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Annex 6
Objective 6: Veterinary and Human Disease Risks
Contents
1. Hazard Identification & Characterisation
1.1 Livestock Diseases
1.2 Bacteria
1.3 Common Foodborne Bacteria
1.4 Other Bacteria
1.5 Viruses
1.6 Parasites
1.7 Prion Diseases
1.8 Mycotoxins
1.9 Heat Treatment
2. Disease Risk Assessment
References
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Table 1. Potential Food waste-borne Infectious Disease Agents of
Ruminants, Pigs and Poultry.
Table 2. Disease Risks from pathogens of Ruminants, Pigs and Poultry
contaminating Food waste.
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1.
Hazard Identification & Characterisation
Food waste containing meat or meat products can be a potential source of infection from a
range of bacteria (including antimicrobial-resistant strains which may also be able to transfer
resistance genes to new hosts) viruses, and parasites. Contaminated foods can also lead to
exposure to various toxins. Whilst prion diseases would also pose a serious risk from food
waste, there is stringent legislation in force requiring the removal and disposal of Specified
Risk Material (SRM) at the abattoir prior to entering the food chain. The feeding of food
waste to livestock has therefore been implicated as a means of international transmission of
major exotic livestock diseases, and of the spread of these diseases within infected
countries.
1.1 Livestock Diseases
Bacterial, viral and parasitic disease agents of livestock considered in the risk assessment
are listed in Table 1. As bacterial identification and classification are constantly changing, the
terminology used in this report will follow the classification based on the International Code
of Nomenclature of Bacteria system wherever possible. The system of virus classification
referred to throughout is that used by the Foodborne Viruses in Europe network (FBVE) joint
electronic database to (www.rivm.nl/bnwww) (Koopmans et al., 2003). For parasites the
system of classification is that used by standard parasitological texts (Taylor Coop and Wall
2007). Many of the listed agents are also zoonotic.
1.2 Bacteria
Many bacteria can cause foodborne illness in humans and disease in animals. In the UK,
Campylobacter, Salmonella, Escherichia coli and Clostridium are the commonest bacterial
causes of foodborne infection in humans. In addition to disease caused by direct bacterial
infection, some foodborne illnesses are caused by exotoxins which are excreted as the
bacteria grow, and they can cause illness even when the microbes that produced them have
been killed.
1.3 Common Foodborne Bacteria
Campylobacter jejuni is recognized as one of the main causes of bacterial foodborne
disease in humans in many countries, with poultry an important source of infection (Hermans
et al 2012). While C. jejuni is the commonest species found in poultry it is not considered to
be pathogenic in poultry, unless co-infections with other pathogenic organisms are present.
C. coli frequently infects pigs (Thakur and Gebreyes, 2005), and can cause foodborne
disease in humans (Humphrey et al., 2007). C. fetus is a cause of spontaneous abortions in
cattle and sheep, as well as an opportunistic pathogen in humans. The common route of
transmission is by the ingestion of contaminated food or water, and the eating of raw meat,
particularly poultry in humans. Infection in calves produces diarrhoea, sometimes bloody,
mainly in young animals.
Salmonella infections are zoonotic and can be transferred between humans and animals.
Current nomenclature suggests that Salmonella consists of two species - S. enterica and
S. bongori, with six subspecies; however, traditional nomenclature is still commonly used by
specialists in microbiology. Many infections are due to ingestion of contaminated food. Thus
food is an important infection route for enteritic Salmonella including those that are resistant
to antimicrobials (European Food Safety Authority, 2006). Antimicrobial-resistant Salmonella
causing foodborne human disease are well documented. Implicated foods are typically beef,
pork, poultry, dairy products, but also eggs and fresh produce.
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Virulent strains of Escherichia coli (enteropathogenic [EPEC], enterohaemorrhagic [EHEC]
and enterotoxigenic [ETEC] strains) can cause gastroenteritis, urinary tract infections, and
neonatal meningitis. Infections with multi-resistant E. coli are an important public health
problem. Transmission of pathogenic E. coli often occurs via the faecal-oral route. Common
routes of transmission include unhygienic food preparation, and a range of food products
have been associated with E. coli outbreaks. Dairy and beef cattle are primary reservoirs of
E. coli O157:H7 and can carry it asymptomatically and shed it in their faeces. Enteric
colibacillosis is a common disease of young calves and piglets caused by colonisation of the
small intestine by enterotoxigenic strains of E. coli.
Clostridia are a group of obligate anaerobic bacteria consisting of around 100 species that
include common free-living bacteria as well as important pathogens in animals and humans.
Clostridia are motile bacteria that are ubiquitous in nature and are especially prevalent in soil
and decomposing plant material. Some species are normal inhabitants of the intestines and,
after the death of the animal, rapidly invade the blood and tissues playing a major role in
decomposition of the carcass. Pathogenic clostridia affecting cattle and sheep have been
divided into three main groups. Neurotrophic clostridia include C. tetani and C. botulinum,
which produce powerful neurotoxins giving rise to the diseases tetanus and botulism
respectively. Histotoxic clostridia produce exotoxins that cause local tissue necrosis and
systemic toxaemia. Examples include C. chauvoei, the major cause of blackleg; C. novyi
type B, which causes black disease; C. septicum which causes malignant oedema and
braxy; C. haemolyticum (C. novyi type D), which causes bacillary haemaglobinuria; and
C. sordelli which causes gas gangrene. Enterotoxic clostridia include C. perfringens type D,
which causes pulpy kidney disease; C. perfringens type C, which causes struck; and
C. perfringens type B, which causes lamb dysentery.
C. difficile is a commensal bacterium of the human intestine but has become increasingly
important as a cause of antibiotic-associated diarrhoea in humans. Foodborne transmission
of C. difficile has been suggested as a possible source of human infections, but evidence to
confirm this is incomplete.
Listeria are Gram-positive, non-spore forming bacteria, which can be often be found in the
environment of farms (Nightingale et al., 2004) and food processing plants (Chasseignaux et
al., 2002). There are several species, most of which cause opportunistic infections in
humans. The most significant pathogen is L. monocytogenes. Infection by this agent can
cause several symptoms including meningitis and endocarditis, and complications of
pregnancy (Farber and Peterkin, 1991) L. monocytogenes has been isolated from cattle,
sheep, goats and poultry (Gray and Killinger, 1961). A survey performed in the UK in 2003 of
2981 samples of modified-atmosphere-packed and vacuum-packed cooked ready-to-eat
meats sold at retail found that 1 % contained L. monocytogenes at levels >102 cfu per gram
(Sagoo et al., 2007), and a later UK survey of speciality meats sold at retail found several
samples containing similar levels (Gormley et al., 2010).
