1. RICKETTSIA ORIENTIA EHRLICHIA ANAPLASMA COXIELLA BARTONELLA

2. General introduction Gram-negative, obligate intracellular coccobacilli bacteria that infect mammaols and arthropods Rickettsiae are transmitted in the arthropods,which serves as both vector and reservior Both DNA and RNA Is sensitive to antibiotic.

3. Category of rickettsia Genus Rickettsia, Coxiella,Orientia,Ehrlichia Bartonella Species Rickettsia prowazekii (epidemic typhus), Rickettsia typhi (endemic typhus), Rickettsia rickettsii (spotted fever), Rochalimaea quintana (trench fever), Coxiella burnetii (Q fever)

4. Bilogical features Variable shape, coccobacilli Gram negative Microcapsule and slim layer Culture : in york sacs of embryonated eggs

5. Antigenic structure LPS Rickettsia tsutsugamushi Coxiella burnetii (Q fever) LPS Ⅰ smooth LPS Ⅱ rough Weil-Felix reacrion Surface protein(SPA)

7. Transmission Typhus, spotted fever and trench fever are transmitted via arthropod vectors; Q fever is acquired via inhalation or ingestion of contaminated milk or food.

8. Pathogenesis Virulence factors: endotoxin, phospholipase A, and slime layer Sites: vascular system producing vasculitis 血管炎 Characteristic triad of symptoms: fever, headache and rash (no rash with Q fever).

9. Rickettsia prowazekii 普氏立克次体 epidemic typhus average incubation periods (days):8 the louse Respiratory tract and conjunctiva Latent period: 2 weeks Abrupt onset,fever,chills,headache, myalgia,arthralgia

10. Replication cycle of Rickettsia and Orientia

11. Rickettsia typhi 地方性斑疹伤寒立克次体 endemic typhus 7-14 days Mice the louse&flea Mouth,nose and conjunctiva Gradual onset,fever,headache,myalgia, cough

12. Rickettsia tsutsugamushi 恙虫病立克次体 Tsutsugamushi disease(scrub typhus) Mice tsutsugamushi Black eachar 焦痂

13. Coxiella burnetti 贝纳柯斯体 Q fever Cow and sheep tick High resistance abrupt onset,fever,headache,chills, myalgia,granulomatous hepatitis chronic diaease with subacute onset,endocarditis,hepatic dysfunction

14. Replication of C. burnetii

15. Generalized Life Cycle of Dermacentor variabilis and Dermacentor andersoni Ticks

16. Bartonella henselae 汉赛巴通体 CSD (cat scratch disease) Cat and dog Conjunctiva inflammation and lymph node swell

17. Ehrlichia 埃里希体属 Ehrlichia chaffeensis: human monocytotropic ehrlichiosis Ehrlichia sennetsu : human granulocyto tropic ehrlichiosis

18. Replication of Ehrlichia 埃里希体

19. Proposed life cycle for the agent of Human Granulocytic Ehrlichiosis 埃里希体病

21. Diagnosis The use of immunofluorescent antibodies to examine a biopsy can be diagnostic. The organism can be inoculated into tissue culture and grown over 4-7 days but this is very hazardous to personnel. The Weil-Felix test looks for the production of serum antibody that is reactive against Proteus OX19, OX2 or OXK antigens but it is not always reliable.

22. Control Sanitary: Arthropod and rodent control Immunological: No vaccines are currently available. Chemotherapeutic: Tetracycline or chloramphenicol are drugs of choice.