by Pedro Diniz, DVM PhD. Copyright CC BY-NC-ND. 1

Transcription

1 Bartonella New Understandings of a Steath Pathogen Pedro Diniz, DVM PhD Associate Professor Western University of Health Sciences College of Veterinary Medicine diniz@westernu.edu 1 Importance Emerging infectious diseases of humans and animals 22% of professionals with animal contact (veterinarians!!) were infected Cat scratch disease: 24,000 human cases per year = $ million per year Human hospitalization costs = $6,140 Animal costs??? Minnesota zoo photo IFAW F. Graner Rev. chil. infectol. vol.24 no.2 Santiago Apr Microbiology Short pleomorphic Gram-negative rods Genetically close to Brucella spp. Fastidious aerobic Hemotropic and endotheliotropic B. henselae expressing adhesin A 1 Bartonella henselae in lymph node tissue stained with Warthin-Starry silver stain CC BY-NC-ND. 1

2 History Daniel Carrion (Peru) Fonte: History Trench Fever during World War I 1/5 of British, German and Austrian troops had the disease Fonte: Fonte: 13 Species suggested/described 1. Bartonella alsatica 2. Bartonella australis 3. Bartonella bacilliformis 4. Bartonella birtlesii 5. Bartonella bovis (weissii) 6. Bartonella capreoli 7. Bartonella chomelii 8. Bartonella clarridgeiae 9. Bartonella coopersplainsensis 10. Bartonella doshiae 11. Bartonella elizabethae. Bartonella grahamii 13. Bartonella henselae 14. Bartonella japonica 15. Bartonella koehlerae 16. Bartonella peromysci 17. Bartonella phoceensis 18. Bartonella queenslandensis 19. Bartonella quintana 20. Bartonella rattaustraliani 21. Bartonella rattimassiliensis 22. Bartonella rochalimae 23. Bartonella schoenbuchensis 24. Bartonella silvatica 25. Bartonella silvicola 26. Bartonella talpae 27. Bartonella taylorii 28. Bartonella tribocorum 29. Bartonella vinsonii 1.Bartonella vinsonii subsp. arupensis 2.Bartonella vinsonii subsp. berkhoffii 3.Bartonella vinsonii subsp. vinsonii 30. Bartonella phoceensis 31. Bartonella washoensis 32. Candidatus B. antechini 33. Candidatus B. bandicootii 34. Candidatus B. breitschwerdtii 35. Candidatus B. durdenii 36. Candidatus B. eldjazairii 37. Candidatus B. mayotimonensis 38. Candidatus B. melophagi 39. Candidatus B. merieuxii 40. Candidatus B. monaxi 41. Candidatus B. rudakovii 42. Candidatus B. tamiae 43. Candidatus B. thailandensis 44. Candidatus B. volans 45. Candidatus B. woyliei 14 CC BY-NC-ND. 2

3 Species B. bacilliformis B. melophagi B. tamiae B. quintana B. henselae B. elizabethae B. clarridgeiae B. vinsonii berkhoffii B. vinsonii arupensis B. koehlerae B. bovis (weissii) B. grahamii B. washoensis B. alsatica B. rochalimae B. volans B. merieuxii B. taylorii Multiple Reservoirs Reservoir(s) Human Human, sheep Human, rat Human, cat, dog, monkey Cat, dog, human, rat, sea turtle, lion, cheetah, porpoise, horse, birds Rat, dog, human Cat, dog, human Dog, coyote, fox, human, sea turtle Cattle, rat, human, dog Cat, human, dog, birds Cattle, cat, deer, elk, dog Human, rodents, dog Rat, human, dog, chipmunk Human, rabbit Human, dog, fox, coyote, raccoon Squirrel, human, dog Dog Wild mouse, dog 16 Bartonella species in dogs in the US 2% (n=1) 6% (n=3) 6% n=3 Bartonella species identified Bartonella henselae 42.5% n= % (n=28) Bartonella vinsonii berkhoffii Bartonella kohlerae Bartonella bovis Bartonella volans-like 21% of 47 dogs were co-infected with more than one Bartonella species Perez C, Diniz PPVP, et al. Comp Immunol Microbiol Infect Dis Sep;36(5): Epidemiology in the US Information is limited, but: 1% - 4.2% of 14,430 dogs are seroreactive in the US (Yancey et al., VBZD 2014;14: ) 9.2% of 663 dogs tested by BAPGM-platform (Culture+PCR) were bacteremic (Perez et al. JVIM 2011;25: ) 20%-30% of canine cases of endocarditis are caused by Bartonella spp. 5% - 40% of cats (up to 90% in flea-infested colonies) in the US (Guptill. Current Vet Therapy, 2014) 18 CC BY-NC-ND. 3

