SADAT CITY UNIVERSITYFACULTY OF VETRINARY
MEDICINEZOONOSES DEPT
CAT SCRATCH DISEASE “ C S D ”
CAT SCRATCH DISEASE
“ C S D ”
PREPARED BY :-
Dr / AHMED ABDEL_RAHMAN MOHAMED ESMAIL
Well you might just want to take a step back……
Cat Scratch Fever/Disease
About Disease
Cat scratch disease is a disease caused by bartonella bacteria. It is believed to be transmitted by cat scratches and bites, or exposure to cat saliva.
The Organism
MORPHOLOGY B. henselae is a small Gram negative bacillus
measuring 2.0-2.5 X 0.5-0.6µ. Like other Bartonella species, it can grow on
chocolate agar or Columbia agar supplemented with 5% sheep or rabbit blood.
B. henselae produces 2 morphological types of colonies:
1. Irregular, raised,rough, dry white cauliflower-like colonies.
2. Small, circular, tan & moist, tending to pit the agar and adhere to the agar after 5-15 days of incubation at 35-37°C in the presence of 5% CO 2 .
Presence of B. henselae) arrow) within naturally infected cat erythrocytes, as seen by confocal microscopy. Natural History of Bartonella Infections (an Exception to Koch’s Postulate) CVI, 2002
History
History 1950: Clinical syndrome described 1889: Similar disease reported 1983: Bacterial cause described
Gram negative bacillus Found in lymph nodes of patients
1988: Organism successfully isolated and cultured
History 1991: CSD bacillus named Afipia
felis 1992: Rochalimaea henselae
isolated Patients with bacillary angiomatosis Refuted role of A. felis in CSD
1993: Genera Rochalimaeaand Bartonella united B. henselae currently recognized
as causative agent of CSD
Epidemiology
EPIDEMIOLOGY
Worldwide distributionPrevalence in warm/humid
climates~ 20,000 cases annually in US
80% under the age of 20yrs30% of domestic cats are
infected
Geographic Distribution
Worldwide B. henselae type I
Eastern U.S. Asia
B. henselae type II Europe
Temperate climates Seasonal variation Peak August to October (North)
Transmission
Cat contact(scratch, bite, ? cat flea bite)
1 - 3 weeks
Resolutionin weeks tomonths
Disseminationin immuno-compromisedhosts
Human InfectionsVascular endothelial cells
Monocytes/macrophages Immunocompenent host
Self-limiting CSDSwollen lymph nodes and fever
Immunocompromised hostBacilliaryangiomatosis-peliosis (BAP)Tumour-like vasoproliferative lesions
Symptoms Bump (papule) or blister (pustule)
at site of injury (usually the first sign occurs 3-10 days after infected)
Fatigue Fever (in some patients) Headache Lymph node swelling near the
scratch or bite (occurs 1 to 4 weeks after infected)
Overall discomfort (malaise)Less common symptoms: Draining lymph nodes' Enlarged spleen Loss of appetite Sore throat Weight loss
Cat-scratch disease
Worst Case Scenario It is usually worse with
those who have weaker immune systems and those with AIDS. Also with younger children symptoms can be worse. Causing bigger bumps, lymph nodes to swell bigger, wider spread of lesions, and sometimes bumps can appear on eyes (Parinaud oculoglandular syndrome). Plus an inflammation of the brain can occur causing seizures. In any of these cases it is recommended to take antibiotics.
PATHOGENESISEndothelial Cell Invasion and
Colonization: Human umbilical endothelial cells
(HUVECs) Bacterial adhesion and invasion
Actin-dependant mechanisms Intracellular membrane-bound compartments
B. henselaeinfection leads to: Secretion of vascularproliferative compounds Inhibition of host cell apoptosis Host cell proliferation
Morbidity and Mortality Humans
22,000 to 24,000 annual cases in U.S.
3 to 6% of general population seropositive
Higher in veterinarians Most cases in children
Most infections self-limiting Death is rare
Morbidity and Mortality
Seroprevalence in cats 14 to 55% in U.S. 40 to 70% in warm, humid
climates 30% of captive wild felids
Higher in feral cats vs. pets No reported morbidity or
mortality
Cat Scratch Disease:Complications
Parinaud’s oculoglandular syndrome Encephalitis Endocarditis Disseminated disease
AIDS patients Rashes Bone/joint lesions Pneumonia
Disease in Animals
Species Affected
Cats, felids are reservoir hosts Experimental infection
Dog Armadillo Mice
Feline Infections Erythrocytes
Firm bacterial adhesion Internalization
Membrane-bound compartments Bacteria replicate within
erythrocytes Circulate in the bloodstream (weeks to
months) Long-lasting intraerythrocytic
infection Specific adaption to the mode of
transmission
Disease in Other Animals Experimental infections
Dogs No bacteremia
Rodents Asymptomatic Granulomatous hepatitis
Non-human primates Asymptomatic Fever Subcutaneous skin lesions at inoculation
site
Post Mortem Lesions
Lymphadenomegaly Multiple histopathologic
lesions Blood-filled cysts and cavities in the liver Peliosis hepatitis Granulomatous hepatitis
Diagnosis
DiagnosisCulture
Time consuming, used mainly in research
SerologyCross reactions possible
PCR
CureUsually the
disease does not need medical treatment, but in severe cases treatment with antibiotics such as azithromycin can be helpful.
Prevention
Avoid bites and scratches Kittens
Wash woundsimmediately
Flea control? Clip nails Keep cats indoors Antimicrobials?
Disinfection
Susceptibility of B. henselae not specifically known Closely related organism B.
bacilliformis Susceptible to:
70% ethanol 1% sodium hypochlorite 2% formaldehyde
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