Contagious state - bacteria + mycosis (q1-12)

Tuberculosis and paratuberculosis (+ activation of disinfectants)

Etiology

• TB: M. bovis (mammals, man), M. tuberculosis (man, car, su), M. avium complex (birds, pigs)

• ParaTB (Johne’s disease): M. avium subsp. paratuberculosis

• Acid-fast, aerobic, very resistant in environment, chronic granulomatous diseases.

Tuberculosis (TB)

Epizootology

• Worldwide, zoonotic, WOAH-listed.

• Controlled in many countries, but wildlife reservoirs persist.

• Reservoirs: badgers, deer, wild boar, possums.

• Slovakia TB-free; Norway had M. bovis reappearance in 2022.

Transmission

• Mainly aerogenic (inhalation).

• Also milk/feed, vertical transmission, contact with tissues.

Pathogenesis

• Inhalation/ingestion → granulomas/tubercles → caseous necrosis ± calcification → chronic systemic disease.

Clinical signs

• Cattle (M.bovis): Chronic cough, Weight loss, Dyspnoea, Fever, Enlarged LN, Often asymptomatic

• Birds (M. avium): Often asymptomatic, Weight loss, ↓ egg production, Bone lesions

• Pigs: Usually alimentary form, Intestinal lesions/LN lesions, Often asymptomatic

• Humans: Pulmonary TB with Productive cough, Hemoptysis, Chest pain, Fever, fatigue

Diagnosis

• Tuberculin skin test (main test), IFN-γ test, PM inspection, Histology (granulomas), Ziehl-Neelsen staining, Culture, PCR. (Serology is NOT used for tuberculosis)

Public health risk

• Zoonotic - Infection from raw milk, meat, aerosols. Risk groups: vets, farmers, slaughterhouse workers. M. bovis is resistant to pyrazinamide.

Paratuberculosis (Johne’s disease)

Epizootology

• Worldwide, chronic wasting disease of ruminants. High economic losses. Not officially zoonotic.

Transmission

• Ingestion of contaminated milk, colostrum, faeces. Vertical transmission possible. Faecal shedding before clinical signs.

Pathogenesis

• MAP in ileum/Peyer’s patches → granulomatous enteritis → malabsorption/protein loss.

Clinical signs

• Adult ruminants: Chronic watery diarrhoea, Progressive weight loss despite appetite, ↓ milk production, Bottle jaw, Cachexia

• Young animals: Usually infected young, Clinical disease appears in adulthood (long incubation).

Diagnosis

• History + CS, ELISA (important screening test), PCR, Faecal culture, Histology, Tuberculin test with avian tuberculin

a) Prevention, control, outbreak measures, legislation

Legislation: Regulation (EU) 2016/429, Commission Delegated Regulation (EU) 2020/689, Commission Implementing Regulation (EU) 2020/200

Prevention & control

• Veterinary supervision of animal movement, Quarantine of healthy animals, Tuberculin testing (TB), Surveillance/screening, PM meat inspection, Pasteurisation of milk, Biosecurity & hygiene, Identification & traceability, Movement restrictions

Outbreak/suspicion

• Mandatory reporting, Isolation of suspect animals, Testing, Test & slaughter / depopulation, Rendering plant disposal, Epidemiological investigation, Final disinfection, Observation period (~110 d)

b) Sanitation, focal disinfection, activation of disinfectants

Environmental resistance

TB: Soil: 4 y, Pasture: 2 y, Water: 2 y, Slurry: 100–200 d

ParaTB: Soil: 11 mo, Faeces: 240 d

Focal disinfection: Chloramine T 6–10%, Peracetic acid 1%, Alkaline formalin 3%,

Environmental disinfection; Glutaraldehyde 2%, Formaldehyde, lime powder

Disinfection of objects: Sodium hypochlorite 2%

Excrements/slurry: 0.3% peracetic acid, 3% lime, Slurry storage >6 months

Activation of disinfectants:

Activation of disinfectants means increasing disinfectant efficacy by heating, adding alkalis/detergents, and removing organic material before disinfection!

• Heating: Chloramine T: 50–60°C, NaOH: 70–80°C

• Addition of detergents: sodium carbonate added to water (Detergents help disinfectants penetrate fat-rich mycobacterial cell walls)

• Alkaline formaldehyde = NaOH + formaldehyde

Factors decreasing efficacy: Organic matter, Low temperature

Brucellosis (+ biothermic treatment of manure)

WOAH-listed, Contagious + zoonotic (except B. ovis)

Causes: Abortion, placentitis in females, Epididymitis/orchitis in males, and intracellular bacteria surviving in macrophages. Virulence factor: LPS endotoxin.

Etiology + Main hosts

• Brucella abortus → cattle

• Brucella melitensis → sheep/goats (Malta fever in humans)

• Brucella suis → pigs

• Brucella canis → dogs

• Brucella ovis → rams (NOT zoonotic)

Epizootology

• Worldwide. Endemic mainly in Africa, Asia, Middle East, eastern Europe. Wildlife reservoirs complicate eradication.

• Norway & Slovakia: Free from: B. abortus, B. melitensis, B. suis, B. canis

• Recent situation: B. melitensis: France & Italy, B. suis: wild boar in Finland; domestic France

Transmission

• Horizontal: Ingestion of aborted material/milk, Direct contact with placenta, foetus, birth fluids

• Venereal transmission

• Vertical - Especially B. abortus* and B. canis

Important: Brucella survives for months in cool, moist environments.

Pathogenesis

• Entry → survival in macrophages → spread to reproductive organs → placentitis/abortion.

Clinical signs

• Cattle (B. abortus): Late abortion (5–7 month), Retained placenta, Infertility, Weak calves

• Rams (B. ovis): Epididymitis, Orchitis, Infertility

• Males generally: Testicular swelling, Arthritis/lameness possible

• Horses: Fistulous withers, Poll evil

• Humans: Malta fever/Undulating fever, Sweating, Weakness, Weight loss, Arthralgia

Differential diagnosis of abortions

Cattle: Tritrichomonas foetus (2–4 mo), Campylobacter foetus (4–6 mo), Leptospira (6–7 mo), Listeria (6–8 mo), Herpesvirus, Aspergillus

Sheep/goats: Campylobacter, Chlamydia psittaci, Listeria, Salmonella, Coxiella burnetii, Toxoplasma gondii, Pestivirus

Pigs: Leptospira, Parvovirus, Pestivirus, Herpesvirus

Diagnosis

Samples: Placenta, Aborted foetus, Vaginal swab, Milk, Semen, Blood

Tests: Serology (Rose-Bengal test, Complement fixation test, Serum agglutination, Milk ring test (cattle)

Other: Culture + modified Ziehl-Neelsen stain, PCR, Brucellin skin test, Guinea pig bioassay

Public health risk assessment

Important zoonosis. Risk groups are Veterinarians, Farmers, Slaughterhouse workers. Infection via: Raw milk, Contact with aborted material, Aerosols

Prevention in humans: Pasteurisation, PPE (gloves, masks, goggles)

a) Prevention, control, outbreak measures, legislation

Prevention & control

• Surveillance + serology, Milk ring test/Rose-Bengal, Test breeding animals, Quarantine + testing (>12 mo), Movement control, Pasteurisation, Rodent/insect control, Use Brucella-free breeding animals, Vaccination (Only in endemic areas, mainly ruminants), No human vaccine!

