First report of identification of livestock-associated MRSA ST9 in retail meat in England

First report of identification of livestock-associated MRSA ST9 in retail meat in England

V. DHUP,A. M. KEARNS,B. PICHON and H. A. FOSTER (2015).
Epidemiology and Infection, Volume 143, Issue14, October 2015, pp 2989-2992
http://journals.cambridge.org/action/displayAbstract?aid=9947180

Abstract

Sixty percent of all meat consumed in the UK is imported from European countries where there have been increasing reports of methicillin-resistant Staphylococcus aureus (MRSA) identified in food-producing animals, but rarely from such animals in the UK. Thirty samples each of raw chicken, pork and beef, sourced in England, were collected from retail outlets in Greater Manchester. MRSA was recovered from three chicken samples and one each of pork and beef, all from prepackaged supermarket meat. Four isolates were identified as representatives of the most common human healthcare-associated MRSA clone in the UK [EMRSA-15, spa type t032, belonging to multilocus sequence type clonal complex 22 (MLST-CC22)], suggesting contamination from human source(s) during meat processing. The fifth isolate (from chicken) was multiply-resistant (including oxacillin, ciprofloxacin, erythromycin, clindamycin and tetracycline), identified as ST9-SCCmecIV, spa type t1939 and lacked the immune evasion cluster, a characteristic of livestock-associated strains. This lineage has been identified previously from animals and meat products in Asia and mainland Europe but not the UK.

Typical blue colored MRSA colonies on MRSA ID Agar

Influence of Risk on US and UK Regulatory Authority towards Incineration of Hazardous Waste

Hazardous Waste and Incineration:

Hazardous waste is waste that is dangerous or potentially harmful to human and animal health or the environment. Hazardous wastes can be liquids, solids, gases, or sludges. They can be discarded commercial products, like cleaning fluids or pesticides, or the by-products of manufacturing processes (US-EPA, 2009).

Before a material can be classified as a hazardous waste, it must first be a solid waste as defined under RCRA. Hazardous wastes are divided into (US-EPA, 2009)

1. listed wastes,
2. characteristic wastes,
3. universal wastes and
4. mixed wastes

Incineration is “an engineered process using controlled flame combustion to thermally degrade waste materials” (Travis, 1989). It involves the process of complete combustion of solid or liquid waste, an oxidative process used for; detoxification and sterilization, volume reduction, energy recovery, by-product chemical recovery (Cheremisinoff, 1995).

Regulatory Considerations for Hazardous Waste Incineration:

The regulatory bodies are:

• United States – Environmental Protection Agency (US-EPA),
• United Kingdom’s – Environmental Agency & DEFRA – Department for Environment, Food and Rural Affairs

The Resource Conservation and Recovery Act (RCRA), enacted in 1976, were written to provide “cradle to grave” tracking of hazardous waste. Pursuant to RCRA, EPA developed hazardous waste management regulations for generators and treatment, storage, and disposal facilities (TSDFs). In 1984, Congress expanded the scope of RCRA with passage of the Hazardous and Solid Waste Amendments (HSWA). HSWA directed EPA to adopt regulations governing small quantity hazardous waste generators (SQGs) such as many small labs. Most labs routinely generate hazardous waste and, therefore, are subject to RCRA hazardous waste management regulations (40 CFR Parts 260 to 270) (US-EPA, 2009).

These regulations include requirements governing waste classification, accumulation, disposal, recordkeeping, and emergency preparedness. EPA has delegated authority to implement and enforce hazardous waste management programs to the states and tribes. State and tribal regulations are at least as stringent as EPA’s hazardous waste regulations. Still, it is important to keep up with the EPA regulations since EPA regularly publishes new hazardous waste management regulations that are enforceable in the states even though they may not yet be included in a given state’s hazardous waste regulations (US-EPA, 2009).

The Hazardous Waste Regulations in UK which came into force on 16 July, 2005 set down the regime for the control and tracking of the movement of hazardous waste for the purpose of implementing the Hazardous Waste Directive (Directive 91/689/EC). The Regulations include a requirement for hazardous waste producers to notify their premises to the Environment Agency before hazardous wastes can be removed from the premises. They also exempt certain low risk premises from the requirement as long as they produce less than a specified amount of hazardous waste per annum (DEFRA, 2009).

Emissions from Hazardous Waste Incinerators: 

EPA promulgated MACT standards for the Phase I facilities on September 30, 1999 (64 FR 52828). The hazardous waste combustor MACT, codified in 40 CFR Part 63, Subpart EEE, subjects affected sources to stringent emission limits for the following HAPs:

1. dioxins/furans,
2. hydrocarbons,
3. carbon monoxide (CO),
4. particulate matter,
5. non-dioxin organic HAPs (principal organic hazardous constituents [POHCs]),
6. mercury,
7. semi-volatile metals (i.e., lead and cadmium),
8. low volatility metals (i.e., arsenic, beryllium, and chromium), and
9. Hydrochloric acid/chlorine gas.

POHCs include halogenated and non-halogenated organic compounds (e.g., polycyclic aromatic hydrocarbons, polychlorinated biphenyls). Particulate matter is composed of sulphate, nitrate, ammonium, and other ions; elemental carbon; particle-bound water; various organic compounds; and numerous elements contained in various compounds (US-EPA, 2005).

