6. Pet Associated Infections & Rabies

This set of flashcards covers key concepts regarding animal bites, the pathogens involved, associated diseases like rabies and toxoplasmosis, and their treatments, aimed to aid students in preparing for their exams.

Which animal bite is more likely to get infected: Dog or Cat?

Cat bites are more likely to get infected than dog bites.

What is the infection rate for cat bites compared to dog bites?

Cat bites have a >20% infection rate; dog bites have up to 18%.

Why are cat bites prone to deep tissue inoculation?

Cats have thinner, sharper canine teeth that create puncture wounds.

What is the most common pathogen isolated from both dog and cat bites?

Pasteurella multocida.

Which organism found in dog bites can cause bacteremia and fatal sepsis?

Capnocytophaga canimorsus.

What is the first-line antibiotic treatment for animal bites?

Amoxicillin-clavulanate (Augmentin) 875mg PO BID.

If a patient is allergic to Penicillin, what is a common alternative regimen for animal bites?

Doxycycline or TMP-SMX/Cefuroxime/Levofloxacin PLUS Metronidazole or Clindamycin.

When should a bite wound generally be left open?

Most cat or human bites, and wounds located on the hands or feet.

Which specific bite wounds might be candidates for primary closure?

Clinically uninfected dog bite lacerations less than 12 hours old.

What is the causative organism of Cat Scratch Disease?

Bartonella henselae.

How is Bartonella henselae transmitted?

Through a scratch or bite from an infected cat or exposure to cat fleas.

What is the hallmark clinical presentation of Cat Scratch Disease?

A red papule at the inoculation site followed by tender regional lymphadenopathy.

What is Parinaud Oculoglandular Syndrome?

A manifestation of Cat Scratch Disease involving conjunctivitis and tender preauricular lymphadenopathy.

What is the antibiotic of choice for Cat Scratch Disease?

Azithromycin (Zithromax).

What is the definitive host for Toxoplasma gondii?

Cats.

How else is Toxoplasmosis transmitted to humans besides cat feces?

Ingesting raw or undercooked meat.

What is the 'Classic Triad' of Congenital Toxoplasmosis?

1. Chorioretinitis 2. Intracranial calcifications 3. Hydrocephalus.

How does Toxoplasmosis typically present in AIDS patients?

Toxoplasmic encephalitis, often visualized as multiple ring-enhancing lesions.

What is the standard treatment regimen for active Toxoplasmosis?

Pyrimethamine + Sulfadiazine + Leucovorin.

What family does the Rabies virus belong to?

Rhabdoviridae.

Describe the pathophysiology of the Rabies virus movement in the body.

It enters through a bite, replicates locally, enters nerve endings, and advances to the CNS.

What is the incubation period for Rabies?

Typically 1–3 months.

What pathognomonic finding is seen in brain tissue of rabies patients?

Negri bodies.

What are the symptoms of the 'Furious' phase of Rabies?

Hydrophobia, pharyngeal spasms, hyperactivity, autonomic instability.

What constitutes Rabies Post-Exposure Prophylaxis (PEP) for a non-vaccinated person?

Rabies Immune Globulin and Rabies Vaccine on specified days.

What is the protocol for bat exposure?

Any direct contact with a bat indicates PEP.

How many days is the Rabies Vaccine administered for non-vaccinated persons?

Days 0, 3, 7, and 14.

What are Negri bodies?

Cytoplasmic inclusion bodies found in brain tissue of rabies patients.

What type of lesions are observed in Toxoplasmosis in AIDS patients?

Multiple ring-enhancing lesions in the basal ganglia.

What role does Leucovorin play in Toxoplasmosis treatment?

It is given alongside Pyrimethamine and Sulfadiazine to reduce side effects.

What is the primary source for Toxoplasmosis transmission?

Cats.

What symptoms indicate a cat bite might be infected?

Redness, swelling, tenderness, and purulent drainage.

What should be monitored in patients treated for animal bites?

Signs of infection and response to antibiotics.

Why is it important to treat animal bites promptly?

To prevent infection and potential systemic complications.

Which animal is known for a higher risk of infection in bite wounds?

Cats.

What initial management should be done for a bite wound?

Thorough cleaning and assessment of the wound.

What are some possible complications from untreated animal bites?

Infection, abscess formation, and systemic illness.

What general advice is given for prevention of animal bites?

Avoid provoking animals and ensure pets are well-socialized.

What bacteria are often implicated in infections from dog bites?

Pasteurella multocida and Capnocytophaga canimorsus.

What is the main concern with bites from wild animals?

Potential transmission of rabies virus.

What is PEP in the context of rabies?

Post-Exposure Prophylaxis to prevent rabies after potential exposure.

What factors influence the decision to close a bite wound?

Infection status, time since injury, and wound location.

What type of laceration can often be sutured?

Clinically uninfected dog bite lacerations that are simple.

What indicates that a cat scratch might lead to disease?

Presence of symptoms like swollen lymph nodes following the scratch.

Why is Azithromycin used in treating Cat Scratch Disease?

It is effective against Bartonella henselae.

What are some challenges in diagnosing Toxoplasmosis?

Symptoms may be nonspecific, and tests may not always be conclusive.

How does Toxoplasmosis affect the immunocompromised?

It can lead to severe neurological disease and is often life-threatening.

