Methods of control

Methods of control

 

Methods of Control

This section covers:

 

Organisations Involved in Communicable Disease Control

Organisations involved in health protection are those whose remit includes protecting populations from infectious or environmental hazards (chemical or radiation).  In practice there tends to be a tiered arrangement of organisations with primary responsibility for health protection, progressing from local to national level.  These tiers may be within a single or separate organisation, and many other organisations will contribute in some way to health protection. 

In most countries, local health authorities conduct health protection activities at a local level such as receipt of case notifications, and investigation and control measures.  National health authorities tend to be responsible for data collation, analysis, and dissemination for action (surveillance).  They may also support outbreak investigation and control, particularly if investigations cross regional borders. 

There will also be a variety of organisations at each level that contribute to the efforts of the health protection team but whose primary function is not health protection, such as local government at a regional or sub-regional level, and food safety and veterinary health agencies at a national level.

For a more detailed example, health protection arrangements in England are discussed briefly below.

Public Health England (PHE) is an executive agency sponsored by, but independent from, the Department of Health.  The Secretary of State for Health has the overarching duty for protecting the health of the public, but in practice this is discharged for him by PHE through its health protection directorate and operations, which has specialist health protection functions such as disease surveillance, laboratory services, investigation and management of health protection incidents and outbreaks. 

 

PHE Structure

Health Protection is one of three professional directorates within PHE.  The directorate delivers health protection services that maintain and deliver best practice to leading international standards. It is a source of expert advice and operational support, and contributes actively to policy-making and implementation in partnership with other PHE directorates and the Department of Health, and externally with the National Health Service (NHS), local authorities, and other agencies.  The Health Protection directorate comprises several specialist national teams:

  • Emergency Response and Preparedness
  • Centre for Radiation, Chemical and Environmental Hazards (CRCE)
  • Field Epidemiology Service (FES)
  • Global Health
  • National specialist epidemiology and intelligence
  • Public Health Strategy (for health protection)
  • Health protection quality, governance and service improvement

Some of these departments are located centrally, others are integrated within local centres.

Sub-national/local Health Protection Teams (HPTs) are organised within the Operations Directorate, which is accountable for delivery of PHE services across England.  They work closely with the Health Protection Directorate.

There are 24 local Health Protection Teams (the most local level of PHE).  The teams are further grouped into 8 sub-regional centres, and then 4 regions including London, which is an integrated centre and region.  

HPTs control communicable disease at a local level with support from the PHE Health Protection Directorate if an incident affects a larger geographical area, is complex, or is of national significance.  The Health Protection Team provides specialist health protection advice as well as operational support on all health protection matters to NHS trusts, local authorities, community health services (including schools and social services), and the general public. Increasingly, these functions are being shared within centres between several teams to improve efficiency. 

HPTs are staffed by CCDCs or CHPs (Consultants in Communicable Disease Control, or Consultant in Health Protection), Health Protection nurse and non-nurse background practitioners, epidemiologists and admin support staff.

The HPT is responsible for the following functions:

  • Surveillance and analysis of trends in communicable disease
  • Liaison with key stakeholders involved in the control of infectious disease
  • Prevention, investigation, and control of health protection incidents including the prevention, investigation and control of outbreaks and incidents involving communicable diseases, chemical, radiological and other environmental hazards
  • Chemical, biological and radiological incident planning and management
  • Provision of advice and support to clinical commissioning groups (CCGs - healthcare commissioning organisations in England), local authorities, hospital and primary care staff and the public on health protection issues
  • Infection control advice and support to nursing and residential homes and schools
  • Acting as the 'proper officer' in relation to public health legislation
  • Advise clinical commissioning groups (CCGs), the local commissioners of NHS services, on commissioning services to prevent, control and treat infection
  • Support the development and implementation of prevention and health promotion programmes
  • Teaching and training of local health professionals in health protection
  • Liaison with local media outlets regarding health protection incidents or outbreaks.

