Lecture 16- Biosecurity and biocontainment and disease control and eradication Flashcards
What is the goal of biosecurity or biocontainment
Prevent the transmission of infectious agents into and among individuals, groups of animals, farms or regions
What are the principles of biocontainment
Increase host resistance, eliminate disease reservoirs, prevent/minimize transmission
What are intrinsic elements to biosecurity plan
Immune status, nutrition, genetics
What are extrinsic elements to biosecurity plan
Movement pathways, segregation, and physical barriers
Biosecurity
Result of management practice to avoid (re) introduction of sense agents to a facility or region
What are the exposure pathways to dairy cattle
Oral- contaminated feed or water
Inhalation-dust and manure particles
Physical- oronasal cavities, teat ends, wounds
Indirect- fomites, vectors
What are some farm biosecurity risks
Cattle from other premises, feedstuffs, vehicles and people, drinking water
What are the most common infectious diseases in dairy operations
Bovine virus diarrhea (BVD), brucellosis, tuberculosis, mycobacterium Avium, mycoplasma, staphylococcus aureus, streptococcus agalactiae, neospora, salmonella
Biocontainment
The results of actions to prevent the spread of disease agents among groups of animals at farm or facility- serves as an important backup to biosecurity
Biocontainment maintenance
Vaccination, unidirectional flow of animals, people, material, scheduled cleaning of facilities, separation of 4 major animal groups- newborns, young stock and heifers, lactating cows, non-lactating cows
What are biocontainment measures for newborn calves
Move to individual hutches, 4 quarts of colostrum within 24 hours of birth, no waste milk, vaccinate 3-4 weeks prior to movement to group pens
What is the logical milking order (lowest to highest mastitis rates)
First lactation and recently calved cows, high producing cows, lower producing cows, cows at end of lactation period
What were the natural contributors to HPAI outbreak
Virus was introduced to US via wild bird migration, windborne detection of virus up to 1km from source
What are some USDA epi report major biosecurity breaches
Equipment sharing among farms, lack of vehicle cleaning and disinfection, rodent and wild birds inside poultry barns, bird/poultry exhibits at state/county fairs
What percentage of people infected with monkeypox in 2003 were veterinarians
25%
What percentage of veterinarians report animal related injury resulting in lost work or hospitalization
66%
What is the most frequent accident in veterinary hospital
Needle sticks
What are some common zoonoses in veterinary personnel
Salmonellosis, cryptosporidosis, plague, sporotrichosos, MRSA, psittacosis, dermtaphytosis, leptospirosis, q fever
What are 3 veterinary standard precautions
PPE, protective actions during veterinary procedures, environmental infection control/sanitation
What are the personal protective equipment and actions
Hand hygiene, use of glove and sleeves, facial protection, respiratory tract protection, protective outwear, animal related injury prevention (physical restraints, gloves, sedation, escape plan with large animals)
Patient intake protective actions during procedures
Intake is clean and safe
Examination of animals protective actions during procedures
Clean and dedicated
Injections, venipuncture, and aspiration protection actions during procedures
Always use sharps container, use gloves
Dentistry, bronchoscopy, and transtracheal washes protective actions during procedures
These procedures often generate aerosols requiring PPE
Resuscitation and obstetrics protection actions during procedures
Never blow into mouth or nose of animal or endotracheal tube
Diagnostic specimen handling protective actions during procedures
No eating or drinking in laboratory
Wound care protective actions during procedures
May require appropriate PPE
What are ways to control environmental infections
Cleaning and disinfection of equipment and surfaces, isolation of animals with IDs, laundry handling, decontamination and spill response, veterinary medical waste, rodent and vector control, other controls- employee break room
What should be the vaccination policy at minimum to prioritize employee health
Rabies, tetanus, influenza
Disease control
Reduction of disease incidence, prevalence, morbidity, or mortality to a locally acceptable level as a result of deliberate efforts or continued intervention measures are required to maintain reduction
Disease control is a combination of hat 3 things
Initial intervention strategies, on going disease control strategies and monitoring and surveillance activities
What was disease control like in early 1900s
Do nothing, quarantine, slaughter/cull, control host movement, fomite control clean and disinfect
What is disease control like now
Control hose movement, quarantine, slaughter/cull, fomite control, C+D, vaccintion
Eradication
Permanent reduction to zero of the worldwide incidence of infection cause by a specific agent as a result of deliberate efforts; intervention measures are no longer needed
What are two successful global eradication programs
Smallpox 1980
Rinderpest 2011
What are some ongoing global eradication programs
Guinea worm disease, lymphatic filariasis, leprosy, tetanus, chagas disease, measles, polio
What are the control and eradication options
