Animal bites, envenomation, and ABLV PEP — Australian general practice

Bites from animals, spiders, snakes, and ticks are regular presentations in Australian general practice. Most dog bites are manageable in the community with wound care and targeted antibiotics; cat bites and human bites almost always need antibiotics; and Australian bat exposure is a medical emergency requiring immediate post-exposure prophylaxis for a uniformly fatal virus. Australia’s unique fauna means general practitioners need a working framework for funnel-web and snakebite pressure-immobilisation, the specific circumstances where antivenom is and is not recommended, and the removal technique that prevents tick-related sensitisation to red meat.

A. Core clinical — the AU general-practice framework

Dog bites cause approximately 80% of animal bites, primarily in children. The infection rate is relatively low — 5–15% — compared to cat or human bites. Common organisms include Pasteurella canis, Streptococcus, Staphylococcus aureus (including community-acquired MRSA), Capnocytophaga canimorsus (dangerous in the asplenic), and anaerobes.

Cat bites carry a 30–50% infection rate due to the puncture nature of the wound: fine, sharp teeth penetrate deeply into tendons and joint spaces before the small surface entry closes over. eTG and IDSA 2014 both recommend antibiotics for all cat bites without exception. Pasteurella multocida is the dominant pathogen; Bartonella henselae (cat scratch disease) and Capnocytophaga are also possible.

Human bites carry high infection risk from mixed oral flora: Streptococcus, Staphylococcus aureus (including MRSA), Eikenella corrodens, and anaerobes including Prevotella and Fusobacterium. “Fight bites” — lacerations over the metacarpophalangeal joints from closed-fist injuries — can penetrate the extensor tendon and joint space; these require urgent hand surgery assessment regardless of apparent wound severity.

Wound management for all bite wounds: irrigate copiously with tap water or normal saline under pressure to reduce bacterial load; debride devitalised tissue; identify and remove foreign bodies (tooth fragments are common in fight bites); check vascular, tendon, and nerve function distal to the wound; and photograph for documentation. Primary closure is controversial — face wounds (cosmetic priority) are often closed loosely; extremity wounds and cat or human bites are generally managed with delayed primary closure or healing by secondary intention.

Antibiotic selection: First-line for most bite wounds is amoxicillin/clavulanic acid (Augmentin Duo Forte) 875/125 mg twice daily for 5–7 days — this covers Pasteurella, streptococci, staphylococci, and anaerobes. Penicillin allergy: doxycycline 100 mg twice daily plus metronidazole 400 mg twice daily, or clindamycin 300 mg four times daily plus ciprofloxacin 500 mg twice daily. MRSA risk: add doxycycline or trimethoprim-sulfamethoxazole.

Tetanus prophylaxis follows Australian Immunisation Handbook ATAGI guidelines. Animal bites are tetanus-prone wounds. Patients with uncertain immunisation history or fewer than three lifetime doses need ADT (or dTpa) plus tetanus immunoglobulin. Those with three or more doses but last dose more than five years ago (tetanus-prone wound) need a booster.

B. Australian Bat Lyssavirus — mandatory post-exposure prophylaxis

Australia has been free of classical dog-associated rabies since European settlement, but Australian Bat Lyssavirus (ABLV) is endemic in all Australian bat and flying fox species. ABLV causes encephalitis clinically identical to rabies — there have been three documented fatal human cases in Australia, all following bat exposure. There is no effective treatment once symptoms develop.

The threshold for ABLV post-exposure prophylaxis (PEP) is any exposure: any bite or scratch from a bat or flying fox, or any contact of bat or flying fox saliva with mucous membranes (eyes, nose, mouth) or broken skin. This applies even if the bat appeared healthy. ABLV notification is mandatory — contact the state public health unit immediately.

PEP regimen for those never previously vaccinated against rabies (CDNA SoNG):

1. Thorough wound wash with soap and water for at least 5 minutes; apply 70% alcohol or povidone-iodine; do not close the wound primarily.
2. Human rabies immunoglobulin (HRIG) 20 IU/kg total dose — as much as possible infiltrated directly into and around the wound, with the remainder given intramuscularly at a distant site (e.g. gluteal). HRIG is held by hospital pharmacies and state public health units; it is expensive (>$1,000 per vial) and requires public health unit coordination. HRIG can be administered up to 7 days after the first vaccine dose if there is delay in obtaining it.
3. Rabies vaccine (Verorab or Mérieux HDCV/PCEC) intramuscular into the deltoid on days 0, 3, 7, and 14 (4-dose Essen schedule).

PEP for previously vaccinated individuals (completed 3-dose pre-exposure series with confirmed titres): wound care plus rabies vaccine on days 0 and 3 only — no HRIG required.

Pre-exposure vaccination for at-risk groups (veterinarians, wildlife workers, laboratory workers, frequent travellers to rabies-endemic areas): 3-dose series on days 0, 7, and 21 (or 28) intramuscular deltoid; periodic titre checks and boosters per occupational risk assessment.

