Every EHO dreads a food poisoning outbreak, and many have an equal horror of any ensuing court case. Here Miranda Steward and Andrew Bowles explain how to make the most of environmental health legislation and approach an outbreak with confidence and resolve

An investigation into a suspected outbreak of infectious or communicable disease may start with two or more cases which have an association in time, place and symptoms. These symptoms may be caused by the ingestion of toxic chemicals, pathogenic bacteria or viruses by the medium of food or water, person-to-person contact or inhalation of bacteria such as legionella. As Graham Cox QC identified in the fatal accident investigation into the Lanarkshire E. coli outbreak, there are two main tasks to outbreak investigations. Firstly, ensuring that sick people are placed under medical supervision and, secondly, preventing the consumption of contaminated food. These observations should form the philosophical basis for any investigations of communicable or infectious disease. Richard North has further stated that the main concern, if no new cases are occurring, is to identify and inform others of the cause of the infection, in order to prevent similar incidents occurring. The outbreak may appear in a closed or wider community setting, but, as public health professionals, the overriding consideration is to protect public health, which means breaking the cycle of infection or contamination and preventing its recurrence - in other words outbreak control.

OUTBREAK CONTROL
It is essential to find out what has happened as soon as possible. There may be a conflict in the way information is gathered if a criminal prosecution is to be considered at a later stage. There may also be other hearings where evidence of the investigation is required, such as coroner inquests, public inquiries or Commons select committees. It should be remembered that the investigation itself may come under scrutiny and investigators may be required to demonstrate that they understand and have considered all the legal powers available to them.

An investigation into an outbreak relies on three essential components. The first is a systematic approach - an outbreak control plan. The second is good interpersonal skills - people may be worried that they, or their relatives, may not get better; that they have made others ill; that they have fallen foul of the law or that the cause has not been identified. Unpicking circumstances quickly and accurately reduces the likelihood of mistakes or hostility, so environmental health managers should ensure that those involved in investigations are properly skilled in interviewing techniques. The third component, and the focus here, is knowledge of the law and how and when to apply it.

KNOWING THE LAW
Understanding the legal aspects of an outbreak investigation allows investigators to gather information, implement control measures and ensure that evidence which has been gathered for control measures is identified and retained. However, the gathering of evidence in such circumstances may not conform to the procedures required in criminal proceedings and may thus be inadmissible. In such circumstances, the criminal investigation team may need to conduct further investigations and interviews, taking account of the Police and Criminal Evidence Act 1984.

All investigators should be alert to the differences in gathering evidence for control measures and for criminal investigations. The principal statutes on which outbreak control teams are likely to rely are the Health and Safety at Work Act 1974, Public Health (Control of Diseases) Act 1984, the Food Safety Act 1990. While not relevant to outbreak management, the officers should also be familiar with PACE and the Criminal Procedures and Investigations Act 1996, as wrong use of these may compromise control measures or criminal proceedings. Reference should also be made to statutory instruments and codes of practice. Authorities should ensure that anyone investigating an outbreak and involved in any subsequent criminal investigation is properly authorised under the relevant statutes.

Record Keeping
Reference should always be made to previous inspection reports and other relevant records to provide background information. Detailed notes, including dates and times, should be made contemporaneously of all calls; conversations; inspections; seizure or detention of foods; examination of documents; recovery of samples; and minutes of any outbreak control committee meetings. If decisions are made, these should be recorded along with any dissenting views.
Receipts must be given to those in control of premises of any documents or equipment removed or seized and of any samples taken. Any informal arrangements made should be in writing and signed by all relevant parties.

Such attention to detail is critical for two reasons:
1. Justification of actions may be required at a later stage - accurate notes will bring to mind events which may have happened months or years earlier. This is particularly relevant for civil proceedings which can take a long time.
2. At some stage decisions will need to be made as to whether a criminal investigation should be mounted. Witness statements will contain more detailed and reliable information if recorded at the outset.
In addition, the officer in charge of a criminal investigation has a responsibility under the CPI Act 1996 to ensure that all material which may be relevant to an investigation is retained, whether it is helpful to the prosecution or not.

