Healthcare Associated Infections
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath)
Department of Medical Microbiology and Parasitology
drjonahp@yahoo.com
Outline
○ Healthcare associated infections
○ Frequency of HAI
○ Impact of HAI
○ Factors influencing the development of HAI
○ The Chain of Infection
○ Hospital Infection Prevention and Control Guidelines
○ Dealing with Outbreaks
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Healthcare associated infection
Also called “Nosocomial infection ” can be defined as:
(1). An infection acquired in hospital by a patient who was admitted for a reason other than that infection.
(2). An infection occurring in a patient in a hospital or other health care facility in whom the infection was not present or incubating at the time of admission.
(3). This includes infections acquired in the hospital but appearing after discharge, and including occupational infections among staff of the facility.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Frequency of infection
Nosocomial infections occur worldwide and affect both developed and resource-poor countries. Infections acquired in health care settings are among the major causes of death and increased morbidity among hospitalized patients. They are a significant burden both for the patient and for public health. The most frequent nosocomial infections are infections of surgical wounds, urinary tract infections and lower respiratory tract infections.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Impact of nosocomial infections
Hospital-acquired infections add to functional disability and emotional stress of the patient and may, in some cases, lead to disabling conditions that reduce the quality of life. Nosocomial infections are also a leading cause of death.
The economic costs are considerable. The increased length of stay for infected patients is the greatest contributor to cost.
Organisms causing nosocomial infections can be transmitted to the community through discharged patients, staff, and visitors.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Factors influencing the development of nosocomial infections
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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The microbial agent 1
The patient is exposed to a variety of microorganisms during hospitalization. Contact between the patient and a microorganism does not by itself necessarily result in the development of clinical disease; other factors influence the nature and frequency of nosocomial infections.
The likelihood of exposure leading to infection depends partly on the characteristics of the microorganisms, including resistance to antimicrobial agents, intrinsic virulence, and amount (inoculum) of infective material.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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The microbial agent 2
Before the introduction of basic hygienic practices and antibiotics into medical practice, most hospital infections were due to pathogens of external origin, or were caused by microorganisms not present in the normal flora of the patients (e.g. diphtheria, tuberculosis).
Most infections acquired in hospital today are caused by microorganisms which are common in the general population, in whom they cause no or milder disease than among hospital patients (Staphylococcus aureus, coagulase-negative staphylococci, enterococci, Enterobacteriaceae).
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Patient susceptibility 1
Important patient factors influencing acquisition of infection include age, immune status, underlying disease, and diagnostic and therapeutic interventions.
The extremes of life (infancy and old age) are associated with a decreased resistance to infection. Patients with chronic disease such as malignant tumours, leukaemia, diabetes mellitus, renal failure, or the acquired immunodeficiency syndrome (AIDS) have an increased susceptibility to infections with opportunistic pathogens.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Patient susceptibility 2
Opportunistic pathogens are infections with organism(s) that are normally innocuous, e.g. part of the normal bacterial flora in the human, but may become pathogenic when the body’s immunological defences are compromised.
Immunosuppressive drugs or irradiation may lower resistance to infection. Injuries to skin or mucous membranes bypass natural defence mechanisms. Malnutrition is also a risk. Many modern diagnostic and therapeutic procedures, such as biopsies, endoscopic examinations, catheterization, intubation/ventilation, suction and surgical procedures increase the risk of infection.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Environmental factors
Health care settings are an environment where both infected persons and persons at increased risk of infection congregate. Patients with infections or carriers of pathogenic microorganisms admitted to hospital are potential sources of infection for patients and staff. Patients who become infected in the hospital are a further source of infection.
Crowded conditions within the hospital, frequent transfers of patients from one unit to another, and concentration of patients highly susceptible to infection in one area (e.g. newborn infants, burn patients, intensive care) all contribute to the development of nosocomial infections.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Bacterial resistance 1
Many patients receive antimicrobial drugs. Through selection and exchange of genetic resistance elements, antibiotics promote the emergence of multidrug resistant strains of bacteria; microorganisms in the normal human flora sensitive to the given drug are suppressed, while resistant strains persist and may become endemic in the hospital. The widespread use of antimicrobials for therapy or prophylaxis (including topical) is the major determinant of resistance.
