Emerging infectious diseases and AMR Flashcards
Describe types of emerging infectious diseases
Caused by:
- Previously undetected or unknown infectious agents eg COVID19
- Known agents that have spread to new geographic locations or new populations e.g. Japanese encephalitis virus
- Previously known agents whose role in specific diseases has previously gone unrecognized eg Zika
- Re-emergence of agents whose incidence of disease had significantly declined in the past, but whose incidence of disease has reappeared (i.e., re-emerging infectious diseases) eg Syphilis in Au
- Acquired resistance of pathogens to antimicrobials
Factors in (Re-)emergence of Infectious Diseases
- Agent – evolution of pathogens over time, resistance, malnutrition/immunity
- Host - immunosuppression; prolonged infection (cahance to adapt and resist)
- Transmission – changing in living, behaviours, trade, travel, migration, interaction with animals
- Environment – vectors and diseases spread to new areas as global warming accelerates
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- in general, brings pathogen and people together
- ttemperature can also influnce replication and spread
Describe the one health approach
Definition by the One Health High‐Level Expert Panel and adopted by the Quadripartite (FAO, WOAH, UNEP, WHO)
- About 60% of global emerging infections are of zoonotic origin
- Zoonoses are the source of new and re-emerging infectious diseases; some with pandemic potential
- Control of zoonoses requires a One Health approach
Discuss the recent avian flu outbreak
Highly pathogenic Avian Influenza A
- A is divided into subtypes based on surface proteins haemagluttinin and neuraminidase
- Human flu usu. H1/3
- Avian flu usu. H5/7
- ## transmits from wild aquatic birds to chickens or to cattle, which interact with the environment r host directly
Global and Local Situation
- In 2020, a Clade (2.3.4.4b) of H5N1 emerged and has become widespread (back to wild birds), with Australia the only continent not yet affected
- The virus has impacted dozens of mammals (unusual)
- WHO current risk assessment to general public health: low
- WHO current risk assessment to people with exposure: low-to-moderate
- Australia has recently experienced outbreaks of other avian influenzas including H5N8 in poultry
Tracking Animal Spread
- Global AIV with Zoonotic Potential
- HPAI_incursion_risk_assessment_Australia.pdf and image Tom Benson
Predicting Future Spread – Including into Australia
- wild bird migartion patterns
- further influenced by weather patterns
Potential Impact on Animals and Ecosystems in Australia
- Could cause bird species extinctions and decrease in populations
- Could cause indirect ecological effects (increase in other species such as vectors, pest species)
- Mortality rates can be very high → large volume of dead birds → impacts on mental health and wellbeing (and physical health risks)
- Poultry → mass deaths or depopulation → financial impacts, food security, animal welfare implications
Human Cases of Avian Influenza
- Relatively rare given how widespread the outbreak is
- Approximately 30 cases, 15 severe/critical with 7 deaths
- One severe case reported in a returned traveller in Australia
- No confirmed human-to-human transmission
- Human-to-human transmission unlikely unless reassortment occurs with human influenza virus during co-infection that will enable it to bind to specific receptors in human respiratory tract
- Technical Report: Highly Pathogenic Avian Influenza A(H5N1) Viruses | Avian Influenza (Flu)
Bringing All the Sectors Together on Prevention and Control of Avian Influenza
Animal Health:
- Biosecurity at commercial poultry farms
- Surveillance of poultry and wild birds
- Vaccination
- Culling/decontamination at affected farms
Human Health:
- Food safety
- Hand hygiene and use of PPE
- Surveillance of people who have been exposed
- Vaccinations
- Antivirals
- Laboratory testing capability
- International collaboration via WHO on human cases and influenza surveillance
Ecosystem:
- Modelling of climatic conditions and species migration informs risk assessments
Define AMR
- Antimicrobial resistance (AMR) is the resistance of pathogenic organisms to anti-bacterial, anti-viral, anti-fungal, anti-parasitic, and other agents which were previously effective against them
- “Superbugs” / multidrug-resistant bacteria are resistant to most classes of antibiotics (e.g., MRSA)
Discuss the health impacts of AMR
Infections Caused by Drug-Resistant Organisms:
- Require prolonged and/or costlier treatments
- Extend hospital stays (increased resourcing for staff, diagnostic testing, environmental cleaning, and personal protective equipment)
- Necessitate additional doctor visits/healthcare use
- Contact with animals with antibiotic-resistant infections can transfer resistant pathogens to humans and vice versa
Factors Contributing to Emergence of AMR
- mutations causing survival advantage enable cells to replicate and take over other populations
- contaminated crops or infected organisms are consumed by humans
- humans transmit in the community, or get antibiotics developing resistance, spread bacteria to patients and workers in health institutions –> community
Health Impacts of AMR
- Deaths attributable to AMR every year compared to other major causes of death: 10 mil in 2050
- Antimicrobial Resistance: Tackling a crisis for the health and wealth of nations, 2014.
- Deaths attributable to AMR every year by 2050- high in Africa and Asia, increasing in all continents
- Antimicrobial Resistance: Tackling a crisis for the health and wealth of nations, 2014.
Discuss N.gonorrhoeae as an example of AMR
- Predominantly sexually transmitted
- Common – increasing in the ACT particularly in young women
- Urethritis and cervicitis, blood stream infection, joint infections
- Often asymptomatic in women but can cause infertility even if asymptomatic
- Infection in late pregnancy vertical transmission neonatal eye disease
- Resistance to many antibiotics has emerged (penicillins, tetracyclines, fluoroquinolones, macrolides, oral cephalosporins)
- Ceftriaxone (IM) is first-line therapy
- Resistance to ceftriaxone is a major concern → SUPER GONORRHOEA
Highlights from AURA 2023
- Antimicrobials continue to be prescribed in Australia at much higher rates than most European countries and Canada
- High use of antimicrobials that are associated with AMR, particularly in private hospitals
- Stagnated AMR improvements in hospital system but improvements in primary care
- High rates of inappropriate prescribing for COPD
- High rates of inappropriate use of antimicrobials for surgical prophylaxis
- Increasing rates of critical AMR – particularly carbapenemase-producing Enterobacterales
What are some emerging AMR threats facing Aus?
- different in healthcare settings vs the community
- in healthcare: carbapenem resistant P. aeruginosa, VRSA
- in community: cephalosporin-resistant non-typhoidal Salmonella enterica, multi-drug resistant Shigella species
Discuss how AMR impact might be reduced
Reducing AMR impact
- preventing infections and spread of resistance
- tracking infections
- improving antibiotic stewardship
- developing new drugs and diagnostic tests to identify resistant organisms
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### AMR Requires a Global Response
- WHO’s Global Action Plan endorsed at WHA in May 2015
- UN General Assembly held a high-level meeting on AMR in September 2016
- Agreed to M&E in Global action plan (GAP)
Australia’s Response to Antimicrobial Resistance
The 2020 Strategy Focuses on 7 Objectives:
- Clear governance for antimicrobial resistance initiatives
- Prevention and control of infections and the spread of resistance
- Greater engagement in the combat against resistance
- Appropriate usage and stewardship practices
- Integrated surveillance and response to resistance and usage
- A strong collaborative research
agenda across all sectors
7. Strengthen global collaboration and partnerships
