Infection and Immunity Session Eleven: Hospital Acquired Disease & Control

What 6 microorganisms are mostly associated with respiratory infections?

- Haemophilus influenzae - Streptococcus pneumoniae - Staphylococcus aureus - Enterobacteriaceae - Respiratory viruses (influenza, respiratory synctial) - Fungi (candida spp, Aspergilli

What is meant by self infections?

Infection caused by the movement of a microorganism part of the patient's normal flora from its normal site to a different site upon the patient's body e.g. a wound

What is meant by primary and secondary causes of bacteraemia?

Primary - Due to the direct introduction of the organism into the blood e.g. contaminated IV fluids Secondary - Due to an infection already within the body e.g. UTI

What is meant with single occupancy rooms for the immunocompromised that are rooms with negative pressure ventilation?

This allows the inflow of air into the room (negative pressure) to prevent the escape of contaminated e.g. smear positive TB

What is meant by 'hospital flora'?

These are microorganisms within the healthcare environment including MRSA that spread to patients admitted in hospital

What is meant by a hospital acquired infection?

This is an infection occurring in a patient during the process of care in a hospital or other health care facility which was not present / incubating at the time of admission

What are endogenous healthcare acquired infections?

This is an infectious agent present at the time of admission but has no clinical features of infection an subsequently develops signs of infection during the stay in hospital

What is airborne transmission?

This is when microorganisms are contained within droplet nuclei (residue from evaporated droplets) or dust particles, which can remain suspended in air for long periods of time and travel to people

In what people are pseudomonas likely to cause infection?

Those who are immunocompromised and have: - Severe burns - Diabetes mellitus - Cystic fibrosis

How can foodborne spread be prevented?

Through proper hygiene and sanitation practices

What is meant by cross infections?

Infection caused by a microorganism from other patients of healthy staff carrier

What are the symptoms of acute gastroenteritis?

- Acute onset - Vomiting - Diarrhoea - Nausea - Watery diarrhoea - Abdominal cramps

What most commonly causes UTIs in a hospital setting?

- Catheter associated UTI Up to 56% of UTIs due to indwelling urethral catheter

What organisms are the most associated with HCAIs?

- Coagulase negative staphylococci - Staphylococcus aureus - Enterococci These account for the majority of HCAIs

What chemical methods can be used to interrupt the chain of infection?

- Decontamination and sterilisation - Cleaning and disinfection - Skin disinfection and antiseptics - Chemical agents of microbial control (phenols, alcohols, halogens, oxidising agents, surfactants, heavy metals, aldehydes, gaseous agents, enzymes, antimicrobials)

What 5 microorganisms are mostly associated with UTIs?

- Escherichia coli - Klebsiella, Serratia, Proteus spp - Pseudomonas aeruginosa - Enterococcus spp - Candida albicans

What type of organism is pseudomonas?

- Gram negative - Rod - Commonly found in soil, ground water, plants - Opportunistic pathogen

What three things need to be controlled to exclude the pathogen from the hospital?

- Infection control policy - Hospital building and design - Personnel

What is the SICPs bundle?

- Isolation based on risk assessments - Hand hygiene - Personal Protective Equipment (PPE) - Management of Care Equipment - Control of Environment - Safe Waste Disposal - Respiratory Hygiene

What organisms are diseases requiring special infection control (alert organisms)?

- MRSA - Antibiotic resistant organisms e.g. Glycopeptide Resistant, Enterococci (GRE) and Extended Spectrum Beta-lactamases, Clostridium difficile, Streptococcus pyogenes, Norovirus and Respiratory Syncytial Virus (RSV)

What are the features of the norovirus?

- Non-enveloped - Single stranded RNA virus

What microorganisms is isolation advised for in HCAIs?

- Norovirus - Clostridium difficile - Rotavirus - MRSA - TB - Influenza A and other viral respiratory infections - Respiratory Syncytial Virus - Extended spectrum beta-lactamase producers (ESBL) - Carbapenemase-Producing Enterobacteriacea (CPE)

How can we enhance the host's ability to resist infection?

- Offer vaccination to immunocompromised patients - Prophylatic antibiotics - Reduce risk of post-operative infections

When a HCAI is suspected what is needed to be found out for epidemiological investigation?

- Patient details - Date of admission - Specimen details - Site of and extent of infection - Operative procedures - Ward - Staff details

Where can a healthcare acquired infection arise?

- Patients - Health care worker - Hospital environment - Social care setting

What are the two methods by which we can interrupt the chain of infections?

- Physical methods - Chemical methods

What infections are most associated with Pseudomonas aeruginosa?

- Pneumonia - UTIs - Surgical wound infections - Bloodstream infections

What physical methods allow the disruption of the chain of infection?

