Rickettsiae

rickettsial diseases

1. DR . SHAAN AHMED JR ,Community Medicine, NMCH RICKETTSIAL DISEASES

2. Introduction:- Rickettsial diseases are considered some of the most covert emerging or reemerging diseases. Rickettsial infections are difficult to diagnose clinically hence occurrence often goes unrecognized. Failure of timely diagnosis – Significant morbidity & mortality.

3. History:- Hippocrates in 460 BC used the term Typhus, meaning ‘smoke’ to describe the confused state of i ntellect i.e . stupor. Rickettsia named after HOWARD TAYLOR RICKETTS died of Typhus fever contracted during his studies discovered Spotted fever Rickettsia (1906). It has been documented in India since 1930s with reports of Scrub typhus from Kumaon region, Assam in soldiers during 2 nd world war & Murine typhus from Jabalpur, M.P and Kashmir.

4. Distribution:- Epidemic typhus was most formidable disease in past. No case of this disease reported from South East Asia since 1978. Endemic typhus prevalent in South-East Asian region and Western Pacific countries . Scrub typhus is endemic in Northern Japan, Russia SEA, Western Pacific Island, China, India and Sri lanka . Q fever outbreaks are most common in, slaughterhouses and research facilities. Trench fever is limited to Central Europe. Commonly reported diseases in India are Scrub typhus, M urine typhus, I ndian tick typhus, Q fever.

5. Rickettsia inside the host cell TICK FLEA LICE MITE Obligate intracellular parasite. Gram negative pleomorphic bacteria. Most are zoonoses spread to humans by arthropods (except Q fever). Cannot grow in culture media, but cultivable only in living tissue. No human to human transmission. Rickettsial characteristics:

6. Rickettsial infections- classification

7. Epidemic typhus/ Classical typhus

8. 1812-1813: Napoleon suffers the greatest loss of troops to Epidemic typhus. Typhus was particularly associated with siege warfare which had a high population density and poor hygiene. Still endemic in Africa (Burundi, Rawanda , Ethiopia) and South America (Peru, Bolivia, Ecuador)

9. Epidemic typhus/ Classical typhus Rickettsial agent : - Rickettsia prowazekii Insect vector : - Louse Mammalian Reservoir :- Human, flying squirrels Transmission :- Human to human via louse vector, directly in blood, or as the contaminated louse feces is scratched into the bite wound, or inhalation of infected louse feces or dust. Incubation period: 5-21 days

10. Symptoms: Acute febrile illness Headache Myalgia Neurologic manifestations- Stupor, delirium Vasculitis Gangrene Rash : 40-80% macular, centrifugal spread, spare palms and soles

11. Brill –Zinsser disease/Recrudescent typhus (or these days “jail fever”) This occurs after the person recovered from epidemic typhus and reactivation of the Rickettsia prowazekii which remained latent for years. Mild illness and low mortality rate.

12. Control measures Diagnosis:- based on clinical suspicion with Serology Treatment:- Doxycycline (DOC) Preventive measures:- Delousing - insecticides Improvement of personal hygiene and living conditions Louse borne typhus is under WHO surveillance

13. Murine typhus/Endemic typhus Rickettsial agent: - Rickettsia typhi Insect Vector: Flea Mammalian Reservoir: Rodents Transmission :- inhalation of infected louse feces or dust. inoculation into skin with feces of infected fleas. Incubation period: 1-2 weeks Symptoms: Gradual onset- fever, Headache, myalgia , cough Rash: > 55% maculopapular rash on trunk

14. Control measures Diagnosis:- liver enzyme elevated Treatment :- Doxycycline (DOC) Preventive measures :- Residual insecticides – BHC, Malathion Rodent control measures in infested areas

15. Scrub typhus

16. Scrub typhus Rickettsial agent : Orientia tsutugamushi Insect Vector: Mite infective larvae CHIGGERS Transmission :- larval forms - chiggers found in areas of scrub vegetations. Common in military and Jungle warfare, farmers Mammalian Reservoir: - Rodents Incubation period: - 10-12 days

17. . Symptoms :- Acute onset with chills and Fever, headache, myalgia , Dry cough with Escher- the punched out ulcer covered with black scab –indicates a site of the bite Macular rash appears around the 5 th day of the bite Lymphadenopathy Lymphocytosis Cardiac and cerebral involvement

18. An Eschar of Scrub Typhus 17 Feb 2016 18

19. Control measures Treatment:- tetracycline (DOC) Vector control:- Clearing the vegetation where rats and mice lives Application of insecticides:- Lindane , Chlordane to the ground and vegetation Personal prophylaxis :- Impregnating clothes and blankets with miticial chemicals, i.e. benzyl benzoate. Mite repellant:- Diethyl toluamide application on exposed skin surfaces.

20. NRHM/IDSP 17 Feb 2016

21. Spotted fever group .

22. Rocky mountain spotted fever Rickettsial agent :- R. rickettsii Insect Vector : - Tick Mammalian Reservoir : -Rodents, dogs Incubation period :- 3-7 days Symptoms :- Abrupt onset fever, chills, headache, myalgia Rash : first appears in extremities, moves centripetally and involve palm. Mortality: 70% if left untreated in elderly Complications :- HSM, jaundice, myocarditis , uremia, ARDS

23. The clinical symptoms of other spotted fevers are very similar to Rocky mountain spotted fever Late petechial rashes on palm and forearm. Early (macular) rash on sole of foot. 

24. Control measures Treatment :- tetracycline (DOC) Personal prophylaxis :- Tick infected area should avoided Disinfection of dogs Health education about mode of transmission Clearing the vegetation where rats and mice lives

25. Rickettsial pox Benign febrile illness with vesicular rashes resembling chickenpox. Vector:- Liponyssoides sanguineus Reservoir:- Domestic mouse ( Mus musculus ) Self-limiting, non-fatal.

26. Q FEVER (QUERY FEVER)

27. Q fever Etiology: Coxiella burnetti Vector : None Reservoir: Cattle, sheep, goat MOT: ingestion of dust containing organisms or aerosols excreted in urine, feces, milk etc. I.P:- 2-3 wks C/F:- resembles influenza or non bacterial pneumonia Individuals at risk : food handlers, veterinarians Infective endocarditis occasionally in chronic Q fever

28. Control measures Treatment:- tetracycline (DOC) ,prolong for 18 months. Preventive measures:- Pasteurization/boiling of milk Providing sanitary cattle sheds Adequate disinfection and disposal of products. Personal prophylaxis :- Coxiella vaccination to occupationally exposed workers.

29. Trench fever Rickettsial agent : - Rochalimaea quintana Insect vector : - Louse Mammalian Reservoir :- Human MOT:- louse feces. disease limited to central Europe.

30. Diagnosis of Rickettsial Diseases No rapid laboratory tests are available to diagnose rickettsial diseases early in the course of illness. Rise in serum antibody/often do not develop in early stages.

31. 17 Feb 2016 Older techniques Newer techniques Giemsa Staining Technique Immunological Assays Indirect Immuno -Peroxidase / Immunoflouroscent assay 2.ELISA 3.PCR Rapid Detection Kits 1.Dip-S-Ticks 2.Scrub typhus RCT 3.Scrub typhus IgM / IgG Rapid Immunochromatographic Assay Multitest 4.Dip-S-Ticks Scrub Recombinant Assay Weil-Felix Proteus Agglutination Test Diagnostic Techniques

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33. When you Suspect sooner ….. Treatment is easier ……. 1.Clinically 2.Tick exposure 3.Epidemiological data 4.Lab features 5.Rapid defervescence with proper antibiotics

34. I am dangerous, don’t underestimate me.