Recent studies show, the major toxic metals are lead (Pb), chromium (Cr), cadmium (Cd), and arsenic (As). Mercury (Hg) and Beryllium (Be), is more frequently encountered in this range for hazardous waste incinerators (if at all), even though may be present at higher or lower concentrations with other types of incinerators. The traces of volatile organic compounds (VOCs) and semi-volatile compounds (SVOCs) would include dozens of volatile compounds and perhaps hundreds of semi-volatile compounds, but each compound is present at a very low (sub-ppb) level. Examples include xylenes, ethylbenzene, chlorinated aliphatics, and chlorinated aromatics, as well as various oxygenated compounds (aldehydes, ketones, alcohols) (Hinshaw and Trenholm, 2001).

Risk Associated with Hazardous Waste Incineration:

A risk assessment is an analysis that uses information about toxic substances at a site to estimate a theoretical level of risk for people who might be exposed to these substances. The information comes from scientific studies and environmental data from a site. A risk assessment provides a comprehensive scientific estimate of risk to persons who could be exposed to hazardous materials present at a site (ATSDR, 1999).

Risk assessments, prepared by EPA and other agencies, which are used to determine if levels of toxic substances at hazardous waste sites pose an unacceptable risk as defined by regulatory standards and requirements. It helps regulatory officials determine hazardous site cleanup strategies that will ensure overall protection of human health and the environment. A risk assessment does not measure the actual health effects that hazardous substances at a site have on people. Risk assessments often are conducted without considering actual or possible exposure (ATSDR, 1999).

The potential adverse effects i.e. risk, of hazardous waste incinerators (HWI) continue to be a subject of worry (Carmen Agramunt et al., 2003).

Risk assessment is considered to be an effective scientific tool which enables decision makers to manage hazardous waste-contaminated sites in a cost-effective manner while preserving public health. However, the current risk assessment framework proposed by the US Environmental Protection Agency (US EPA) has limitations in addressing the true variability of population characteristics (Zhao and Kaluarachchi, 2002).

Human activities have always generated waste. This was not a major issue when the human population was relatively small and nomadic, but became a serious problem with urbanisation and the growth of large conurbations. Some highly publicised pollution incidents with incorrect waste management practices, led to public concerns about lack of control, inadequate environmental and human health impact. This forced many national regulatory bodies to implement new regulatory framework to deal with the hazardous and unsustainable waste management operations, which are based on waste prevention or minimisation, re-use, recycling and composting. But in many countries large percentage of waste cannot be recycled and re-used or composted as the main disposal methods are land filling and incineration (Giusti, 2009).

The studies so far have uncovered inconsistent and implausible evidence for a low level of risk. It is only natural that people living near huge incineration plants want more assurance — but epidemiology simply cannot provide it. The type of study needed is financially, logistically and ethically out of the question and there are, of course, genuine reasons to be concerned about incinerators. They are noisy, they damage air quality and they increase traffic levels. You don’t need subtle statistical analysis to detect the roar of a waste-laden truck (Matthews, 2006).

The UK government estimates that dioxin emissions from hazardous waste incineration reduced by around 99% between 1990 and 2000, even though the amount of waste being incinerated remained largely the same during this period. Dioxin emissions from incineration have been dramatically reduced in recent years, thanks to technology developments, which in turn were prompted by stricter regulations, particularly the EU Waste Incineration Directive which came fully into force in December 2005. The conditions under which dioxins are formed are well understood, making it possible to limit dioxin formation in incineration plants (2009).

Recent research for the government showed that all waste processes – including recycling and composting – are responsible for some emissions, but that none poses a threat to human health or the environment (DEFRA, 2004).

Changes in US and UK Regulations: 

Recent finalization of air emission standards under the Clean Air Act (CAA) have some standards, which are premised on the concept of maximum achievable control technology (MACT), impose stricter limits on hazardous air pollutant (HAP) emissions from all regulated major and area sources. Under CAA Section 112(d)(5), EPA must regulate area sources in a given source category if the emissions from such sources are a threat to human health or the environment. To find the existing source MACT floor for each HAP discharged, EPA has identified the primary emission control technology that is employed by sources with emission levels equal to or lower than the median of the best performing 12% of sources (USEPA, 2005).

The U.S. Environmental Protection Agency (EPA) has issued standards that would decrease emissions of key pollutants from waste incinerators. The EPA rules require incinerators to reduce emissions to a standard known as “maximum achievable control technology,” or MACT. The Research Council report says compliance with MACT regulations will diminish the exposure of local populations to emissions, but it is unclear what effect compliance will have on a metropolitan or regional scale, since little is known about the risks posed by collective emissions from several incinerators. The committee noted that cumulative emissions of dioxins and metals are of substantial concern since those pollutants are capable of traveling long distances and persisting in the environment. It also recommended that all medical- and municipal-waste incinerators have uniform limits for each pollutant irrespective of plant size, age, or design, as is currently the case for hazardous-waste incinerators (USEPA, 2005).

A new European Regulation (1272/2008) on the classification, labelling and packaging of chemicals was adopted by Europe on December 2008 (the CLP Regulation). The Globally Harmonised System for chemical will be implemented in stages between now and 2015. CHIP3 was replaced by CHIP 4 in April 2009 to adopt this into UK legislation (EA, 2009).