1.4 Other Bacteria
A range of other bacteria found in livestock have the potential for foodborne transmission
and are summarised in Table 1.
The spore-forming bacterium Bacillus anthracis, the causative agent of anthrax, commonly
infects wild and domesticated herbivorous mammals. The disease is endemic but sporadic in
the UK and can be spread by consumption of contaminated meat and meat products.
Anthrax spores can survive for very long periods of time in the environment.
Bacillus cereus is a facultative anaerobic bacterium associated with food poisoning in
humans. The food poisoning is a result of ingesting heat-stable enterotoxins produced by the
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bacterium. B. cereus is widespread in the soil and can contaminate such foods as herbs,
spices, milk and vegetables. Spores of this organism are heat-resistant and can survive
cooking, and a broad range of cooked or processed foods have been associated with
infection including vegetables and meats, boiled or fried rice, soups, ice cream, herbs and
spices.
Methicillin-resistant S. aureus (MRSA) is recognised as a zoonotic agent following detection
in various companion and food-producing animals, including horses, dogs, cats, pigs, cattle,
chickens, rabbits and birds. A particular MRSA strain (NT “non-typeable”) has increasingly
been isolated from pigs and pig farmers. A recent Dutch study showed that MRSA can be
detected at very low concentrations (<10 cfu/g) in unheated meats from various domestic
animals and poultry (de Boer et al., 2009). A UK study conducted between 2006 and 2007
(Food Standards Agency Report B18018) indicated that approximately 8 % of red meat
produced and sold at retail in the UK was contaminated with S. aureus; no information is
available on whether these harboured antibiotic resistance determinants however. Another
UK study found MRSA in bulk milk (Garcia-Alvarez et al., 2011).
Mycobacterium bovis is a slow-growing, aerobic bacterium and the causative agent of
tuberculosis in cattle (bovine TB). M. bovis may be transmitted to humans via infected milk,
although it can also spread via aerosol droplets. Human infections are rare, mostly due to
pasteurisation killing any bacteria in infected milk. Cattle are randomly tested for the disease
and immediately culled if infected, and depending on the lesions found at meat inspection,
the whole carcase is either condemned, or an infected organ or part of the carcase declared
unfit for human consumption.
Mycobacterium avium subsp. paratuberculosis is the aetiological agent of ruminant
paratuberculosis, commonly referred to as Johne’s disease. The disease is characterised by
a chronic granulomatous ileocolitis that ultimately terminates in diarrhoea, weight loss,
debilitation, and death. In recent years, there has been an interest in the possible
association of paratuberculosis and human Crohn’s disease. M. avium subsp.
paratuberculosis may also enter the milk by faecal contamination and is more thermotolerant than Mycobacterium bovis and may still remain viable following pasteurisation.
1.5 Viruses
There are a number of viruses that are foodborne, or have the potential to be foodborne to
humans and also be transmitted to animals. Viral infections are common causes of food
poisoning in humans in developed countries. Several major economically important disease
outbreaks in livestock, notably Foot and Mouth Disease and Classical Swine Fever, have
occurred by feeding food waste containing meat or meat products. The UK operates strict
controls over the import of meat and meat products primarily to guard against the
introduction of animal diseases. A ban on swill feeding introduced in May 2001 (now
included in the Animal By-Products Regulations) was also put into place following the
outbreak of FMD in the UK in 2001.
Foot and Mouth Disease (FMD) is an acute infectious disease, causing fever, followed by
the development of blisters, chiefly in the mouth and feet cloven-hoofed animals, in particular
cattle, sheep, pigs, goats and deer, although other ruminants including deer and camelids
can also be affected.
Swine Vesicular Disease, which first occurred in the UK in 1972, has identical symptoms to
Foot and Mouth disease. SVD is an acute, contagious viral disease characterized by fever
and vesicles with subsequent ulcers in the mouth and on the snout, feet, and teats. The
pathogen is relatively resistant to heat, and can persist for a long time in salted, dried, and
smoked meat products. The disease can be introduced into a pig herd by feeding food waste
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containing infected meat scraps, by bringing in infected animals, or by direct contact with
infected faeces.
Classical swine fever (CSF) is a highly contagious disease of pigs and wild boar. CSF is
primarily spread by direct contact or by contact with fomites contaminated with virus. CSF
virus can survive in meat and pig products for many months.
African swine fever (ASF) is a serious viral disease of pigs, endemic in Africa. The African
swine fever virus (ASFV) is highly contagious, and can spread very rapidly in pig populations
by direct or indirect contact.
In poultry several economically important diseases have the potential for foodborne
transmission. Newcastle disease (ND) is a contagious disease affecting many domestic and
wild avian species. Its effects are most notable in domestic poultry due to their high
susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It
is endemic to many countries but is absent from the UK. ND is spread primarily through
direct contact between healthy birds and the bodily discharges of infected birds. NDV can
survive for several weeks on birds' feathers, manure, and other materials and can survive
indefinitely in frozen material.
Avian influenza (avian flu or bird flu) refers to influenza caused by viruses adapted to birds.
Of the greatest concern is highly pathogenic avian influenza (HPAI). All known viruses that
cause influenza in birds belong to the Influenzavirus A genus. All subtypes (but not all strains
of all subtypes) of influenza A virus are adapted to birds, although some subtypes are
adapted to multiple hosts such that subtypes H7N7 and H5N1 are able to infect humans
(Koopmans et al., 2004; Yuen et al., 1998).
The highly pathogenic influenza A virus subtype H5N1 is an emerging avian influenza virus
that has been causing global concern as a potential pandemic threat. H5N1 has killed
millions of poultry in a growing number of countries throughout Asia, Europe and Africa.
Most human infections with avian flu are a result of either handling dead infected birds or
from contact with infected fluids. Infectious H5N1 avian influenza virus has been grown from
duck meat and the consumption of duck blood has resulted in the infection of humans
(Tumpe et al., 2002). This has raised the question if foodborne introduction could be one of
the routes by which new viral diseases can enter the human population, although to date
there is no evidence that the AI viruses can be transmitted through poultry products or eggs
(http://www.efsa.europa.eu/en/topics/topic/avianflu.htm).
There exists a range of endemic viruses that could potentially spread through the feeding of
unprocessed food waste. These are also listed in Table 1, and associated risks are
summarised in Table 2.
Rotaviruses infect a variety of animals, including cattle, pigs, sheep, horses, chickens, dogs
and cats and there is evidence for zoonotic transmission (Cook et al., 2004). There are a
number of various rotavirus antigenic groups (A-G) and serotypes. In calves for example,
Group A rotaviruses are the most prevalent in many countries including the UK and are
commonly associated with neonatal calf diarrhoea (Bezek 1994). There are few reported
outbreaks of foodborne gastroenteritis due to rotaviruses, although it is likely that
contamination of foodstuffs can occur.