Approach
The investigation may initially commence with what appears to be a closed community outbreak, but investigators should always bear in mind that they may be dealing with a wider problem. The approach to the investigation should be open-minded and emphasise public protection; such an approach will foster better relationships with all involved.
The investigation will rely upon a number of matters, principally questioning individuals, examining documents, the taking of samples and the power of entry.

INTERVIEWING INDIVIDUALS
Individuals may be suspected of committing offences, however, the role of public protector should prevail until the cause has been reasonably identified and the outbreak controlled. It should be remembered that the caution under code C, para. 10.1 of PACE need only be given if the answers or silence are to be used in court. Inviting a potential defendant to rely on his right of silence could prevent the team from establishing all the facts, which may in turn lead to the delay of control measures, a failure to implement them properly, or the failure to identify sources or outlets of potentially contaminated food.
If a criminal investigation is launched, individuals suspected of committing offences should be re-interviewed under PACE as any incriminating answers or statements made in earlier stages of the investigation are likely to be inadmissible in any prosecution.

Powers of persuasion
If persuasion to answer questions is unsuccessful, there are other routes which could be explored, including the Health and Safety at Work Act 1974.

Sections 2 and 3 of HASWA place general duties on employers to ensure, so far as is practicable, the health, safety and welfare of their employees and to ensure that persons not in their employment, who may be affected, are not exposed to risks to their health and safety.

Section 20 provides the authorised health and safety inspector with wide-ranging powers, including the power to require any person whom the inspector believes can give relevant information to any examination or investigation, to answer any questions he thinks fit to ask and to sign a declaration as to the truth of the answers given. There is protection in section 20(7) which restricts evidence obtained in this way from being used against him. For this to be used, the local authority would have to be the enforcing authority for the business implicated and assistance from the HSE could be sought here.

Section 33 of the Food Safety Act 1990 deals with obstruction and assistance, making it an offence to intentionally obstruct any person executing the act, or, without reasonable cause, fail to give assistance or information which that person may reasonably require of him for the performance of his functions under this act. It is also an offence to furnish or recklessly furnish information which is knowingly false or misleading in a material particular. However, the officer cannot require any person to answer any questions which might incriminate him. Recent Lacots guidance has indicated that an officer investigating alleged offences is entitled to ask questions of employees. A failure to answer these, even under the instructions of a superior, may amount to an offence, although section 33(3) protects them from answering questions if it might incriminate them.
Clearly, this section could be used if a food business was implicated in selling, offering, exposing or having in possession food which was unfit or contaminated.

Alternatively, section 18 of the Public Health (Control of Diseases) Act 1984 states "that on the application of the proper officer, the occupier of any premises in which there has or has been any person suffering from a notifiable disease or food poisoning, should provide information for the purpose of enabling measures to be taken to prevent the spread or to trace the source of food poisoning". This is however of limited value if questioning is directed at their food business, as it would need to be demonstrated that the patient was actually suffering from food poisoning while still on the premises.

Section 22 requires the principal of a school in which any pupil is suffering from a notifiable disease to provide a list of names and addresses of non-boarding pupils in or attending the school or any specified department.

CONFIDENTIALITY OF INFORMATION
The outbreak control committee may need to consider naming businesses or individuals. An assessment of the risk to consumers in not publicly issuing names must be undertaken, along with consideration of the risk of compensation claims if the information is provided injudiciously.
Regulation 12 of the Public Health (Infectious Disease) Regulations 1998 states that the information in any certificate or copy and in any accompanying or related document, shall not be divulged unless the proper officer considers it necessary for preventing the spread of disease.
Section 32 of the FSA prohibits the officer disclosing any trade secret if it is obtained whilst using their powers to enter premises or inspect records.