Antimicrobial agents are, in some cases, becoming less effective because of resistance.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Bacterial resistance 2
As an antimicrobial agent becomes widely used, bacteria resistant to this drug eventually emerge and may spread in the health care setting. Many strains of pneumococci, staphylococci, enterococci, and tuberculosis are currently resistant to most or all antimicrobials which were once effective.
Multi-resistant Klebsiella and Pseudomonas aeruginosa are prevalent in many hospitals. This problem is particularly critical in developing countries where more expensive second-line antibiotics may not be available or affordable.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Chain of infection
There are six elements in a chain of infection, and all six must be present before the transmission of infection can take place.
The pathogen
The portal of entry
The mode of transmission
The reservoir
The portal of exit
The host
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Health Care facility infection control programme
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Hospital programmes 1
Prevention of nosocomial infections is the responsibility of all individuals and services providing health care. Everyone must work cooperatively to reduce the risk of infection for patients and staff. This includes personnel providing direct patient care, management, physical plant, provision of materials and products, and training of health care workers.
Infection control programmes are effective provided they are comprehensive and include surveillance and prevention activities, as well as staff training.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Hospital programmes 2
The major preventive effort should be focused in hospitals and other health care facilities. Risk prevention for patients and staff is a concern of everyone in the facility, and must be supported at the level of senior administration.
A yearly work plan to assess and promote good health care, appropriate isolation, sterilization, and other practices, staff training, and epidemiological surveillance should be developed. Hospitals must provide sufficient resources to support this programme.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Infection Prevention and Control Committee
An Infection Prevention and Control Committee provides a forum for multidisciplinary input and cooperation, and information sharing.
This committee should include wide representation from relevant programmes: e.g. management, physicians, other health care workers, clinical microbiology, pharmacy, central supply, maintenance, housekeeping, training services.
In an emergency (such as an outbreak), this committee must be able to meet promptly.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Infection Prevention and Control Committee 2
It has the following tasks:
● to review and approve a yearly programme of activity for surveillance and prevention
● to review epidemiological surveillance data and identify areas for intervention
● to assess and promote improved practice at all levels of the health facility
● to ensure appropriate staff training in infection control and safety
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Infection Prevention and Control Committee 3
● to review risks associated with new technologies, and monitor infectious risks of new devices and products, prior to their approval for use
● to review and provide input into investigation of epidemics
● to communicate and cooperate with other committees of the hospital with common interests such as Pharmacy and Therapeutics or Antimicrobial Use Committee, Biosafety or Health and Safety Committees, and Blood Transfusion Committee.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Infection Control Team (ICT)
The infection control team is responsible for the day-to-day functions of infection control, as well as preparing the yearly work plan for review by the infection control committee and administration.
These individuals have a scientific and technical support role: e.g. surveillance and research, developing and assessing policies and practical supervision, evaluation of material and products, control of sterilization and disinfection, implementation of training programmes.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Infection control manual
A nosocomial infection prevention manual, compiling recommended instructions and practices for patient care, is an important tool.
The manual should be developed and updated by the infection control team, with review and approval by the committee.
