Interventions Flashcards
Methods of diagnosis/detection of tuberculosis infection in non-human primates
- Tranquilise animal
- Inject 0.1ml containing 1250 iu mammalian PPD tuberculin in sterile water i/d into upper lid of left eye (or i/d in mid abdomen or thigh) with 27 or 25G needle (PPD = precipitated fractions of culture filtrates)
- Check for swelling at 8, 24, 48, 72 hours and score.
0 No reaction Negative
1 Bruise Negative
2 Erythema of palpebrum and no swelling Negative
3 Erythema of palpebrum and slight swelling ?
4 Swelling of palpebrum, drooped eyelid and erythema Positive
5 Swelling and/or necrosis, eyelid closed Positive
No true gold standard, except finding disease lesions
- tuberculin testing
- BLOOD γ- INTERFERON (PRIMAGAM ASSAY)
Reasons for unreliability of tuberculosis detection and dealing with false positives and false negative results.
False positives:
• Use of buffered diluents instead of sterile water for diluting the tuberculin
• Impurities in the Tuberculin - especially
Koch’s old TB (= unfractionated heated concentrates of Mycob. culture filtrates)
• Trauma due to poor injection technique
• Previous BCG vaccination
• Cross reaction with atypical or saprophytic mycobacteria which share some antigens
False negatives
• Anergy due to overwhelming pulmonary tuberculosis
• Testing early in infection before development of hypersensitivity
• Systemic fungal disease
• Concurrent measles infection or vaccination
• Immunosuppressive drugs
• Technical errors
• Localized desensitization if the test is repeated in the same site
Use of tuberculosis diagnostic methods
Prevention
Differential diagnosis of enteric disease in non-human primates and methods of detection of shigella infection
Collection and transport of samples: • Rectal swabs vs. faecal samples • Transport time to lab • Transport media • Temperature
Differential diagnoses:
- Bacteria (shigella, salmonella, e.coli, campylobacter, yersinia)
- Environmental factors (diet)
- Parasites (entamoeba, balantidium, nematodes, cestodes)
- Viruses (rotavirus)
Frequency of sampling:
• Detection rate from known clinical cases = 44% on any one sample
• Sample on three consecutive days = 82% (P = 1-(1-x)n, x = detection rate, n = no. of days)
• Probability = 90% for 4 days sampling and 94.5% for 5 days
Poor detection due to: • intracellular maintenance • dilute/bloody sample • faeces not fresh • insufficient selective media – overgrowth especially by E.coli
Control of endemic shigellosis in non-human primate colonies
Consider: • number of animals involved • type of housing • number of staff • in vitro sensitivity of bacterium to antibiotics • stress factors for the animals
What to do:
• Monitor all cases of diarrhoea
• Dose adequately
• Monitor staff
• Oral vs. injectable medication
• Good sampling methodology
• Good hygiene
• Good clinical monitoring
• Elimination of carrier state or reduction of bacteria below detectable level?
• Vaccination – oral vaccines have been tried but high doses are needed and cause shedding of bacteria (protect against disease but do not prevent carrier state)
Control depends on breaking the cycles of infection and transmission by 1) improving hygiene by:
• restricted entry to units to prevent cross infection
• protective clothing which is disposed of when soiled.
• disinfectant footbaths, used correctly.
• uncontaminated water supply
• washing fruit in chlorinated water
• barriers between areas to limit contact
• power washing with hot water and disinfection
2) detecting and treating carriers. Include the following groups when screening:
• all clinical cases of diarrhoea
• new arrivals: no animals should be moved to another unit until the entire batch is free from infection (all in, all out)
• post weaning
• following any period of stress, e.g. surgery, movement
• random sampling of all animals on a regular basis
And 3) reducing stress by:
- Enrichment
- socialisation
Risk assessment and considerations of endemic enteritis in non-human primates
Assessment of the problem: • Number of clinical cases - correct diagnosis • Routine screening results • Number of carriers • Health and safety assessment • Staff:animal proximity • Stress levels in animals • Use of animals
Recognise that human-mediated translocations of wild animals occur for many reasons, such as trade, rehabilitation and conservation.
- Organised sport hunting
- Rehabilitation
- Trade
- Conservation
- Human-wildlife conflict
Critically analyse the potential changes in host-parasite interactions as a consequence of wild animal translocations, and the effect of these changes on risk from disease.
Translocation cause changes in host-parasite interactions as a result of:
• Introduction of an alien parasite
• Aggregation of hosts – amplification parasites (R0 changes)
• Host loses parasites (enemy release)
• Released animals contract destination parasite
• Gain parasite during transport
• Stressors influence immunity / parasite interactions
• Altered parasite communities
Alien parasites more likely to become established at release sites if they have:
• a widespread geographic distribution
• a direct transmission life cycle
• high prevalence and intensity of infection
• infective for other species at the release site
(No evidence - guesses based on epidemiological principles)
- Translocated animals affected by endemic infectious disease
- Stressor-induced disease
- Translocated animals affected by non-infectious disease
Be able to list methods available for wild mammal capture and translocation
Physical capture and restraint:
• Cage, pit traps, plastic corrals or nets.
• Animals restrained for sampling, treatment, or translocation with or without tranquilisation
Chemical immobilisation:
• Restrained chemically using remote injection systems - inject anaesthetics into a muscle mass with subsequent immobilisation.