Outbreak/suspicion

• Mandatory reporting, Isolation/quarantine, Test & slaughter, Selective or radical depopulation, Disposal at rendering plant, Epidemiological investigation, Final disinfection, disposal at rendering plant: 133°C for 20 min

b) Sanitation, focal disinfection, biothermic manure treatment

Resistance: Brucella survives months in Manure, Slurry, Cool/moist environment. But easily destroyed by common disinfectants

and at 50–60°C heat

Focal disinfection

• Housing: Chloramine T 4%, Peracetic acid 0.3–0.9%

• Surfaces: Formalin 2%, NaOH 2–3%, Sodium hypochlorite 2.5%

• Skin: Ethanol, Iodophores

• Equipment: Autoclave (121°C/15 min), Dry heat (160–170°C/1 h)

• Manure: composting with lime

• Slurry: 3% lime, 0.3% peracetic acid (Slurry storage: 6 months storage with lime )

Biothermic treatment of manure (composting)

= Thermophilic aerobic composting producing heat that kills pathogens.

• Contaminated manture is placed on a surface layer of non-infected manure, straw and dry leaves, and covered with non infected manure.

Conditions:

• Temperature: 55–70°C

• minimum for 4 weeks

• Aeration: O2 for the composting process

• Moisture: 40–60%

• C:N ratio: 25:1

• pH: 5.5–8

Important:

• Improves soil quality

• Kills vegetative bacteria, larvae, eggs

• Spores may survive → combine with disinfectants (3% lime for 4 weeks)

Anthrax, tetanus, botulism, and other anaerobic infections (+ conditions for the use of formaldehyde for disinfection with regard to protection of human and animal health)

Anthrax

WOAH-listed | Zoonotic

Etiology:

• Bacillus anthracis

• Spore-forming bacterium, produces: lethal toxin + oedema toxin

Epizootology

• Worldwide except Antarctica, Endemic: Africa, Asia, southern/eastern Europe

• Spores survive in soil for decades. Rain/flooding may expose spores

• Norway: no reported cases

Transmission

1. Inhalation (most fatal), 2. Ingestion, 3. Cutaneous inoculation

Pathogenesis

• Spores → macrophages → lymphatics → septicaemia → sudden death → sporulation after death.

Clinical signs

• Peracute: Sudden death, No rigor mortis, Cherry-red unclotted blood from orifices, Rapid bloating

• Acute/subacute: Fever, Dyspnoea, Convulsions, Depression

Human forms

• Cutaneous: black ulcer

• Pulmonary: severe pneumonia

• Intestinal: bloody diarrhoea

Pathology

• Splenomegaly (“blackberry jam spleen”), Haemorrhages, Congested organs, DO NOT OPEN CARCASS

Diagnosis

• Report immediately! Blood from a live animal, Ear tissue from a dead animal

• PCR, ELISA, Culture (“Medusa head” colonies), Ascoli precipitation test, Giemsa/McFadden stain

Treatment/prevention

• Penicillin, oxytetracycline

• Annual vaccination in endemic areas

• Never necropsy!! Incineration preferred

Tetanus (“lockjaw”)

Zoonotic

Etiology:

• Clostridium tetani → Neurotoxins: tetanospasmin + tetanolysin

Transmission

• Contaminated wounds, Soil/manure contamination

Pathogenesis

Toxin blocks inhibitory neurotransmitters (GABA/glycine) → spastic paralysis

Clinical signs

• Horse: Sawhorse stance, Third eyelid prolapse, Tail elevated

• Dog: Muscle rigidity, Retracted lips, Often localised form

• Humans: Lockjaw, Risus sardonicus, Opisthotonus

Cause of death: Respiratory paralysis

Diagnosis

• History + wounds, Toxin serology, Culture (“drumstick” appearance)

Treatment/prevention

• Antitoxin, Metronidazole/penicillin, Wound cleaning + oxygenation, Vaccination (tetanus toxoid)

Botulism (“limber neck”)

WOAH-listed | Zoonotic

Etiology

• Clostridium botulinum, Toxins A–G, Animals mainly C & D, Humans mainly A, B, E

Epizootology

• Worldwide, Toxin in decaying food/carcasses, Birds infected through maggots

• Norway: rakfisk, cured meats (spekemat), contaminated needles

Transmission

• Ingestion of toxin/spores, Improper canned food, Honey in infants, Iatrogenic injections

Pathogenesis

• Blocks acetylcholine release → flaccid paralysis.

Clinical signs

• Birds: Limber neck, Paralysis, Cannot fly/walk

• Mammals: Dysphagia, Weakness, Drooling, Progressive paralysis

• Horse: Colic, Ileus, Shaker foal syndrome

Diagnosis

• Feed history, Toxin ELISA/neutralisation, Serum/GIT samples

Treatment/prevention

• Antitoxin, Gastric lavage, Remove contaminated feed, Proper food preservation

Other important anaerobic infections

Clostridium perfringens → Enterotoxaemia (Diarrhoea, Bloody faeces, Malabsorption)

Clostridium chauvoei → Blackleg (Young cattle, Gas-producing myonecrosis, Lameness + dark muscle)

Clostridium septicum → Malignant edema (Wound contamination, Necrosis + gangrene, Fatal septicaemia)

Clostridium haemolyticum → Bacillary haemoglobinuria (Intravascular haemolysis, Haemoglobinuria)

Fusobacterium necrophorum → Necrobacillosis (Calf diphtheria, Hepatic necrosis, Foot rot)

Public health risk

• Anthrax: inhalation spores = most dangerous

• Botulism: food poisoning

• Tetanus: wound contamination

• PPE + hygiene important

a) Prevention, control, outbreak measures

Anthrax: Do NOT open carcass, Incineration, Vaccination in endemic areas, Rodent/insect control, Disinfection before restocking, Prophylactic ATB for exposed workers

NB! If the carcass accidentally opens → ATB to exposed people, Vaccinate the herd, Soil disinfection

Tetanus: Early wound treatment, Vaccination, Antitoxin therapy

Botulism: Proper canning/storage, Remove dead birds/carcasses, Rodent control, Antiserum

b) Sanitation & focal disinfection, conditions for use of formaldehyde

Anthrax

• Resistance: Spores survive: heat, UV, desiccation, survives for decades in soil

