Photo by  Tanarus via Wikimedia Commons

June 18, 2010

On June 4, 2010, at the request of the Food and Drug Administration, federal marshals seized 64 drums of imported honey, worth about $32,000.  This honey, from Cheng Du Wai Yuan Bee Products Company Limited in China, was contaminated with the antibiotic chloramphenicol.

Chloramphenicol is a powerful and inexpensive drug used to treat a wide variety of bacterial infections, and particularly effective against meningitis and typhoid fever.  The antibiotic has a fatal side effect in some people; aplastic anemia, a disorder where the bone marrow becomes damaged and can’t make enough red blood cells, white blood cells or platelets.  An estimated 1 in 30,000 individuals in the US may develop aplastic anemia weeks or months after ingesting even small doses of chloramphenicol.  (In comparison, fatal reactions to penicillin affect approximately 1 in 177,000.)

Antibiotics can contaminate honey when beekeepers need to treat their hives against the crippling foulbrood disease, caused by the bacteria Paenibacillus larvae.  In a foulbrood infection, larval bees eat the spores of the bacteria, the spores germinate in the developing bee’s gut and reproduce until the larval bee dies.  The new bacteria form more spores, which adult bees inadvertently carry around the hive, exposing more larvae to the disease.  Left unchecked, foulbrood destroys the hive’s bee population and can annihilate an apiary.  Since the bacterial spores can lie dormant for up to 40 years, the only way to eradicate an infection is to kill the honey bee colony and incinerate all of the contaminated equipment – a costly remedy.

Foulbrood can be kept in check by antibiotics, which can only mitigate – not eliminate – the disease.  Infected hives must be treated constantly to prevent a fouldbrood outbreak.  Beekeepers mix powdered antibiotic with powdered sugar and spread it within the hives.  Bees walk on the antibiotic-laced sugar, it adheres to their bodies and spreads through the hive as the bees travel, thus treating the disease.  If the bees walk through a honey-filled comb while coated with antibiotic, the antibiotic can then stick to the honey.  Antibiotic left on the hive can also fall into the honey during the extraction process. Good beekeeping practices dictate that beekeepers remove treatments from the hive at least six weeks before they plan to harvest honey to prevent such contamination.

In 1997, foulbrood ravaged the Chinese beekeeping industry, reducing its honey exports by two-thirds.  Beekeepers in China adopted chloramphenicol and streptomycin to save their hives and their industry.  But much Chinese honey – up to 80% according to a Canadian survey – still contains the drug.  (US beekeepers may use terramycin to prevent foulbrood infections from starting in the first place.)

Citing the ongoing investigation, the FDA declined to say why the honey was tested in Philadelphia and not California, where it was imported by Sweet Works, Inc. of Monterey.  The FDA also declined to note other potential buyers (if any) of this honey shipment.

Individuals concerned with the origin of their honey blends can purchase directly from local beekeepers, from US suppliers online, or contact the honey producer directly.  Sue Bee Honey, perhaps the most well-known honey brand in the US, replied promptly to such a request.  “Sioux Honey Association has never purchased any honey from Sweet Works Inc.,” David Allibone responded, and cited several safeguards the company employes to maintain the quality of its product including screening honey for adulterants.

Until the 1960’s, chloramphenicol was a best selling drug in the US.  It is still used to treat certain infections when other antibiotics fail.

The levels of chloramphenicol found in Chinese honey in Canada were miniscule (one thousandth to one millionth less than what the FDA considers a theraputic dose of the antibiotic), but researchers have been unable to identify a safe amount that will not cause aplastic anemia in susceptible people.

The FDA has also found chloramphenicol contamination in shrimp and crayfish imported from China and Vietnam.

According to the National Institutes of Health, aplastic anemia is 2 to 3 times more common in Asian countries.