Hepatitis E virus causes disease in humans and is widespread in Southeast Asia, northern
and central Africa, India, and Central America. Reported symptomatic infection is uncommon
in the UK and has generally been attributed to acquisition during foreign travel (Sadler et al.
2006), although it is likely that autochthonous infection does occur (Dalton et al., 2008). It is
spread mainly through faecal contamination of water and by food. Domestic animals have
been reported as a reservoir for the hepatitis E virus, with some surveys showing infection
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rates exceeding 95% among domestic pigs. Transmission after consumption of wild boar
meat and uncooked deer meat has been reported. A link between human hepatitis E cases
and hepatitis E virus (HEV) in pig livers, possibly through foodborne transmission of HEV
has been suggested (Wichman et al., 2008). HEV has been found in pig populations and in
commercial pig livers in several countries; other possible food sources include shellfish
(bivalved molluscs). A recent study found HEV in pork sausages sold at retail in the UK
(Berto et al., 2012). For taste and other sensory reasons, inadequately cooked pig livers are
preferred by some consumers, but the heat treatment thus applied may not be sufficient to
inactivate hepatitis E virus. To prevent hepatitis E, food trade and consumers need to cook
food thoroughly. Thus for example, with sliced pig liver, depending on thickness and
quantity, there is a need to boil at 100°C or stir-fry in hot skillet/wok for at least three to five
minutes. Heating to an internal temperature of 90°C for 90 seconds is required for cooking of
molluscan shellfish; hence, boil at 100°C until their shells open; boil for additional three to
five minutes afterwards. In addition, food trade and consumers are also advised to observe
good personal and food hygiene practices. Consumers could ask for thoroughly cooked food
when eating out; this is particularly important for high risk populations such as the elderly or
pregnant women.
1.6 Parasites
Many types of parasites are foodborne, and humans can become infected following the
ingestion of infected or contaminated meat, fish, molluscs, vegetables, fruit, or products
derived from these foods. In most cases, parasitic infections are acquired by eating raw or
incompletely cooked food, or food that is or poorly preserved. Most, if not all, infections are
preventable if the food is cooked sufficiently to destroy the infective stages of the parasite.
Meat from many species of animals has been a recognized source of many zoonotic
helminth infections but few are likely to pose a risk from recycled food as they will have been
identified and removed during meat inspection. A number of foodborne helminth infections
have been reported worldwide but have not been recorded in the UK.
Tapeworm cysts (Taenia and Echinococcus species) are found on occasions and will be
removed at meat inspection and as such should not have entered the food chain. Illegally
imported food, especially bush meat, which has the potential to carry viable cysts, is only
potentially infective to the final host (humans or carnivores) and not to livestock. The
possible exception is with Trichinella, where there is a risk from imported meats or meat
products, particularly pork, or other pig products such as sausages.
Whilst not occurring in the UK, there are a range of other helminth parasites that are
foodborne and found throughout the world. The majority of these infections are commonly
associated with cultural and eating habits and occur following the ingestion of infected or
contaminated meat, fish, molluscs, vegetables, or fruit, or products derived from these foods.
In most cases, parasitic infections are acquired by eating raw or incompletely cooked food,
or food that is partially pickled or smoked or poorly preserved. Most, if not all, infections are
preventable if the food is prepared sufficiently to destroy the infective stages of the parasite.
There are a number of foodborne protozoal infections that pose a potential risk. Infections
with Cryptosporidium species are a significant cause of diarrhoea in humans and also in
domesticated animals. Transmission is via a resistant oocyst stage, usually through faecal
contamination of water or food, or by direct contact. In humans, foodborne transmission of
cryptosporidiosis has been reported following the consumption of certain foods, notably raw
sausage, offal, chicken salad, and milk. Evidence suggests that untreated milk, undercooked
sausage meat, and offal have been implicated in outbreaks, but heat treatments such as
those used for the pasteurization of foods are likely to destroy the oocysts. Toxoplasma
gondii has worldwide distribution and differs from other coccidian protozoa in that it shows a
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complete lack of host specificity. Foodborne transmission by the ingestion of tissue cysts in
raw or undercooked meat from a variety of livestock and game animals has been well
documented as a major source of human infection. Adequate cooking kills the organism, and
all meat should be cooked thoroughly before eating. Infections with Cyclospora cayetanensis
in man can cause protracted diarrhoea with nausea, and vomiting. Food outbreaks have only
been associated with eating fresh fruit.
Giardia duodenalis is a major cause of diarrheal disease. It can be zoonotic, being found in a
variety of animal species, including cattle and sheep (Smith et al., 2007). Transmission is via
a resistant cyst stage, and the median infectious dose is between 25 and 100 cysts
(Rendtorff, 1979). It can contaminate foods via handling by infected persons, and fresh
produce can be contaminated at source through irrigation with sewage-contaminated water,
or contact with infected animals or their manure (Cook and Lim, 2012). Several outbreaks of
giardiasis transmitted by consumption of foods including tripe, salmon and vegetables have
been described (Smith et al. 2007).
1.7
Prion Diseases
Prions are proteinaceous transmissible agents that cause abnormal folding of certain brain
proteins resulting in brain damage and death (Collins et al. 2004). This is in contrast to all
other known infectious agents, which must contain nucleic acids (either DNA, RNA, or both).
All known mammalian prion diseases (transmissible spongiform encephalopathies) are
caused by the prion protein, PrP and include scrapie, bovine spongiform encephalopathy
(BSE), chronic wasting disease (CWD), and Creutzfeldt-Jakob disease (CJD) in humans.
(Belay and Schonberger 2005). Although BSE and CJD are not directly related, a variant of
CJD, vCJD appears to be caused by the same agent as BSE. Current research suggests
that the primary method of infection in animals is through ingestion and that prions may be
deposited in the environment through the remains of dead animals and via urine, saliva, and
manure (Gough and Maddison 2010). The UK BSE epidemic was thought to be caused by
cattle being fed the remains of other cattle in the form of meat and bone meal (MBM), which
caused the infectious agent to spread. The cause of BSE is thought to have been caused
through the contamination of MBM from sheep with scrapie that were processed in the same
slaughterhouse and probably accelerated by the recycling of infected bovine tissues prior to
the recognition of BSE. A ban on feeding cattle meat and bone meal to cattle resulted in a
significant reduction in cases in the UK. At the abattoir, the brain, spinal cord, trigeminal
ganglia, intestines, eyes and tonsils from cows are classified as Specified Risk Material
(SRM) and must be disposed of appropriately. Continuing control relies on import control,
feeding regulations and surveillance measures.