• Housing: 10% Chloramine T, 10% chlorinated lime, 10% NaOH, 10% formalin, 4% glutaraldehyde, 1% peracetic acid

• Soil: Lime, Phosphoric acid, Peracetic acid

• Manure: Incineration, Composting + formaldehyde/glutaraldehyde

• Slurry: 3% phosphoric acid, 1% peracetic acid

• Spores destroyed by Autoclaving

Tetanus: 10% chlorinated lime, 3% formaldehyde, Autoclaving

Botulism: Autoclaving, Gamma radiation, Heating:100°C/10 min or 80°C/30 min

Formaldehyde — conditions of use

Properties

• Effective against: bacteria, fungi, viruses, mycobacteria, spores (it is not stable)

Usage

• 30% active formalin

• Spray: 2% (max10%)

• Focal: 3% + 3% NaOH (alkaline formaldehyde)

• Vapour: humidity 70–90%, temperature >15°C

Risks

• Carcinogenic (Category 1B)

• Suspected mutagen (class 2 mutagen)

• Irritating/toxic by inhalation/contact

Important

• Use only by trained professionals with PPE!!!

• approved for animal housing, animal feet, vehicles, and eggs in hatcheries in 2015

Salmonelloses of animals and poultry (+ physical disinfection)

WOAH-listed* | Contagious | Zoonotic

Etiology

• Main agent: Salmonella enterica

Important serovars:

• S. typhi → enteric fever in humans

• S. pullorum* → pullorum disease (septicemic disease in young chicks)

• S. gallinarum *→ fowl typhoid (older chickens)

• S. typhimurium → fowl paratyphoid, zoonotic, not host specific

• S. dublin → cattle

• S. abortusovis* → sheep → abortions

• S. bongori → reptiles

Epizootology

• Worldwide. Common in intensive poultry farming. Associated with poor hygiene and stress/immunosuppression. Wildlife birds maintain infection.

• Public health importance: Eggs and egg products = highest-risk foods. Major foodborne zoonosis.

• Europe 2022: Kinder chocolate products of S. typhimurium

• Europe January 2023-2025: outbreak with 509 confirmed cases inlcuding Norway, Finland and Sweden, traced to sprouts, especially alfalfa and clover from a supplier in Italy, and the investigation is still ongoing

• Norway: B-disease. Most human infections are acquired abroad or from imported food, except S. typhimurium 50% of cases contracted in Norway.

• Slovakia & Norway: S. abortusovis absent!

Transmission

• Horizontal: Faecal–oral route, Contaminated feed/water, Raw diets, Carrier animals, Rodents/insects

• Vertical: Through eggs

• Human infection: Raw eggs, Meat, Milk, handling exotic pets/reptiles

Pathogenesis

• Ingestion → intestinal replication → enteritis → possible septicaemia → possible infection of CNS, bones, uterus etc.

• Important: LPS endotoxin released during bacterial lysis causes: endotoxaemia, vascular damage and shock

Clinical signs

• General: Many healthy adult animals are asymptomatic.

• Young animals: Septicaemia, Sudden death, Fever, Severe diarrhoea

• Calves: Acute enteritis, Bloody diarrhoea, Fever

• Cattle (S. dublin): Abortion, Septicaemia

• Sheep (S. abortusovis): Abortion

• Pullorum disease (S. pullorum): Young chicks → White diarrhoea, Weakness, Dehydration, Septicaemia, High mortality

• Fowl typhoid (S. gallinarum): Older chickens → Septicaemia, Sudden death, High mortality

• Fowl paratyphoid (S. typhimurium): Arthritis, Lameness, Conjunctivitis, Blindness, Enteritis, Sudden death

Diagnosis

• Samples: Faeces, Shoe-cover swabs, Serum

• Methods: Culture (main) XLD agar: red colonies with black centre (H₂S), PCR

• Serovar differentiation: Serology → Rapid slide agglutination, CFT, ELISA

Treatment

• Humans: usually self-limiting, fluids, severe cases: ciprofloxacin

• Animals: Ampicillin/other ATB, NSAIDs, Fluid therapy

Public health risk assessment

• Important foodborne zoonosis. Eggs/poultry major source. Raw foods and reptiles important reservoirs.

• Risk groups: Poultry workers, Farmers, Veterinarians, Consumers of raw eggs/meat

a) Prevention, control, outbreak measures, legislation

Prevention & control:

• There is legislation that requires monitoring of breeding flocks and hatcheries for S.enteritidis and S.typhymurium + slaughter of positive flocks

• Risk management: culture day-old chicks and 4 + 2weeks before laying

• Serology: test swabs on 2 pairs of boots in broilers and pooled fecal samples of layers (60 samples)

• Take dust samples for annual monitoring and control feed

• Biosecurity: Rodent control, Insect/vector control, Hygiene “Black & white system.”

• Important: Do NOT brush eggs → removes protective cuticle, bacteria enter pores

• Food safety: Pasteurisation of milk, Proper cooking

Outbreak measures

• Slaughter/elimination of positive flocks, Movement restriction, Cleaning/disinfection, Vaccination in countries with prevalence >10%

b) Sanitation, focal disinfection, physical disinfection

• Resistance: Wet faeces (1 week), Dry faeces (up to 6 years), Dust (1–4 years), Biofilms (months)

• Destroyed by: Heat, Sunlight, High pH, Ozone, Disinfectants

Sanitation

• Housing: Chloramine T 6%, Peracetic acid

• Manure: Composting at 65°C

• Slurry: 0.3% peracetic acid, 3% lime, Ammonia

• Water: Chlorination

• Eggs: 2% formaldehyde vapours

• Meat cooking temperatures: Steak: 63°C, Ground beef: 71°C, Poultry: 77°C

Physical disinfection

1. Moist heat (most effective → coagulation of proteins)

• Boiling/hot water: 80C for 10 min (vegetative organisms), or 100C for 5min (C.perfringens spores), 10min (B.anthracis)

• Autoclaving (steam): 121°C, 1atm/bar, 15 min → kills spores/endospores

• Pasteurisation: 72°C for 15 sec

• UHT: Ultra-high temperature treatment (140C for 2sec)

2. Dry heat (on animal housings like floor, walls, kill MO by oxidation)

• 140–200°C for 1–2 h

• Flame gun/blow lamp for housing/tools

• Direct heat by using flame or hot air oven with 170C for 2h (mention this one!)