Local government is also charged with planning for and responding to public health emergencies and incidents at a local level; in practice, this entails emergency response planning in cooperation with PHE, and providing assurance for their populations of the specialist functions provided to them by PHE teams.  Environmental health support also sits within local government.  Due to differences in organisational ‘footprint’, each HPT will work in cooperation with several local governments.

 

Prevention of infection

Methods to prevent infection can be directed either to host or environment and include:

 

Standard Precautions

  • Hand Hygiene
         -  Single most important part of infection control
         -  Hand washing before any contact with patients, after any activity that contaminates the hands, after removing protective clothing, after using the toilet and before handling food
  • Use of personal protective equipment (PPE): gloves, aprons, eye protection, face masks, etc.
  • Handle and dispose of sharps safely
  • Dispose of contaminated waste safely
  • Managing blood and body fluids: spillages and transport of specimens
  • Decontaminating equipment: cleaning, disinfection and sterilisation
  • Maintain a clean clinical environment
  • Prevent occupational exposure to infection
  • Manage sharps injuries and blood splash incidents
  • Manage linen safely
  • Place patients with infections in appropriate accommodation.

Enteric Precautions

  • Handwashing (see above)
  • Correct disposal of excretions and soiled material
  • Soiled clothing and bed linen - place in a hot wash (>60°C)
  • Disinfection, especially important in nurseries, schools and residential institutions
  • Education
         -  Emphasise personal hygiene and hygienic preparation and serving of food
         -  Children and adults in jobs likely to spread infection should stay away from school for 48 hours after any diarrhoea has stopped.

Routine and selective immunisation > (see Immunisations)

Tuberculosis screening services

Changes to risk behaviour - This can be achieved through general or targeted education campaigns, e.g. avoid sharing personal items, safe sex, careful disposal of needles / clinical waste with blood borne pathogens.

 

Organisation of infection control

Settings and persons responsible:

  • Hospital - infection control team
     
  • Community - HPT (all environments outside hospital including nursing / residential homes, nurseries and schools, workplaces)
     

1.   HOSPITAL infection control

Healthcare-associated infections (HCAI) are infections that occur in patients or health care workers as a result of healthcare interventions. Control of HCAI is an important part of risk management and clinical governance programmes. Overall responsibility rests with the chief executive and the trust board and the Director of Infection, Prevention and Control (DIPC).

A hospital infection control team (ICT) comprises an Infection Control Doctor (usually a medical microbiologist), one or more infection control nurses and clerical support. They report to a multi-disciplinary Infection Control Committee who liaises with senior management.

Aims of an Infection Control team

  • Maintain an effective programme for the prevention of hospital acquired infection
  • Containment of infections brought into the hospitals by patients, staff or visitors.

Roles and Responsibilities of Infection Control Team

  • Hospitals must ensure the management of infection control programmes is undertaken by competent, qualified Infection Control nurses
  • Provision of ongoing education for all healthcare staff
  • Develop infection control policies and ensure accessible to all staff
  • Facilities and equipment are available to enable compliance with policies
  • Ensure all clinical staff have received appropriate training
  • Infection control audits
  • Surveillance.

The hospital infection control team works with the Hospital Infection Control Committee. A Hospital Infection Control Committee consists of the ICT (see above), hospital chief executive or senior director, CCDC/CHP, Occupational Health Consultant and others as needed.
 

2.  COMMUNITY Infection Control

The local HPT takes a main role in community infection control. It works with all community organisations that provide care, healthcare or treatments outside hospital including nursing / residential homes, nurseries and schools. The HPT advises and helps maintain good infection control practices in these community settings. This is achieved through the direct input of health protection practitioners, who provide most of the HPT infection control advice and the CCDCs/CHPs being the main link between the clinical commissioning group (CCG - healthcare commissioning organisations in England) infection control teams and hospital ICTs. Health Protection Practitioners work through educational means to raise awareness of infection control issues and provide advice on infection control measures, exclusion, risk / hazard reduction and screening to the community organisations listed above as needed.