1.8 Mycotoxins
Mycotoxins are toxic secondary metabolites produced by fungii or moulds that readily
colonise crops. Mycotoxins can appear in the food chain as a result of fungal infection of
crops, either by being eaten directly by humans or by being used as livestock feed.
Mycotoxins greatly resist decomposition or being broken down in digestion, so they remain
in the food chain in meat and dairy products and cooking and freezing do not destroy them.
Aflatoxins are a type of mycotoxin produced by Aspergillus species. Four different types of
aflatoxins are produced, which are B1, B2, G1, and G2. Aflatoxin B1, the most toxic, is a
potent carcinogen and has been directly correlated to adverse health effects, such as liver
cancer, in many animal species. Aflatoxins are largely associated with commodities
produced in the tropics and subtropics, such as cotton, peanuts, spices, pistachios and
maize.
Ochratoxins are produced by Penicillium and Aspergillus species. Aspergillus ochraceus is
found as a contaminant of a wide range of commodities including beverages such as beer
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and wine. Ochratoxin A is relatively thermostable and is not destroyed by most food
processes. It can also pass through the food chain and may be found in meat products,
especially pork.
Citrinin is a mycotoxin originally isolated from Penicillium citrinum, but has been found to be
produced by a variety of other fungi which are found or used in the production of human
foods, such as grain, cheese, sake and red pigments.
Patulin is a toxin produced by a number of fungal species associated with a range of mouldy
fruits and vegetables, in particular rotting apples and figs.
Fusarium toxins are produced by over 50 species of Fusarium and infect the grain of
developing cereals such as wheat and maize. They include a range of mycotoxins, such as:
the fumonisins, which affect the nervous systems of horses; the trichothecenes, which are
strongly associated with chronic and fatal toxic effects in animals and humans. Fumonisins
are relatively stable to elevated temperatures, and survive a range of cooking processes.
1.9 Heat Treatment
Heat treatment is generally lethal to microorganisms, but each species has its own particular
heat tolerance. During pasteurisation for example, the rate of bacterial destruction is
logarithmic, and bacteria are killed at a rate that is proportional to the number of organisms
present. The process is dependent both on the temperature of exposure and the time
required at this temperature to accomplish the desired rate of destruction. Thermal
calculations thus involve knowledge of the concentration of microorganisms to be destroyed,
the thermal resistance of the target microorganisms, and the temperature time relationship
required for destruction of the target organisms. Cooking is the usual way of destroying
microbes in food, although the process is neither uniform nor instantaneous. Some
microorganisms are more heat-resistant and survive cooking, so as a consequence more
stringent time and temperature combinations are required.
Several parameters are used in thermal calculations and define the rate of thermal lethality.
1.
The Thermal Death Time (TDT) is the time needed to kill a given number of organisms
at a specified temperature.
2.
Thermal Death Point (TDP) is defined as the temperature needed to kill a given
number of microorganisms in a fixed time – usually 10 minutes.
3.
The D-value (Decimal Reduction Time) is the time required to destroy 90 % of the
organisms and is a measure of the heat resistance of a microorganism. It is the time in
minutes at a given temperature required to destroy 1 log cycle (90%) of the target
microorganism.
4.
The z-value is the number of degrees (oC or oF) required to change the D value by a
factor of ten; z values thus provide information on the destruction rate at different
temperatures, allowing for the calculation of equivalent thermal processes at different
temperatures.
These thermal destruction parameters assume that the effects of heat on microorganisms
are constant and unaffected by the heating rate in the sub-lethal temperature range. Grampositive bacteria tend to be more heat resistant than Gram-negative bacteria; yeasts and
moulds tend to be fairly heat sensitive as are parasites. Compared to bacteria, foodborne
viruses are generally more resistant to heat. In addition, persistence of the viruses may be
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different in different food substrates, e.g. hepatitis A virus in bivalve molluscs needs more
stringent conditions than the virus in milk for the same level of inactivation. The effects of
temperature on the range of microorganisms considered in this risk assessment are shown
in Table 2. Wherever possible, D-values are provided for comparison but for a number of
organisms, specific heat inactivation data are not available and requires further research.
2.
Disease Risk Assessment
A number of pathogenic viruses, bacteria, and parasites are foodborne, or have the potential
to be transmitted via food to both livestock and humans. As part of the risk assessment,
hazard identification was conducted for those pathogens that may constitute a hazard in
food waste and can infect humans and livestock. The complete lists of diseases considered
in the risk assessment are provided in Table 1. These represent either diseases endemic to
the UK, notifiable, or exotic diseases considered to be zoonotic or of economic importance.
Meat products originating from the UK or from within the EU , which have entered the food
chain and been through the appropriate inspection processes, should in theory present little
additional risk if re-fed as food waste to animals unless cross-contamination with other
foodstuffs or spoiling through poor storage occurs. The greatest risk is through illegally
imported meats, and meat products, which could potentially cause outbreaks of exotic
animal diseases.
The majority of disease agents are sensitive to temperature and are killed at the higher
temperatures that occur during cooking. For many of the identified bacteria, the vegetative
forms are killed rapidly at boiling point (100oC). Bacterial spores are common contaminants
of food products, and may cause food spoilage or food-borne illness. They are extremely
resistant to heat and other preservation treatments in comparison to vegetative cells. The
inactivation of spores requires high temperatures and long heating times. Anthrax bacteria,
for example, are killed at 92-100oC for 2 hours but the spores are killed at higher
temperatures of 140oC for 30 minutes or at 160oC for 8 minutes.
Spores of Bacillus cereus are also heat-resistant and can survive cooking. B. cereus also
produces toxins and foods contaminated with the emetic toxin produced by these bacteria
need to be heated to (126oC) for more than 90 minutes to destroy the toxin.
Species of clostridia produce a range of toxins including neurotoxins (C. tetani and
C. botulinum); exotoxins (C. chauvoei, C. novyi, C. haemolyticum and C. sordelli) and
enterotoxins (C. perfringens, C. difficile). Spores and toxins exhibit varying degrees of heat
resistance.
A study conducted by the VLA to assess the thermo-stabilities of viruses during composting
indicated that parvoviruses (bovine parvovirus (BPV) and porcine parvovirus (PCV)) appear
to be the most resistant to heat at 56oC, 60oC and 70oC respectively when considering a 3log reduction and were the most appropriate markers for ensuring that this reduction can be
achieved for viral hazards potentially present in Category 3 ABPs (this conclusion may also
be applicable to food waste). The study looked at published decimal reduction times (DRT
or D-values), for 20 viruses (adenovirus, astrovirus, avian circoviruses, avian parvovirus blue
tongue virus, bovine parvovirus, bovine rotavirus, canine parvovirus, feline calicivirus, foot
and mouth disease virus, Hepatitis E virus, infectious bursal disease virus, infectious
pancreatic necrosis virus, other calciviruses, other circoviruses, porcine circovirus type 2,
porcine parvovirus, rabbit haemorrhagic disease virus, and swine vesicular disease virus)
(Defra project SE4401 2011), many of which have been included in this risk-assessment.