Powers of Entry
Section 32 of the FSA provides the authorised officer with powers to enter any premises within the authority's area and also to inspect any business premises within or outside the area in order to investigate whether there is evidence of a contravention which may have occurred within the authorised officer's area. A warrant may be obtained to enter premises and, if granted, shall be in force for a period of one month, but can only be used to effect one entry. It should be remembered that 24-hour notice must be given prior to entering domestic premises. This may be relevant in outbreaks involving a home caterer. However, if the inspector believes immediate entry is required, he may apply to a magistrate for a warrant.

Section 20 of HASWA also provides powers of entry for the authorised inspector, who once in the premises, can then implement a range of subsidiary powers. It also allows the inspector to make such examination as may be necessary in order to take measurements, photos and recordings. Under subsection 2(e), the inspector can direct that any premises or part, or anything therein, should be left undisturbed for the purpose of any examination or investigation. Clearly this is useful where swabbing is required and the inspector needs to restrict access, cleaning or sanitation until that part of the investigation is complete.

The authorised officer, under section 32 of the FSA, may inspect records in whatever form they are held, and may seize and detain any records which he has reason to believe may be required as evidence. Section 20 of HASWA provides the inspector with powers to require the production of any books or documents, extending to allow him to inspect and take copies. This could be notes on envelopes, marks in trade directories which may indicate suppliers or customers, reservation books, staff attendances, training, auditing papers, temperature checks etc.

TAKING SAMPLES
Samples can include food, environmental and body specimens. Under section 3 of the FSA, there is a presumption that any foods commonly used for human consumption if sold, offered, exposed or kept, are for sale for human consumption unless the contrary is proved. Section 29 allows an authorised officer to take a sample of food or substances which appear intended for human consumption or food source; a sample of any contact material found in any premises he is authorised to enter; or a sample of any article or substance on or in any premises which he has reason to believe may be needed as evidence under this statute.

Equally, HASWA permits the taking of samples of any articles or substances. It should be noted that section 20 allows the officer to take samples for two purposes.
1. Under subsection 2(g) an officer can take samples of articles or substances for surveillance purposes. In this case there is no obligation to provide the responsible person with a part of the sample.

2. If the article or substance is taken under subsection 2(h), where the officer believes that it is likely to cause danger to health and safety, then he can have it dismantled or subjected to any process or test. Needless to say it should not be destroyed or damaged unless absolutely necessary.
However, under subsection 6 the inspector must:
a) leave a notice giving particulars to identify the sample with a responsible person or displayed in a conspicuous position
b) give a portion of the sample to a responsible person, if practicable.
If the inspector takes possession of these articles or substances he can ensure they are not tampered with before his examination is completed and ensure they are available to use as evidence. Such a provision will allow an inspector to take food equipment for testing purposes to see whether it operates within specification or whether it is itself contaminated.

FORMAL SAMPLES OF FOOD
In such investigations, samples of food should be taken formally. A proper chain of evidence from the taking of the sample to its receipt at the laboratory would be a prerequisite if legal proceedings were to be instituted at a later stage. The number of individuals handling this sample should be restricted and records to properly identify the sample should be made. Its integrity with respect to storage at controlled temperatures must be maintained.
There are no legal requirements to compel somebody to give a body fluid sample, so powers of persuasion are imperative. The receiving laboratory should be advised of the actual or potential outbreak and that legal proceedings may be considered, so proper records should be kept.

CONTROL MEASURES
In any outbreak, once the investigation reveals a possible source of infection, control measures need to be implemented. The purpose of these is to prevent persons at risk of contracting the illness from doing so.
However, it may be that there is strong evidence that the premises is associated with the outbreak but not sufficient to deem it an immediate risk. Pennington, in his preliminary report, suggested that the outbreak control committee could consider entering a 24 hour informal agreement with the proprietor to close the premises to allow further investigations. However, it must be in writing and care needs to be taken to ensure the proprietor is given every opportunity to take advice. Once the 24 hours has expired, the authority should either implement the emergency prohibition powers or allow the premises to reopen.
Such an agreement might also include the suspension of a process or activity, the exclusion of individuals from the premises or the destruction of food. Any voluntary agreement should be documented, signed and dated by all parties.