For example, a HPT may advise private nursing home staff about infection control principles, advise schools and nurseries on infection control principles and in conjunction with the local authority, and review the infection control practices of tattoo parlours and beauticians.

 

Regulations and legal powers used in the control of infection

In England, the HPT in conjunction with the local authority have responsibility for enforcing key regulations relating to protecting the health of the public. These include:-

Public Health Law

The Public Health (Control of Disease) Act 1984 (amended by the Health and Social Care Act 2008), and subsequent Health Protection Regulations 2010 and Health Protection (Part 2A orders) Regulations 2010 concern two key areas of health protection.  Firstly, they outline the statutory notification duties of registered medical practitioners (see notification of infectious diseases section below), and secondly, they give UK local authorities powers to enable restrictions or requirements to be imposed on people and in respect of things and/or premises to protect human health, provided strict criteria are met. The powers are exercised either directly or indirectly through the 'Proper officer', an officer appointed by (or employed by PHE to whom the duty is delegated) the local authority for a specific purpose. The Proper Officer is usually the Consultant in Communicable Disease Control (CCDC)/ Consultant in Health Protection (CHP).

Broadly, there are 2 types of powers:

  • Local authority powers;
  • The 2A Orders.

 

Local authority powers provide a range of measures that can be to used to prevent, protect against, control or provide a health protection response to an incident or spread of infection or contamination that presents, or could prevent, significant harm to human health.  They can be exercised without applying to a Justice of the Peace but specific criteria must be satisfied.  The powers include:

  • require that a child is kept away from school;
  • require a teacher to provide a list of contact details of pupils attending their school;
  • disinfect/decontaminate articles on request;
  • request (but not require) individuals or groups to co-operate for health protection purposes;
  • restrict contact with, or relocate, a dead body for health protection purposes.

 

Part 2A Orders are obtained by local authorities on application to a Justice of the Peace and impose restrictions or requirements on a person, thing, a body or human remains, or a premises, e.g. for a person to be detained in hospital; to restrict a person’s movements or contact with other people; or to require that a premises is closed or decontaminated.  The power also includes a requirement for a person to give information about a ‘related party, person, or thing’, as relevant to the case.

 

Other powers  include powers of entry or inspection to carry out health protection functions.

 

Broad principles should be met before powers can be applied:

  • a person, thing, dead body or premises is, or may be, infected or contaminated
  • a risk assessment that the threat must present, or could present significant harm to human health
  • there is a risk of spread of contamination/infection
  • use of the power is necessary to reduce that risk
  • the action is proportionate to reduce that risk
  • use of the power is only to reduce that risk
  • use of a Part 2A Order is for a specified time period.

There are specific criteria for certain local authority powers and 2A orders, see the regulations for details.  Note a 2A order cannot be used to impose medical treatment or vaccination on an individual.

 

The Environment Agency (‘EA’, the national environmental regulatory body, an executive non-departmental public body, sponsored by the Department for Environment, Food & Rural Affairs) and Local Authority Environmental Health Departments have legal powers to control (by giving permits to operate under certain conditions, or enforcement notices) aspects of the environment that could be a threat to human health, specifically:

  • Waste operations (including mining waste and waste incineration plants)
  • Radioactive substances activity
  • Water discharge and groundwater activities (including sewage disposal).

Whether the EA or local environmental health departments are the regulator depends on the nature and size of the facility/establishment.