• NB: some organisms like prions may not be killed by dry heat

3. Desiccation: Removes moisture, variable effect. great for materials contaminated witg urine, pus, mucus

4. Osmotic pressure: High salt/sugar

5. Radiation

• nonionizing (UV, food industry, surgery), ionizing (Gamma/X-ray)

6. Filtration & freezing

Campylobacterioses, yersinioses (+ disinfection in food production)

Campylobacteriosis

WOAH-listed | Contagious | Zoonotic

Etiology

* Campylobacter fetus venerealis → Ru → bovine genital campylobacteriosis

* Campylobacter fetus fetus→ Ru

* Campylobacter jejuni → poultry, mammals, man

* Campylobacter coli → animals, man

Important: C. jejuni and C. coli are normal intestinal flora in many animals and poultry. Poultry = major reservoir.

Epizootology

• Worldwide. Most commonly reported food-borne zoonosis in Europe.

• The main human source = undercooked poultry.

• Europe: C. fetus venerealis reported in cattle in France and Ireland.

• Norway: C. fetus venerealis = B-listed disease.

Transmission

• Genital forms (C. fetus): Venereal transmission (Bulls are asymptomatic carriers → Spread during natural breeding/AI)

• Enteric forms (C. jejuni, C. coli): Faecal–oral route, Contaminated food/water, Raw poultry, Unpasteurised milk

Pathogenesis

• GIT form → Colonisation of jejunum/ileum/colon → enteritis. Toxin: Cytolethal distending toxin → inflammation + villous atrophy.

• Genital form → Catarrhal inflammation of the reproductive tract.

Clinical signs

• GIT form: Diarrhoea (may be bloody), Enteritis, Abdominal pain, Anorexia, Often asymptomatic adults

• Genital form: Bulls → Usually asymptomatic carriers. Cows → Endometritis, Metritis, Infertility, Irregular oestrus, Early embryonic death, Abortion

Diagnosis

• GIT: Faecal culture (Skirrow selective agar and blood agar), Oxidase positive (reagent turn purple), PCR, Gram stain

• Genital: Vaginal/preputial wash culture (skirrow agar), PCR, ELISA (use on vaginal mucus), VMAT (vaginal mucosal agglutination test, a field test)

Treatment

• GIT: ATB, often limited usefulness

• Genital: Vaccination, Streptomycin in bulls

• Humans: Erythromycin, Gentamicin

Public health risk

• Major food-borne zoonosis. Poultry = highest risk. Infection mainly from undercooked chicken/raw milk.

Yersiniosis

Contagious | Zoonotic

Etiology

* Yersinia pestis → black death, pneumonic plague (pest) in man. mammals are PH.

* Yersinia enterocolitica → enteritis in man and pigs.

* Yersinia pseudotuberculosis → birds, rodents, swine, car, cervids

Epizootology

• Y. pestis: Historical Black Death pandemic (bubonic plaque pandemic in europe and asia in 1300)

• Endemic in East Africa, Asia, South America

• Cats are highly susceptible. Rodents = reservoir.

• 2009 china: pneumonic plague outbreak

• 2021 madagascar: pneumonic and bubonic plaque

Transmission

• Y. pestis: Rat fleas, Aerosols, Skin wounds/contact with infected animal

• Y. enterocolitica: Ingestion of contaminated pork

Pathogenesis

• Y. pestis: Skin inoculation → buboes (lymph node abscesses) → septicaemia/pneumonia.

• Severe forms: Bubonic plague, Septicaemic plague, Pneumonic plague

• Y. enterocolitica: Colonises ileum/cecum → enteritis + lymph node enlargement.

Clinical signs

• Y. pestis

→ Bubonic: Painful enlarged lymph nodes

→ Pneumonic: Respiratory failure

→ Septicaemic: DIC and tissue necrosis

• Y. enterocolitica: Usually self-limiting enteritis

Diagnosis

• History + CS, Blood agar culture (Blood/nasal swabs, LN aspirates), PCR, ELISA, Agglutination tests, Gram stain

Treatment

• Rodent control, Flea treatment, Gentamicin, Doxycycline

Public health risk assessment

• Campylobacter: Major zoonotic foodborne disease. Poultry = main source.

• Yersinia: Third most important zoonosis after Campylobacteriosis and Salmonellosis

a) Prevention, control, outbreak measures

Campylobacter:

• Prevention: Cook meat properly, Pasteurise milk, Hygiene/biosecurity, Remove faeces, Rodent & insect control, Bull examination, Vaccination before breeding

• Outbreak: Treatment or culling/selection

Yersinia:

• Prevention: Cook pork properly, Milk hygiene, Rodent control, Flea treatment, Water hygiene

• Outbreak: Treatment or selection/culling, No vaccine

b) Sanitation, focal disinfection, food production disinfection

• Resistance: Low environmental resistance, Survive best in moist conditions

Campylobacter sanitation

• Housing: 4% chloramine T, 0.3% peracetic acid, 2% formalin, 2% NaOH, 20% slaked lime, Cresol-sulphuric mixture

• Water: Chlorination

• Physical methods: Moist heat, Dry heat, UV, Gamma radiation

Yersinia sanitation

• Easily destroyed by: Heat, Drying, Sunlight, Disinfectants

• Disinfectants: 2% NaOH, 2% chloramine T, 0.5% formaldehyde, Other: Drying for 2 days, Moist/dry heat

Disinfection in food production

HACCP (Hazard Analysis Critical Control Points)

• identifies contamination risks in food production.

Cleaning/disinfection steps:

1. Remove food

2. Mechanical cleaning

3. Pre-rinse: high pressure water

4. Detergent cleaning: remove biofilm (washing soda, Na2CO3).

• alkaline cleaning agent: Removes fats/proteins

• acid cleaning agent: Removes encrusted residues like milkstone/waterstone

• neutral cleaning agent: Smooth surfaces wo dirt/manual cleaning

5. Rinse

6. Drying (to not dilute the disinfectant)

7. Disinfection

Disinfection methods:

• Physical: Hot water, Steam, UV, Radiation, Ultrasound

• Chemical: Iodonal A, Sodium hypochlorite, Nitric acid, QUACs (Despon). MUST NOT LEAVE TOXIC RESIDUES!

Borreliosis and other tickborne diseases (+life cycle of ticks and their prevention and control)

Borreliosis (Lyme disease) — Vector-borne | Zoonotic | Natural focal disease

Etiology

* Borrelia burgdorferi sensu stricto → Lyme disease

* Borrelia afzelii, Borrelia garinii

* Borrelia anserina → avian spirochaetosis

Important: Borrelia burgdorferi s.l. complex causes Lyme disease in mammals and humans.

Reservoirs = small rodents, birds, and insectivores.

Natural focality

Natural focus includes:

• Pathogen (pathoergont), Reservoir host, Vector (blood-sucking arthropod), Recipient host (animal/man) and Suitable environment

• Other natural focal diseases: leptospirosis, rabies, TBE, ehrlichiosis, babesiosis.

