Zoonotic Diseases and Infections Overview

Zoonotic Infections

Infections that jump from animals to humans.

Transmission Methods

Includes bites, inhalation, and skin contact.

Dead End Host

Infections not contagious between humans.

West Nile Virus

A zoonotic virus transmitted by mosquitoes.

Rabies

Viral infection primarily transmitted by animal bites.

Ehrlichiosis

Bacterial infection transmitted by tick bites.

Bubonic Plague

Caused by Yersinia pestis, transmitted by fleas.

Tularemia

Bacterial infection from contact with infected animals.

Brucellosis

Bacterial infection from livestock, causing flu-like symptoms.

Leptospirosis

Bacterial infection from water contaminated by animal urine.

Lyme Borreliosis

Tick-borne disease caused by Borrelia burgdorferi.

Emerging Infections

75% are zoonotic according to recent studies.

Pasteurellosis

Infection caused by Pasteurella multocida from animal bites.

Clinical Manifestations of Pasteurellosis

Includes sepsis, meningitis, and septic arthritis.

Erysipelothrix rhusiopathiae

Gram-positive bacillus causing erysipelas, primarily in pigs.

Erysipeloid

Skin infection characterized by blue-red patches.

Capnocytophaga canimorsus

Gram-negative bacillus from canine oral flora.

Septicemia

Severe infection leading to systemic inflammation.

Cat Scratch Disease

Caused by Bartonella henselae from cat scratches.

Clinical Manifestations of Cat Scratch Disease

Includes lymphadenopathy and flu-like symptoms.

Anthrax

Caused by Bacillus anthracis, known as woolsorter's disease.

Epidemiology of Anthrax

Occurs worldwide, primarily in grazing animals.

Spore Longevity

Anthrax spores can survive in soil for 20 years.

Vaccines for Anthrax

Available for humans in high-risk occupations.

Transmission of Anthrax

Through direct contact with infected animals or products.

Clinical Manifestations of E. rhusiopathiae

Includes localized lesions and systemic bacteremia.

Predisposing Factors for Capnocytophaga

Includes splenectomy, cancer, and drug abuse.

Symptoms in Splenectomized Patients

Severe symptoms like purpura and septic shock.

Cutaneous anthrax

Most common anthrax form, painless black eschar.

Gastrointestinal anthrax

Caused by contaminated meats, leads to septicemia.

Pulmonary anthrax

Inhalation of spores, 85% mortality without treatment.

Francisella tularensis

Aerobic gram-negative bacillus causing tularemia.

Tularemia

Plague-like disease transmitted from rabbits and ticks.

Type A tularemia

More virulent biovar affecting humans.

Type B tularemia

Less virulent, transmitted by rodents and mosquitoes.

Incubation period

3-10 days for tularemia symptoms to appear.

Ulceroglandular tularemia

Direct contact with infected vertebrates causes ulcers.

Pneumonic tularemia

Aerosol exposure leading to fever and chills.

Typhoidal tularemia

Caused by contaminated food, high fatality with pneumonia.

Brucellosis

Also known as Mediterranean fever, caused by Brucella.

Brucella melitensis

Most common species causing brucellosis.

Brucella species

Includes B. abortus, B. canis, B. suis.

Granuloma formation

Response to Brucella infection in macrophages.

Leptospirosis

Disease caused by spirochetes from contaminated water.

Leptospires

Spirochetes with two subterminal flagella.

Icteric leptospirosis

Weil's syndrome with jaundice and renal failure.

Anicteric leptospirosis

Biphasic disease with febrile and immune phases.

Yersinia pestis

Gram-negative rod causing plague, endemic in Southwest.

Bubonic plague

Characterized by buboes in lymph nodes.

Pneumonic plague

Result of septicemia, spreads via aerosols.

Xenopsylla cheopis

Fleas that transmit plague and murine typhus.

Borrelia burgdorferi

Bacterium causing Lyme borreliosis, natural host is mice.

Septicemia

Presence of bacteria in the bloodstream.

Fluid loss

Gastrointestinal anthrax can cause 12 L daily.

Macrophages

Cells involved in granuloma formation during brucellosis.

Chills and fever

Common symptoms of brucellosis and tularemia.

Yersinia pestis

Bacterium causing plague, gram-negative rod.

Endemic

Regularly found in a specific geographic area.

Vectors

Organisms transmitting pathogens between hosts.

Bubonic plague

Characterized by swollen lymph nodes called buboes.

Pneumonic plague

Lung infection from plague, can spread person-to-person.

Xenopsylla cheopis

Flea species that carries plague and typhus.

Borrelia burgdorferi

Bacterium causing Lyme disease, transmitted by ticks.

Erythema migrans

Bull's-eye rash associated with Lyme disease.

Juvenile arthritis

Possible complication of Lyme borreliosis in children.

Rickettsiae

Obligate intracellular bacteria, transmitted by arthropods.

Anaplasmataceae

Family of bacteria including Ehrlichia and Anaplasma.

Rocky Mountain spotted fever

Tick-borne illness with high mortality if untreated.

Dermacentor variabilis

Common tick vector for Rocky Mountain spotted fever.

Flulike symptoms

Common initial symptoms of many infectious diseases.

Oriental rat flea

Primary vector for endemic typhus, R. typhi.

R. typhi

Bacterium causing endemic typhus, transmitted by fleas.

Epidemic Louse-Borne Typhus

Caused by R. prowazekii, transmitted by lice.

Brill-Zinsser disease

Reactivation of dormant epidemic typhus in humans.

Boutonneuse Fever

Mediterranean spotted fever, rash on palms and soles.

Taches noires

Black spots at primary infection site in Boutonneuse Fever.

Ehrlichia

Intracellular bacteria causing human monocytic ehrlichiosis.

Human monocytic ehrlichiosis

Infection by E. chaffeensis, diagnosed by serology.

Emerging zoonoses

New diseases jumping from animals to humans.

SARS

Severe acute respiratory syndrome, emerged in 2003.

H1N1

Swine flu pandemic strain identified in 2009.

Zika virus

Emerging virus linked to birth defects, identified in 2016.

Ebola

Viral hemorrhagic fever, outbreak in 2015.

Global surveillance

Monitoring to reduce impact of emerging diseases.

Mortality rate

Percentage of deaths in untreated cases.

Spirochete

Spiral-shaped bacteria, includes Borrelia species.

Tick bite

Mechanism of transmission for Lyme disease and RMSF.

Complications

Adverse effects or conditions resulting from an infection.