Biosecurity Flashcards
Goal of bio security/bio containment plan
prevent the transmission of infectious agents into
and among individuals, groups of animals, farms, or
regions
3 principles of bio security and bio containment
**epidemiologic triangle
– Increase host resistance
– Eliminate disease reservoirs
– Prevent/minimize transmission
Bio security plan: intrinsic and extrinsic elements
– Intrinsic: Immune status, nutrition, genetics
– Extrinsic: Movement pathways, segregation, physical barriers
Biosecurity plan depends on which principles (hint: there’s 7 principles)
HACCP= hazard analysis and critical control points
Between 1995 and 2005, number of dairy farms
Decreased by 44%
4 exposure pathways to dairy cattle
–Oral: Contaminated feed or water
• Inhalation - Dust & manure particles
• Physical – Oronasal cavities, teat ends, wounds
• Indirect – Fomites and Vectors
4 farm biosecurity risks
• Cattle from other premises – Ideally all should have complete health & vaccination records, New cattle should be isolated for 10 days – 3 weeks
• Feedstuffs – Commonly contaminated by manure, water or wildlife
• Vehicles and People
– Dairy farms are the hub of many logistical systems
– Restricting access is of paramount importance
– Even farm workers can be the source of contamination
• Drinking water
– Restrict wildlife access and perhaps filter or treat
Most common infectious diseases in dairy operations (7)
Bovine virus diarrhea
Brucellosis
Tuberculosis
Staph
Salmonella
Mycobacterium
Neospora
2 control methods for infectious diseases: dairy operations
Testing
Vaccination
Bio containment definition
-The result of actions to prevent the spread of
disease agents among groups of animals at a
facility or farm
-Serves as an important backup to biosecurity (When biosecurity is breached, biocontainment
lessens the damage)
Biosecurity definition
The result of management practices to avoid
(re)introduction of disease agents to a facility or
region (e.g., farm, veterinary hospital, nation)
New cattle entering farm should be isolated for how long
10 days-3 weeks
Bio containment maintenance methods (10)
-vaccination
-unidirectional flow of animals, people, material (separate 4 major animals groups)
-scheduled cleaning of facilities and equipment
-logical milking order (lowest to highest mastitis rates)
-move newborn calves to individual stalls immediately
-avoid direct contact between animal groups (don’t share food)
-limit exposure to recycled water
-proper manure handling
Bio containment maintenance: newborn calves
– Move to individual hutches/stalls immediately after birth
– 4 qts of colostrum w/in 24 hrs of birth
– No waste milk (normal milk or milk replacer) —> Unless Pasteurized
– Vaccinate 3-4 wks prior to movement to group pens
Bio containment maintenance: logical milking orde
– LOWEST MASTITIS RATE: First-lactation & recently calved cows
– High-producing cows
– Lower-producing cows
– HIGHEST MASTITIS RATE: Cows at the end of lactation period
Bio containment maintenance: separation into 4 major animals groups
Newborns
Young stock and heifers
Lactating cows
Non lactating cows
H5N2 spread: causes and biosecurity breaches
– Virus was introduced into US via wild bird migration
– Windborne detection of virus up to 1 km from source
– Equipment sharing among farms
– Lack of vehicle cleaning & disinfection
– Rodents and wild birds inside poultry barns
– Bird/poultry exhibits at State/county fairs
Importance of hospital precautions (examples)
-Monkey pox outbreak in 2003 —> 25% of infected people were vet personnel
-66% of vets report animal related injury resulting in lost work or hospitalization
-needle sticks are one of most frequent accidents
Common zoonoses in vet personnel (9)
Salmonellosis
Cryptosporidiosis
Plague
Sporotrichosis
MRSA
Avian chlamydiosis/psittacosis
Dermatophytosis
Leptospirosis
Q fever
Which precaution method gets the most emphasis
PPE
PPE and actions (6)
-wash hands
-use gloves and sleeves if infectious disease suspected
-facial protection
-use masks for respiratory tract protection
-protective outerwear
-animal related injury prevention (restraint, escape plans)
Hand sanitizers should be what percent alcohol
60-90
Protective actions during procedures
-clean and safe patient intake
-exam animals
-infection, venipuncture (always use sharps container, use gloves, never remove caps with mouth)
-dentistry, bronchoscopy (aerosols require PPE)
-resuscitation (don’t blow into mouth of animal via endotracheal tube)
-obstetrics
-necropsy
-diagnostic specimen handling (no food or drink in lab)
-wound care may require PPE
Environmental infection control
- Cleaning & disinfection of equipment/surfaces
- Isolation of animals with IDs
- Laundry handling
- Decontamination & spill response
- Veterinary medical waste
- Rodent & vector control
Vaccination policy for employees (3)
Rabies
Tetanus
Influenza
Disease control definition
The reduction of disease incidence, prevalence,
morbidity or mortality to a locally acceptable level as
a result of deliberate efforts; continued intervention
measures are required to maintain the reductionq
Disease control is combination of (3)
Initial intervention strategies
• On-going disease control strategies
• Monitoring and surveillance activities
Fibromuscular dysplasia early 1900s vs today: ranked disease control mechanisms
-early 1900s: do nothing, quarantine, slaughter/cull, control host movement, FOMITE CONTROL, CLEAN AND DISINFECT
-today: control host movement, quarantine, slaughter/cull, fomite control, vaccination?