The immediate changes are (EA, 2009);

1. The Approved Supply List is no longer used for chemical classification,
2. The Approved Classification and Labelling Guide has been reissued,
3.  Test methods are now found in the Annex of European Regulation 440/2008/EC. which sets out the test methods under REACH Legislation

Conclusion: 

From above explanation, I would like to comment, certain changes have been made in a period from 2005-2009 in incineration regulations depending upon the risk to the public health, up-to some extent. Regulatory bodies have been successful in implementing the laws regarding hazardous waste incineration and bust the emissions from the same. From this study it concludes both US and UK regulatory bodies have controlled emissions levels till date, but still some strict rules regarding long-term health effects for the people living in vicinity of hazardous waste incinerators is necessary.

References:

(2009) Emission and Health.

ATSDR (1999) ‘A Citizens Guide to Risk Assessments and Public Health Assessments at Contaminated Sites’ 3.

CARMEN AGRAMUNT, M., DOMINGO, A., DOMINGO, J. L. & CORBELLA, J. (2003) Monitoring internal exposure to metals and organic substances in workers at a hazardous waste incinerator after 3 years of operation. Toxicology Letters.

CHEREMISINOFF, N. (1995) Handbook of Emergency Response to Toxic Chemical Releases.

DEFRA (2004) Review of Environmental and Health Effects of Waste Management.

DEFRA (2009) Explanatory Memorandum to Hazardous Waste (England and Wales)(Amendment) Regulation. 9.

EA (2009) Hazardous Waste – August 2009 Update.

GIUSTI, L. (2009) A review of waste management practices and their impact on human health. Waste Management, 29, 2227-2239.

HINSHAW, G. D. & TRENHOLM, A. R. (2001) Hazardous waste incineration emissions in perspective. Waste Management, 21, 471-475.

MATTHEWS, R. (2006) No such thing a zero risk. New Scientist, 189, 24-24.

TRAVIS, C. (1989) Hazardous Waste Incineration and Human Health.

US-EPA (2005) MACT Standards for Hazardous Waste Combustors Finalized. Hazardous Waste Consultant, 23, 4.1-4.33.

US-EPA (2009) Waste – Hazardous Waste. United States – Environmental Protection Agency.

ZHAO, Q. & KALUARACHCHI, J. J. (2002) Risk assessment at hazardous waste-contaminated sites with variability of population characteristics. Environment International.

One World One Health Concept by the means of Zoonoses and MRSA

In recent years, several major human epidemics had occurred on a pandemic scale. Notable examples include SARS, avian influenza and swine flu, each of which had spread over a number of continents and caused widespread morbidity and mortality. Similar occurrences have been observed in animal populations, to consider foot-and-mouth-disease (FMD) in the United Kingdom, avian influenza in the Netherlands and bluetongue disease in Europe. In each cases, first the pathogens were considered as “exotic” prior to their introduction and spread (DEFRA, 2009).

Influenza pandemic across globe, such a complex scenario creates an arena in which the medical and veterinary disciplines bring distinct, but interrelated, professional skills together to help solve any problems associated with the interaction between  human and animals. The outbreaks of avian influenza are not the first zoonotic infections to show the importance of having a close working relationship between the veterinary and medical officers. The emergence of variant Creutzfeldt-Jakob disease in humans and the possibility that this might be linked to the epidemic of bovine spongiform encephalopathy (BSE) in cattle highlighted the need to collaborate in assessing the potential threats to human health posed by animal diseases. The chief veterinary and medical officers say, “there is need to collaborate with our chief medical and chief veterinary counterparts in European Union member states and worldwide via the World Organization for Animal Health (OIE), the World Health Organization, and the various expert advisory groups” (Reynolds & Donaldson, 2005).

In 2007, campylobacteriosis was again the most frequently reported zoonotic disease in humans in the European Union with 200,507 reported confirmed cases and most Member States reporting an increased number of cases. Salmonellosis was still the second most commonly recorded zoonoses accounting for 151,995 confirmed human cases’ (EFSA, 2009). There 61% of human infectious diseases are zoonotic, 75% of human EID are zoonotic, 33% of zoonoses are transmissible between humans’ (Taylor et al, 2001).

There can be little doubt that the majority of veterinarians and human health professionals have a basic knowledge about zoonoses and have some theoretical understanding of the threat that they might pose to human health. But it is also apparent that in practice many health workers either fail to consider the possibility that they may be dealing with a zoonoses or ignore the public health implications of these type of infections’ (Cripps, P. J., 2000).

Zoonoses are simply multi-host infections in which one host happens to be human. The humans are still the part of the greater ecosystem’ (Bennett M., 2006). In the Europe, food is thought to be the most common source of zoonotic diseases in public health’ (EFSA, 2009). The importance of zoonotic diseases is well demonstrated by a survey of infectious organisms which showed that, of the 1415 species known to be pathogenic to humans, 61% (868) are zoonotic, while 75% of diseases considered to be ’emerging’ are also zoonotic. It is perhaps worth noting that many of the zoonotic agents causing disease in humans cause little or no obvious clinical disease in their animal hosts’ (Taylor et al, 2001).