- Protective clothing - Isolation A single patient with a known or suspected viral infection may present a potential risk to other patients and / or staff and could serve as the point source of nosocomial outbreaks (isolation of infected patients) Another option is to use barrier control methods to isolate susceptible patients - Physical antimicorbial methods (temperature, desiccation, filtration, osmotic pressure, radiation) - Aseptic techniques

What are the 6 most common types of HCAIs?

- Respiratory infections - UTIs - Surgical site infections - Sepsis - GI infections - Bloodstream infections

What 3 microorganisms are most associated with gastrointestinal infections?

- Salmonella serotypes - Clostridium difficile - Viruses (norovirus, rotavirus)

Why is it important to minimise HCAIs?

- Serious patient safety issues - Infection with antibiotic resistant bugs - Ward closures in outbreak situations - Health service disruption - Blockage of hospital beds due to prolonged hospital stays - Long-term disability to patient - Death due to sepsis especially in frail and elderly population - Economic impact

What are the types of isolation practices?

- Single occupancy isolation rooms - Cohorting groups of infectious patients - Isolation wards - Isolation for immunocompromised patients - Isolation hospitals - High security infectious disease units

What respiratory precautions should be taken with someone with TB, seasonal flu, chicken pox?

- Single room occupancy and doors must be closed - Masks must be worn - Masks taken off outside of room - Gloves and aprons - Hand washing followed by alcohol gel - Terminal clean with Tristel

What does prognosis of a Pseudomonas spp depend on?

- Site of infection - Underlying health of the individual patient Acute fulminant infections such as: - Bacteraemic pneumonia - Septicaemia - Burn sepsis - Meningitis Are associated with significant mortality

What 7 microorganisms are mostly associated with wounds and skin sepsis?

- Staphyloccus aureus - Streptococcus pyogenes - Escherichia coli - Proteus spp - Anaerobes - Enterococcus spp - Coagulase negative staphylococci

What are the most common HCAIs?

- Surgical wound infections - Respiratory tract infections - Urinary tract infections - Bacteraemia

In what populations can the norovirus be serious for?

- Younger children - Older adults - People with compromised immune systems

What is the most common mode of transmission of hospital acquired infections?

Contact spread

What three steps need to be taken to prevent and control pathogens in hospitals?

1) Exclude pathogen from the hospital 2) Interrupt the chain of infection 3) Enhance the hosts ability to resist infection

What percentage of hospital acquired infections are caused by Pseudomonas aeruginosa?

10%

When do symptoms of acute gastroenteritis caused by the norovirus start?

12-48 hours after being exposed to the virus

What is healthcare waste?

A reservoir of pathogenic microorganisms

What condition does the norovirus cause?

Acute gastroenteritis

How are alert conditions identified and state the implications of this?

Alert conditions are identified through clinical diagnosis, not laboratory tests, and therefore staff in clinical areas must inform Infection Prevention and Control Team of any suspected occurrence of these conditions at the earliest opportunity.

What needs to be done for staff in order to prevent any pathogens from being in the hospital?

All health workers should undergo health screening both prior to and throughout their employment Staff should have the correct immunisations as outlined by regulations To date all healthcare workers are screened in the UK for HIV, hep C and hep B status All hospitals will have a policy for blood borne virus exposure including HIV, HCV, HBV from needle sticks, splash or other exposure Any healthcate worker suffering from a short term infection (diarrhoea, herpes simplex on hands, Streptococcus pyogenes infections, Staphylococcus aureus skin lesions, childhood disease, Varicella-zoster infections, upper respiratory tract infections) should also have limited contact with high risk patients Any persons that is found to have be of a status that may limit their field of work will be supported by occupational health services

Describe the process of monitoring and surveillance to exclude the pathogen from the hospital

All hospital equipment and machinary, especially those used to disinfect and sterilise, should be monitored regularly to ensure against contamination

However what is on the rise since the use of large scale broad spectrum antibiotics?

Antibiotic resistant Gram +ve bacteria e.g.: - Coagulase negative staphylococci - Enterococci MRSA Multi-resistant Gram -ve organisms - Expanded spectrum beta lactamases - Candida

80% of cystic fibrosis patients may be colonised in the lungs with Pseudomonas aeruginosa, What is the dangers of this?

Because once established it is very resistant to antibiotic treatment

Why should catheter associated UTIs be prevented?

Because they cause patient discomfort, risk patient safety, sepsis and increased hospital stay and hence expenses to the NHS

How is hospital acquired pneumonia diagnosed?

By culture primarily

What is low-level disinfection?

Can kill most bacteria, some viruses, and some fungi, cannot kill tubercle bacilli / bacterial spored

How can blood borne disease by spread in hospital?

Can occur through needle stick of contaminated sharps or blood products

What organisations are involved in controlling HCAIs?

