Bugs in your berry juice

This is the first of 16 student posts, guest-authored by Riva Ben-Ezra.

Acai fruit comes from the Brazilian Amazon forests and is one of the main dietary staples of the native population.  It has been touted as having potent antioxidant properties 1,2 as well as being a stimulant for weight loss3, a cancer cure and an anti-aging miracle drug.  Whether these claims are true or not remains to be seen4,5; however the FDA has clamped down on Acai products claiming to perform health benefits without classifying themselves as drugs (see here, here and here).

Something that the FDA has not taken into consideration, however, is the presence of triatomines in Acai juice.  Triatomines are blood-sucking insects that have been found in South America (mainly Brazil), Texas and Mexico.6 These bugs can carry a protozoan parasite called Trypanosoma cruzi, which is the causative agent for Chagas disease.6  Chagas disease is considered a “Neglected Disease” by the CDC because:

These infections are considered neglected because relatively little attention has been devoted to their surveillance, prevention, and/or treatment.

Chagas disease can be divided into two phases: acute and chronic.  In the acute phase, the most common symptoms are fever and swelling where the parasite feces entered the patient.  The chronic phase is hallmarked by the development of cardiomyopathies, arrhythmias, and megaesophagus or megacolon. 6 The disease can “hibernate” in the body and re-activate during times of stress or immunosuppression.   The WHO estimates that 10,000,000 people worldwide have been infected with Trypanosoma cruzi, and the CDC estimates that approximately 300,000 of those people are living in the United States.  The most common methods of becoming infected include:

  • being bitten by a triatomines insect
  • receiving a contaminated blood transfusion
  • transferring it through the placenta to a fetus
  • receiving a contaminated organ transplant, and
  • ingesting contaminated food

Since 2009, the last option mentioned above was considered to be rare.  However, in the past three years, several studies have been published confirming the transmission of Chagas disease through contaminated food in Brazil, Venezuela and Colombia (not the US).7  The suspected or confirmed culprits include acai juice/paste, orange juice, guava juice, sugarcane juice, and other (unknown) meal items.7  An epidemiological trace-back to discover the source of the protozoa on infected food revealed the presence of feces from either triatomine bugs or other animals such as opossum, marsupial or rodent8 9 already infected with the protozoa7.  From observing the processing of Acai fruit and sugar cane, it was revealed that conditions are frequently unsanitary and that there are many instances when the triatomine bugs are ground up with the fruit to make juice.10  In 2007, the Brazilian authorities drafted a guidance document to control foodborne transmission of Trypanosoma cruzi, but as evidenced by the data above, there is little compliance with these recommendations.7
Triatomine bug

Triatomine bug, Trypanosoma cruzi vector, defecating on the wound after taking a blood meal.

 Source: http://dpd.cdc.gov/dpdx/HTML/ImageLibrary/TrypanosomiasisAmerican_il.htm

So, given the fact that people can and do become infected with Trypanosoma cruzi through eating contaminated fruit and other foods, and given the fact that the WHO, EFSA, and the CDC all recognize that oral transmission of Chagas disease is an emerging infectious disease, how have our regulators addressed this risk?

The simple answer is: not at all.

In the United States, fruit juice must be processed under a food safety system called HACCP- Hazard Analysis and Critical Control Points.  HACCP requires the manufacturer to identify the possible hazards associated with the production of this food, and preventing those hazards from being present in the final product.  The FDA’s Guidance for Industry: Juice HACCP Hazards and Controls Guidance was published in 2004 as a response to an outbreak of E. coli 0157:H7 in apple juice11,12.  It states:

The HACCP regulation requires you to use treatments capable of consistently achieving at least a 5-log reduction (using ten as the base number) in the level of the pertinent microorganism in your juice…The “pertinent microorganism” is the most resistant microorganism of public health significance that is likely to occur in the juice and is the pathogen that you must target for the 5-log pathogen reduction treatment (21 CFR 120.24(a)). By choosing the most resistant pathogen as your target, you are also treating the product for all other pathogens that are less resistant to the means of treatment.  One way to identify the pertinent microorganism for your juice is to consider whether there have been any illness outbreaks associated with this type of juice, and what microorganisms have caused the outbreaks. If certain pathogens have been demonstrated, i.e., through outbreaks, to be potential contaminants in certain juices, then the pertinent microorganism for your process typically should be one of these pathogens.

Sounds good, however further on it lists the various hazards that may be present in fruit juice, and it does not include the protozoan parasite Trypanosoma cruzi.  It also does not require pasteurization for all fruit juices, the only known method to destroy Trypanosoma cruzi.10  The FDA permits other methods to create a 5-log reduction such as high-pressure, UV radiation, or surface sanitation; none of which have been shown to be effective in destroying Trypanosoma cruzi.

The CDC published an article entitled “Preventing Health Risks Associated with Drinking Unpasteurized or Untreated Juice” on their web site.  Their recommendations are as follows:

Untreated (raw) juice has not been treated in any way to kill pathogens that may be present. This type of juice may be found in the refrigerated sections of grocery stores, health-food stores, cider mills, and farm markets. Another form of untreated juice is untreated cider. One way to make this cider safer is to heat it to at least 170° F. Prepackaged, untreated juice must bear a warning label that looks similar to this one:

sign

To minimize health risk, young children, the elderly and people with weakened immune systems should not consume packaged juice that bears the above warning label or any other form of juice that is known to be untreated (e.g. untreated juice served by the glass at a roadside cider stand). Anyone who wishes to reduce their risk may follow this recommendation.
If it is unclear that a juice has been treated to destroy harmful bacteria, avoid drinking it.

