A laboratory technician works to identify a worm pest.
Photo: © FAO

FAO/WHO release “Top Ten” list of food-borne parasites

Following a request by the Codex Alimentarius Commission, the FAO and the WHO have prepared a report on the most serious food borne diseases and are developing new guidelines to control parasites in food.

A “Top Ten” list identifying the food-borne parasites of greatest global concern was released in the beginning of July 2014, and new guidelines are being developed to control them, the UN Food and Agriculture Organization (FAO) has announced. The parasites affect the health of millions of people every year, infecting muscle tissues and organs, and causing epilepsy, anaphylactic shock, amoebic dysentery and other problems, the FAO notes, adding that some can live on in human bodies for decades.

Despite their huge social costs and global impacts, information is generally lacking regarding just where these parasites come from, how they live in the human body, and – most importantly – how they make us sick.


As a first step in tackling the problem, the FAO and the World Health Organization (WHO) are initially focusing on the ten food-borne parasites with the greatest global impact. The top ten diseases are being ranked in the FAO-WHO report, “Multicriteria-based ranking for risk management of food-borne parasites”. The ranking is based on the parasites’ burden on human health and other factors, and includes information on where they can be found.



The top ten are:

  1. Taenia solium (pork tapeworm): in pork
  2. Echinococcus granulosus (hydatid worm or dog tapeworm): in fresh produce
  3. Echinococcus multilocularis (a type of tapeworm): in fresh produce
  4. Toxoplasma gondii (protozoa): in meat from small ruminants, pork, beef, game meat (red meat and organs)
  5. Cryptosporidium spp.(protozoa): in fresh produce, fruit juice, milk
  6. Entamoeba histolytica (protozoa): in fresh produce
  7. Trichinella spiralis (pork worm): in pork
  8. Opisthorchiidae (family of flatworms): in freshwater fish
  9. Ascaris spp. (small intestinal roundworms): in fresh produce
  10. Trypanosoma cruzi (protozoa): in fruit juices


According to the FAO, the list and supporting report were developed following a request by the global food standards body, the Codex Alimentarius Commission (Codex), for the FAO and the WHO to review the current status of knowledge on parasites in food and their public health and trade impacts. The FAO’s food safety and quality unit and the WHO responded by jointly organising a global call for information on the problem.

Twenty-two nations and one regional body responded, followed by an assessment and analysis by 21 experts on the impact of food-borne parasites, the FAO reported and added that from this work, an initial list of 93 parasites was developed. The list was then narrowed down to the 24 most damaging parasites based on the following criteria: 1) number of global illnesses, 2) global distribution 3) acute morbidity 4) chronic morbidity and 5) economic impact.

What next?


The Codex Committee on Food Hygiene is now developing new guidelines for the control of these parasites. The FAO and the WHO are supporting the process by providing scientific and technical information. The aim is to develop new standards for the global food trade that will help countries control the presence of these parasites in the food chain, the FAO notes.

The FAO-WHO report lists a number of ways to reduce the risk of parasite infections. For farmers, it advises that the use of organic fertiliser, particularly on produce, should be closely monitored to ensure that it is composted properly and all faecal matter is removed. Water quality must also be carefully checked. For consumers, the report advises that all meat should be well cooked and that only clean water should be used to wash and prepare vegetables.

Parasites by continent

Classified biologically as protozoa and helminths (but better known as tapeworms, flatworms and roundworms), it is difficult to know how widespread parasites are globally because in many countries it is not compulsory to notify public health authorities of their presence.

In Europe, more than 2,500 people are affected by food-borne parasitic infections each year. In 2011 268 cases of trichinellosis and 781 cases of echinococcosis recorded in the European Union.

In Asia, there is no precise national data, but parasitic diseases are known to be widespread and are recognised as major public health problems in many countries.

In most African nations, there is no data at all on the prevalence of food-borne parasites in humans because of a general lack of surveillance systems.

In the United States of America, Neurocysticercosis, caused by Taenia solium, is the single most common infectious cause of seizures in some areas, where 2,000 people are diagnosed with neurocysticercosis every year. Toxoplasmosis is a leading cause of food-borne illness and death.


(FAO/wi)

More information:  FAO