6. Borreliosis and other vector-borne diseases

Plan

• Borreliosis

• Avian borreliosis

• Ticks-borne diseases

• Other vector-borne diseases

• Procedures

• Sanitation

  • Ticks, their LC and control

Borreliosis

= Lyme disease

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AETIO.

Caused by Borrelia burgdorferi sensu stricto, B. afzelii, B. garinii: G-, motile, double membraned, non-capsulated, and non-sporulating bacteria from the family Spirochetaceae order Spirochetales

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EPIZOO.

• Zoonotic

• Natural focal character

• Seasonal in temperate areas

  • Typical in spring (nymphs feeding) and summer /autumn (adult feeding)

• Wide range of hosts

• Reservoir: small mammals and birds

• WW: wherever the tick vector is present

  • Highest number of cases in central Eu and Sweden

• Transmission:

  • Ticks of family Ixodae

• IP is variable: days to years

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PATHO.

1. Feeding tick midgut to salivary glands

2. Deposition of skin

3. Evasion from IS

4. Adherence and migration through endothelial barrier

5. Bloodstream

6. Distal tissues

7. Immunocomplexes formation

8. Alteration in kidneys and joints

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CS

• Lameness

• Fever

• Anorexia

• Lethargy

• Lymphadenopathy w/ or w/o swollen and painful joints

Polytrophism:

CNS

Seizures, facial paralysis

Skin

Local irritation

Polyarthritis

Lamaness, swollen painful joints

Kidneys

Uremia, hyperphosphatemia, protein-losing nephropathy

Generally fatal

Heart

Cardiac syndrome + bradycardia + conduction disorders

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CS IN Hu

• Extensive erythema chronicum migrans

  • Not itchy nor painful

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Dx

• Isolation: samples from blood, urine, CSF, haemolymph of ticks

  • Culture

• Detection

  • Native prep. under microscopy

  • Ag impregnation

  • PCR

• Serology: Ab detection

  • ELISA

  • IFA

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Tx

• ATBs: penicillin, tetracycline

  • 2 weeks

Avian borreliosis

AETIO.

Caused by B. anserine.

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EPIZOO.

• Affects poultry, waterfowl, and game birds

• In Asia

• Transmission:

  • Argas tick

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PATHO.

1. Entry

2. Bacteremia

3. Other organs

   • Haemorrhages and necrosis

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CS

Non-specific:

• Anaemia

• Cyanotic comb

• Green diarrhoea

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Dx

• History

• Culture

• Microscopy

• PCR

• Serology

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Tx

• ATBs

Ticks-borne diseases

• Anaplasmosis

  • Ixodes

• Babesiosis

  • Babesia microti

  • Ixodes

• Bourbon virus

  • USA

• Colorado tick fever

  • Rocky mountains

• Eihrlichiosis

  • Amblyomma

• Powassan disease

• Rickettsiosis

  • Amblyomma

• Rocky mountain spotted fever

  • Dermacantor, Rhipicephalus

  • Rhi

• Southern tick-associated rash illness

  • Amblyomma

• Tick-borne relapsing fever

  • Soft tick

• Tularaemia

  • Dermacantor

Other vector-borne diseases

• Trypanosomiasis (Q35)

• Theileriosis (Q36)

• Babesiosis (Q36)

• Leishmaniasis (Q39)

Procedures

GENERAL PREV.

• Insect control

  • Repellents

  • Removal of ticks

  • Ascaricides: permethrin, amitraz collar, fipronil spot-on

• Protection of pets against

  • Ingestion of carcasses

  • Tick bites

  • Contact w/ wild animals

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BORRELIOSIS

Prev.

• Tick avoidance: permethrin spray, amitraz collar, fipronil spot-on

• Vaccination in dogs

• Owner awareness

• Pre-vaccination infection:

  • Long incubation

  • Persistence after ATBs treatment may lead to disease in immune dogs

• Pesticides

• Landscape and deer management

• Repellents and toxicants to skin or clothing

• Tick checks

• Showering after being in tick habitat

• Host-targeted intervention

Sanitation

BORRELIOSIS

Killed by common disinfectants, heat, and UV light.

Repellents keeping ticks away:

• 25-30% DEET (N,N-diethyl-meta-toluamide)

• 20% IR3535

• 20% Picaridin

• 30% Oil of lemon eucalyptus

• Para-menthane-diol - PMD

• 2-undecanone

In external environment and on farm: only pyrethroids - permethrin. Measures to apply:

• Repellents for people, appropriate clothes (long)

• Permethrin-based solution

• Treatment of hats, shoes, jackets, camping gear up to 48h before the protection is needed (CDC recommendation)

• Never applied on skin

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TICKS

Ixodae (hard)

• Incomplete metamorphosis / hemimetabolous

  • Egg → larva → nymph → adult

• Ixodes, Dermacantor, Rhipicephalus, Haemaphysalis

Argasidae (soft)

• Both sexes feed on blood

• Multi-hosts

• Egg → larva → nymph → adult

• Larval stage feeds once before moulting and reaching 1^st nymphal stage

• 2-7 nymphal stages

  • Each stage feeds, leaves the host, and moults

• Completed in 4-5 weeks

• Adults can survive years w/o a host and feeding

• Argius, Otobius

Tx

Ascaricides: fipronil, imidacloprid, amitraz

• Spot-on, dipping bath, spray

Organophosphates and pyrethroids are not used in cats.

LC

~ 60 days:

1. Females detaches from host and lay eggs in soil

2. Eggs hatch into 6 legged larval stage: seed-tick

3. Growth in soil

4. Opportunistically attaches onto the host

5. Change into 4 legged nymphal stages

6. Adults

7. Permanent feeder: remain on host

Control

• Killing insect

  • Mechanical: killing, adhesive substances, light and fall traps, screened windows

  • Physical: T, steam, heat, light, radiation, ultrasonic vibrations

  • Biological: natural enemies, micorbial agents

  • Chemical: insecticides

• Reproduction of reproductive capacity, slowing growth