potential for the virus to spread grows, as those who are diagnosed are usually tasked with informing those who were potentially exposed to the virus. Should someone not be aware of their own diagnosis, it’s possible that spread could affect many before it is caught.

Outbreaks of mpox could also be affected, as the CDC works with public health partners around the world to make sure that mpox does not spread.⁴ With diagnosis rates that are not up-to-date, it could make tracking global mpox cases that are traced to traveling to other parts of the world difficult. State diagnostic testing will be vital to pick up any additional work from the federal laboratories during this time to make sure monitoring of these viruses does not lapse across the board.

Although rabies is also paused as a diagnostic test, most patients who suspect rabies should receive treatment before getting an official diagnosis, as the virus is fatal if not treated before symptoms begin.⁵ Delays in diagnosis, in this case, may not be as detrimental to humans. However, it could delay pinpointing the animals that are carrying the virus in the wild, which could lead to more spread in areas where stray animals are common, as the CDC recommends that stray animals in the neighborhood be removed by animal control to prevent rabies.⁵

Other diagnostic testing that is temporarily paused includes fungal identification, varicella zoster virus detection, human herpesvirus 6 and 7, adenovirus, cysticercosis, and schistosomiasis serology.⁶ Testing for parasitic worms and the virus that causes “sloth fever” are also on the list of testing that is currently paused.¹

References

1. Stobbe M. CDC pauses dozens of types of lab testing during evaluation and in wake of downsizing. AP News. Updated April 1, 2026. Accessed April 2, 2026. https://apnews.com/article/cdc-testing-pause-90cad1748a35d3cd68234f37d70036d1
2. Munz K. 5 things to know about the current mpox outbreak. AJMC. August 23, 2024. Accessed April 2, 2026. https://www.ajmc.com/view/5-things-to-know-about-the-current-mpox-outbreak
3. U.S. case data: monkeypox. CDC. Updated March 2, 2026. Accessed April 2, 2026. https://www.cdc.gov/monkeypox/data-research/cases/index.html
4. Monkeypox in the United States and around the world: current situation. CDC. March 23, 2026. Accessed April 2, 2026. https://www.cdc.gov/monkeypox/situation-summary/index.html
5. About rabies. CDC. January 27, 2026. Accessed April 2, 2026. https://www.cdc.gov/rabies/about/index.html
6. Test directory. CDC. March 30, 2026. Accessed April 2, 2026. https://cdc.gov/infectious-diseases-labs/php/test-directory/index.html