This is definitely a step in the right direction-however, not only high-risk individuals can become infected with Trypanosoma cruzi, and the recommendations should reflect that.

Looking at other countries, we find a variety of responses.

The Codex General Standard for Fruit Juices and Nectars does not include any reference to pasteurization or other treatment to control the transmission of Trypanosoma cruzi in fruit juice.  The Code of Hygienic Practice for Fresh Fruits and Vegetables does address the general notion of prevention of contamination during harvesting and storage.

 

The Australia New Zealand Food Authority discussed the possibility of requiring orange juice to be pasteurized or to require a label stating that the product is unpasteurized as in the US, and recommended similar requirements as the FDA in 2001.  As of 2008, however, the Fruit Juice Standard does not require any form of pathogen reduction treatment or labeling.

 

The European Union, similar to Australia, does not have any requirement for pathogen reduction treatment or labeling within their legislation.  They do require HACCP for all factories manufacturing fruit juice and with that should be the listing of the presence of Trypanosoma cruzi as a hazard to be eliminated.

 

The Canadian Food Inspection Agency published the “Code of Practice for the Production and Distribution of Unpasteurized Apple and Other Fruit Juice/Cider in Canada” which addresses the possibility of fecal contamination of the fruit used to make juice and outlines procedures to minimize the presence of microbial contamination in the final product.  It also requires manufacturers to label unpasteurized products as such.  In their Holiday Food Safety Tips for consumers, they write:

  • When making punch or serving cider, check the product label to make sure the juice or cider has been pasteurized.
  • If the juice or cider has not been pasteurized, bring it to a rolling boil and then cool before serving.
  • Unpasteurized fruit juice and cider may contain bacteria like Salmonella and E. coli that can cause serious illness, especially in children, seniors and people with weakened immune systems.

Again, similar to the CDC recommendations, they do not address the fact that healthy people can become infected with Trypanosoma cruzi by drink unpasteurized juice.

Returning to Acai berries, what is the take-home message for you, the consumer?

 

  • Make sure you only drink pasteurized juice.
  • Don’t use skin products with Acai berries in them unless the product has undergone a heat treatment.
  • Don’t accept claims that Acai berries cure disease.
  • When travelling to Latin and South America, be sure to eat food from a reliable source and do not eat fruit that has not been pasteurized.

 

 

Sources:

1. Lichtenthler R, Rodrigues R, Maia JGS, Papagiannopoulos M, Fabricius H, Marx F. Total oxidant scavenging capacities of euterpe oleracea mart. (açaí) fruits. Int J Food Sci Nutr. 2005;56(1):53-64.

2. Jensen G, Wu X, Patterson K, et al. In vitro and in vivo antioxidant and anti-inflammatory capacities of an antioxidant-rich fruit and berry juice blend. results of a pilot and randomized, double-blinded, placebo-controlled, crossover study. J Agric Food Chem. 2008;56(18):8326-8333.

3. Udani J, Singh B, Singh V, Barrett M. Effects of açai (euterpe oleracea mart.) berry preparation on metabolic parameters in a healthy overweight population: A pilot study. Nutrition journal. 2011;10:45-45.

4. Are some of the more exotic berry types, such as goji and açaí berries, better for health than the more common berries such as strawberries, blueberries and raspberries? Mayo Clinic health letter. 2010;28(11):8-8.

5. Marcason W. What is the açaí berry and are there health benefits? J Am Diet Assoc. 2009;109(11):1968-1968.

6. Pereira K, Schmidt F, Guaraldo AMA, Franco RMB, Dias V, Passos LAC. Chagas’ disease as a foodborne illness. J Food Prot. 2009;72(2):441-446.

7. Shikanai Yasuda M, Carvalho N. Oral transmission of chagas disease. Clinical infectious diseases. 2012;54(6):845-852.

8. de Noya B. Large urban outbreak of orally acquired acute chagas disease at a school in caracas, venezuela. J Infect Dis. 2010;201(9):1308-1315.

9. Miles M. Orally acquired chagas disease: Lessons from an urban school outbreak. J Infect Dis. 2010;201(9):1282-1284.

10. Barbosa R, Dias V, Pereira K, et al. Survival in vitro and virulence of trypanosoma cruzi in açaí pulp in experimental acute chagas disease. J Food Prot. 2012;75(3):601-606.

11. Cody SH, Glynn MK, Farrar JA, et al. An outbreak of escherichia coli O157:H7 infection from unpasteurized commercial apple juice. Ann Intern Med. 1999;130(3):202-209.

12. Vojdani J, Beuchat L, Tauxe R. Juice-associated outbreaks of human illness in the united states, 1995 through 2005. J Food Prot. 2008;71(2):356-364.

 

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  1. [...] Smith is posting essays by her students on her blog, Aetiology. This one by Riva Ben-Ezra concerns the latest miracle fadfood: Acai fruit comes from the Brazilian Amazon forests and is one [...]