Epizootology

• Worldwide, endemic in Central Europe and Southern Scandinavia

• Seasonal: spring–autumn. Professional risk for outdoor workers

• Norway: endemic areas in the southern regions

Transmission

Ixodidae hard ticks (Ixodes*)

• Transstadial transmission, occasionally transplacental

• B. anserina is transmitted by soft ticks (Argas) via transstadial + transovarial transmission

Pathogenesis

Tick bite → skin penetration → bacterial replication → spread via blood/lymph → immune complex formation → kidney/joint damage.

Clinical signs

Animals:

• Fever, Lethargy, Enlarged lymph nodes, Arthritis, swollen joints, lameness, Glomerulonephritis, Uveitis, Arrhythmias, Abortion

Humans:

1. Flu-like signs, 2. Erythema migrans, 3. CNS/joint involvement (facial paralysis, headache, neck stiffness)

Birds:

• Anaemia, Cyanotic comb, Green diarrhoea

Diagnosis

• Culture: Barbour–Stoenner–Kelly II medium at 33C

• PCR

• Dark-field microscopy

• ELISA, indirect IFA

Cross-reactions with Leptospira* and Treponema

Treatment

• Doxycycline, Penicillin, Amoxicillin, Erythromycin

• Symptomatic + anti-inflammatory therapy

Other vector-borne infections

Tick-borne:

• Ehrlichiosis, Rickettsiosis, Babesiosis, Tularaemia, Tick-borne encephalitis (TBE), Crimean–Congo haemorrhagic fever

Mosquito-borne:

• West Nile fever, Dengue, Yellow fever, Equine encephalitis

Culicoides-borne:

• Bluetongue, African horse sickness

Public health risk assessment

Major zoonotic vector-borne disease. Expanding tick populations and climate change increase risk to animals and humans.

a) Prevention, control, outbreak measures

• Tick control with acaricides (Permethrin): Amitraz collar for dogs, Fipronil spot on, Fluralaner (bravecto)

• Rodent control (deratization)

• Protective clothing, avoid tick habitats

• Vaccination in endemic areas

• Tick repellents: DEET, Picaridin, IR3535

Outbreak measures

• Antibiotic treatment, Tick elimination, Monitoring of exposed animals/humans

b) Sanitation, focal disinfection, tick life cycle & control

Borrelia destroyed by:

• Chloramine T, Peracetic acid, Sodium hypochlorite, 70% ethanol

• UV light

• Heat

Tick life cycle (Ixodidae – hard ticks)

• incomplete metamorphosis

Egg → larva (6 legs) → nymph (8 legs) → adult (8 legs)

Types:

• One-host ticks, Two-host ticks, Three-host ticks (Ixodes = Borrelia vector)

• Ixodes larva and nymphal stage feed on reservoirs (small mammals and birds) and get infected by the pathogen, then they feed on man/animal and spread the pathogen.

Soft ticks (Argasidae)

• Multi-host life cycle, Can survive years without feeding

• they have several nymphal stages and may feed on several hosts like rodents and birds, and transmit borrelia at anyh developmental stage

Tick/insect control methods

• Mechanical: traps, screens

• Physical: heat, UV, steam

• Biological: natural enemies

• Chemical: insecticides/acaricides (permethrin, amitraz, ivermectin)

Mycoplasmosis (+ aerosol disinfection)

WOAH-listed | Contagious | Mostly respiratory diseases | Zoonotic risk low/no in animals

Etiology

• Mycoplasma capricolum subsp. capripneumoniae → Contagious caprine pleuropneumonia (CCP)

• Mycoplasma mycoides mycoides → Contagious bovine pleuropneumonia (CBP)

• Mycoplasma bovis → mastitis, pneumonia, arthritis, vulvovaginitis

• Mycoplasma agalactiae → contagious agalactia in sheep/goats

• M. gallisepticum → chronic respiratory disease in poultry

• M. synoviae → arthritis/synovitis in poultry

• M.hyopneumonia, M.hyosynovia, M.hyogenitalia (PIGS)

• M.genitalium, M.pneumonia (mild “walking pneumonia” in humans)

Important: Mycoplasma lack a cell wall → fragile in environment but resistant to some antibiotics.

Epizootology

• Worldwide: Africa: endemic CBP with high mortality, Europe: CBP eradicated since 1999

• Norway: M. bovis free country

• Backyard poultry in Nordic countries is commonly affected by avian mycoplasmosis (yearly in Iceland), and in Finland in 2024)

• CCP outbreaks associated with stress, transport, cold

Transmission

• Horizontal transmission: Inhalation (main route), Milk/dairy products, Venereal transmission

• Wind spread possible up to 200 m (M. mycoides*)

Location

• Mainly respiratory tract, but also Mammary gland, Joints, Eyes, Urogenital tract

Pathogenesis

• Inhalation → pneumonia, pleuritis, hepatization of lungs

• Ingestion → spread via blood to mammary gland, joints, eyes

• Chronic latent infections are common

Clinical signs

Cattle (CBP / M. bovis):

• Fever, Pneumonia, Dyspnoea, chest pain, Mastitis (“sand-like” milk), Vulvovaginitis, Otitis media

Goats/sheep:

• Mastitis, Arthritis, Keratoconjunctivitis, Abortion, Septicaemia

Poultry:

• Airsacculitis, Tracheitis, Sinusitis, Swollen joints

Diagnosis

• Culture on PPLO agar (“fried egg” colonies) and PCR

• ELISA, HIT

• Samples: Nasal swabs, Pleural fluid, Synovial fluid, Lung lesions, Lymph nodes

Treatment

• Often difficult/not recommended due to latent carriers

• Culling + quarantine preferred

• Vaccination in endemic areas

• Antibiotics: Enrofloxacin, Tulathromycin, Gamithromycin

Public health risk assessment

Animal mycoplasmoses are mainly veterinary/economic problems. Human mycoplasmas exist (*M. pneumoniae*, M. genitalium), but animal strains are generally not zoonotic.

a) Prevention, control, outbreak measures

Prevention & control

• Quarantine + movement restrictions

• Serological screening and Vaccination in endemic areas

• Good husbandry and milking hygiene

• Test breeding bulls

• Expand poultry flocks from seronegative birds

• Rodent/insect control

Outbreak measures

• Eliminate positive animals, Quarantine affected herds/flocks

• Antibiotic treatment is usually not sufficient

b) Sanitation, focal disinfection, aerosol disinfection

Resistance

• Poor survival in environment, but can survive for years when frozen

Destroyed by:

• Heat: 55–60°C for 30 min or 100°C for 1 min

• Extreme pH

• Chloramine T, Peracetic acid, NaOH, Formalin, Chlorinated lime, cresol-sulphuric, peracetic and formaldehyde vapours for eggs in hatcheries.

Aerosol disinfection

• Common in the poultry industry.