Peter J. Cripps (2000) concludes, “The zoonoses must be considered seriously as possible future human communicable diseases, and that ignoring them will pose a threat to public health. Secondly, many zoonoses are able to cause very significant human morbidity and mortality. Amongst these are brucellosis, leptospirosis, salmonellosis, tuberculosis and echinococcosis, and a large number of other bacterial, viral and parasitic infections”. There is also strong evidence to suggest that other communicable diseases, such as influenza, may have originated from non-human animals.

In order to prevent zoonoses from occurring, it is important to identify which animals and foodstuffs are the main sources of infections. For this purpose and to follow the developments on food safety in the European Union, information aimed at protecting human health is collected and analyzed from all European Union Member States. The collected data is published in Community Summary Report on trends and sources of zoonotic agents in European Union in 2007 (EFSA, 2009).

This concept applies to methicillin-resistant Staphylococcus aureus (MRSA) infection as well, at present, MRSA is considered as one of the key potential zoonotic pathogens (Epstein & Price, 2009). Staphylococcus aureus had continuously evolved since the discovery of penicillin in 1940 as first resistant strain was discovered in UK hospital in 1960 (Lowy, 2003). MRSA has become an emerging public health problem worldwide, no longer only associated with healthcare-associated infections. With the exception of some recent reports confirming infections in cattle, cats, dogs and horses, infections with MRSA in companion animals have been infrequently reported (Cuny et al., 2006). MRSA have been detected in foods such as bovine milk, cheese, meat products and raw chicken meat (Vanderhaeghen et al., 2010). It was first recognized as zoonosis in the Netherlands (Voss et al., 2005; Cuny et al., 2008) when same strain of MRSA was isolated from the pigs, pig farmers, veterinarian, veterinarian’s son and the nurse who treated veterinarian’s son; all of them were directly or indirectly related to pig farming (Voss et al., 2005). MRSA can be transmitted between people and animals during close contact (Seguin et al., 1999; Weese et al., 2005; Cuny et al., 2006; Weese et al., 2006). There is much more need to monitor MRSA infection. As there are recent reports of USA300 which is untreatable and causing lots of problems and spreading across globe.

References:

Bennet Malcolm (2006) Zoonoses – what on horizon? Presentation at the Zoonoses Training Day on 7^th July 2006.

Cripps, P. J. (2000). “Veterinary education, zoonoses and public health: a personal perspective.” Acta Tropica 76(1): 77-80.

Cuny, C., Kuemmerle, J., Stanek, C., Willey, B., Strommenger, B., & Witte, W. (2006). Emergence of MRSA infections in horses in a veterinary hospital: Strain characterisation and comparison with MRSA from humans. Euro Surveill, 11(1), 44-47.

Cuny, C., Strommenger, B., Witte, W., & Stanek, C. (2008). Clusters of infections in horses with MRSA ST1, ST254, and ST398 in a veterinary hospital. Microbial Drug Resistance, 14(4), 307-310.

Debby Reynolds, Liam Donaldson (2005) UK government collaborations to manage threats to animal and human health. BMJ  2005;331:1216-1217, doi: 10.1136/bmj.331.7527.1216

DEFRA (2009) Data mining for exotic pathogen spread, (Background) http://www.defra.gov.uk/vla/science/sci_phd.htm

EFSA (2009) The Community Summary Report on Trends and Sources of Zoonoses and Zoonotic Agents in the European Union in 2007. The EFSA Journal (2009) 223. http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1211902269834.htm

Lowy, F. (2003). Antimicrobial resistance: the example of Staphylococcus aureus. Journal of Clinical Investigation, 111(9), 1265-1273

Seguin, J. C., Walker, R. D., Caron, J. P., Kloos, W. E., George, C. G., Hollis, R. J., et al. (1999). Methicillin-resistant Staphylococcus aureus outbreak in a veterinary teaching hospital: potential human-to-animal transmission. Journal of Clinical Microbiology, 37(5), 1459.

Taylor, L. H., S. M. Latham, et al. (2001). “Risk factors for human disease emergence.” Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 356(1411): 983-989.

Vanderhaeghen, W., Hermans, K., Haesebrouck, F., & Butaye, P. (2010). Methicillin-resistant Staphylococcus aureus (MRSA) in food production animals. Epidemiology and infection, 138(05), 606-625.

Voss, A., Loeffen, F., Bakker, J., Klaassen, C., & Wulf, M. (2005). Methicillin-resistant Staphylococcus aureus in pig farming. 11(12).

Weese, J. S., Archambault, M., Willey, B., Hearn, P., Kreiswirth, B., Said-Salim, B., et al. (2005). Methicillin-resistant Staphylococcus aureus in horses and horse personnel, 2000–2002. Emerg Infect Dis, 11(3), 430-435.

Weese, J., Dick, H., Willey, B., McGeer, A., Kreiswirth, B., Innis, B., et al. (2006). Suspected transmission of methicillin-resistant Staphylococcus aureus between domestic pets and humans in veterinary clinics and in the household. Veterinary Microbiology, 115(1-3), 148-155.

 

MRSA in British Milk

As my daily routine I was checking my mails and I came across one my old post on Linkedin about MRSA in raw meat. There was a comment about the article in The Independent news paper, who claims themselves as a views-paper! It was about ‘MRSA ‘superbug’ is found in British milk.’ this study was led by Mark Holmes, based at University of Cambridge.
My earlier blog about MRSA, questioned about entry of MRSA in food chain, if yes it has entered food chain then, how and what routes it gains entry. similar questions are raised in this article. Mark Holmes says, “It is still not known for certain if cows are infecting people, or people are infecting cows. This is one of the things we will be looking into next.”