Care Quality Commission (CQC): Regulation 12 for providers to provide - Safe care and treatment CQC assesses NHS hospital against "sustained improvement in infection prevention and control practices that reduce HCAIs" Focus on improving staff education and accountability Public Health England (PHE) runs national surveillance programmes to collect data on HCAI Surveillance protocols and on the potential involvement of patients and their families in reporting and control of HCAI Ongoing research to validate surveillance protocols

Based on Health Protection Scotland outlines, what outbreak control measures should be taken on the wards?

Close affected bays to admissions and transfers Keep doors to single-occupancy rooms and bays closed Place signage on the doors informing all visitors of the closed status and restricting visits to essential staff and essential social visitors only Place patients within the ward for the optimal safety of all patients Prepare for re-opening by planning the earliest date for a terminal clean

What are the four classifications of healthcare associated infections?

Community acquired infections - Either those contracted or developing outside hospitals which require admissions of the patient e.g. pneumococcal pneumonia Infections contracted and developing within hospital (e.g. device associated bacteraemia) Infections contracted in hospital but are not becoming clinically apparent until after the patient has been discharged (e.g. post-operative wound infections) Infections contracted by healthcare staff as a consequence of their work, whether or not this involves direct contact with patients (e.g. hepatitis B)

What is the most common complication of acute gastroenteritis?

Dehydration

What are the sources of endogenous healthcare acquired infections?

Derived from the patient's own skin, GI or upper respiratory flora

What is meant by high level disinfection?

Destroy all microorganisms, with the exception of bacterial spored

What is meant by direct and indirect contact spread?

Direct - From person to person. Includes toughing of an infected individual, contact with oral secretions, or contact with body lesions. Hands and clothing can be vectors for the transmission of both Gram +ve and -ve bacteria. Disease spread exclusively by direct contact are unable to survive for significant periods of time away from the host. Indirect - Via contaminated hands or equipment. Spread during procedures that involve mucosal surfaces e.g. potential to directly introduce a microorganism into the normally sterile bladder from the patient's own microflora, or the hand from the operator during the insertion of a urinary catheter.

Based on Health Protection Scotland outlines, what outbreak control measures should be taken on healthcare workers?

Ensure all staff are aware of the norovirus situation and how norovirus is transmitted Ensure all staff are aware of the work exclusion policy and the need to go off duty at first symptoms Allocate staff to duties in either affected or non-affected areas of the ward but not both unless unavoidable e.g. therapists

What two tests are used to detect the norovirus?

Enzyme-linked immunosorbent assays (EIA) to detect the norovirus antigens Polymerase chain reaction (PCR) tests to dectect norovirus nucleic acid

How are high impact interventions of HCAIs achieved?

Evidence-based approach that relate to key clinical procedures or care processes that can reduce the risk of infection is performed appropriately Developed to provide a practical way of highlighting the critical elements of a care process (care bundle) , the key actions needed to prove reliability

When is a single occupancy room with postive pressure ventilation used for the immunocompromised?

For neutropenic patients (i.e. have a low immune system so this prevents them becoming infected by airborne pathogens)

What is the responsibility of staff, patients / carers and visitors when an illness is encountered due to occupational exposure?

For them to report it and any incidents that may have resulted in cross contamination. To continue professional development - continuous updating of knowledge Update with local / national policies, procedures and campaigns

What can be done to reduce transmission by indirect contact?

Frequent touch surfaces should be properly disinfected

What factors determine if a microorganism will cause disease?

General health status (weight, smoking status) and underlying diseases (diabetes, cancer, immunosuppression) Age - The very young are susceptible due to the immaturity of the immune system, while the elderly are at high risk due to predisposing disease, immobility and impaired blood supply Disease treatment - Cytotoxic drugs and steroids all increase the risk of infection Undergoing invasive treatments or surgery - The length and type of surgery as well as the introduction of foreign objects i.e. the shunts all contribute to the chance of an individual developing HAI Wounds (surgical) and trauma (burns, stab wounds and RTA) - Exposing previously protected tissues and sites within the body. Wet or open wounds are more likely to become infected

What is required of a microorganism to be able to be spread via airborne transmission?

In order for a microorganism to remain infectious they must be capable of surviving for long periods of time outside the body and must be resistant to dying. Airborne transmission allows organisms to enter the upper and lower respiratory tracts (e.g. TB, chickenpox and measles)

Describe how may hospital acquired infections are spread via food borne spread?

In rare occasions infections may arise in hospital kitchens. Faecal-oral transmission is usually associated with organisms that infect the digestive system. If the infected individual is a cook, or food handler, then inadequate handwashing may result in food being contaminated with microorganisms

What is intermediate disinfection?

Inactivates Mycobacterium TB, vegetative bacteria, most viruses, and most fungi, does not kill bacterial spored

What happens when a needle stick injury occurs to cause transmission of a blood borne virus through parenteral exposure?

