Food Safety Focus (98th Issue, September 2014) – Incident in Focus
Ebola Virus Disease and Food Safety
Reported by Dr. Ivan CHONG, Veterinarian,
Risk Assessment Section,
Centre for Food Safety
On 13 March 2014, the Ministry of Health of Guinea notified the World Health Organization (WHO) of a rapidly evolving outbreak of Ebola virus disease (EVD) in forested areas of south eastern Guinea. The disease has since then spread to other parts of West Africa, causing illnesses and deaths in affected countries. Given the fact that Ebola viruses have previously been detected in animals, there are concerns over the risk of transmission of EVD through animals and animal products to humans. This article aims to explore food safety issues associated with Ebola viruses.
Ebola viruses are a group of viruses that are capable of causing severe illness in human and certain species of animals. There are to date five known species of Ebola viruses and samples taken from the current outbreak in West Africa have been tested positive for a species called Zaire ebolavirus. Fruit bats are considered possible natural hosts for this virus which is believed to be introduced into human population through close contact with the blood, secretions, organs or other bodily fluids of infected wild animals. In Africa the initial cases most likely occurred during hunting, butchering and preparing meat from infected wild animals.
Geographic distribution of EVD outbreaks in human and animals, updated on 7 August 2014 (adapted from World Health Organization).
Ebola Virus Disease in Humans
EVD in humans is caused by infection of a pathogenic species of Ebola virus. It is a severe and often fatal illness in human. Signs and symptoms of EVD include sudden onset of fever, intense weakness, muscle pain, headache and sore throat, followed by vomiting, diarrhoea, rash, impaired kidney and liver function and sometimes internal and external bleeding. While the initial cases of EVD in the current outbreak are believed to be contracted by handling infected wild animals or carcasses, the majority of cases in humans have occurred as a result of human-to-human transmission through direct or indirect contact with the blood, secretions, organs or other bodily fluids of infected people.
Thus far, the Zaire ebolavirus that is responsible for the current EVD outbreak is not known to be endemic outside Africa. However, in the past, another species of Ebola virus known as Reston ebolavirus was detected in Asia in non-human primates and pigs.
Unlike Zaire ebolavirus, human infections with Reston ebolavirus have not been associated with EVD and so far all infected individuals did not develop clinical symptoms. Available evidence suggests that Reston ebolavirus is less capable of causing illness in humans when compared to other Ebola viruses such as Zaire ebolavirus.
Is It Safe to Consume Animal Products?
EVD is not generally transmitted by food. Thorough cooking of food products with core temperature reaching at least 70oC can inactivate Ebola virus. The WHO therefore advises that it is safe to consume food products that are properly prepared and cooked. However, it is important that general principles for good hygiene are observed when preparing raw meat and animal products. Hands should be washed thoroughly with soap before and after handling raw meat and other products of animal origin (e.g. offal, bones, blood etc.). Working surfaces, utensils and equipment that have been in contact with the above should also be cleaned thoroughly before and after use.
Actions Taken by the Centre for Food Safety
The Centre for Food Safety (CFS) will remain vigilant and continue to monitor for the latest development of the current EVD outbreak in Africa. Imported meat must be accompanied by a health certifi cate issued by the competent authority of the exporting country. On the other hand, live animals, including pigs, entering the local slaughterhouses are subject to stringent ante-mortem and post-mortem inspection and only meat from animals that have passed relevant inspections will be allowed to enter the food chain.
Key Points to Note
- EVD can be introduced into human population during hunting, butchering and preparing meat from infected wild animals.
- So far, outside Africa, there has been no report of cases of EVD in humans that is associated with the preparation or consumption of meat.
- It is safe to consume food products that are properly prepared and cooked as Ebola virus is inactivated by thorough cooking.
Advice to the Public
- Avoid contact with wild animals when travelling to the affected areas.
- Food of animal origin should be thoroughly cooked before consumption.
- Wash hands thoroughly with soap before and after handling raw meat and animal products. All working surfaces, utensils and equipment should also be cleaned before and after handling the above products.
Advice to the Trade
- Farm and slaughterhouse workers should wear appropriate personal protective equipment such as gloves, masks, boots and aprons. Proper hand washing should be practised.
- Unusual occurrence of herds with sick or dying pigs should be reported. Sick or dying pigs, including raw meat, blood and other bodily secretions should be handled and disposed of properly.
- IMeat from dead pigs or pigs that did not pass ante-mortem and postmortem inspection should not enter the food chain.