All parasites are destroyed by adequate cooking at temperatures >60oC and should present
little risk to re-cycled food when processed correctly.
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Transmissible spongiform encephalopathies (Scrapie, BSE, CJD, v-CJD, CWD) are highly
resistant to heat and chemical inactivation. In the UK, specified risk materials (SRM) from
cattle and sheep do not enter the food chain and are currently disposed of by incineration. It
is assumed in this risk assessment that this situation will continue and therefore there should
be no additional risk to the feeding of food waste containing meat products to livestock.
Food waste has been fed to domestic animals particularly pigs and poultry, whilst
historically, ruminants have been fed meat and bone meal produced from rendered
carcasses. The feeding of food waste to pigs is a traditional practice that is still carried out in
a number of countries. For example, in New Zealand, legislation requires that any waste
containing meat is cooked (100°C for 1 hour). This was the situation in Britain, where swill
feeding to pigs was controlled under the Food waste Order 1973, and the subsequent
Animal By-Products Order 1999 and its amendments. However, following the outbreak of
Foot and Mouth Disease in 2001, the Government prohibited the feeding of catering waste to
animals that contained, or had been in contact with animal by-products. This restriction was
subsequently reflected by the EU Animal By-Products Regulation and became mandatory in
all Member States. Feeding catering waste to farmed livestock is currently not permitted.
The Spongiform and Encephalopathy Advisory Committee (SEAC) also recommended that
all intra-species recycling should be avoided to prevent the risk of a TSE being spread
through recycling in animal feed. These restrictions, amongst others, are implemented under
the previous (EC No 1774/2002), and the newly revised (EC No 1069/2009), Animal ByProducts Regulations.
If conducted according to prescribed guidelines and stringent supervision and enforcement,
then heat-treatment at 100oC for 1 hour is adequate to destroy identified endemic pathogens
in the low risk category (Table 2). These organisms have been considered low risk because
thermal-inactivation data indicates that a 6-log10 or greater reduction in their numbers would
be obtained by this treatment.
Agents in the low to medium-risk category include those spore -forming bacteria (e.g. B.
anthracis) which thermal inactivation data indicates that a 6- log10 or greater reduction in their
numbers would be obtained by cooking contaminated foods at 100oC for 1 hour, but their
ability to form spores confers a higher potential for heat resistance than those agents in the
low risk category. Also included in this category are FMDV and SVD, which may not be
inactivated if they are located within bone tissue.
Diseases in the medium to high risk category (Table 2) comprise spore -forming bacteria
(e.g. C. botulinum) where insufficient information may be available to determine if cooking at
100oC for 1 hour will reduce their numbers in contaminated foods by 6 log10.
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15
Table 1. Potential Food waste-borne Infectious Disease Agents of Ruminants, Pigs and Poultry.
Group
Family
Genus
Bacillaceae
Bacillus
Brucellaceae
Brucella
Species
anthracis
cereus
melitensis
abortus
ovis
suis
jejuni
Campylobacteraceae
Campylobacter
fetus
chauvoei
novyi
Bacteria
Clostridiaceae
Enterobacteriacae
Clostridium
haemolyticum (novyi D)
septicum
Escherichia
sordelli
botulinum
tetani
coli
Salmonella
enterica
Disease
Anthrax in ruminants
Enterotoxin -producing bacteria causing foodpoisoning
All species cause zoonotic brucellosis.
B. melitensis infects goats and sheep;
B. abortus which infects cattle; B. suis infects
pigs and B. ovis infects sheep. All species
cause abortion in their respective hosts.
Main cause of foodborne gastroenteritis and
pathogen in poultry
Abortion in cattle and sheep
Blackleg in cattle and sheep
Type B causes black disease in cattle and
sheep
Bacillary haemogobinuria in cattle and sheep
Malignant oedema in cattle and sheep, and
braxy in sheep
Gas gangrene
Botulism
Tetanus
Enterotoxigenic strains (O157:H7) cause
gastroenteritis, nephritis, meningitis etc.
Cattle are reservoirs; contamination risks.
Many serovars. Includes subspecies
Typhimurium found mainly in cattle and
Enteridis in poultry, Serovar paratyphi
(Paratyphoid) includes S. pullorum in poultry.
16
Group
Family
Genus
Mycobacteriaceae
Mycobacterium
Species
bovis
Avium Subsp.
paratuberculosis
pyogenes
Staphylococcus
Staphylococcaceae
Bacteria
agalactiae
suis
pneumoniae
Enterococcus
durans
Listeriaceae
Listeria
monocytogenes
Spirochaetaceae
Vibrionaceae
Brachyspira
Vibrio
hyodysenteriae
cholerae
Erysipelotricidae
Erysipelothrix
rhusiopathiae
Staphylococcaceae
Staphylococcus
aureus
Disease
Important cause of bovine TB and transmitted
to humans through milk.
Found mostly in birds causing avian TB but
occasionally also in other animals and in
humans
Cause of Johne’s disease in cattle. Link to
Crohn’s disease in humans
β haemolytic group causing endocarditis in
pigs
β haemolytic group causing mastitis in cattle
Significant zoonosis found in pigs and other
domestic animals
Also known as Pneumococcus an important
cause of meningitis in humans. Infects calves
and cattle and a cause of mastitis.
ϒ-haemolytic group causing diarrhoea in pigs.
Reservoir of vancomysin-resistance.
Virulent foodborne pathogen and causes
meningo-encephalitis in ruminants
Cause of swine dysentery
Cause of cholera associated with
contaminated water. Other species
associated with shellfish.
Causes erysipelas in animals and erysipeloid
in humans
Range of illnesses from abscesses to
pneumonia, meningitis, endocarditis,
bacteraemia, and sepsis. MRSA is a zoonotic
issue and has been detected in food
producing animals including an NT strain in
pigs.
17
Group
Family
Asfaviridae
Genus
Asfivirus
Arteriviridae
Arterivirus
Caliciviridae
Vesivirus
Species
African Swine Fever
(ASF) Virus
Porcine Reproductive
and Respiratory
Syndrome (PRRS)
Virus
Vesicular exanthema
virus
Circovirus
Porcine Multisystemic
Wasting Syndrome
(PMWS) Virus
Gyrovirus
Chicken Anaemia (CA)
Virus
Viruses
Circoviridae
Coronoviridae
Coronovirus
Severe Acute
Respiratory Syndrome
SARS) Virus
Transmissible
Gastroenteritis (TGE)
Virus
Disease
Causes a haemorrhagic fever with high
mortality rates in pigs.
