The 1979 Sverdlovsk Anthrax Outbreak: How a Deadly Lab Leak Was Hidden for Decades

In 1979, in the midst of the Cold War, a deadly anthrax outbreak struck Sverdlovsk. For years, the Soviet Union blamed contaminated meat, but in reality, it was one of history’s most chilling biological accidents — a laboratory leak hidden for more than a decade.

The city of Sverdlovsk in the former Soviet Union (now Yekaterinburg, Russia) faced one of the deadliest outbreaks of inhalational anthrax ever recorded. Around 66 people were confirmed to have died, though some estimates put the toll closer to 100.¹ Spores of Bacillus anthracis had escaped from a military laboratory, but for years, officials attributed the outbreak to contaminated meat. Later investigations revealed the true cause — an accidental release of anthrax spores into the air.

What Happened in Sverdlovsk

Between April and May 1979, hospitals in Sverdlovsk reported sudden cases of severe respiratory illness. Many patients developed high fever, difficulty breathing, and shock, and most did not survive. Soviet authorities quickly announced that people had consumed meat from animals infected with anthrax.

However, the pattern of illness did not fit this explanation. Inhalational anthrax, the form seen in Sverdlovsk, is extremely rare in natural outbreaks and is far more lethal than anthrax acquired through eating contaminated food.

Evidence of an Accidental Release

Years later, researchers gained access to data that challenged the official story. A team led by Dr. Matthew Meselson from Harvard University studied hospital records, death certificates, and geographic patterns of the outbreak. Their findings, published in 1994, pointed to a very different source.

• Most victims lived or worked in a narrow strip of land running south of a military microbiology facility.

• Animal deaths were reported further down the same path, extending several kilometers.

• Weather records from the time showed strong northerly winds, carrying spores from the facility directly through the affected zone.

Breaking these findings down, the alignment of human cases, livestock deaths, and wind direction strongly supported the conclusion that anthrax spores had escaped into the air from the laboratory.

Why the Meat Theory Did Not Add Up

The government’s explanation of tainted meat did not align with the facts. If meat were the source, cases would have been scattered across households that purchased or shared the same supply. Instead, cases clustered along the path of the airborne release. Some victims also had no exposure to meat at all but were simply present in areas downwind of the facility.

How Inhalational Anthrax Works

Anthrax is caused by the bacterium Bacillus anthracis, which forms durable spores capable of surviving for decades in soil or the air. When inhaled, the spores lodge deep in the lungs and travel to lymph nodes, where they multiply and release toxins. This leads to rapid disease progression, often resulting in death if untreated.

Unlike cutaneous anthrax, which is more common and usually treatable, inhalational anthrax carries a very high fatality rate, especially before the availability of antibiotics.

A Cover-Up That Lasted Years

For more than a decade, Soviet officials maintained that contaminated meat was to blame. Access to medical records and the outbreak site was restricted, preventing independent investigation. It was only after the collapse of the Soviet Union that international scientists could study the incident openly.

The evidence confirmed what many had long suspected: the Sverdlovsk outbreak was the result of a laboratory accident involving **weaponized anthrax spores, produced as part of the Soviet Union’s biological weapons program.²

Lessons for Public Health and Safety

The Sverdlovsk incident highlighted important lessons that remain relevant today:

1. Transparency saves lives — Open communication about outbreaks allows rapid response and prevents misinformation.

2. Biosafety is critical — Laboratories handling dangerous pathogens must maintain the highest safety standards to prevent accidental releases.

3. Epidemiology reveals hidden truths — Careful mapping of cases and environmental data can uncover causes that official narratives may try to conceal.

The Legacy of Sverdlovsk

The 1979 anthrax outbreak is remembered as one of the most serious laboratory accidents in history. Beyond the immediate human toll, it serves as a reminder of the risks tied to biological research without strict oversight.

More than four decades later, the Sverdlovsk incident continues to shape global discussions about biosafety, disease surveillance, and the need for transparency when public health is at stake.

Reference:

1. Meselson, Matthew, Jeanne Guillemin, Martin Hugh-Jones, Alexander Langmuir, Inna Popova, Aleksandr Shelokov, and Olga Yampolskaya. “The Sverdlovsk Anthrax Outbreak of 1979.” Science 266, no. 5188 (1994): 1202–08. https://doi.org/10.1126/science.7973702.

2. Alibek, Ken, and Stephen Handelman. Biohazard: The Chilling True Story of the Largest Covert Biological Weapons Program in the World—Told from Inside by the Man Who Ran It. New York: Random House, 1999.

3. Centers for Disease Control and Prevention (CDC). “Anthrax Outbreak of 1979, Sverdlovsk.” Accessed October 3, 2025. https://www.cdc.gov/anthrax/basics/history.html.