CDC definition of eradication
Permanent reduction to zero of the worldwide
incidence of infection caused by a specific agent as a
result of deliberate efforts; intervention measures
are no longer needed
2 successful global eradication programs (diseases)
Smallpox in 1980
Rinderpest in 2011
Control and eradication options (4)
- Animal depopulation & quarantine of new animals
- Quarantine and remove positives
3 . Quarantine and remove positives, vaccinate
susceptible animals - Quarantine and vaccination (or treatment)
Control and eradication option: animal depopulation and quarantine of new animals
– Highly contagious diseases, short incubation period
(explosive)
– Test and slaughter (entire herds, not individual animals)
– Disease is disruptive to production and economy
– Good diagnostic test is available (even though clinical
recognition may be difficult)
– No reservoir species exists
– Quick response & outcome
-examples: foot and mouth disease, bovine spongiform encephalopathy
Control and eradication option: quarantine and remove positives
– Agent is not highly contagious or communicable, there is
a long incubation period, and infection is detectable during incubation period
– Test and slaughter (individual animals)
– Prevalence of the disease is low
– Requires a diagnostic test
– Not devastating enough to justify option #1
– Examples: Bovine TB, Equine infectious anemia
Control and eradication option: quarantine and remove positives, vaccinate susceptible animals
– Used when prevalence of disease is higher and
segregation of the herds or populations is inadequate
and the removal of positives will not stop transmission – Once prevalence is reduced and the herds closed,
vaccination can be discontinued
– Surveillance must be continued, positive/reactor herds quarantined, and positives eliminated
– Example: Brucellosis
Control and eradication option: quarantine and vaccination/treatment
– Used when prevalence is high but economic &
production costs are not catastrophic
– Slows (but does not totally prevent)
transmission to other animals/herds
– Examples: Leptospirosis, Infectious bovine rhinotracheitis, Bordetella
Disease eradication: criteria for success (2 types)
Biological
Social and political
Biological vs social and political criteria for disease eradication (general)
Biological = objective
Social/political = subjective
Disease eradication: biological criteria for success
– An effective method is available to interrupt transmission
– Practical diagnostic tools are available to detect infection
– Only one vertebrate reservoir & no environmental amplification
Disease eradication: social and political criteria for success
– Societal/political will
– Disease must be significant in terms of morbidity and/or mortality
– Intervention & eradication must be technically feasible
– Medical, scientific, and legislative bodies must agree on justification
– Advocacy must exist for national/regional/global support
– Focuses on one clear and unambiguous goal
– Scope is clear and duration is limited
Bio safety level 1 labs
-work with least dangerous agents, require fewest precautions
-Agents not known to cause disease in healthy adults
– Some organisms may cause disease in
immunocompromised individuals
• Agents include Bacillus subtilis, Naegleria gruberi,
infectious canine hepatitis virus, non-pathogenic E. coli species
bio safety level 4 labs
-have strictest methods because dealing with agents that are most dangerous to human
health
-Dangerous and exotic agents with high risk of life-
threatening disease, aerosol-transmitted
– Related agents with unknown risk of transmission
• Agents (all viruses) include Marburg virus, Ebola
virus, viruses that cause Congo-Crimean hemorrhagic fever, Lassa fever
Bio safety level 4 precautions
Bio safety lab 3 plus:
– Highly specialized training in handling extremely dangerous infectious agents, containment equipment and functions
– Strict access to lab; immunocompromised persons are never allowed to enter the lab
– Standard practices include BSL-3 plus: Changing clothing before entering and exiting lab, showering at exit; Decontaminating all material exiting facility
Bio safety level 1 precautions
– Frequent handwashing
– Limited access to the lab space when working;
– No smoking, eating, drinking, storage of food in laboratory;
– Minimize splashes and actions that may create aerosols;
– Decontamination of work surfaces after every use or spill;
– Decontamination of laboratory wastes;
– Mechanical pipettes only (no mouth pipetting);
– Sharps precautions for needles and other sharp objects;
– Insect/rodent control program;
– Personal protective equipment (lab coats, latex gloves, eye protection or face shields)
Bio safety level 2 labs
• Agents do not cause lethal infections, are not
transmissible via airborne route
• Agents are pathogens for which immunization or
antibiotic treatment is available
• Include measles virus, Salmonella species, pathogenic
Toxoplasma, Clostridium botulinum, hepatitis B virus
Bio safety level 2 precautions
• Standard practices plus:
– Greater access restrictions to lab;
– Biohazard warning signs posted outside lab;
– Surveillance & immunization of laboratory personnel; – biosafety manual with definitions of needed waste decontamination or medical surveillance policies;
– supervisory staff who have experience working with infectious agents and specific training for laboratory personnel in handling these agents
Bio safety level 3 labs
• Agents with potential for respiratory transmission,
may cause serious and potentially lethal infection
• Either prevention or treatment options exist ( May be less effective than for BSL-2 pathogens)
• Includes M. tuberculosis, St. Louis encephalitis virus,rabies
Bio safety level 3 precautions
• Biosafety level 2 plus:
– Strictly controlled access to the lab;
– Pathogen-specific training for lab personnel;
– Decontaminating all waste;
– Changing clothing prior to entering/exiting lab;
– Policies for testing workers & storing samples
Primary barriers: biosafety level 1 vs 2 vs 3 vs 4
1- N/A
2- biosafety cabinets, containment
3- biosafety cabinets + respiratory PPE
4- biosafety cabinets + full body, air supplied, positive pressure personnel suit