4 Epidemiology in the US Pet cats exposure to Bartonella henselae States with high percentage of pet cats exposed States with moderately high percentage of pet cats exposed States with moderate percentage of pet cats exposed States with low percentage of pet cats exposed Adapted from Guptill-Yoran, Y. Feline bartonellosis. In Greene, C.E (Ed) Infectious diseases of the dog and cat, p.513, Known Vectors Vector name Bartonella species Sandfly B. bacilliformis Lutzomia verrucarum Human body louse B. quintana Pediculus humanus humanus Cat flea Ctenocephalides felis Dog flea Ctenocephalides canis Tick Ixodes ricinus B. clarridgeiae B. henselae B. elizabethae B. vinsonii berkhoffii B. henselae B. birtlesii Life Cycle Harms A, Dehio C. Intruders below the radar: molecular pathogenesis of Bartonella spp. Clin. Microbiol. Rev CC BY-NC-ND. 4

5 Life Cycle Deformations in human erythrocytes caused by B. bacilliformis, as seen by scanning electron microscopy Benson L.A. et al. Entry of Bartonella bacilliformis into erythrocytes. Infect. Immun Bartonella strategy Pathogenesis blog.lightsoutfilms.com Stealth attack Incubation may be indeterminate Indolent or asymptomatic carriage Avoids or manipulates the immune system Carrier state is common Rarely induces sterilizing immunity Merrell DS, Falkow S. Frontal and stealth attack strategies in microbial pathogenesis. Nature, 430: , Associated Medical Problems Cardiac Endocarditis Myocarditis Ocular Uveitis and choroiditis Systemic IMHA? IM Trombocytopenia Polyarthritis Pyogranulomatous Inflammation 25 CC BY-NC-ND. 5

6 Associated Medical Problems Central Nervous System Myelopathy Meningoencephalitis Hepatic Peliosis hepatis Lymphocytic hepatitis Dermal Cutaneous vasculitis Panniculitis Hemangiopericytoma Miscellaneous Idiopathic effusions Hyperviscosity syndrome Reproductive disorders Rossi et al. Veterinary Dermatology, 26:60-e22, Clinical Signs in Dogs Infected dogs (n=47) Perez C, Diniz PPVP, et al. Comp Immunol Microbiol Infect Dis Sep;36(5): Clinical Signs in Cats Perez C, et al. Successful treatment of Bartonella henselae endocarditis in a cat. J Feline Med Surg 2010; : CC BY-NC-ND. 6

7 Clinical Signs in Cats Varanat, M. et al. Recurrent osteomyelitis in a cat due to infection with Bartonella vinsonii subsp berkhoffii genotype II. J Vet Intern Med 2009; 23: Clinical Signs Dog Cat Cattle Human Fever of unknown origin Lymphadenomegaly Lethargy & anorexia Lameness Cardiac arrhythmias Endocarditis Myocarditis Abdominal distension Chronic weight loss Encephalitis Nystagmus Seizures Repeat breeding Abortion Fetal resorption 30 Laboratory findings in dogs Infected dogs (n=47) Perez C, Diniz PPVP, et al. Comp Immunol Microbiol Infect Dis Sep;36(5): CC BY-NC-ND. 7

8 Laboratory findings in cats Frequently none Some cats had transient anemia early in the course of infection Some had persistent eosinophilia. Mature neutrophilia occurred in some cats Left shift in endocarditis 32 Diagnosis Serology (IFA, ELISA, Western Blotting) Limited sensitivity and specificity Positive results usually present in endocarditis >50% of infected dogs do not develop detectable antibodies (Perez et al. Comp Immunol Microbiol Infect Dis Sep;36(5):481-7) Antibodies are not only species specific but also genotype or strain specific (Hegarty et al. JVIM 2014;28:38 41) Negative results in serological tests do not rule out Bartonella infection Diagnosis Polymerase Chain Reaction (PCR) Negative PCR does not rule out infection! Antibiotic therapy causes false-negative Available through commercial labs. 18% of healthy dogs have Bartonella DNA Sensitivity limited by magnitude of bacteremia (good for cats, limited for dogs) Cats: organisms/ul Dogs and humans: 1 10 organisms/ul Breitschwerdt, EB et al. Journal of Veterinary Emergency and Critical Care 20(1) 2010, pp CC BY-NC-ND. 8