DETENTION, SEIZURE AND DISPOSAL OF FOODS
Early indications may suggest a particular ingredient, such as undercooked eggs, or a precooked product which has not been subjected to further treatment. Alternatively, there may be concern that a process may have failed or evidence to suggest widespread cross-contamination.
Clearly, if any of these foods are available and appear likely to cause food poisoning or any disease communicable to human beings, section 9 of the FSA allows for them to be detained for up to 21 days and/or seized, in order to have it dealt with by a justice of the peace.
Alternatively, proprietors may wish to enter an agreement not to sell certain foods until results are available. The outbreak control committee may wish to consider this as an alternative, particularly where controlled temperature storage is required and food can therefore be maintained on the site. Ultimately, it is the authorised officer who will take the legal responsibility of such a proposal, with regard to the integrity of the proprietor and the clear separation of such foods. A written agreement, signed by all parties, should be drawn up stating the description of the food, the quantity, storage and security arrangements.

A clear statement should be made that the local authority or proprietor can withdraw from the agreement, providing this is undertaken in writing and handed to each party, and that an authorised officer can at any time use their powers to detain or seize the food. It should also be made clear that if the proprietor reneges on the agreement, they will likely be prosecuted for breach of section 33 of the FSA for failing to give assistance and intentionally obstructing the authorised officer.
The proprietor may voluntarily surrender the food and if this happens the authority needs to take responsibility to ensure it does not re-enter the food chain. In any event, authorities may need secure arrangements in place to remove and store the food. For example, arrangements to have controlled temperature vehicles in a vehicle pound.

EMERGENCY PROHIBITION
If the authorised officer believes an imminent risk of injury to health exists, he may serve an emergency prohibition notice under the FSA. The evidence used to seek the emergency prohibition order, to have the emergency prohibition notice confirmed, or to justify any claim for compensation, will be on the balance of probabilities, as the magistrates will deal with the matter in their civil capacity. It should be noted that PACE does not apply in this case and should not be used for the reasons previously stated.
As code of practice 6 states - the word "imminent" qualifies the word "risk". Therefore it is the risk of injury which must be imminent. The code of practice clearly states it is appropriate to consider exercising the emergency powers when premises or practices which seriously contravene food hygiene regulations have been or are involved with an outbreak of food poisoning. This could include one or all of the alternatives laid down in section 11(2)(I), ie: state of the premises or equipment; condition of the premises or equipment. There may be a need for expert advice if the matters relate to a specific process.

Officers should remember that the application for the emergency prohibition order, which is made by way of one or more complaints, will have to be made on the third day after the emergency prohibition notice has been served and the proprietor must be given at least one day's notice of the authority's intention to apply for the order. In relation to the matter of the premises being associated with food poisoning, a medical opinion is critical. This may be obtained from the consultant in communicable disease control, who can provide epidemiological evidence associated with the point source or vehicle of infection.
The basic information obtained from cases, detailing onset dates, symptoms and duration, together with information connecting the case to the source premises, can be put before the court. It should be pointed out that very often this is hearsay evidence, which will have been obtained during the normal investigation procedures for outbreak control and the magistrates sitting in their civil capacity can, at their discretion, take account of such evidence.