So, in coming blogs I will try to elaborate more on MRSA and its entry in food chain.

Public Health Importance of Zoonotic Diseases

In recent years, several major human epidemics have occurred on a world-wide scale. Notable examples include SARS, avian influenza and swine flu, each of which have spread over a number of continents and caused widespread morbidity and mortality. Similar occurrences have been observed in animal populations, for example foot-and-mouth-disease in the United Kingdom, avian influenza in the Netherlands and bluetongue disease in Europe. In each of these examples, the pathogens were considered “exotic” prior to their introduction and spread’ (DEFRA, 2009)

In 2007 there were total 25 outbreaks that were designated as foodborne outbreaks. The most common causative organism identified was Salmonella species. Almost 387 people were affected by this foodborne outbreak; there were 30 hospitalizations and 5 deaths in total’ (DEFRA, 2007).

Zoonoses are defined by the World Health Organization as ‘diseases and infections which are transmitted naturally between vertebrate animals and man’ (WHO, 1959).

Influenza pandemic across globe, such a complex scenario creates an arena in which the medical and veterinary disciplines bring distinct, but interrelated, professional skills together to help solve any problems associated with the interaction between people and animals. The outbreaks of avian influenza are not the first zoonotic infections to show the importance of having a close working relationship between the veterinary and medical officers. The emergence of variant Creutzfeldt-Jakob disease in humans and the possibility that this might be linked to the epidemic of bovine spongiform encephalopathy (BSE) in cattle highlighted the need to collaborate in assessing the potential threats to human health posed by animal diseases. The chief veterinary and medical officers say, “there is need to collaborate with our chief medical and chief veterinary counterparts in European Union member states and worldwide via the World Organization for Animal Health (OIE), the World Health Organization, and the various expert advisory groups” (Reynolds & Donaldson, 2005).

Humans have enjoyed a long and intimate relationship with other animals. Some animals are reared to provide food, milk or clothing, some for recreational purposes and others are brought into the home for companionship or to act as guards. Most often those interactions are decidedly to human benefit. However, there are occasional disadvantages to humans including transmission of infection. Such infections are usually called zoonoses’ (Hart CA et al, 1999).

In 2007, campylobacteriosis was again the most frequently reported zoonotic disease in humans in the European Union with 200,507 reported confirmed cases and most Member States reporting an increased number of cases. Salmonellosis was still the second most commonly recorded zoonoses accounting for 151,995 confirmed human cases.’ (EFSA, 2009).

Recommendations made Chief Medical Officer in his 2002 annual report lead to the establishment of the National Expert Panel on New and Emerging Infections facilitated the integration of data gathering for animal and human health surveillance and strengthened the assessment of potential threats to health from new and emerging diseases, particularly zoonoses in 2003. This was supported by the foundation of Health Protection Agency’ (Reynolds & Donaldson, 2005).

The 10-year UK Veterinary Surveillance Strategy was launched in October 2003, to collect information about diseases affecting animals and to make sure that the information gets to those who need it’(DEFRA, 2010).

Recently, the HPA published Guidelines for the Investigation of Zoonotic Disease, version 1. To clarify the roles and responsibilities of different organizations with respect to zoonotic incidents and outlines, how they should best work together in different situations’ (HPA, 2009).

Zoonoses:

Zoonoses are defined by the World Health Organization as ‘diseases and infections which are transmitted naturally between vertebrate animals and man’ (WHO, 1959). They are an heterogenous group of infections with a varied epidemiology, clinical features and control measures. The causative organism may be viral, bacterial, fungal, protozoan, or parasitic’ (HPA, 2009). Any disease or infection that is naturally transmissible from vertebrate animals to humans and vice-versa is classified as a zoonoses according to the PAHO publication “Zoonoses and communicable diseases common to man and animals”. Over 200 zoonoses have been described and they have been known for many centuries. They are caused by all types of agents: bacteria, parasites, fungi, viruses and unconventional agents’ (WHO, 2010).

There 61% of human infectious diseases are zoonotic, 75% of human EID are zoonotic, 33% of zoonoses are transmissible between humans’ (Taylor et al, 2001).

There can be little doubt that the majority of veterinarians and human health professionals have a basic knowledge about zoonoses and have some theoretical understanding of the threat that they might pose to human health. But it is also apparent that in practice many health workers either fail to consider the possibility that they may be dealing with a zoonoses or ignore the public health implications of this type of infection’ (Cripps, P. J., 2000).

Zoonoses are simply multi-host infections in which one host happens to be human. The humans are still the part of the greater ecosystem’ (Bennett M., 2006). However, there are several diseases listed below that occur primarily in humans and that may also be transmitted between humans and animals, with some animals serving as reservoirs for human infection (eg. Trichuristrichiura). The following common bacterial and viral diseases of humans are not found as naturally occurring diseases in animals (i.e. animals are not a reservoir): diphtheria (Corynebacterium diphtheriae), Legionnaires’ disease (Legionella pneumoniae, L pneumophila , and related organisms), syphilis (Treponema pallidum ), trachoma (Chlamydia trachomatis ), typhoid fever ( Salmonella typhi ), poliomyelitis, hepatitis B, mumps, chickenpox, smallpox, and measles’ (Merk’s Vet., 2008).