9 Diagnosis Organism IDEXX ANTECH Zoologix NCSU Kansas UC Davis CSU Illinois Bartonella spp. Yes Yes Yes Yes Yes Yes B. henselae Yes B. v. berkhoffii Yes B. quintana Human, cat, dog, monkey B. elizabethae Rat, dog, human B. vinsonii berkhoffii Dog, coyote, fox, human, sea turtle B. koehlerae Cat, human, dog, birds B. grahamii Human, rodents, dog B. volans Squirrel, human, dog B. taylorii Wild mouse, dog B. henselae Cat, dog, human, rat, sea turtle, lion, cheetah, porpoise, horse, birds B. clarridgeiae Cat, dog, human B. vinsonii arupensis Cattle, rat, human, dog B. bovis (weissii) Cattle, cat, deer, elk, dog B. washoensis Rat, human, dog, chipmunk B. rochalimae Human, dog, fox, coyote, raccoon B. merieuxii Dog Diagnosis Blood culture: Gold-standard, but it takes several weeks to grow BAPGM medium increases detection of several species Better sensitivity is achieved when culture + PCR are combined ( 38 Endocarditis Standard Blood culture (if negative) Serology and/or PCR Enrichment PCR (BAPGM + PCR) (at 2 and 6 weeks after therapy) Diagnosis Suspected Bartonella infection Other local or systemic disease Rule out: Fungal Bacterial (acid-fast bacilli) Neoplastic Other VBD Systemic Lupus Erythematosus Genetic or degenerative diseases (if negative) Enrichment PCR (BAPGM + PCR) Initial diagnosis and at 2 and 6 weeks after therapy Serology 39 CC BY-NC-ND. 9

10 Human Bartonellosis 50% of immunocompetent professionals with frequent animal contact and arthropod were seroreactive, with 1 in 4 bacteremic for Bartonella spp. (Maggi et al., Diagn Microbiol Infect Dis. 2011; Lantos et al. VBZD, 2014) Non-specific signs: headache and irritability statistically associated with Bartonella infection (Lantos et al., VBZD, 2014) 1 out of 30 blood donors was bacteremic for Bartonella spp. (Pitassi et al., PLOS NTD, 2015) 41 Human Bartonellosis Prevention FLEA CONTROL! FLEA CONTROL! TICK CONTROL! TICK CONTROL! DO NOT RECAP NEEDLES! No rough play with dogs and cats. Don t mess with unknown cats. Cats should be kept indoors No licking of wounds. Trim claws regularly No young cats for immunocompromised people 44 Treatment Previously: Azithromycin or Doxycycline Now: Standalone therapy no longer recommended. Antibiotic resistant documented in vitro / in vivo IDEAL PROTOCOL IS CURRENTLY UNKNOWN! Empirical use: Endocarditis: Doxy + Enrofloxacin + Amikacin CNS disease: Doxy + Rifampin Other presentations in dogs: Doxy + Enroflox 4 6 weeks Cats: Doxy + Pradofloxacin 6 weeks Check therapy efficacy with serology and BAPGM culture Please consult Kirk s Current Veterinary Therapy XV (2014) for doses and more details about therapy. 46 CC BY-NC-ND. 10

11 Jarisch-Herxheimer Reaction Shock-like syndrome after the antibiotic therapy is initiated: Lethargy Vomiting Tachycardia Tachypnea Fever Do not interrupt antibiotic therapy! Provide palliative support. 47 Summary Bartonella infection occurs at least 1 of each 10 dogs suspected of a tick-borne disease. Serology alone has poor diagnostic value, but it is a good tool to monitor treatment. Special culture + PCR offers the best sensitivity to date. Bartonella can be resistant to antibiotic therapy using one single drug. Veterinarians are at risk of chronic infection with cyclic non-specific clinical signs. 49 Do you want to learn more? CC BY-NC-ND. 11

12 Treatment in Dogs (?) Drug Doxycycline with Enrofloxacin Azithromycin with Rifampin Doxycycline with Rifampin Doxycycline with Amikacin Dose 5 10 mg/kg 5 mg/kg 5 10 mg/kg 5 mg/kg 5 10 mg/kg 5 mg/kg 5 10 mg/kg mg/kg Interval (hours) Route IV/IM/ SC Duration (weeks) b Treatment in Cats (?) Drug Dose Interval (hours) Route Duration (weeks) Doxycycline 5 mg/kg 4 Enrofloxacin 5 mg/kg 24 >2 Pradofloxacin mg/kg 24 >2 Monitor therapy with serology or PCR/Culture, but clearance of organism is difficult 54 CC BY-NC-ND.