zoonotic diseases of animals

1. Cat scratch
disease
Dr.Sivasankar.P
Vet. Microbiology
sankarsiva905@gmail.com

2. HISTORY
• 1930s: Robert Debre, parisian physician, first documented the syndrome
of the disaease
• 1988: Organism successfully isolated and cultured (English et al.,1988)
• 1991: CSD bacillus named Afipia felis
• 1992: Rochalimaea henselae isolated-Patients with bacillary angiomatosis
• 1993: Genera Rochalimaea and Bartonella united, B. henselae currently
recognized as causative agent of CSD

3. Synonym of the disease
• Cat scratch fever
• Bartonellosis
• Other Bartonella spp infection in human: Trench fever

4. About etiology
• B. henselae is a small Gram negative, intracellular, oxidase negative,
pleomorphic, aerobic, non motile, curved 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 butt not on blood agar
or MacConkey agar
• 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% CO2
• Two human strain: Houston-1, Marseile strain

5. Susceptibility of the organism
• Specifically not known
• closely related to B. bacilliformis
• Susceptible to 70% ethanol, 2% formaldehyde, 1% sodium hypochlorite

6. Epidemiology
• Worldwide distribution, Prevalence in warm/humid climates
• 22,000 to 24,000 new cases annually in US
• Common in childrens
• Most infection self limiting, Death is rare
• Seroprevalence in domestic cats 14 to 55% and 30% in wild feral cats in
U.S
• No report of morbidity and mortality
• In the United States, 28% of surveyed cats had antibodies against the
organism
• In California, blood cultures were positive in 56% of domestic cats younger
than 1 year and in 34% of cats older than 1 year
• B. henselae is endemic in Europe, Africa, Australia, and Japan

7. Transmission
• How transmission: Cat to human and
cat to cat ?
• Ctenocephalides felis
• ~ 50% of cats harbor B . henselae and
are entirely asymptomatic. (Massei et
al.,2005)
• Kittens less than 1 year more likely to
have carry infection
• In approximately 1% of diagnosed
cases, no animal scratch is implicated

8. Transmission
3-14 days
The hallmark of CSD is regional adenopathy proximal to the site of inoculation
Plaque
Lymphadenopathy

9. Disease in human
Bartonella is able to promote angioproliferation through adhesin A, which is observed in bacillary
angiomatosis, peliosis

10. Species affected
• Cats, felids are reservoir host
• In experimental infection dog- No bacteremia
• Mice- Asymptomatic, Granulomatous hepatitis
• Non human primates-Asymptomatic, fever, skin lesion at inoculation site

11. Symptoms in human
• self-limiting disease classically characterised by regional lymphadenopathy
with or without systemic features
• Lymph node swelling near the scratch or bite, occurs 1 to 4 weeks after
infected (main clinical feature)
• 90% people will have lymphadenopathy, sometime suppurates (Carithers
et al., 1985)
• Fatigue
• Fever (in some patients)
• Headache
• Overall discomfort (malaise)
• Less common symptoms:
Draining lymph nodes, Enlarged spleen
Loss of appetite, Sore throat, Weight loss

12. Symptoms in human
papular pruritic dermatitis
neck abscess
Parinauds occloglandular syndrome
Regional lymph adenopathy

13. Complication of the disease in human
• Upto 14 percent of persons develop dissemination to the liver, spleen, eye
or central nervous system and antibiotics may help
• Parinauds occloglandular syndrome
• Bacillary angiomatosis in AIDS patient
• Neuroretinitis
• Encephlitis
• Endocarditis
• Pneumonia
• Rashes
• Osteomyelitis
(Carithers et al.,1985)

14. Disease in cat
• No signs of illness
• Occassionally causes inflammation of heart
• Making very sick and laboured breathing
• Infected cat or human being excrete the viable organism in urine
Diagnosis in cat:
• Culture – cat blood
• B. henselae has been isolated from bacteremic cats, with transmission
among cats thought to be via the cat flea

15. Diagnosis in human
• History -Exposure to cat and by clinical symptoms
• Culture- Lymph node
• Warthin-starry silver stain
• Lymph node biopsy is not indicated for most patients
• Serology- IFAT(highly sensitive, specific), ELISA
• PCR
• CSD skin test- Induration of 5mm within 2-3 days is positive

16. Carither’s ``Rule of Five’’
• Carither`s developed ‘Rule of Five’ as a diagnostic tool in his original series.
• Points are given to each of the four criteria:
• Total of 5 points strongly suggest CSD
• while 7 points make the diagnosis confirmed.
Regional lymphadenopathy =1 point
Cat exposure =2 point
Presence of an inoculation site =2 point
Positive skin test with CSD antigen =2 point
Total = 7 points

17. Differential diagnosis
• Neoplasm of lymphnode
• Tuberculosis
• Brucellosis
• Tick borne disease
• Syphilis
• Lymphogranuloma venerum

18. Treatment of humans
• Usually does not need treatment, in severe case antibiotics helpful
• Azithromycin-azithromycin led to a more rapid resolution of
lymphadenopathy than placebo(Bass et al.,1998)
• In cases with complications, azithromycin 500 mg daily for 1 week
followedby 250 mg for 4 weeks is recommended.
• In bacillary angiomatosis erythromycin 500 mg once daily for 3 months or
doxycycline 100 mg twice dailyfor 3 months may be required to prevent
relapse and effect a full cure
• Rifampin
• Ciprofloxacin
• Trimethoprim/sulfamethoxazole
• Gentamicin- reserved drug

19. Prognosis of the patient
• The prognosis for immunocompetent patients with CSD is excellent
• Children with normal immune system should recover without treatment
• Complete recovery in 2-5 months
• Rarely leads to granular hepatitis, peripheral neuritis, neuroretinitis
• The condition is more severe in immunecompromised persons

20. Prevention
• Cat owners are advised to avoid rough play with cats to reduce the risks of
scratches and bite
• Any wounds inflicted by the cat should be washed and disinfected
immediately.
• Nail clipping
• Flea control
• Patient education

21. Vaccine
• There is no vaccine available
• Infection gives life long immunity