• Ultrafine dispersions of solid of solid or liquid disinfectant in gases

• not uniform deposition: 75-85% of aerosol particles is captured on horizontal surfaces

Conditions:

• Particle size: 0.5–10 µm (max 20)

• Humidity: 70–90%

• Temperature: >15°C

• Exposure: overnight (≥6 h)

• Volume: 5-25ml per 1m3. 5ml/m3 in presence of animals.

Methods:

• Karcher, Igeba, Formalin lamp, Exothermic reaction

Disinfectants used:

• Peracetic acid vapours (non-stable, min.15%. not by thermomechanical reaction → explosion. 12mil Pedox + 4g chlorinated lime is very effective)

• Formaldehyde aerosols (non-stable, min 30%. exothermic reaction → inactivate virus, fungi, spore forming. use Formalin + potassium permanganate mixtures or mixed with chlorinated lime)

Q fever & other rickettsioses (+Treatment and disinfection of soil and pastures)

WOAH-listed | Vector-borne | Zoonotic

Etiology

* Coxiella burnetii → Q fever

* Reservoirs: ruminants, birds, various mammals

* Humans are infected mainly through farm animal exposure

Other rickettsioses:

* Rickettsia rickettsii → Rocky Mountain spotted fever

* Ehrlichia canis → canine ehrlichiosis

* Ehrlichia ruminantium → heartwater disease

* Rickettsia prowazekii → epidemic typhus

* Anaplasma phagocytophilum → granulocytic anaplasmosis

Epizootology

• Q fever worldwide except New Zealand

• Large outbreak: Netherlands 2007–2011 (>4000 human cases)

• Norway: 8 human cases in 2019

• Slovakia: largest outbreak in 1993 after men handled aborted goat kid. 2011 - goat cheese. 1 human case in 2019.

• Spread possibly over long distances by aerosolized spore-like forms

• Tick-borne diseases are increasing due to climate change/global warming

• Seasonal tick activity mainly spring–autumn

Transmission

Q fever:

• Inhalation (main route)

• Ingestion of contaminated milk/food

• Exposure to birth fluids, placenta, aborted foetuses

• Tick transmission possible

Rickettsioses/ehrlichiosis:

• Hard ticks (Dermacentor, Amblyomma, Rhipicephalus*)

• Transstadial/transovarial transmission

Pathogenesis

Q fever:

• Inhalation → replication in macrophages → lymph nodes → bacteraemia → uterus, placenta, mammary gland.

Rickettsioses:

• Attack vascular endothelium or WBCs → vasculitis/DIC → multiorgan damage.

Clinical signs

Animals (Q fever):

• Often asymptomatic, Abortions, Weak offspring, Endometritis, Agalactia

Humans (Q fever):

• Flu-like disease, Chronic endocarditis, Hepatitis, Arthritis, Premature birth

Rocky Mountain spotted fever:

• Fever, Rash, CNS signs, Endothelial damage

Ehrlichiosis:

• Fever, Lymphadenopathy, Thrombocytopenia, DIC, Seizures/coma in severe cases

Diagnosis

• PCR, ELISA / IFA, Blood smears, Cell culture / embryonated eggs, Giemsa or Stamp staining

Samples: Blood, Birth fluids, Placenta/foetus, Milk, Vaginal discharge

Treatment

• Doxycycline (main antibiotic), Supportive therapy, Q fever in animals: usually no treatment

Public health risk assessment

• Important zoonotic diseases. The highest risk during animal parturition and handling of contaminated birth materials.

• Aerosol spread creates major outbreak potential.

a) Prevention, control, outbreak measures

Prevention & control

• Proper disposal of birth products/manure

• Cleaning and disinfection

• Tick control: Permethrin, Amitraz, Fipronil

• Pasteurization of milk

• Vaccination in endemic areas

• Awareness and biosecurity

• Remove contaminated birth fluids immediately

Outbreak measures

• Treatment where appropriate

• Elimination/isolation of positive animals

• Movement restrictions

b) Sanitation, focal disinfection, treatment and disinfection of soil/pasture

Resistance

• Survive for months in environment. Aerosol spread over large distances

Disinfection

• Chloramine T (4%), Peracetic acid (0.5%), NaOH (2%), Formaldehyde (2%), Lime (3%), Moist/dry heat

• Manure compost

• Slurry:  3% lime, 1.5% phosphoric

• Pasture: 3% lime & no grazing for 90 days

• Tick bite disinfection: 70% isopropyl alcohol and 2% tincture iodine

Manure/slurry treatment

* Composting (biothermic treatment)

* Lime or phosphoric acid treatment

* Burning/burying if necessary

• Storage condition: minimum 15m from milking parlour & 50m from well

Pasture/soil disinfection

• 3% lime

• 1–1.5% phosphoric acid

• 0.3-0.5% peracetic acid

• all 10L per 1m2

* No grazing for 90 days

Chlamydiosis (+hygiene measures to reduce airborne diseases)

WOAH-listed: Yes*  C: Yes  Z: Yes*

Aetiology

* Chlamydia psittaci → birds (avian chlamydiosis), zoonotic

* C. abortus → sheep/goats, enzootic abortion, zoonotic

* C. felis → cats, conjunctivitis

* C. suis → pigs, respiratory/enteric/reproductive disease

* C. trachomatis → humans (STD)

* C. pneumoniae → mild respiratory infection in humans

Unique reproductive cycle

* Elementary body (EB) = infectious, small, metabolically inert

* Reticulate body (RB) = intracellular replicative form

EB enters host cell → RB replicates in inclusion bodies → cell lysis → spread

Epizootiological situation

• Worldwide distribution

• Avian chlamydiosis common in psittacines & poultry

• Reported in Norway in 2019

• Enzootic abortion of sheep is endemic in UK, France, Spain, Germany

• An important cause of abortion in sheep in Europe

Transmission

Horizontal:

• Inhalation of dust/faeces/discharges

• Ingestion

• Direct contact with afterbirth/vaginal discharge

• Venereal transmission

• Milk ingestion

Vertical:

• Placenta & milk (especially C. abortus)

Pathogenesis

• Inhalation/ingestion → EB enters host cell → RB replication → cell lysis → infection of mucosal epithelial cells & macrophages → possible septicaemia

Clinical signs

Birds:

• Anorexia, lethargy, weight loss, Yellow droppings, Conjunctivitis, sinusitis, sneezing, Hepatosplenomegaly, airsacculitis, pericarditis

Mammals:

• Late-term abortion, Stillborn/weak offspring, Inflamed placenta

• Cats: conjunctivitis, rhinitis, bronchopneumonia

Humans:

• Flu-like illness to severe pneumonia/encephalitis

• Pregnant women at risk from C. abortus

Diagnosis

• History + clinical signs

• PCR = method of choice

• McCoy/BHK cell culture

• Giemsa, Ziehl-Neelsen, Macchiavello staining

• ELISA, CFT serology

Treatment

• Long-course doxycycline/tetracycline

a) Prevention & control

Avian:

• No vaccine, Monitoring, All-in/all-out, Remove dead birds

Mammalian:

• Vaccination (C. abortus, C. felis), Quarantine & isolation, Disinfection after abortions, Veterinary surveillance, Doxycycline treatment

General:

• Pasteurise milk, Control rodents, insects & wild birds, Avoid contact with aborted material

Outbreak measures

• Depopulation/slaughter, Incineration of carcasses/material, Vaccination in mammals

b) Sanitation & disinfection

• Sensitive to most disinfectants: Sodium hypochlorite, Ethanol, Peracetic acid, Glutaraldehyde, Hydrogen peroxide, Lime, Heat (autoclave 121°C/15 min), chlorination of water, quick lime on pasture, manure composting

Hygiene measures against airborne spread

• Max gases in animal housings: CO2 (0,25%), H2S (10ppm), methane, ammonia (25ppm), N2O (nitrous oxide)

• Air of animal house differ from atmospheric: No UV (disinfection), high humidity (no dehydration of MO), higher dust (carriers of MO), aerosol droplets (carry MO)

• Reduce dust & aerosols

• Good ventilation

• Proper humidity: Most airborne bacteria survive better at RH either higher or glower than 50-80% RH range

• Regular manure/bedding removal

• Adequate animal spacing

• Biosecurity distances between farms

Public health risk assessment: Important zoonosis. Avoid contact with aborted foetuses, placentas, discharges, contaminated dust, and unpasteurised milk. Pregnant women should not handle suspected cases.

Listeriosis and other bacterial encephalitis (+microbiological control of disinfection)

Listeria:

C: No  Z: Yes

Important food-borne zooanthroponosis, especially in immunocompromised individuals.

Etiology

• Listeria monocytogenes

Produces Listeriolysin O (LLO)

• FH: mammals (ruminants, humans), birds asymptomatic

• Listeria ivanovii → Sporadic abortions in sheep & cattle.

• Reservoir: rodents → urine contaminates silage, vegetables etc. (tror e ho sa på epizoo eksamen)

Epizootiological situation

• Worldwide: soil, water, silage, faeces, plants

• Grows at 4–44°C (important food-borne pathogen)

• Survives: Soil: up to 5 years, Silage: 12–16 month, Faeces/water: 1–2 years, Winter–spring disease in colder climates

• 2023: Norway (dogs in Bergen), Italy, Austria, Netherlands

• 2024: USA

Transmission

Horizontal:

• Contaminated silage/feed, Unpasteurised dairy products, Undercooked meat, Direct contact/inhalation

Vertical:

• Placenta, milk

Excreted in:

• Faeces, urine, milk, uterine discharge, aborted foetuses

Pathogenesis

• Entry via alimentary tract/conjunctiva → blood & lymph → CNS, liver, spleen, genital tract

• Migrates along peripheral nerves to CNS

• Survives in macrophages using *Listeriolysin O**

• Pregnancy/immunosuppression predispose disease

Clinical signs

Mammals

Septicaemic form (young):

• Fever, diarrhoea, weakness, Nasal/ocular discharge, Death within 24–48 h

Encephalic form (adults):

• Circling, Facial paralysis, Torticollis, Opisthotonus, Paralysis/coma

Abortion form:

• Late gestation abortion, Retained placenta, Mastitis

Sheep

• Rapid encephalitis, Droopy ears, protruding tongue, Excess salivation, Circling

Birds

• Septicaemia in young, CNS signs in adults

Humans

• Pregnancy infections, Neonatal sepsis/meningitis, Gastroenteritis, Encephalitis/meningitis, Cutaneous listeriosis in veterinarians

Pathology

• Liver & spleen necrosis, Brain oedema, Suppurative meningitis, Placental inflammation, Oedematous/mummified foetus

Diagnosis

• Clinical signs + necropsy, Blood agar/BHI culture, PCR, IFA, Gram stain, Serology not recommended

Treatment

* Penicillin + gentamicin

* Dexamethasone for CNS inflammation

Other bacterial encephalitis

* Streptococcus suis — pigs

* Streptococcus equi — strangles

* Haemophilus parasuis — Glässer disease

* Histophilus somni — cattle

a) Prevention & control

* Avoid spoiled silage (pH 4.5), Good farm hygiene, Burn aborted material, Pasteurise milk, Cook food properly, Rodent/vector control, Regular disinfection, All-in/all-out, Isolation of affected animals

outbreak: Isolation of affected animals – Tx (if CNS is not involved)

Vaccine: in sheep – but not very effective 

b) Sanitation and disinfection

Sensitive to:

* Chloramine T, Formaldehyde, NaOH, Peracetic acid, Heat, Chlorination/ozone

Microbiological control of disinfection efficiency

1.          Chemical control – determines concentration of active substance by chemical swabs

2.          Microbial control – the most objective test – based on microbial swabs (area – 10cm2)

a.         Total no. of bacteria or presence of indicator microbes is established

b.         Preventative (quantitative), focal (qualitative), direct or indirect

Before disinfection - Evaluation of effect of disinfectant

1. Take sterile swabs from 10cm^2

2. Total no. of Mo on nutritive agar and indicator on endo agar

3. CFU = colonies grown on plate x 00 (dilution)

-        e.g.: 86 colonies x 00= 8.6x10^3CFU/cm^2

 After disinfection

1. Preventive

   1. 30 sterile swabs on 10cm^2 area into physiological solution

   2. Measures total no. of MO & indicator MO

   3. Make decimal dilutions 10^1, 10^2, 10^3, 10^4

   4. On nutritive agar

   5. Max 10% positive indicator MO

2. Focal

   1. 30 sterile swabs on 100cm^2 area & into selective liquid broth

   2. Make decimal dilutions

   3. On endo agar

   4. Should be negative!!

   5. CFU: Colonies x 00(dilution) x 0

   6. Total no. can be 1.2x10^3CFU/10cm^2

Public health risk assessment

Major zoonotic food-borne disease.