What might suggest a serious infection from a bite?

Persistent fever and systemic symptoms after initial treatment.

What is the usual treatment duration for uncomplicated animal bite infections?

Typically 5 to 10 days, depending on severity.

Why is rabies considered a medical emergency?

It is almost universally fatal once symptomatic.

What precaution is taken for pets at risk for rabies?

Vaccination against rabies is recommended.

How is cat feces related to Toxoplasmosis transmission?

It contains oocysts that can infect humans if ingested.

What is the risk of Toxoplasmosis during pregnancy?

It can result in severe congenital defects.

What treatment options exist for patients with Toxoplasmosis besides the standard regimen?

Alternative antibiotics may be considered based on patient needs.

What mechanism does the Rabies virus use to invade the nervous system?

Retrograde axonal transport along nerve fibers.

How should a suspected rabies exposure from a bat be managed?

Immediate PEP is required as bites can be tiny or unnoticeable.

What public health measures can help reduce rabies cases?

Vaccination of pets and public education about animal bites.

What kind of patients are at high risk for severe outcomes from animal bites?

Immunocompromised individuals and the elderly.

What is initially done with a bite wound to prevent infection?

Immediate thorough cleansing with soap and water.

What symptom is commonly associated with severe rabid animal attacks?

Hydrophobia.

Why might some animal bites require surgical intervention?

To drain abscesses or repair deep tissue injuries.

What should be done if a dog bites a human?

The dog's vaccination status should be checked, and the wound treated.

How prevalent is rabies in domestic animals?

Rare in vaccinated pets but still a concern in wild animals.

What symptoms specifically characterize the 'dumb' phase of rabies?

Lethargy, paralysis, and decreased responsiveness.

What is the forecast for untreated rabies once symptoms appear?

High mortality rate within days to weeks.

What is the role of leucovorin in Toxoplasmosis therapy?

Protects against bone marrow toxicity of pyrimethamine.

What can a healthcare provider do if suspicious of a rabies infection?

Initiate PEP immediately.

In what scenario is rabies vaccine postexposure treatment administered?

After a potential exposure to rabies, especially from wildlife.

Why do animal bites require individualized treatment?

Each bite can differ significantly in risk factors and contamination.

What specific actions should be taken with a bite wound on the hands?

Refer for evaluation due to high infection risk.

What recommendations exist for cat owners to prevent Cat Scratch Disease?

Keep the cat's nails trimmed and discourage biting.

What is the time frame for seeing symptoms after cat scratch exposure?

1–3 weeks after exposure.

What common household pets can transmit zoonotic diseases?

Cats and dogs are primary sources.

What type of testing is crucial for diagnosing Toxoplasmosis?

Serology for IgM and IgG antibodies.

What should be done with bite wounds that exhibit signs of infection?

They should be evaluated for possible drainage and antibiotic therapy.

What unique challenges does Toxoplasmosis present in pregnancy?

Risk of transmission to the fetus.

What factors can increase the likelihood of an animal bite becoming infected?

Delay in treatment and bite location.

What are related symptoms to watch for after a potential Cat Scratch encounter?

Lymphadenopathy and flu-like symptoms.

What underlying condition increases the risk of severe Toxoplasmosis?

HIV/AIDS.

How is rabies primarily transmitted?

Through the saliva of an infected animal, typically via bites.

What kind of closure is typically recommended for bite wounds in high-risk areas?

Secondary intention healing.

What diagnostic techniques can help identify Rabies?

PCR testing on saliva or brain tissue.

What is the role of patient education regarding animal bite injuries?

To instill awareness of risks and prompt treatment.

How can a patient mitigate the risk of infection after an animal bite?

Follow up with a healthcare provider and adhere to treatment plans.

What can be a common sequelae of untreated dog bites?

Severe infections leading to hospitalization.

What hygiene practices should be emphasized in children to prevent bites?

Teach safe interaction with animals.

Why might Toxoplasmosis be difficult to diagnose?

Due to often asymptomatic cases or vague symptoms.

What factors regarding the source species can influence the prognosis of a bite?

Species virulence, bite site, and wound care.

How do healthcare providers approach potential rabies exposure?

Assess risk, provide education, and initiate PEP as necessary.

What might a growing abscess indicate following a bite?

Progression of infection requiring surgical intervention.

What public health strategy is effective in rabies control?

Animal vaccination and monitoring of wildlife rabies outbreaks.

What elements can signify an animal is rabies-infected?

Behavioral changes, aggression, and paralysis.

What is the incubation period for Toxoplasmosis after exposure?

Varies but often 1–3 weeks.

What general health education is important for pet owners?

Understanding zoonotic diseases and responsible pet care.

What can complicate management of Toxoplasmosis in pregnant women?

Potential need for more aggressive monitoring and therapy.

What vaccinations are critical for preventing rabies in pets?

Domestic rabies vaccines as per veterinary guidelines.

What is the importance of rabies vaccine timing after exposure?

Timing is crucial to preventing the virus from reaching the CNS.

How can the risk of serious bite wounds in children be minimized?

Supervision around unfamiliar animals.

What is an important step for authorities during a rabies outbreak?

Vaccination campaigns for pets.

What signs indicate potential complications from animal bites?

Increased pain, swelling, and systemic symptoms.