Causes PPRS, a highly contagious viral
disease leading to reproductive failure,
respiratory tract illness in young pigs and
cyanosis (blue ear pig disease).
Produces disease clinically indistinguishable
from FMD and SVD. Thought to have arisen
from feeding uncooked waste sea food to
pigs.
Porcine circovirus type 2 causing illness in
piglets, loss of body condition, enlarged
lymph nodes, dyspnoea, diarrhoea and
jaundice.
Causes Infectious Chicken Anaemia with
bone marrow atrophy and severe
immunosuppression in young chicks.
Zoonotic disease (SARS) in humans linked to
Chinese markets and bushmeat.
Highly infectious disease in pigs (TGE)
causing vomiting and diarrhoea.
18
Group
Family
Genus
Flaviviridae
Pestivirus
Species
Bovine Viral Diarrhoea
(BVD) Virus
Border Disease (BD)
Virus
Classical Swine Fever
(CSF) Virus
Hepeviridae
Herpesviridae
Viruses
Hepevirus
Hepatitis E Virus
Varicellovirus
Suid herpesvirus 1
(Pseudorabies virus)
Lltovirus
Gallid herpesvirus 1
(Avian herpesvirus 1)
Influenzavirus A
Orthomyxoviridae
Influenzavirus C
Avulavirus
Highly Pathogenic
Avian Influenza (HPAI)
Virus
Swine Influenza Virus
Swine Influenza (SI)
Virus
Newcastle Disease
(ND) Virus
Paramyxoviridae
Henipavirus
Nipah Virus
Disease
Common in cattle and a cause of respiratory
disease and acute enteric disorders (BVD or
Mucosal Disease)
Congenital disorder of lambs characterized
by low viability, poor conformation, tremor,
and an excessively hairy birth coat
Highly contagious disease of pigs and wild
boar causing fever, skin lesions, convulsions
and death
Human infection but found in pigs with
reported foodborne transmission from eating
uncooked wild boar meat
Causes Aujesky’s Disease (Pseudorabies)
which may lead to abortion and high mortality
in piglets
Infection causes inflammation of the trachea
and larynx (Avian infectious laryngotracheitis
)
Avian influenza viruses adapted to birds but
includes important subtypes (e.g. H7N7 and
H5N1) able to infect humans
Swine flu leading to respiratory disease and
infertility caused by various subtypes (H1N1,
H1N2, H2N1, H3N1, H3N2, and H2N3)
Also linked to swine flu
Several strains causing Newcastle disease,
which is a highly contagious bird disease
affecting many domestic and wild avian
species.
Bat virus highly contagious in pigs causing
respiratory symptoms
19
Group
Family
Genus
Parvoviridae
Parvovirus
Apthovirus
Species
Porcine Parvovirus
(Porcine Enterovirus)
Bovine Parvovirus
Foot and Mouth
Disease Virus
Swine Vesicular
Disease Virus
Picorniviridae
Enterovirus
Viruses
Porcine Enterovirus
Orbivirus
Bluetongue Virus
Rotavirus
Bovine Rotavirus
Ovine Rotavirus
Porcine Rotavirus
Avian Rotavirus
Vesicular stomatitis
virus
Reoviridae
Rhabdoviridae
Vesiculovirus
Disease
With porcine enterovirus causes SMEDI
(stillbirth, mummification, embryonic death
and infertility) in pigs
Neonatal diarrhoea
Foot and mouth disease (FMD) is an acute
infectious disease, causing fever, followed by
the development of blisters, chiefly in the
mouth and feet cloven-hoofed animals, in
particular cattle, sheep, pigs, goats, deer
Causes swine vesicular disease (SVD),
which is an acute, contagious viral disease of
pigs characterized by fever and vesicles with
subsequent ulcers in the mouth and on the
snout, feet, and teats.
With porcine parvovirus causes SMEDI
(stillbirth, mummification, embryonic death
and infertility) in pigs
Bluetongue disease or catarrhal fever is a
non-contagious, non-zoonotic, insect-borne,
viral disease of ruminants, mainly sheep and
less frequently cattle, goats and other
ruminants.
Rotaviruses infect many species of animals
and humans causing diarrhoea notably in
young neonates. Zoonotic transmission may
occur.
Vector-borne, zoonotic diseases with clinical
symptoms identical to FMD - vesicles in the
mouth and on the coronary band.
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Group
Family
Genus
Nematodes
Trichinellidae
Trichinella
Species
spiralis
nativa
britovi
saginata
Cestodes
Taeniidae
Taenia
solium
parvum
Cryptosporidiidae
Cryptosporidium
hominis
suis
baileyi
meleagridis
Eimeriidae
Protozoa
Cyclospora
Sarcocystis
cayetanensis
Spp.
gondii
Sarcocystiidae
Toxoplasma
Giardiidae
Giardia
duodenalis
Disease
Encapsulated clade or group of species infecting
a wide range of animals including humans.
Asymptomatic in animals. Human infection with
T. spiralis often through ingestion of
undercooked pork or game meats.
Generally asymptomatic human tapeworm with
intermediate host cattle. Metacestodes present
in meat and viscera of infected cattle.
Generally asymptomatic human tapeworm with
intermediate host pigs. Metacestodes present in
meat and viscera of infected pigs.
Diarrhoea in neonatal ruminants and pigs.
Important zoonosis causing diarrhoea in
humans.
Human species causing diarrhoea in humans
but can infect ruminants.
Generally asymptomatic
Respiratory disease in chickens
Diarrhoea in turkeys
Infections can cause protracted diarrhoea, and
vomiting in humans. Food outbreaks have only
been associated with eating fruit or salads.
Infection usually asymptomatic but can
occasionally cause severe symptoms in infected
animals and occasionally humans. Large
number of species with a complex life cycle
involving intermediate hosts (ruminants, pigs
etc.) and final carnivore hosts (dogs, cats,
humans etc)
Infects all warm blooded animals; important
zoonosis and cause of abortion in sheep.
Affects humans causing diarrhoea; also a variety
of animal species including cattle and sheep
where infections are often asymptomatic
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Table 2. Disease Risks from pathogens of Ruminants, Pigs and Poultry contaminating Food waste.