- Animal depopulation and quarantine new animals
- Quarantine and remove positives
- Quarantine and remove positives, vaccinate susceptible animals
- Quarantine and vaccinations/treatment
Animal depopulation and quarantine of new animals is used when
Highly contagious disease and short incubation, disease is disruptive to production and economy, good diagnostic test is available, no reservoir species exist, quick response and outcome, test and slaughter entire herd
What diseases would require use of animal depopulation and quarantine of new animals
Foot and mouth disease, exotic Newcastle disease, bovine spongiform encephalopathy, highly pathogenic avian influence, cholera, scrapie
quarantine and remove positives is used when
Agent is not highly contagious, long incubation period, test and slaughter individual animals, prevalence is low, requires diagnostic test, not devastating enough to justify killing entire herd
What diseases require quarantine and removal of positives
Bovine tuberculosis, equine infectious anemia
Quarantine and remove positives, vaccinate susceptible animals is used when
Prevalence of disease is higher and segregation of herds or populations is inadequate, removal of positives will not stop transmission, once prevalence is reduced and herds closed, vaccination can be discontinued, surveillance must be continued, positives are quarantine and some eliminated
What is an example of a virus when we would quarantine and remove positives, vaccinate susceptible animals
Brucellosis
When would we quarantine and vaccinate animals
Used when prevalence is high but economic and productions costs are not catastrophic, slow transmission
What are some examples of viruses when we would quarantine and vaccinate
Leptospirosis, infectious bovine rhinotecheitis, bordetella
What is the biological criteria for disease eradication success
Effective method is available to interrupt transmission, practical diagnostic tools are available to detect infection, only one vertebrate reservoir and no environmental amplification
What are the social and political criteria for disease eradication success
Societal/political will, disease must be in significant terms of morbidity and/or morality, intervention and eradication are feasible, medical, scientific and legislative bodies must agree on justification, advocacy exist, focuses on one clear goal, scope is clear and duration is limited
Biosafety level 1
Agents not known to cause disease in healthy adults- some can cause disease in immunocompromised individuals
What agents are included included in bio safety level 1
Bacillus subtitles, naegleria gruberi, infectious canine hepatitis virus, non-pathogenic E. coli species
BSL-1 Precautions standard practices
Frequent handwashing, limited access to lab space, no smoking, eating drinking in lab, minimize splashes and actions that create aerosols, decontamination of work surfaces after every use, decontamination of laboratory wastes, mechanical pipettes, sharp precautions, insect/rodent control program, PPE
Biosafety level 2
Agents do not cause lethal infections, are not transmissible via airborne route, agents re pathogens for which immunization or antibiotic treatment is available
What viruses are included in Biosafety level 2
Measles virus, salmonella species, pathogenic toxoplasma, clostridium botulinum, hepatitis B virus
Biosafety level 2 precautions standard practices plus
Greater access restrictions to lab, biohazard warning signs outside lab, surveillance and immunization of lab personnel, Biosafety manual, supervisory staff who have experience working with infectious agents
What are the primary barriers in Biosafety level 2
Biosafety cabinets or other containment devices
Biosafety level 3
Agents with potential for respiratory transmission may cause serious and potentially lethal infection, either prevention or treatment options exist
Biosafety level 3 precautions
BSL-2 plus:
Strictly controlled access to lab, pathogen specific training for lab personnel, decontaminating all waste, changing clothing prior to entering/exiting lab, policies for testing workers and storing samples
What are the primary barriers to biosafety level 3
Similar to BSL-2, add respiratory PPE when appropriate
Biosafety level 4
Dangerous and exotic agents with high risk of life threatening disease, aerosol transmitted
What agents are included in biosafety level 4
Marburg, Ebola, viruses that can cause Congo-Crimean hemorrhagic fever, lassa fever
What are the biosafety level 4 precautions
BSL3 plus:
Highly specialized training in handling extremely dangerous infectious agents, containment equipment and functions, strict lab access, immunocompromised never allowed in lab, changing clothing, showering at exit, decontaminating all material exiting facility
What are the primary barrier to biosafety 4 precautions
Biosafety cabinets, full body, air-supplied, positive pressure personnel suit
biosafety level 1 locations
High schools, community colleges, municipal drinking water treatment facilities
Biosafety level 2 locations
Local health departments, universities, state laboratories, private laboratories, industrial laboratories
Biosafety level 3 locations
State health departments, universities, private companies, industries, federal government
Biosafety level 4 locations
Only 13 facilities in US, mot are federal, few universities, 1 private
