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