CDC Suspends Domestic Testing Programs for Rabies and Pox Viruses

On March 30, 2026, the Centers for Disease Control and Prevention quietly updated its online Test Directory. Two entries — Rabies Antemortem Human Testing (CDC-10392) and Rabies Antibody Titer (CDC-10393) — were marked as paused [1]. Poxvirus assays, covering the family of viruses that includes smallpox and mpox (monkeypox), were also removed from the roster of reference testing services the agency has long offered to state and local health departments [2]. The changes were part of a broader suspension affecting more than two dozen categories of diagnostic tests — the largest simultaneous pause in CDC testing history, according to Scott Becker, chief executive officer of the Association of Public Health Laboratories (APHL) [3].

A government spokesman, Andrew Nixon, called the pause temporary, attributing it to "a routine review to uphold our commitment to high quality laboratory testing" [3]. But the timing — coming after more than a year of layoffs, hiring freezes, and program cuts at the agency — has alarmed public health officials, infectious disease experts, and the state laboratories that depend on CDC as the nation's diagnostic backstop.

The Scale of What Was Lost

The CDC's National Rabies Reference Laboratory has historically served as the final arbiter for ambiguous or high-stakes rabies diagnoses in the United States. More than 100 state and local labs test roughly 100,000 animal specimens for rabies each year using the fluorescent antibody test (FAT), a method the World Health Organization recommends as giving reliable results in 95–99% of cases on fresh specimens [4][5]. But when results are inconclusive, when the specimen is degraded, or when the case involves a human patient, those labs send samples to the CDC for confirmatory testing.

The agency also maintains the only federal-level capacity for advanced rabies serology — measuring antibody levels in patients who have received post-exposure prophylaxis (PEP) or pre-exposure vaccination — a function no state lab currently replicates at scale [1].

For pox viruses, the stakes involve a different kind of infrastructure. As part of national smallpox preparedness, the CDC developed an FDA-approved nonvariola orthopoxvirus (NVO) polymerase chain reaction test deployed across the Laboratory Response Network (LRN) — 68 federal, state, and military labs originally designed to detect biological threats [6]. During the 2022 mpox outbreak, that network was expanded in collaboration with five commercial laboratory companies, scaling national testing capacity from 6,000 to more than 80,000 specimens per week [6]. The LRN labs can still run preliminary orthopoxvirus tests. But confirmatory identification — determining whether a sample is mpox, cowpox, vaccinia, or something else — has depended on CDC's specialized reference lab [7].

Source: AP / Association of Public Health Laboratories

Data as of Apr 1, 2026CSV

Staffing: The Real Story Behind the "Routine Review"

The official framing of the pause as a quality review has drawn skepticism. The CDC's workforce has declined by an estimated 20–25% since early 2025, a contraction driven by layoffs, retirements, voluntary resignations, and the nonrenewal of temporary and fellowship appointments [3][8].

Source: Multiple sources / APHL estimates

Data as of Apr 1, 2026CSV

The poxvirus and rabies laboratories specifically lost approximately half their prior staff, according to the National Public Health Coalition, an organization of current and former CDC employees that formed in the wake of the downsizing [3]. The malaria branch experienced even steeper reductions [3].

The staffing trajectory is worsening. By July 2026, the rabies team is projected to be down to a single person with the clinical expertise to advise state and local officials on human rabies cases. The pox virus team will have none [2][3].

Daniel Jernigan, former director of the CDC's National Center for Emerging and Zoonotic Infectious Diseases, is among the senior scientists who have departed [8]. The agency itself has operated without a permanent director since Susan Monarez was removed in August 2025. Acting director Jay Bhattacharya simultaneously leads the National Institutes of Health, headquartered in Bethesda, Maryland — hundreds of miles from CDC headquarters in Atlanta [8].

The deeper fiscal context: the HHS budget proposal for fiscal year 2026 would cut CDC funding by approximately $3.8 billion net — a 42% reduction from the agency's operational budget, and a 53% reduction compared to FY 2024 levels [9][10]. The budget eliminates funding for the Global Health Center, the Office of Readiness and Response, and nearly the entirety of the Prevention and Public Health Fund [10]. Against that backdrop, Becker acknowledged that staffing losses are a contributing factor in the testing pause, calling it "concerning, only if it's permanent" [3].

Rabies: A Disease That Kills 100% of the Time Once Symptoms Appear

Rabies occupies a singular position in infectious disease: it has a case-fatality rate of effectively 100% once clinical symptoms develop [4][11]. No other common infectious disease in the United States carries that distinction. The virus, typically transmitted through animal bites, travels along peripheral nerves to the central nervous system. The incubation period averages 20 to 90 days in 75% of patients, though it can extend beyond a year in rare cases [11]. Once neurological symptoms emerge — agitation, hydrophobia, paralysis — death follows within one to two weeks [11].