Local authorities also have regulatory powers or an enforcement role over:

  • Supplies and suppliers of food and feedstuffs (see Food Safety Act below)
  • Private water supplies (public supplies are regulated by the Drinking Water Inspectorate in England, a public body)
  • Pest control and other ‘nuisances’ that could be harmful to health e.g. fumes, smells, smoke, noise (Statutory Nuisances and Clear Air section of the Environmental Protection Act 1990).  This may include premises that are potentially harmful to health due to probable legionella contamination of the water system (PHE Joint Single Case Legionella Plan V6 2014).  The Act allows local authorities to inspect and investigate if a nuisance is present, and to serve an ‘abatement’ notice on the responsible person to remove the nuisance.
  • The Health and Safety at Work Act may be used in an occupational setting to compel premises occupiers to clean and disinfect plant which is not being maintained to a standard required by ‘Legionnaires’ disease

 

Food Safety Act 1990 (Amended 2004)

Framework for regulations that govern:

  • activity of food businesses
  • composition and labelling of foods
  • chemical safety
  • food hygiene

Enforcement is the responsibility of local authority environmental health officers at a local level, and the Food Standards Agency nationally.

 

Notification of communicable diseases to HPTs

HPTs are notified of patients with communicable diseases via a Statutory Notification form or a lab report.

 

Statutory Notification of Infectious Diseases (NOIDS)

‘Notification of infectious diseases’ is the term used to refer to the statutory duties for reporting notifiable diseases in the Public Health (Control of Disease) Act 1984 and the updated Health Protection (Notification) Regulations 2010.

Registered medical practitioners in England and Wales have a statutory duty to notify the ‘proper officer’ of their local authority or local Health Protection Team of suspected cases of certain infectious diseases.  In practice, this tends to be a CCDC/CHP within the local HPT. 

Practitioners are asked to send the form by fax, post or encrypted email within 3 days, or to report orally by telephone if urgent.  A few other countries use web-based notification forms that will automatically pre-populate surveillance databases.  Diagnostic laboratories in England can notify by electronic means (using the Second Generation Surveillance System (SGSS)).

The aim is to detect possible outbreaks of disease and epidemics as rapidly as possible. Accuracy of diagnosis is secondary, and since 1968 clinical suspicion of a notifiable infection is all that’s required.  PHE collects these notifications and publishes analyses of local and national trends every week.

The Health Protection Regulations 2010 extended the duty of RMPs above the duty to inform the proper officer of the list of notifiable diseases given below, to also notify of infections or contamination which they believe present, or could present, a significant threat to human health i.e. an ‘all hazards approach’.

 

Diseases notifiable to local authority proper officers under the Health Protection (Notification) Regulations 2010:

  • Acute encephalitis
  • Acute infectious hepatitis
  • Acute meningitis
  • Acute poliomyelitis
  • Anthrax
  • Botulism
  • Brucellosis
  • Cholera
  • Diphtheria
  • Enteric fever (typhoid or paratyphoid fever)
  • Food poisoning
  • Haemolytic uraemic syndrome (HUS)
  • Infectious bloody diarrhoea
  • Invasive group A streptococcal disease
  • Legionnaires’ disease
  • Leprosy
  • Malaria
  • Measles
  • Meningococcal septicaemia
  • Mumps
  • Plague
  • Rabies
  • Rubella
  • Severe Acute Respiratory Syndrome (SARS)
  • Scarlet fever
  • Smallpox
  • Tetanus
  • Tuberculosis
  • Typhus
  • Viral haemorrhagic fever (VHF)
  • Whooping cough
  • Yellow fever
  • Report other diseases and contamination that may present significant risk to human health under the category ‘other significant disease’ – this measure prevents a requirement for updates to legislation whenever a novel infection of public health importance arises, and mandates reporting of cases that may form part of an emerging public health threat for which there is no specific notification duty, e.g. Middle Eastern Respiratory Syndrome (MERS), radioactive agent release due to terrorism.