High risk for:

• Pregnant women, Elderly, Immunocompromised people

• Avoid contaminated silage, raw milk, undercooked food, unwashed vegetables, and aborted material

Leptospirosis and other spirochetosis (+stages of rodent control)

Spirochaetosis

* Gram-negative, motile, spiral bacteria

* Endocellular flagella

* Mostly anaerobic

Order: *Spirochaetales**

Includes:

* Leptospira → leptospirosis

* Borrelia → Lyme disease

* Borrelia anserina → avian spirochaetosis

* Brachyspira → intestinal spirochaetosis

Leptospirosis

C: No  Z: Yes

Aetiology

* Leptospira interrogans

Reservoir: *rodents**

Common serovars:

* Dogs: canicola, icterohaemorrhagiae, grippotyphosa, pomona

* Cattle/horses: grippotyphosa, pomona

* Pigs: pomona, bratislava

FH:

* Dogs, cattle, pigs, horses, humans

Epizootiological situation

• Worldwide

• Associated with muddy water, lakes, riverbanks

• Natural focal disease - More common after rainfall, Seasonal in temperate climates

Europe:

• 2021: 1246 human cases in Europe (mainly France)

• Slovakia: 21 cases (2017–2021)

• Norway: B-listed disease, mainly in wild rats/imported cases

Transmission

* Urine-contaminated water (main source)

* Contact through skin or mucous membranes

* Ingestion

* Venereal

* Placental transmission

* Rodent vectors

Dogs:

* Infection often from bites, carcasses, placenta

Pathogenesis

• Skin/MM contact → bloodstream → bacteraemia → kidney, liver, uterus

→ intravascular haemolysis & liver injury

• Leptospira persist in renal tubules → shedding in urine

Clinical signs

Dogs

• Vomiting, Icterus, Renal failure, Severe lung disease, Death

Ruminants

• Abortion

Horses

• Uveitis, Conjunctivitis, Photophobia

Pigs

• Usually mild/subclinical

Humans

• Fever, myalgia, Meningitis, Pulmonary haemorrhage, Icterus - Weil disease

Diagnosis

• EMJH culture medium, Dark-field microscopy, Levaditi silver stain, PCR

• Serology: ELISA, MAT = gold standard

Samples:

• Blood, urine, placenta, Kidney, liver, brain, eye

NB:

• Intermittent shedding → paired samples after 3–4 weeks

Treatment

• Penicillin, Tetracycline, Streptomycin, Supportive therapy

• Annual vaccines: Dogs, Cattle, Swine

Other Spirochaetoses

• Brachyspira (Swine dysentery → Mucohaemorrhagic diarrhoea)

• Borrelia burgdorferi (Lyme disease - Tick-borne → Kidney & joint damage)

• Borrelia anserina (Avian spirochaetosis - Soft tick transmission → Septicaemia, liver/spleen necrosis)

• Treponema cuniculi (Rabbit syphilis → Papules & erosions)

a) Prevention & control

• Rodent control, Tick removal (<12 h), Vaccination, Fence open water sources, Proper sanitation, Quarantine, Black & white system, All-in/all-out

• Outbreak: Isolation, Treatment, Vaccination

b) Sanitation, focal disinfection and rodent control stages

Sensitive to:

• Chloramine T, NaOH, Formaldehyde, Peracetic acid, Chlorination of water, Heat/pasteurisation

Rodent control stages

1. Assessment of rodent population (number based on feces etc)

2. Choose control method:

• Mechanical, Physical, Biological, Chemical

3. Protection of non-target animals (bait box etc)

4. Assess effectiveness

5. Protocol/documentation

Public health risk assessment

• Important zoonosis. Humans infected mainly from contaminated water or urine.

• High-risk groups: Farmers, Veterinarians, People exposed to floodwater or rodents.

Mycoses (+ use of acids for disinfection)

• Mycoses = fungal diseases of humans & animals

• Worldwide distribution

Cause:

• Dermatomycoses (skin)

• Systemic mycoses (internal organs)

Dermatomycosis (Ringworm)

C: Yes  Z: Yes*

Key facts

• Affect skin, hair, nails, Caused by dermatophytes, Colonise stratum corneum

• Hyphae & spores highly resistant in environment

Types of dermatophytes

1. Anthropophilic: Human hosts, Do not survive in soil. T. rubrum

2. Zoophilic: Animal → human transmission. Microsporum canis, Trichophyton verrucosum, T. mentagrophytes

3. Geophilic: Soil fungi. M. gypseum

Aetiology

Family: Arthrodermataceae

Important species:

• Trichophyton verrucosum,T. mentagrophytes, T. equinum,T. gallinae

• Microsporum canis, M. nanum, M. gypseum

Transmission

• Direct contact, Indirect contact with spores, Soil contamination, Animal/vector transmission

Pathogenesis

• Spores attach to skin/hair follicles

→ hyphae develop (~2 weeks)

→ invade hair centre

→ circular alopecia/crusts

→ regression after ~2 months

Clinical signs

• Red, itchy, scaly circular lesions + Alopecia

Typical locations:

* Dog: head, neck, limbs

* Cat: neck, chest

* Calves: around eyes & ears

Diagnosis

• Wood’s lamp, KOH microscopy, Sabouraud agar culture, Serology

Treatment

Usually self-limiting.

Cats: Itraconazole

Dogs: Itraconazole, Ketoconazole (toxic in cats)

Cattle/Horses: Enilconazole, Iodine antiseptics

NB: Remove crusts before topical therapy, Burn removed scabs

Systemic Mycoses

C: Yes  Z: Yes*

Aetiology

• Histoplasmosis: Histoplasma capsulatum → Dogs, horses, humans

• Candidiasis: Candida albicans → Ruminants, birds

• Blastomycosis: Blastomyces dermatitidis → Dogs, humans

• Aspergillosis: Aspergillus fumigatus, A. flavus, A. niger

Transmission

* Inhalation of spores

* Opportunistic infection

* Egg contamination (Aspergillus)

Clinical signs

• Histoplasmosis: Pulmonary/generalised disease, Equine lymphangitis

• Candidiasis: White cheesy plaques, Oral/vaginal lesions, Crop stasis in birds

• Blastomycosis: Respiratory & skin lesions

• Aspergillosis: Respiratory disease, Yellow nodules, Gaping, Voice changes, Embryo death, Mycotic abortion

Diagnosis

• Histoplasmin skin test, Smears/culture, Sabouraud agar, ELISA, X-ray

Treatment

• Fluconazole, Lime sulphur dips

Other mycoses

• Malassezia pachydermatis: Dogs/cats, Opportunistic dermatitis/otitis

• Cryptococcus neoformans: Inhaled spores → CNS/respiratory disease

• Coccidioides immitis → Valley fever, Inhalation of arthroconidia

a) Prevention & control

• Clip hair, 70% ethanol disinfection, Rodent control, Good hygiene, Remove mouldy feed, Good ventilation, Avoid dusty environment, Regular testing

• Outbreak: Treat animals and owners (zoonotic)

b) Resistance & sanitation

• Fungal spores survive: 12 months–2 years

• Disinfection: Sodium hypochlorite, Peracetic acid, NaOH, Formalin, Ethanol

Use of acids for disinfection

Inorganic acids: Hydrochloric acid, Sulphuric acid, Nitric acid, Phosphoric acid

Organic acids: Peracetic acid, Virkon-S

Public health risk assessment

Many mycoses are zoonotic. Transmission mainly through:

• Direct animal contact, Spores in environment, Contaminated dust/hair/soil

High risk for:

* Immunocompromised people, Veterinarians, Animal handlers.