Appendix I: List of Zoonotic Diseases and Organisms.

Appendix II: Classification of Zoonoses

Public Health Importance of Zoonotic diseases:

Zoonotic diseases are the diseases transmitted between animals and humans. Transmission may occur in a number of settings, ranging from indirect contact through food or drinking water to direct contact through occupational exposure on farms, during leisure pursuits or from pets’ (DEFRA, 2008). e.g. Rabies through a bite; via a contaminated environment e.g. anthrax; and via food e.g. campylobacteriosis and salmonellosis or indirectly via vectors, such as mosquitoes or ticks e.g. West Nile fever and Lyme disease, respectively. The organisms causing zoonoses include viruses, bacteria, fungi, protozoa and other parasites, with both domestic and wild animals acting as reservoirs for these pathogens. The diseases they cause in humans range from mild and self-limiting e.g. most cases of toxoplasmosis to fatal e.g. Ebola haemorrhagic fever (WHO, 1959).

Population is increasing day-by-day continuously and there is rise in the food demand, which lead to open new areas for food production both for humans, and their domestic animals are more frequently exposed to diseases as a result of encounters with “wild” animals, thus increasing human exposure to once rare zoonotic infections. Increasing animal trade for food is also contributing to spread of zoonoses. Rapid development, urbanization and faster means of transport such as air travel are triggering the spread of zoonotic diseases in a particular areas and also across the globe, comparatively within shorter period of time’(Seimenis A., 1998).

In the Europe, food is thought to be the most common source of zoonotic diseases in public health’ (EFSA, 2009).

The importance of zoonotic diseases is well demonstrated by a survey of infectious organisms which showed that, of the 1415 species known to be pathogenic to humans, 61% (868) are zoonotic, while 75% of diseases considered to be ’emerging’ are also zoonotic. It is perhaps worth noting that many of the zoonotic agents causing disease in humans cause little or no obvious clinical disease in their animal hosts’ (Taylor et al, 2001).

Pathogens that can be transmitted between different host species are of fundamental interest and importance from conservation, public health and economic perspectives’ (Cleaveland et al 2001). The outbreak of bovine spongiform encephalopathy (BSE) and Foot and Mouth Disease (FMD) in cattle and the consequent new variant Creutzfeldt-Jakob disease (nvCJD) in humans well illustrates this point’ (Abdou AE., 1998; Reynolds & Donaldson, 2005).

There is also strong evidence to suggest that other communicable diseases, such as influenza, may have originated from non-human animals. Also the present Acquired Immuno Deficiency Syndrome (AIDS) pandemic almost 38 – 44 million people across globe are carrying infection is supposed to be the result of zoonoses, but now the virus is maintaining itself well in human population’(Cripps, P. J., 2000).

The physicians and veterinarians held very different views about the disease risks from certain animals and infections agents, and also they communicated very little to each other about zoonotic diseases and their prevention’ (Grant S & Olsen CW 1999).

Peter J. Cripps (2000) concludes, “The zoonoses must be considered seriously as possible future human communicable diseases, and that ignoring them will pose a threat to public health. Secondly, many zoonoses are able to cause very significant human morbidity and mortality. Amongst these are brucellosis, leptospirosis,salmonellosis, tuberculosis and echinococcosis, and a large number of other bacterial, viral and parasitic infections”.

Success in the prevention and control of major zoonoses depends on the capability to mobilize resources in different sectors and on coordination and intersectoral approaches, especially between national (or international) veterinary and medical services’ (Abdou AE., 1998; Reynolds & Donaldson, 2005).

How Veterinary and Medical services can co-operate for better disease surveillance and risk reduction:

The confluence of human and animal health was under the spotlight due to epidemic of avian influenza (H5N1 virus) affecting poultry and humans across South East Asia and by its spread into Europe. Understanding and developing the multiple links between animal and human health fields, is essential for establishing effective surveillance, preparedness, and response strategies and for developing appropriate, government-wide mechanisms for risk assessment and management’ (Reynolds & Donaldson, 2005).

Reynolds & Donaldson, 2005, “The 2001 epidemic of foot and mouth disease (FMD) and the challenge it posed for the disposal of infected animal carcasses reminded us of the need to consider the wider potential impacts of animal diseases even when the disease itself seemed to have little public health importance for humans. Furthermore, the emergence of severe acute respiratory syndrome (SARS) clearly showed the need to collaborate with our chief medical and chief veterinary counterparts in European Union member states and worldwide via the World Organization for Animal Health (OIE), the World Health Organization, and the various expert advisory groups”

The veterinary and medical officers have a shared responsibility to report occurrences of new and emerging zoonoses and to advise ministers on appropriate risk management measures. At the heart of this shared responsibility is a commitment by both the veterinary and medical officers to rapid and open sharing of information, transparency in the risk assessment process, and communication’(Reynolds & Donaldson, 2005).

In order to prevent zoonoses from occurring, it is important to identify which animals and foodstuffs are the main sources of infections. For this purpose and to follow the developments on food safety in the European Union, information aimed at protecting human health is collected and analyzed from all European Union Member States. The collected data is published in Community Summary Report on trends and sources of zoonotic agents in European Union in 2007’(EFSA, 2009).