Genus
Species
anthracis
Bacillus
Risk*
Category
(H/M/L/ U)
L-M
cereus
L-M
melitensis
abortus
U
L
ovis
suis
jejuni
fetus
L
L
L
L
Details
References
Bacteria are killed at 92-100oC for 2 hours and spores are killed
at 140oC for 30 minutes or at 160oC for 8 minutes. Boiling at
100oC or dry heat at 150oC for 10 minutes kills spores.
D-value of spores in milk (2% fat) at 80, 85, and 90oC s were
30.09, 9.30, and 3.86 min, respectively
In skim milk, log CFU per ml reductions for B. anthracis spores
were 0.45 after 90 min at 72 oC, 0.39 after 90 min at 78 oC, and
8.10 after 60 min at 100 oC.
D-values were in the range of 3.45 min at 60o C to 10.6 min at
56oC in saline. The z-values recorded ranged from 9.3 oC in
culture broth to 24o C in whole milk. The inactivation pattern for
spores for the same isolates was curvilinear with D-values
ranging from 4.4 min at 95oC in whole milk to 19.45 min at 85oC
in saline. The z-values for spores ranged from 16.6oC in saline
to 38.4o C in whole milk.
In skim milk log CFU per ml were 0.39 after 90 min at 72 oC,
0.21 after 60 min at 78 oC, and 7.62 after 60 min at 100 oC.
No details available on thermal inactivation.
63 oC for 30 mins, or 72 oC 15 secs can kill B. abortus
Whitney et al (2003)
Brucella
Campylobacter
No details available on thermal inactivation.
62oC for 30 mins kills 6 log B. suis.
60oC 0.8 min kills 1 log C. jejuni
Inactivated by moist heat (121°C for at least 15 min)
or dry heat (160-170°C for at least 1 hour)
Cruz and Montville
(2008)
Novak et al. (2005)
Shivalingsarj and
Mandyam (2010)
Van de Heever et al.
(1982)
Park et al. (1932)
Nguyen et al. (2006)
http://www.phacaspc.gc.ca/labbio/res/psdsftss/msds29e-eng.php
22
Clostridium
chauvoei
novyi
haemolyticum
U
U
M-H
septicum
U
sordelli
M-H
botulinum
M-H
tetani
M-H
No details available
No details available
Spores of 15 of 18 strains of Clostridium were inactivated by
exposure to moist heat at 90oC for 4 min with D values for
linear inactivation varying from 26.6, 8.0, and 4.3 min at 70°C,
80°C, and 90°C, respectively.
No details available
D values for C. sordellii ATCC 9714 spores ranged between
175.60 min for D(80) (the D value for spore suspensions
treated at 80oC) and 11.22 min for D(95). The thermal
resistance (Z) value of spores was 12.59oC.
Heat treatments at up to 85oC for 120 min failed to cause a
100-fold destruction in spore populations. By contrast, spore
counts were reduced by 2 log(10) within 73 mins and 23 mins
at 90oC and 95oC, respectively.
Time-temperature combinations of 90°C for 10 min, 85°C for 36
to 52 min, and 80°C for 129 to 270 mins have been suggested
to reduce the number of spores of non-proteolytic C. botulinum
by a factor of 106. However, in the absence of additional
controlling factors such as chill storage, these heat processes
have since been shown to fail in controlling growth and toxin
production from 106 spores of non-proteolytic C. botulinum
types B, E, and F in meat.
20 minutes at 79°C or 5 min at 85°C is recommended as the
minimum heat treatment for inactivation of 103 LD50 botulinum
toxins per gram of the foods tested.
When cooked in rice at 100c for 30 min, inactivation of 3 - 4
log10 could be observed.
Thermal resistance of spores revealed a biphasic inactivation
at lower temperatures with D values for linear inactivation
varying from 26.6, 8.0, and 4.3 min at 70 oC, 80 oC, and 90 oC,
respectively.
Fuentes and Garcia
(1980)
Sipos-Kozma et al.
(2010)
Lindstrom et al. (2003)
Woodburn et al. (2006)
Konagaya et al. (2009)
Dixit et al. (2005)
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Escherichia
Salmonella
coli
L
enterica
L
bovis
L
avium
Subsp.
paratuberculosis
aureus
L
pyogenes
L
agalactiae
L
suis
L
Enterococcus
pneumoniae
durans
U
L
Listeria
monocytogenes
L
Brachyspira
Vibrio
hyodysenteriae
cholerae
U
Mycobacterium
Staphylococcus
L
Streptococcus
Heating at 60oC from 0.4 to 0.8 min can reduce E. coli
O157:H7 in ground meats by 1 log.
E. coli O157 was found to survive after 30 min at 55°C, but not
after 60 min at 55°C.
A D-value of 2.20 min was reported for S. typhimurium on
chicken meat at 85 oC.
D-values of 293, 40.8 and 5.7 min at 50, 55 and 60 oC
respectively have been calculated for the relatively heatresistant Salmonella strain S. senftenberg 775W in liquids.
Meat from partially condemned carcasses of TB reactor cattle
may be used for the preparation of meat food products, if
heated to a temperature > (76oC (170°F) for >30 minutes.
Bacteria are killed when heated to 63°C for 30 minutes or 72°C
for 15 seconds.
Heating at 72oC for 4.2 sec can reduce MAP by 1 log.
Ahmed et al. (1995)
Heating at 66.5oC for 15 secs can reduce S. aureus in milk by >
6 log.
82oC (180oF) would provide adequate pasteurization of milk,
taking an arbitrary destruction level of 15 D-values
After 4 min of traditional thermal pasteurization treatment in
human milk resulted in an 8-log inactivation.
At 60oC S. suis only survived for 10 minutes in water or broth.
Pearce et al. (2012)
No details available
Heat resistance in enterococci is highly variable with D values
extending from 0.3 – 5.1 minutes. Two isolates of E. durans
were the most heat-resistant with z-values of 8.7 and 8.8oC.
Bacteria present in mussels killed after 17mins at 58oC, and
3mins at 62oC
No information
Heat resistance of V. cholerae expressed in decimal reduction
values (D) in foods at aw 0.99 and pH = 6.5-7.0, has been
reported to be 18 seconds at 72 °C
Sahlström et al (2008)
de Jong et al. (2012)
www.food.gov.uk/multime
dia/pdfs/board/fsa010803
.pdf
Foddai et al. (2010)
Evans, D.A (1969)
Viazis et al. (2008)
Clifton-Hadley and
Henright (1984)
McAuley et al. (2012)
Bremner andOsborne
(1997)
Mossel et al., (1995).
