How often is botulism found in honey?

December 1, 2025 •

3 min read

While botulism is extremely rare overall, international studies show that the prevalence of Clostridium botulinum spores in honey can vary significantly, from as low as 1% to over 20% in some regions. The spores themselves are harmless to most people but pose a serious risk to infants under one year of age. Therefore, understanding how often is botulism found in honey is crucial for infant feeding safety.

Quick Summary

The frequency of botulism spores in honey varies globally, with international studies showing differing prevalence rates. This risk, primarily a concern for infants, is due to their underdeveloped intestinal flora.

Key Points

Prevalence Varies: The frequency of Clostridium botulinum spores in honey differs significantly across regions and studies, with some finding rates from 2% to over 20%.
Infant-Specific Risk: Botulism spores in honey are primarily a danger for infants under 12 months because their immature digestive systems allow the spores to germinate and produce toxin.
Adults are Safe: Older children and adults are not at risk from honey-borne spores due to their mature gut flora, which prevents germination.
Contamination Sources: Spores from the environment, including soil, dust, and pollen, are carried into beehives by bees, contaminating the honey.
No Safe Honey for Infants: Both raw and processed honey can contain botulism spores, as they are heat-resistant and survive standard pasteurization.
Follow Health Guidelines: Major health organizations like the CDC and AAP recommend never giving honey to children under one year of age.

Prevalence of Clostridium botulinum Spores

Studies on the prevalence of Clostridium botulinum spores in honey demonstrate significant geographical and methodological variations. An aggregation of international data suggests an average prevalence of around 4%, although individual study results range widely. For example, US studies indicate approximately 10% of honey samples contain spores, while a Polish study found just over 2%. A study of Nordic honeys showed a high prevalence of 26% in Danish honey compared to lower rates in Norway and Sweden. These variations mean not all honey carries the same likelihood of contamination, but caution is necessary for vulnerable populations.

How Honey Becomes Contaminated

Clostridium botulinum spores are common in soil and dust globally. Honey contamination occurs through environmental exposure during foraging, collection, or processing. Bees can transport spores from soil, water, and plants to the hive. Spores can persist in beeswax and honey and can also be introduced during processing if hygiene is inadequate. Honey's properties prevent spores from germinating into toxin-producing bacteria, but the spores remain viable. Standard processing like pasteurization does not reliably eliminate these heat-resistant spores, so commercial honey can still contain them.

Why Honey is Dangerous for Infants

Honey is a risk almost exclusively for infants under 12 months. Older children and adults have mature digestive systems with sufficient gut bacteria to prevent spore germination and toxin production. However, an infant's underdeveloped gut lacks this protection, allowing spores to germinate, colonize, and produce the botulinum neurotoxin. This can cause infant botulism, leading to muscle weakness, breathing issues, and difficulty swallowing. Health organizations like the CDC and AAP strongly advise against feeding honey to infants under one year.

Sources of Botulism Spore Contamination

Environmental: Soil, dust, and sediments are significant natural sources of spores.
Water: Bees can collect spore-contaminated water.
Pollen: Spores can be picked up by bees and accumulate in pollen.
Beeswax: Spores found in beeswax can contaminate honey during extraction.
Processing: Contamination can happen during harvesting and bottling without strict hygiene.

Infant Botulism and Other Food Contaminants

Honey is the primary identified dietary risk for infant botulism, but environmental exposure is the most frequent overall cause. In many cases, the source remains unknown, often attributed to dust or soil exposure. The table below compares botulism risks.


Feature	Botulism from Honey	Other Sources (Soil, Dust)
Mode of Contamination	Inadvertently introduced into honey via bees, pollen, or processing.	Inhalation or ingestion of microscopic environmental spores.
Relative Frequency	An identified, but less common, cause of cases.	Believed to be the most common cause of infant botulism.
Preventability	Entirely preventable by avoiding honey in infants under one year.	Cannot be fully prevented, only mitigated with general hygiene.
Effectiveness of Heat	Botulism spores are heat-resistant; standard pasteurization does not eliminate the risk.	Irrelevant for spores in dust. Toxin from foodborne illness is destroyed by heat, but not the honey spores.
Risk Group	Exclusively for infants under 12 months.	Exclusively for infants under 12 months.

Geographical Variation in Spore Prevalence

Spore prevalence in honey varies globally due to factors like climate, soil, and agriculture. Areas with extensive farming might have higher soil spore concentrations transferable to honey. This means local honey prevalence can differ from national averages. Both raw and commercially processed honey can pose a risk as spores resist processing.

Conclusion

Botulism spores are found in honey with varying frequency, though infant botulism from any source is rare. Since honey is a preventable dietary source, health authorities recommend avoiding it for infants under 12 months. Older individuals are not at risk due to mature digestive systems. The variation in spore prevalence globally underscores the widespread presence of Clostridium botulinum spores. Avoiding honey for infants is a simple, effective way to eliminate this specific risk.

For more information on infant botulism and food safety, the Centers for Disease Control and Prevention (CDC) website provides resources.

Frequently Asked Questions

While the spores of Clostridium botulinum are found in a varying percentage of honey samples, the disease known as infant botulism is extremely rare. The risk is specifically to infants under one year old.

Yes, even commercially processed and pasteurized honey can contain botulism spores. The spores are highly resistant to heat, meaning standard processing methods are not enough to reliably eliminate them.

Bees can pick up Clostridium botulinum spores from soil, dust, and pollen in the environment and carry them back to the hive. Contamination can also occur during harvesting and processing if hygienic conditions are not met.

Adults and older children have mature, acidic digestive systems with established gut bacteria that prevent botulism spores from germinating and producing toxins. Infants, however, lack this protective gut flora, making them susceptible.

No. The spores of Clostridium botulinum are heat-resistant and can survive cooking and baking temperatures. Therefore, cooked or baked goods containing honey should also be avoided for infants under one year.

The most effective way to protect an infant is to follow health guidelines and never feed honey or any food containing honey to a child under 12 months of age. While most infant botulism cases are not linked to honey, avoiding it removes this one specific dietary risk.

Early signs of infant botulism often include constipation, followed by symptoms like weak cry, loss of appetite, a 'floppy' appearance due to muscle weakness, and trouble swallowing or breathing.