C. Spider envenomation

Sydney funnel-web spider (Atrax robustus and related Hadronyche species) is one of the world’s most dangerous spiders. Symptoms develop rapidly: severe local pain, profuse sweating, agitation, hypertension, tachycardia, salivation, lacrimation, nausea, and potentially autonomic storm, pulmonary oedema, and coma. Immediate pressure-immobilisation bandage (firm broad crepe from distal limb over the bite site, then splint) and urgent transfer to an emergency department with antivenom and ICU capability. Funnel-web antivenom is produced by the Australian Reptile Park and is lifesaving.

Redback spider (Latrodectus hasselti) causes latrodectism: severe local pain, sweating, abdominal and chest pain, hypertension, and agitation. The RAVE-II randomised controlled trial (2014) found no significant benefit of redback antivenom over placebo. Current Australian guidance: redback antivenom is not routinely recommended. Management is symptomatic — ice packs, paracetamol, opioid analgesia if pain is severe, antiemetic. Call the Poisons Information Centre (13 11 26) for case-by-case advice.

White-tailed spider (Lampona cylindrata): there is no credible evidence supporting necrotic arachnidism from white-tailed spider bites (Isbister 2003 and subsequent reviews). Most cases attributed to white-tailed bites are cellulitis, wound infection, or another dermatological diagnosis; treat the actual condition.

D. Snakebite management

The cornerstone of snakebite management is pressure-immobilisation bandage — applied immediately, from the bite site distally and then proximally over the whole limb, with splinting and patient immobilisation. Do not cut, suck, or apply a tourniquet; do not wash the bite site (residual surface venom is used by the snake venom detection kit in hospital to guide antivenom selection). Transfer urgently by ambulance to the nearest large hospital with antivenom stocks and ICU capability.

Australia’s most medically significant snakes include brown snakes, tiger snakes, taipans, death adders, black snakes, and sea snakes. Envenomation causes coagulopathy (consumptive), neurotoxicity, myotoxicity, and acute kidney injury in varying combinations depending on species. Antivenom is species-specific or polyvalent and is managed in ICU with monitoring for anaphylaxis.

E. Tick bites

Paralysis tick (Ixodes holocyclus) inhabits the east coast of Australia from Queensland to southern Victoria. In pets it causes ascending paralysis; in humans this is rare but serious, particularly in children. The cardinal rule for tick removal is never squeeze the tick body — this forces more saliva and pathogen load into the host.

Recommended removal method: apply permethrin spray (Lyclear) or a freeze spray (Wartoff, Elastoplast Cold Spray) to kill the tick in situ; then remove the dead tick with fine-tipped forceps grasping at the base of the head.

Tick-associated diseases in Australia include Queensland tick typhus (Rickettsia australis — treat with doxycycline), Flinders Island spotted fever, and alpha-gal syndrome (mammalian meat allergy) — an IgE-mediated hypersensitivity to galactose-alpha-1,3-galactose that develops after tick sensitisation and causes delayed urticaria or anaphylaxis 3–6 hours after eating red meat. Alpha-gal syndrome requires specialist allergy assessment.

Note on “Lyme disease in Australia”: the Australian Department of Health position is that classical Lyme borreliosis (Borrelia burgdorferi sensu stricto) is not endemic in Australia. Patients with chronic symptoms attributed to tick exposure are classified under the Debilitating Symptom Complexes Attributed to Ticks (DSCATT) framework and are best supported by specialist referral rather than empirical prolonged antibiotic courses.

When to escalate

Escalate immediately (call 000) for: any bat or flying fox exposure for ABLV PEP coordination; funnel-web spider bite; any suspected snakebite; suspected inhalation injury or haemodynamic compromise. Escalate to emergency department for: human bite with suspected tendon or joint involvement (fight bite); bite wound infection not responding to oral antibiotics within 48 hours; suspected Capnocytophaga sepsis in an asplenic or cirrhotic patient; tick paralysis.

Contact the Australian Poisons Information Centre (13 11 26) — available 24 hours a day — for envenomation management advice for any spider, snake, tick, or marine creature exposure.

What this article is and is not

This article reflects current Australian guidance from eTG, the Australian Immunisation Handbook, CDNA SoNG, and the IDSA 2014 guidelines. It is educational material for adults and is not a substitute for clinical assessment by a qualified health professional. Envenomation management and ABLV PEP require urgent specialist coordination. If you are experiencing a medical emergency, call 000.

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Sources cited

• Australian Immunisation Handbook — Rabies and ABLV
• CDNA Series of National Guidelines — Rabies and ABLV management
• eTG complete — Animal, human, and arthropod bites
• RACGP — Bite management in primary care
• IDSA 2014 — Skin and Soft Tissue Infections (Stevens et al.)
• Australian Snakebite Project — clinical management
• Australian Reptile Park — antivenom and bite management
• TGA — antivenom availability
• HealthDirect — Bites and stings
• Better Health Channel — Spider bites