The corollary is that rabies is also nearly 100% preventable. Post-exposure prophylaxis, consisting of rabies immune globulin and a series of four vaccine doses administered over 14 days, is effective if initiated before symptom onset [11]. The entire public health response to rabies depends on rapid, accurate testing of the animal involved in an exposure — typically a bat, raccoon, skunk, or fox — so that physicians can make informed decisions about whether to begin PEP.

Source: CDC Rabies Surveillance

Data as of Mar 30, 2026CSV

Over the past decade, 17 confirmed human rabies deaths were documented in the U.S. between 2015 and 2024, with bat exposure accounting for roughly 70% of cases [4]. But 2025 saw a notable increase: six deaths, the highest annual toll in years [4]. The diagnostic window between animal exposure and the point at which a testing gap becomes a mortality risk is measured in days. CDC guidelines allow delays of up to five days while searching for a healthy-appearing dog or cat, and up to 10 days while observing a confined animal [11]. If the animal cannot be found or tested, physicians must assume the worst and begin PEP — a course of treatment that costs $3,000 to $7,000 per patient.

The loss of CDC's confirmatory testing capability does not eliminate rabies diagnosis in the U.S. State labs continue to perform the standard FAT on animal specimens. But it removes the safety net for the hardest cases: degraded samples, inconclusive results, human antemortem testing, and antibody titer measurement.

Who Bears the Risk

The populations most immediately affected by the testing gap fall into several overlapping categories.

Rural communities with livestock and wildlife exposure. The roughly 60 million Americans living in rural areas face higher rates of contact with rabies-reservoir species — bats, raccoons, skunks, and foxes — and often have limited access to specialized medical care [4]. A rancher bitten by an unidentified bat in a state without independent confirmatory testing capacity now faces a longer, more uncertain path to a definitive answer.

Wildlife biologists and veterinary workers. Professionals who handle animals as part of their work rely on pre-exposure vaccination and periodic antibody titer checks to confirm their immunity remains protective. CDC was the primary reference lab for those titer measurements [1].

Border-state communities. The U.S.-Mexico border region has distinct rabies ecology, including canine rabies variants that have been controlled but not eliminated in northern Mexico. Cross-border transmission corridors require coordinated surveillance [4].

Immunocompromised patients. Individuals with weakened immune systems may mount an inadequate response to rabies PEP, making serological confirmation of antibody levels — exactly the test CDC has paused — medically necessary rather than optional.

These groups disproportionately lack access to private or academic laboratory alternatives. Commercial reference labs can perform some rabies testing, but their turnaround times, costs, and geographic reach do not match what the CDC provided as a public service.

The Pox Virus Gap and Biodefense

The suspension of poxvirus testing carries a separate set of implications that extend beyond routine public health into national security.

Orthopoxviruses — the genus that includes variola (smallpox), monkeypox, cowpox, and vaccinia — are classified as Category A bioterrorism agents by the CDC itself [12]. The entire Laboratory Response Network was originally built around the need to rapidly detect a deliberate smallpox release. Monkeypox surveillance infrastructure was layered on top of that foundation during the 2022 outbreak, when CDC adapted its existing smallpox preparedness systems to the new threat [6].

The concern is not hypothetical. Of 33 exported mpox cases recorded between January and March 2026, only 8 originated in Central or Eastern Africa, indicating that the more severe clade Ib strain is spreading beyond its historical geographic boundaries [8]. Maintaining the ability to distinguish between orthopoxvirus species — to confirm whether a suspected case is mpox, an unusual vaccinia reaction, or something more alarming — requires the specialized reference capacity that CDC's pox virus lab provided.

Whether the Departments of Defense or Homeland Security have been formally notified of the testing suspension, or asked to compensate through their own laboratory networks, is not publicly known. The biological defense community has relied on the assumption that CDC's civilian laboratory infrastructure would serve as the first line of detection for any orthopoxvirus event [12].

The Case for the Pause

The administration's position, while thinly articulated, rests on a defensible premise: the CDC has been reviewing its testing services since 2024, predating the current round of budget cuts [3]. Some of that review stems from pandemic-era criticism — the agency's early failures in COVID-19 testing led to widespread calls for reform of its laboratory operations.