 

All laboratories in England performing a primary diagnostic role must notify Public Health England (PHE) when they confirm a notifiable causative organism.  The list is slightly different than simply the list of causative organisms for the clinical NOIDs list above:

  • Bacillus anthracis
  • Bacillus cereus (only if associated with food poisoning)
  • Bordetella pertussis
  • Borrelia spp
  • Brucella spp
  • Burkholderia mallei
  • Burkholderia pseudomallei
  • Campylobacter spp
  • Chikungunya virus
  • Chlamydophila psittaci
  • Clostridium botulinum
  • Clostridium perfringens (only if associated with food poisoning)
  • Clostridium tetani
  • Corynebacterium diphtheriae
  • Corynebacterium ulcerans
  • Coxiella burnetii
  • Crimean-Congo haemorrhagic fever virus
  • Cryptosporidium spp
  • Dengue virus
  • Ebola virus
  • Entamoeba histolytica
  • Francisella tularensis
  • Giardia lamblia
  • Guanarito virus
  • Haemophilus influenzae (invasive)
  • Hanta virus
  • Hepatitis A, B, C, delta, and E viruses
  • Influenza virus
  • Junin virus
  • Kyasanur Forest disease virus
  • Lassa virus
  • Legionella spp
  • Leptospira interrogans
  • Listeria monocytogenes
  • Machupo virus
  • Marburg virus
  • Measles virus
  • Mumps virus
  • Mycobacterium tuberculosis complex
  • Neisseria meningitidis
  • Omsk haemorrhagic fever virus
  • Plasmodium falciparum, vivax, ovale, malariae, knowlesi
  • Polio virus (wild or vaccine types)
  • Rabies virus (classical rabies and rabies-related lyssaviruses)
  • Rickettsia spp
  • Rift Valley fever virus
  • Rubella virus
  • Sabia virus
  • Salmonella spp
  • SARS coronavirus
  • Shigella spp
  • Streptococcus pneumoniae (invasive)
  • Streptococcus pyogenes (invasive)
  • Varicella zoster virus
  • Variola virus
  • Verocytotoxigenic Escherichia coli (including E.coli O157)
  • Vibrio cholerae
  • West Nile Virus
  • Yellow fever virus
  • Yersinia pestis

 

HPT Response to a patient with an infectious disease

1.  What investigations (microbiological / environmental / epidemiological) are needed to identify the agent, the cause of the incident?

2.  What is the Source of Infection?

  • Is it a continuing source that may need to be controlled?
  • If so, what generic control measures can be applied to limit morbidity whilst awaiting confirmation e.g. enhanced hand washing, environmental cleaning, etc?
  • Are there others exposed who may need advice / treatment?

3.  What is the likelihood of transmission?

  • Advice / prophylaxis to close contacts, e.g. hepatitis B immunisation
  • Occupational transmission, e.g. exclusion of food handlers with gastrointestinal infection

4.  Is public health action necessary?

     Risk Assessment - how infectious is the source; how close is the contact; how susceptible are those exposed?

  • Is the index case at risk of a poor outcome?
  • Is the index case likely to pass the infection to others?
  • Is there likely to be an ongoing source that needs controlling?
  • Do contacts and others exposed to the same source need to be traced?
  • Do the public need information or reassurance?

5.  Is immediate public health action needed?
 
     To determine this consider:

  • Seriousness of disease
  • Transmissibility of infection
  • Length of incubation period
  • Vulnerability of people exposed
  • Public/ media / political reaction
  • What is good practice

6.  Possible interventions

  • Improve outcome for cases, e.g. antibiotics, immunoglobulin
  • Trace others exposed to source or cases to provide advice, antibiotics or vaccines
  • Prevent others being exposed to cases / contacts by rendering them non-infectious by use of antibiotics and / or isolation
  • Provision of hygiene advice
  • Exclusion from work / school
  • Closure of premises associated with incident e.g. cooling towers, food premises
  • Identify possible source and implement and monitor control measures to contain this source

7.  Communication

  • Cases / contacts / clinicians
  • Internal - specialist advice within HPT / microbiology
  • External - local authorities, press e.g. outbreak of meningococcal disease in a school

 

 

                                              © Sarah Anderson, Gayatri Manikkavasagan 2008, David Roberts 2016