It must be made readily available for patient care staff, and updated in a timely fashion.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the infection control team 1
The infection control team (ICT) is responsible for:
● organizing an epidemiological surveillance programme for nosocomial infections
● participating with pharmacy in developing a programme for supervising the use of anti-infective drugs
● ensuring patient care practices are appropriate to the level of patient risk
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the infection control team 2
● checking the efficacy of the methods of disinfection and sterilization and the efficacy of systems developed to improve hospital cleanliness
● participating in development and provision of teaching programmes for the medical, nursing, and allied health personnel, as well as all other categories of staff
● providing expert advice, analysis, and leadership in outbreak investigation and control
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Hospital Infection Control responsibilities
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of hospital management 1
The administration and/or medical management of the hospital must provide leadership by supporting the hospital infection control programme. They are responsible for:
● establishing a multidisciplinary Infection Control Committee
● identifying appropriate resources for a programme to monitor infections and apply the most appropriate methods for preventing infection
● ensuring education and training of all staff through support of programmes on the prevention of infection in disinfection and sterilization techniques
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of hospital management 2
● delegating technical aspects of hospital hygiene to appropriate staff, such as: nursing, housekeeping, maintenance, clinical microbiology laboratory
● periodically reviewing the status of nosocomial infections and effectiveness of interventions to contain them
● reviewing, approving, and implementing policies approved by the Infection Control Committee
● ensuring the infection control team has authority to facilitate appropriate programme function
● participating in outbreak investigation.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the physician 1
Physicians have unique responsibilities for the prevention and control of hospital infections:
● by providing direct patient care using practices which minimize infection
● by following appropriate practice of hygiene (e.g. handwashing, isolation)
● serving on the Infection Control Committee
● supporting the infection control team.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the physician 2
Specifically, physicians are responsible for:
● protecting their own patients from other infected patients and from hospital staff who may be infected
● complying with the practices approved by the Infection Control Committee
● obtaining appropriate microbiological specimens when an infection is present or suspected
● notifying cases of hospital-acquired infection to the team, as well as the admission of infected patients
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the physician 3
● complying with the recommendations of the Antimicrobial Use Committee regarding the use of antibiotics
● advising patients, visitors and staff on techniques to prevent the transmission of infection
● instituting appropriate treatment for any infections they themselves have, and taking steps to prevent such infections being transmitted to other individuals, especially patients.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the microbiologist 1
The microbiologist is responsible for:
● handling patient and staff specimens to maximize the likelihood of a microbiological diagnosis
● developing guidelines for appropriate collection, transport, and handling of specimens
● ensuring laboratory practices meet appropriate standards
● ensuring safe laboratory practice to prevent infections in staff
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the microbiologist 2
● performing antimicrobial susceptibility testing following internationally recognized methods, and providing summary reports of prevalence of resistance
● monitoring sterilization, disinfection and the environment where necessary
● timely communication of results to the Infection Control Committee or the hygiene officer
● epidemiological typing of hospital microorganisms where necessary.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the hospital pharmacist 1
The hospital pharmacist is responsible for:
● obtaining, storing and distributing pharmaceutical preparations using practices which limit potential transmission of infectious agents to patients
● dispensing anti-infectious drugs and maintaining relevant records (potency, incompatibility, conditions of storage and deterioration)
● obtaining and storing vaccines or sera, and making them available as appropriate
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the hospital pharmacist 2
● providing the Antimicrobial Use Committee and Infection Control Committee with summary reports and trends of antimicrobial use
● having available the information on disinfectants, antiseptics and other anti-infectious agents.
● participation in development of guidelines for antiseptics, disinfectants, and products used for washing and disinfecting the hands
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the nursing staff 1
● participating in the Infection Control Committee
● promoting the development and improvement of nursing techniques, and ongoing review of aseptic nursing policies, with approval by the Infection Control Committee
● developing training programmes for members of the nursing staff
● supervising the implementation of techniques for the prevention of infections in specialized areas such as the operating suite, the intensive care unit, the maternity unit and newborns
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the nursing staff 2
● maintaining hygiene, consistent with hospital policies and good nursing practice on the ward
● monitoring aseptic techniques, including handwashing and use of isolation
● reporting promptly to the attending physician any evidence of infection in patients under the nurse’s care
● initiating patient isolation and ordering culture specimens from any patient showing signs of a communicable disease, when the physician is not immediately available
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the housekeeping service 1
The housekeeping service is responsible for the regular and routine cleaning of all surfaces and maintaining a high level of hygiene in the facility. In collaboration with the Infection Control Committee it is responsible for :
● classifying the different hospital areas by varying need for cleaning
● developing policies for appropriate cleaning techniques
● developing policies for collection, transport and disposal of different types of waste (e.g. containers, frequency)
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the housekeeping service 2
● ensuring that liquid soap and paper towel dispensers are replenished regularly
● informing the maintenance service of any building problems requiring repair: cracks, defects in the sanitary or electrical equipment, etc.