In the UK, Guidelines for the Investigation of Zoonotic Disease, has been published in April 2009 to clarify the roles and responsibilities of different organizations with respect to zoonotic incidents and outlines, how they should best work together in different situations, for example through routine information reporting, formal liaison and outbreak investigations, to ensure a common approach. It is intended for all those likely to be involved in the management of zoonotic incidents in England, including Health Protection Units (HPUs), local authorities (LAs), Primary Care Trusts (PCTs), the Veterinary Laboratories Agency (VLA), Animal Health, the Health and Safety Executive (HSE), private veterinary surgeons and private veterinary laboratories. In Wales, the equivalent organizations to the HPUs are Health Protection Teams (HPTs), and Local Health Boards (LHBs) which have similar roles to PCTs. Separate arrangements exist for Scotland and Northern Ireland. Where cross-border incidents occur these should be managed in collaboration with appropriate agencies, however different agencies have different borders even within a single nation (HPA, 2009).

Also the zoonoses group across the nation depending upon region e.g. North West Zoonoses Group and South West Zoonoses Group are the development of common standard operating procedures by the veterinary and public health Laboratory Test Group for the isolation, identification, and typing of bacterial, viral, and parasitic organisms and for antibiotic sensitivity testing, and the development of shared databases incorporating phenotypic and molecular information from human and animal sources. Other projects integrating human and animal health, such as the harmonization of procedures for the surveillance of animal and human infectious disease and the cross training of veterinary and public health staff in new techniques for handling new or unusual zoonotic pathogens, increase our ability to scale up laboratory diagnostics should the need arise. This lead to the foundation of Health Protection Agency and it continues to operate for the same’ (Reynolds & Donaldson, 2005).

The government had suggested lines of communication for zoonotic disease in animals and humans (Appendix III and IV).

Discussion:

Recent, outbreak of foot-and-mouth-disease in the United Kingdom and avian influenza in the Netherlands and bluetongue disease in Europe, in each of these examples, the pathogens were considered “exotic” prior to their introduction and spread. Foundation of UK Zoonoses Group for gathering information regarding the animals diseases with every aspect and to make it available where it is needed most. Health Protection Agency was founded to protect the people from the threats across UK. HPA conducts training programmes for veterinary and medical professionals, to provide them with better understanding and a platform to communicate which is the most important thing in reducing zoonoses and also these professionals are at the frontline of the risk of zoonoses. There have been a lot of changes in the last decade for the protection of animal and public health. Together we can call it as a Veterinary Public Health. So there’s need of a motto ‘Healthy animals = healthy people’ which has been adopted by the World Veterinary Association.

So in ‘One World-One health concept, is unified approach between veterinary and human medicine to improve global health for people and animals’ (WVA, 2009)should be followed. And it’s the responsibility of the every veterinary and medical professional to work together and co-operate to fight against the zoonotic diseases across the globe.

References:

Abdou AE (1998). Prevention and control of zoonotic diseases. Eastern Mediterranean Health Journal 4 (2): 223-224.
http://www.emro.who.int/Publications/EMHJ/0402/03.htm

Bennet Malcolm (2006) Zoonoses – what on horizon? Presentation at the Zoonoses Training Day on 7^th July 2006.

Cleaveland S, Laurenson MK and Taylor LH. (2001) Diseases of humans and their domestic mammals: pathogen characteristics, host range and the risk of emergence. Philosophical Transactions of the Royal Society of London. B: Biological Sciences 29; 356(1411): 991-9. http://www.ncbi.nlm.nih.gov/pubmed/11516377

Cripps, P. J. (2000). “Veterinary education, zoonoses and public health: a personal perspective.” Acta Tropica 76(1): 77-80.

Debby Reynolds, Liam Donaldson (2005) UK government collaborations to manage threats to animal and human health. BMJ  2005;331:1216-1217, doi: 10.1136/bmj.331.7527.1216

DEFRA (2007) Trends and sources of zoonoses and zoonotic agents in humans, foodstuffs, animal and feedingstuffs.

DEFRA (2008). Zoonoses Report United Kingdom 2008. Department for Environment, Food and Rural Affairs, London.

DEFRA (2009) Data mining for exotic pathogen spread, (Background) http://www.defra.gov.uk/vla/science/sci_phd.htm

DEFRA (2010) UK Veterinary Surveillance Strategy http://www.defra.gov.uk/foodfarm/farmanimal/diseases/vetsurveillance/index.htm

EFSA (2009) The Community Summary Report on Trends and Sources of Zoonoses and Zoonotic Agents in the European Union in 2007. The EFSA Journal (2009) 223. http://www.efsa.europa.eu/EFSA/efsa_locale-1178620753812_1211902269834.htm

Grant S and Olsen CW (1999). Preventing zoonotic diseases in immuno-compromised persons: the role of physicians and veterinarians. Emerging Infectious Diseases 5 (1): 159-163.
http://www.cdc.gov/ncidod/EID/vol5no1/grant.htm

Hart CA, M Bennett and ME Begon (1999) Zoonoses J. Epidemiol. Community Health 1999;53;514-515

HPA (2009) What are Zoonoses? http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Zoonoses/GeneralInformation/zoo005BackgroundInformation/

HPA, (2009) Guidelines for the Investigation of Zoonotic Disease, version 1. Published 23 April, 2009.