If lab reports on patients' specimens are available, these should be produced, as should statements from positive cases, including dates, symptoms and linkage to the suspected source premises. From these, the medical advisor to the council can give an opinion as to the relevance of the evidence in relation to the premises being associated with an outbreak or other infection or contamination.
For example: over the period in question, from the number of people the authority knows to be at risk, a particular number have displayed gastroenteritis symptoms consistent with the organism associated with the outbreak. Further, the laboratory reports which can be produced from cases with symptoms are positive to the organism. Reference could also be made to any telephone reports. Details of incubation periods are relevant. The food examiner could also provide evidence as to the pathogenicity, toxicity of the organism and the likelihood of growth on the suspected foods.
A very short time sequence begins once the emergency prohibition notice is served and officers should have all evidence to hand and available to support the complaints, including; witness statements; laboratory reports; copies of notices; food examiners certificates; orders; scrapings; photographs, equipment; plans etc.

SELECTIVE PROHIBITION
Section 22 of HASWA provides for the inspector under that act to prohibit, by a notice, activities that in the opinion of the inspector are likely to involve a risk of serious personal injury. The notice will take immediate effect if the inspector considers the risk to be imminent or can come into effect at the end of a specified period in other cases.
This can be very useful to those seeking to enforce immediate control measures to premises implicated in an outbreak of infectious disease other than food poisoning. An example where such a notice would be useful would be the prohibition of the operation of a residential home where a person-to-person infection is apparent without the implementation of an effective infectious control policy. Necessary measures would be attached to a schedule to the notice, providing clear instructions on matters such as cleaning, disinfecting and disposal of clinical waste.
It should be remembered that, as for any formal notice, the recipient has the right of appeal. In the case of section 22 notices, the appeal may be made to the employment tribunal who may cancel, modify or affirm the notice and award costs against the respondents. As such, it is recommended that legal advice be sought prior to the service of such notices to control outbreaks of infectious disease.

PRODUCT RECALL
During the investigation it may be suspected that a foodstuff linked to the infection has been distributed beyond the immediate area. Similarly, suspicion may fall on food brought in from elsewhere. Under these circumstances it is essential that the outbreak control committee responds quickly and efficiently to prevent further consumption. Officers should of course have regard to code of practice 16. It is vital that details of the size and nature of the implicated business are obtained at an early stage.
It is recommended that officers not involved in the contact and tracing of suspected cases of food poisoning are given the task of establishing information about any suspected and implicated food. This may involve the examination of invoices and purchase records and detailed discussions with the proprietor, distributors, other outlets etc. The key aim is to stop the public eating food suspected to be unsafe. As Graham Cox QC stated: "The task of preventing consumption of contaminated food is of greater importance than gathering evidence of deficiencies."

When conducting such investigations it is important to consider the characteristics of the pathogen involved and avoid gathering information irrelevant to its control. The identification of any potential outlets for the food should be made early on and contact made with relevant local authorities, ensuring they are provided with full information of the outbreak and details of any suspected food. It may be necessary to discuss voluntary recall of a suspected product with the proprietor. Any sales arrangements should be made in writing to prevent misunderstanding. In high street premises, regard should be had to the placing of a notice in a prominent position requesting that customers return a suspected product.

CONCLUSIONS
There is a plethora of regulations which may assist an outbreak control committee in its primary role of identifying and controlling outbreaks of illness from bacteria, viruses or chemical contamination.
By understanding the legal aspects of outbreak investigations, this should allow for prompt control measures to be implemented and direct the committee to the cause of the outbreak, while allowing for a considered decision to be made at a later stage as to whether or not to mount a criminal investigation. It also allows the criminal investigation team to promptly identify any inadmissible evidence with the intention of gathering it in an admissible form. The outbreak investigation's overriding responsibility must be to control the source of the infection and identify the cause to prevent further recurrences.

Miranda Steward is assistant director of community protection and Andy Bowles is acting head of environmental health, commercial, at Enfield LBC

References
Determination by Graham L Cox, QC, Sheriff Principal at South Strathclyde, Dumfries and Galloway, into the E. coli O157 Fatal Accident Inquiry.
Lacots Chief Officers Circular LAC 10 98 2 - Due Diligence Investigation and the Food Safety Act 1990.