• Once induced manipulated as required – require close monitoring to avoid anaesthetic emergencies
Remote injection approach method: Foot: • low cost • low efficiency. • Low stress on animal • Dangerous with certain species and habitats. • Exhausting on operators. • Requires aircraft support usually. Vehicle: • efficient in open habitats • moderate stress • dangerous in certain habitats • vehicle damage a concern • requires aircraft support usually Helicopter: • highly efficient & effective • moderate stress animals low stress operators • dangerous
Be able to describe which equipment and drugs should optimally be used in different groups of mammals and circumstances
- Corrals (Funnels)
- Drive nets
- Fixed nets (Drop nets, Mist nets, Cannon nets, Net guns)
- Snag poles
- Kick boards
- Crates
- Transport
- Bomas or holding pens
Remote Injection System: • Rifles • Darts, Rubbers, internal charges (all sizes_ • Dart Push Rod • Cartridge holder and spares, charge loads (3 wts) • Silicon gel • Gun oil • Gun Rod and cleaning wads • Spare seals (Gas)
Immobilisation Agents, Drugs and Miscellaneous:
• Immobilising agent, sedatives, tranquilisers
• Adrenaline, respiratory stimulants, reversal drugs
• Antibiotics, wound spray, eye ointment, clean water.
• Knife, pliers, head cover, cotton rope, absorbent paper.
• GPS, binoculars, range finder
Be able to give safety advice on immobilisation of wild mammals
Human Safety Aspects: Use of rifles: • Cleaning, emptying, handling, AD. Use of dangerous anaesthetic agents: • Antidotes and Narcotic emergencies • Dangerous animals and Bush craft: • High risk species • Tracking & animal signs • Clothing, footware • Safety guns Handling injuries: • Head • Kick • Crush
Animal Safety & welfare:
Use of dart rifles:
• Correct charge for distance & dart type
• Use of dangerous anaesthetic agents:
• Appropriate dose for immobilisation.
• Appropriate management of dose effects.
• Antidotes & anaesthetic emergencies
Capture injuries:
• Hypoxia, hyperthermia, acidosis, capture myopathy
• Trauma, wounds, drowning.
• Posture; ischaemia, airway obstruction, bloat
Handling injuries:
• Netted animals: over-restraint
• Rope injuries, strangulation
• Crate injuries
Principles of wildlife capture and immobilisation:
• Use recognised methods for each species
• Have experienced veterinarians & capture team
• Ensure careful planning & preparation
• Keep equipment & drugs in secure containers & in good condition, cool & in date.
• Have at least 2 persons per animal for drug safety, to manipulate, administer & monitor anaesthesia.
• For large animals have cotton ropes, head covers.
• Have correct combinations & adequate amount of drugs
• Ensure continuous monitoring of anaesthesia & emergency drugs to hand. Ensure animal welfare.
Resolution of human-wildlife conflict requires a detailed understanding of the ecology and population dynamics of the conflict-species and how human development and activities influence these.
Need to reduce impacts of wildlife and offset the costs of wildlife
Fencing is associated with reduced carrying capacity – some species can’t be fenced in
Direct payments – difficult large scale
- separation
- reducing impacts
- offsetting the costs (direct payment, ecotourism, sport hunting)
Novel methods for conflict resolution require scientific investigation before they are recommended.
Elephants - Coordinated guarding of crops (lights, noises, chasing, natural repellents e.g. chilli grease)
Wild dogs - Conservation areas that increase food opportunities for predators by restoring prey populations
Wolves – Yellowstone profited from ecotourism because of the reintroduction
Compare and contrast primate pathogen issues between wild and captive housed primates
Dysbiosis:
- Loss of beneficial organisms
- Expansion of pathobiomes of potentially harmful microorganisms
- Loss of overall microbial biodiversity
Langur is folivorous and has a multi-chambered stomach = issues in captivity:
• Shift in gut microbiome in captivity compared to the wild
• Reduction in microbiome diversity associated with reduction in diet diversity
Captive microbiomes cause large weight gains
Overall effects of Langur captivity:
• Reduced microbiome diversity
• Humanises the microbiome
• Reduces amount of dietary fibre – major risk factor
Human pathogens detected in wild primates: TB in captive, and anthrax increasing in free-living primates
URTI can lead to sinusitis, air sacculitis and pneumonia. It can also cause anatomical variation (pneumatised superior turbinate)
Severe sinusitis = swollen mucosal membranes and blocked ostium
Air sacculitis = often clinically silent, chronic suppurative infection, and via inhalation of respiratory secretions of faeces
Develop an understanding of the practicalities, availability, and difficulties of use in a variety of primate pathogen diagnostics
e.g. difficulty with tuberculin testing false positives due to: - Buffered diluents - Impurities in the tuberculin - Trauma due to injection technique - Previous BCG vaccination - Cross reaction with atypical or saprophytic mycobacteria
False negatives due to:
- Anergy
- Testing too early
- Fungal disease
- Measles
- Immunosuppressive drugs
- Technical errors
- Local desensitization if test is repeated in the same site
Begin to critically assess the peer reviewed literature as groundwork for when developing a primate health programme for a perspective employer
Disease outbreak risk management set up:
• Focussed on risk communication
• Surveillance - especially for zoonotic diseases
• Disease fact sheet to analyse situation
• Hygienic measures
• Staff communication
• Public health advisory cmmunication
Have an appreciation of what DRA is, and why it is relevant to wildlife medicine in general
In a captive situation a health system tries to:
• Be Science/ Evidence Based.
• Be able to Highlight Data Gaps.
• Accurately assess Cost-benefit
• Improve communication = improve understanding = improve compliance
What do we ask?
• What question(s) are we trying to answer? (Problem Description)
• Can we interpret the data we get? (Assessment)
• How are we going to manage health situations? (Management)
• How are we going to learn from what we find to improve the situation into the future? (Review and change Problem Description)
Be able to set up a basic primate preventative health programme using DRA principles (Hazard ID thru Risk communication) – relates to learning objective 3 of lecture 1. Main resource: Manual of Procedures for Wildlife DRA.