● caring for flowers and plants in public areas
● pest control (insects, rodents)
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Role of the housekeeping service 3
● providing appropriate training for all new staff members and, periodically, for other employees, and specific training when a new technique is introduced
● establishing methods for the cleaning and disinfection of bedding (e.g. mattresses, pillows)
● determining the frequency for the washing of curtains, screening curtains between beds, etc.
● reviewing plans for renovations or new furniture, including special patient beds, to determine feasibility of cleaning.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Dealing with outbreaks
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Outbreak
An outbreak is defined as an unusual or unexpected increase of cases of a known nosocomial infection or the emergence of cases of a new infection.
Outbreaks of nosocomial infection should be identified and promptly investigated because of their importance in terms of morbidity, costs and institutional image.
Outbreak investigation may also lead to sustained improvement in patient care practices. Systematic planning and implementation of an outbreak investigation is necessary.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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1. Planning the investigation
● Notify the appropriate individuals and departments in the institution of the problem; establish terms of reference for the investigation. This must include development of an outbreak team and clear delineation of authority.
● Infection control staff must be part of the outbreak team.
● Confirm whether there is an outbreak by reviewing preliminary information on the number of potential cases, available microbiology, severity of the problem, and demographic data of person(s), place and time.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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2. Case definition
A case definition should be developed. It must include a unit of time and place and specific biological and/or clinical criteria. The inclusion and exclusion criteria for cases must be precisely identified. A gradient of definition (as definite, probable or possible case) is often helpful. The definition should also differentiate between infection or colonization. Specific criteria to identify the index case may also be developed if relevant information is available.
The case definition can change with time as new information becomes available, or with additional diagnostic information.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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3. Data collection
A data collection form for case-finding should be developed, and include:
● demographic characteristics (e.g. age, sex, cause of admission/leading diagnosis, date of admission, date of any surgery, prior antimicrobials)
● clinical data (e.g. onset of symptoms and signs, frequency and duration of clinical features associated with the outbreak, treatments, devices)
● any other potentially relevant data.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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4. Describing the outbreak
The detailed description includes person(s), place, and time. Cases are also described by other characteristics such as gender, age, date of admission, transfer from another unit, etc. The graphic representation of the distribution of cases by time of onset is an epidemic curve. The epidemic curve should distinguish between definite and probable cases.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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5. Hypothesis
At the end of the descriptive analysis, it should be possible to:
● formulate a hypothesis on the type of infection (exogenous, endogenous)
● tentatively identify the source and route of infection
● suggest and implement initial control measures.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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6. Testing the hypothesis
This includes identifying a potential exposure (type and route) for the outbreak and testing this hypothesis using statistical methods. A review of the current literature may help identify possible routes of infection for the suspected or known infecting agents.
A case-control study is the most common approach to hypothesis testing. This compares the frequency of a risk factor in a group of cases (i.e. individuals with the nosocomial infection) and in a group of controls (i.e. individuals without the infection).
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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7. Control measures and follow-up
The aims are:
● to control the current outbreak by interrupting the chain of transmission
● to prevent future occurrence of similar outbreaks.
The selection of control measures is determined by results of the initial analysis in consultation with appropriate professionals (infection control staff, epidemiologist, clinicians, microbiologists, nursing).
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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8. Communication
During the investigation of an outbreak, timely, up-to-date information must be communicated to the hospital administration, public health authorities, and in some cases, to the public.
Information may be provided to the public and to the media with agreement of the outbreak team, administration and local authorities.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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9. Report
A final report on the outbreak investigation should be prepared.
It should describe the outbreak, interventions, and effectiveness, and summarize the contribution of each team member participating in the investigation.
It should also make recommendations to prevent future occurrence.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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Thank you
Thank you for your attention.
Dr. J. Y. Peter (BMBCh, MSc, FMCPath, MRCPath.)
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