Merks Veterinary Manual (2008) Zoonoses: Introduction. http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/220100.htm

Seimenis A. (1998). Zoonoses: a social and economic burden. Eastern Mediterranean Health Journal 4 (2): 220-222. http://www.emro.who.int/Publications/EMHJ/0402/02.htm

Taylor, L. H., S. M. Latham, et al. (2001). “Risk factors for human disease emergence.” Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 356(1411): 983-989.

WHO (2010) Zoonoses and Veterinary Public Health. http://www.who.int/zoonoses/en/

World Health Organisation (1959). Zoonoses: Second report of the joint WHO/FAO Expert Committee.

WVA (2010) World Veterinary Association Presidents welcome, http://www.worldvet.org/node/9

Appendix I

List of zoonotic diseases

Disease	Organism	Main reservoirs	Usual mode of transmission to humans
Anthrax	Bacillus anthracis	livestock, wild animals, environment	direct contact, ingestion
Avian influenza	Influenza virus, avian strains	poultry, ducks	direct contact
Bovine tuberculosis	Mycobacterium bovis	cattle	milk
Brucellosis	Brucella species	cattle, goats, sheep, pigs	dairy products, milk
Cat scratch fever	Bartonella henselae	cats	bite, scratch
Cysticercosis	Taenia species	cattle, pigs	meat
Cryptosporidiosis	Cryptosporidium species	cattle, sheep, pets	water, direct contact
Enzootic abortion	Chlamydophila abortus	farm animals, sheep	direct contact, aerosol
Erysipeloid	Erysipelothrix rhusiopathiae	pigs, fish, environment	direct contact
Fish tank granuloma	Mycobacterium marinum	fish	direct contact, water
Food poisoning	Campylobacter species	poultry, farm animals	raw meat, milk
	Salmonella species	poultry, cattle, sheep, pigs	foodborne
Giardiasis	Giardia lamblia	humans, wildlife	waterborne, person to person
Glanders	Burkholderia mallei	horse, donkey, mule	direct contact
Haemorrhagic colitis	Escherichia coli O157	ruminants	direct contact (and foodborne)
Hantavirus syndromes	Hantaviruses	rodents	aerosol
Hepatitis E	Hepatitis E virus	not yet known	not yet known
Hydatid disease	Echinococcus granulosus	dogs, sheep	ingestion of eggs excreted by dog
Leptospirosis	Leptospira species	rodents, ruminants	infected urine, water
Listeriosis	Listeria monocytogenes	cattle, sheep, soil	dairy produce, meat products
Louping ill	Louping ill virus	sheep, grouse	direct contact, tick bite
Lyme disease	Borrelia burgdorferi	ticks, rodents, sheep, deer, small mammals	tick bite
Lymphocytic choriomeningitis	Lymphocytic choriomeningitis virus	rodents	direct contact
Orf	Orf virus	sheep	direct contact
Pasteurellosis	Pasteurella multocida	dogs, cats, many mammals	bite/scratch, direct contact
Plague	Yersinia pestis	rats and their fleas	flea bite
Psittacosis	Chlamydophila psittaci	birds, poultry, ducks	aerosol, direct contact
Q fever	Coxiella burnetii	cattle, sheep, goats, cats	aerosol, direct contact, milk, fomites
Rabies	Rabies viruses	cats, dogs, foxes, bats	animal bite
Rat bite fever (Haverhill fever)	Streptobacillus moniliformis	rats	bite/scratch, milk, water
Ringworm	Dermatophyte fungi	cats, dogs, cattle, many animal species	direct contact
Streptococcal sepsis	Streptococcus suis	pigs	direct contact, meat
Streptococcal sepsis	Streptococcus zooepidemicus	horses, cattle	direct contact, milk
Toxocariasis	Toxocara canis/cati	dogs, cats	direct contact
Toxoplasmosis	Toxoplasma gondii	cats, ruminants	ingestion of faecal oocysts, meat
Trichinellosis	Trichinella spiralis	pigs, wild boar	pork products
Tularemia	Francisella tularensis	rabbits, wild animals, environment, ticks	direct contact, aerosol, ticks, inoculation
Zoonotic diphtheria	Corynebacterium ulcerans	cattle, farm animals, dogs	direct contact, milk
West Nile fever	West nile virus	wild birds, mosquitoes	mosquito bite

Source: HPA, 2009

Appendix II

Classification scheme for zoonoses based on likely history

Old zoonoses	Epidemic and endemic human specific infections with a temporally distant non-human source. (for example, measles, common cold,smallpox).
Recent zoonoses	New or emerging human epidemic or endemic infections with a recent non-human source. (for example, HIV).
Established zoonoses	Infectious diseases with a non-human reservoir host that are occasionally transmitted to humans. (for example, rabies, monkey pox, NTS)
New and emerging zoonoses	Infectious diseases with a non-human reservoir host that have only recently (or observed to) spread to humans, (for example, hantaviruses,Ebola virus, Hendra-like virus (Nipah), Ehrlichioses
Parazoonoses	Infectious disease epidemic or endemic in humans but that change in virulence periodically after an input of genes from non-human pathogens. (for example, antibiotic resistance transferred from animal to human bacteria or, genomic reassortment (antigenic shift) in influenza A virus or rotavirus.

Source: Hart CA, M Bennett and ME Begon (1999) Zoonoses J. Epidemiol. Community Health 1999;53;514-515