The argument for consolidation holds that many of the tests CDC performs are duplicative of capacity that exists at state labs, commercial laboratories, or academic medical centers. If state labs in New York and California can run rabies FAT and preliminary orthopoxvirus PCR — and they can [3] — then CDC's role as a reference lab may represent an outdated model in which the federal government performs work that subnational entities are equipped to handle.

The raw count of paused tests has actually declined over time: from nearly 50 in January 2025 to 38 by June 2025 to 27 as of this week [3]. That trajectory suggests the agency is selectively restoring services rather than permanently dismantling them. Nixon, the government spokesman, stated: "We anticipate some of these tests will be available through CDC labs again in the coming weeks" [3].

Prior administrations have also flagged CDC's laboratory portfolio for rationalization. A 2019 HHS Inspector General report recommended that CDC better define which tests it should perform versus those that should be delegated to the broader laboratory network.

The Limits of State Capacity

The counterargument is straightforward: two state labs cannot replace a national reference system.

New York's Wadsworth Center and California's public health laboratory are among the most capable state facilities in the country. In 2025, Wadsworth alone processed more than 13,000 samples from 23 states for diseases including chikungunya, dengue, West Nile virus, and drug-resistant tuberculosis [3]. But Wadsworth was already absorbing overflow from other states before the CDC pause. Adding rabies confirmatory testing and poxvirus reference work to its portfolio stretches capacity that was not built for national-scale demand.

The remaining 48 states, plus territories, must now either send specimens to New York or California, negotiate arrangements with commercial labs, or accept a lower threshold of diagnostic certainty. For rare but high-consequence diseases — which is precisely the category rabies and orthopoxviruses occupy — the loss of a centralized reference lab creates fragmentation that is difficult to reverse quickly.

International Comparisons

The United States' decision to suspend federal rabies and poxvirus reference testing places it out of step with peer nations that maintain endemic wildlife rabies reservoirs.

Canada, which shares cross-border wildlife corridors with the U.S., operates a centralized rabies reference program through the Canadian Food Inspection Agency and classifies itself as "rabies-controlled" with sustained mitigation efforts [13]. Germany, through the Friedrich-Loeffler-Institut, maintains continuous rabies and orthopoxvirus surveillance as part of European Union coordination. Australia, which has remained free of dog-mediated rabies, still funds surveillance of bat lyssaviruses in wildlife and maintains laboratory readiness [13].

The World Organisation for Animal Health (WOAH) — whose work is financially supported by Australia, Canada, the EU, France, Germany, and Japan — sets science-based standards for rabies surveillance and control that member nations are expected to meet [14]. The U.S. has historically exceeded those standards. Whether suspending federal reference testing constitutes a violation of any international obligation is a legal question, but the gap between U.S. capacity and the expectations set by international health bodies is widening.

Source: OpenAlex

Data as of Jan 1, 2026CSV

Academic research on rabies diagnosis and surveillance has grown significantly over the past decade, with publications peaking at 778 in 2023 [15]. That body of work depends in part on the reference data and specimen characterization that CDC laboratories have provided.

The Restart Problem

Even if the pause proves temporary, the damage may not be. Trained rabies and poxvirus diagnosticians cannot be replaced on short timelines. The biosafety infrastructure required for working with these pathogens — BSL-3 facilities for rabies, BSL-4 considerations for certain orthopoxviruses — takes years to build and certify. Reference sample collections, strain libraries, and the institutional knowledge that allows a lab to distinguish an unusual result from a true positive are accumulated over decades.

If the remaining staff leave — through further layoffs, demoralization, or simply better offers elsewhere — restarting these programs would cost not just money but time measured in years. The specialized nature of the work means there is no large pool of qualified replacements waiting to be hired.

The cost calculus also works against delay. Maintaining an existing program with trained staff, established protocols, and functioning equipment is a fraction of the cost of rebuilding one from scratch. Every month the pause continues, the restart price increases as personnel disperse and institutional memory degrades.

What Comes Next

The CDC's testing pause arrives at a moment when the agency is simultaneously losing staff, losing funding, and losing leadership continuity. The question is not whether state labs can perform some of the tests CDC has dropped — they can, in some cases. The question is whether a patchwork of state-level solutions can replicate the national surveillance function that a centralized reference lab provides: consistent methodology, centralized data collection, and the ability to detect patterns across state lines that no individual lab would see on its own.

For rabies, the stakes are measured in individual lives — small numbers, but with a fatality rate that leaves no margin for diagnostic error. For pox viruses, the stakes extend to biodefense preparedness and the country's ability to detect and characterize an emerging orthopoxvirus threat before it spreads.

The administration says the pause is temporary. The staffing numbers suggest otherwise.