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Erysipelothrix
rhusiopathiae
Asfivirus
ASF Virus
L
Arterivirus
Caliciviridae
Circovirus
PRRS Virus
Vesivirus
PMWS Virus
U
U
L
Gyrovirus
Chicken Anaemia
Virus
L
SARS Virus
L
TGE Virus
BVD Virus
BD Virus
Classical Swine F
ever Virus
Suid herpesvirus 1
(Aujesky’s Disease)
Gallid herpesvirus 1
L
L
L
L
Coronavirus
Pestivirus
Varicellovirus
Lltovirus
L
Erysipelothrix cultures are reportedly destroyed by
exposure to moist heat at 55°C for 10 min
Pig meat products reaching 69oC during processing are
unlikely to contain residual virus
No details available
No details available on thermal inactivation.
Infectivity of PCV2 was reduced by approximately 1.6 log by
pasteurization (10 hours at 60oC) and by 0.75 by dry-heat
treatment (80o C for 72 hours). PCV2 was additionally almost
completely resistant to dry-heat treatment up to 120oC for 30
minutes (mean log infectivity reduction 1.25), although it was
more effectively inactivated when the temperature of wet-heat
treatment was increased to 80oC (> 3.2 log infectivity reduction)
Infectivity of CAV was reduced by approximately 1.4 log by
pasteurization (10 hours at 60oC) and by 1.25 log by dry-heat
treatment (80 o C for 72 hours). CAV was additionally almost
completely resistant to dry-heat treatment up to 120o C for
30 minutes (mean log infectivity reduction 0.6), although it was
more effectively inactivated when the temperature of wet-heat
treatment was increased to 80oC ( > 3.6 log infectivity
reduction)
Thermal inactivation at 56oC was highly effective in the
absence of protein, reducing the virus titre to below
detectability. If protein-containing solutions are to be
inactivated, heat treatment at 60oC for at least 30 min must be
used.
No details available on thermal inactivation.
No details available on thermal inactivation.
No details available on thermal inactivation.
CSFV was heat inactivated in slurry within 3 min at 60oC
(Timoney et al., 1988)
ADV was heat inactivated in slurry within 3 min at 62oC
Turner et al. (2000)
McKercher et al (1980)
Welch et al. (2006)
Welch et al. (2006)
Rabenau et al. (2005)
Turner et al. (2000)
No thermal inactivation data available.
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HPA Virus
L
Swine Influenza
Virus A
Swine Influenza
Virus C
Newcastle Disease
Virus
L
Nipah Virus
Porcine Parvovirus
L
L
Bovine Parvovirus
FMD Virus
SVD Virus
Porcine Enterovirus
(SMEDI)
Blue Tongue Virus
L
L-M
L-M
L
Bovine Rotavirus
Ovine Rotavirus
Porcine Rotavirus
Avian Rotavirus
L
Influenzavirus A
Influenzavirus C
Avulavirus
Henipavirus
L
L
Parvovirus
Apthovirus
Enterovirus
Orbivirus
Rotavirus
L
In studies conducted on the thermal inactivation of H5N1 In
thigh and breast chicken, the predicted D-values and the upper
limits of their 95% prediction intervals for 57 to 61oC were
241.2 and 321.1 s, 146.8 and 195.4 s, 89.3 and 118.9 s, 54.4
and 72.4 s, and 33.1 and 44.0 s. D-values and conservative Dvalues predicted for higher temperatures were 0.28 and 0.50 s
for 70oC; and 0.041 and 0.073 s for 73.9oC.
Virus survival in farm slurry under anaerobic conditions
generally ≤1h when heated to 55oC
No information available
Thomas and Swayne
(2007)
Linear regression models on the thermal inactivation data for
two highly pathogenic, and two low pathogenic strains of AIV
and ND predicted that the current USDA-temperature
guidelines for cooking chicken meat to achieve a 7-log
reduction of Salmonella also would effectively inactivate the
AIV and NDV strains tested. Experimentally, the AIV and NDV
strains used in this study were effectively inactivated in chicken
meat held at 70 or 73.9oC for less than 1 s.
56 oC 30 min can inactivate Nipah virus.
Heat treatment at 70oC for 60 min do not completely inactivate
Porcine parvovirus
At least 90oC for 20 minutes for complete inactivation in water.
FMDV was heat inactivated in slurry within 3 min at 67oC
Virus suspended in milk was inactivated in two minutes at 60oC
No thermal inactivation data available
Thomas et al. 2008
Vector-borne. Below Ph6 bluetongue virus was irreversibly
inactivated within 1 minute at 37oC
Heating at 50oC for 30 minutes can result in a 2 log decrease in
rotavirus infectivity.
Svehag et al (1966)
Botner and Belsham
(2011)
Daniels et al. (2001)
Sahlstrom et al (2008)
Rehman (1987)
Turner et al. (2000)
Herniman et al. (1973)
Estes et al., (1979)
26
Hepevirus
Hepatitis E Virus
L
Vesiculovirus
Vesicular stomatitis
virus
spiralis
nativa
britovi
saginata
solium
L
Cyclospora
parvum
hominis
suis
baileyi
meleagridis
cayetanensis
L
L
L
L
L
L
Sarcocystis
spp.
L
Toxoplasma
gondii
L
Giardia
duodenalis
L
Trichinella
Taenia
Cryptosporidium
L
L
L
L
L
HEV in contaminated commercial pig livers can be effectively
inactivated if cooked properly, although incubation at 56oC for 1
hour cannot inactivate the virus.
No thermal inactivation data available
Feagins et al. (2007)
The thermal death point of T. spiralis is approximately 57oC.
The USDA requires pork to be cooked for 2 hours at 52.2°C,
for 15 min at 55.6°C, and for 1 min at 60°C.
Macroscopic parasites removed at meat inspection prior to
entering the food chain. Risk from imported, uncooked meats.
Heating to a temperature of 56°C will inactivate cysticerci.
Freezing meats to -4o F for 24 hours also kills tapeworm eggs.
Zimmer et al. (2008)
Zimmer et al. (2009)
Kotula et al. (1983)
Allen (1947)
Heating to temperatures greater than 72.4oC for one minute, or
greater than 64.2oC for two minutes of a five-minute heating
cycle inactivates oocysts.
Foodborne transmission linked to contaminated fresh produce fruit and herbs. Oocysts killed by cooking.
Sarcocysts in the muscles of pigs became non-infective after
heating infected pork in small pieces at 60oC for 20 min, 70oC
for 15 min and 100oC for 5 min
Cooking at 60oC or higher for 3½ minutes or longer renders
Toxoplasma cysts non-infectious
The thermal death point for Giardia is 68oC
Fayer (1994); Taylor
(2000)
Mansfield and Gajadhar
(2004)
Saleque et al. (1990)
Dubey et al. (1990);
Taylor (2000)
(Myer and Radulescu,
(1978)
H = High; M = Low, M = Medium; U = unknown
27