Incident reporting form to fill in ASAP Urgency is important in these situations as post exposure prophylaxis (PEP) for HIV or other treatments may be required (i.e. ideally PEP should be commenced within 1 hour of the incident)

How does norovirus spread?

It is highly contagious where it can spread: - Close personal contact - Faecal-oral route - Virus also spread through touching contaminated surfaces and objets

What can be the source of exogenous healthcare acquired infections?

May be another person in the hospital (cross-infections) or a contaminated item of equipment or building service (environmental infections)

What happens if waste disposal is inadequately managed?

Microorganisms can be transmitted by direct contact / airborne route / vectors

What does Pseudomonas aeruginosa contaminate in hospitals?

Moist / wet reservoirs such as: - Respiratory equipment - Indwelling catheters

Give an example of an organism that can survive for a long period of time on surfaces

Norovirus

What is an exogenous healthcare acquired infections?

Patients contracts new infective agents while in the hospital which then leads to the development of symptoms of infection.

Define hospital acquired pneumonia

Pneumonia that occurs 72 hours after admission

Based on Health Protection Scotland outlines, what outbreak control measures should be taken on patient and relative information?

Provide all affected patients and visitors with information on the outbreak and the control measures they should adopt Advise visitors of the personal risk and how they might reduce this risk

Based on Health Protection Scotland outlines, what outbreak control measures should be taken in regards to environment?

Remove exposed foods e.g. fruit bowls, and prohibit eating and drinking by staff within clinical areas Intensify cleaning ensuring affected areas are cleaned and disinfected. Toilets used by affected patients must be included Decontaminate frequently touched surfaces with detergent and disinfectant containing 1000ppm available chlorine

List three airborne transmission routes

Respiratory tract - coughs, sneezing, talking Skin scales are often spread via the air (wound dressing, bed making) Equipment that create aerosols (air conditioning, ventilators)

What is the role of the medical microbilogist when alert organisms are identified in the microbiology laboratory?

Responsible for informing clinical teams when a clinical significant alert organism has been identified

What is being done to prevent surgical site infections (SSIs)?

SSI surveillance systems in the UK = Significant reductions in rates of SSI in hospitals that participate in these benchmarking schemes Lessons learnt are shared and fed back to surgical teams to reflect on and improve and follow evidence based interventions

What are notifiable diseases?

Some alert conditions are notifiable diseases. This is a legal term denoting diseases that must, by law, be reported to ;proper office' i.e. the Consultant for Communicable Disease Control (CCDC) It is the responsibility of the physician in charge of each case to make the notification

What is the general course of acute gastroenteritis caused by the norovirus?

Symptoms usually last 24-72 hours with recovery being complete without any serious long term problems

What must be the selection of PPE be based on?

The assessment of the risk of transmission of micro-organisms

What is the function of side room isolation?

To prevent cross contaimination / infection Prevent emergence of health care associated infections Prevent care disruption Reduce closure of bays / wards Reduce wastage of staff time and resources Better management of outbreaks Improving patient experience

What is the function of standard infection control precautions (SICPs):

To prevent cross transmission from recognised / unrecognised sources of infection - Blood and other body fluid secretions - Contaminated equipment in the care environment - To implement SICPs: mandatory updates on infection prevention and control and education sessions for healthcare workers at all levels - SICPs at all times

What is the function of single occupancy rooms for the immunocompromised?

To prevent spread of pathogens by airborne roure

What is the benefit of wearing PPE?

Two fold - Offers protection to both patients as well as the healthcare worker

Based on Health Protection Scotland outlines, what outbreak control measures should be taken about Personal Protective Equipment (PPE)?

Use gloves and apron to prevent personal contamination with faeces or vomit Consider use of face protection with a mark only if there is a risk of droplets or aerosols

Based on Health Protection Scotland outlines, what outbreak control measures should be taken about hand hygiene

Use liquid soap and warm water as per WHO 5 movements Encourage and assist patients with hand hygiene

Based on Health Protection Scotland outlines, what outbreak control measures should be taken with equipment?

Use single patient use equipment wherever possible Decontaminate all other equipment immediately after use

Treatment of hospital acquired pneumonia depends on the organism involved. What happens if the organism is unknown?

Use treatment that covers both Staphylococcus aureus and Pseudomonas aeruginosa

Based on Health Protection Scotland outlines, what outbreak control measures should be taken regarding spillages?

Wearing PPE, decontaminate all faecal and vomit spillages Remove spillages with paper towels, and then decontaminate the area with an agent containing 1000ppm available chlorine Discard all waste as healthcare waste Remove PPE and wash hands with liquid soap and warm water

Based on Health Protection Scotland outlines, what outbreak control measures should be taken regarding linen?

Whilst clinical areas are closed, discard linen from the closed area in water soluble (alginate) bad and then a secondary bag