rickettsial infection approach and treatment

1. APPROACH TO RICKETTSIAL
INFECTIONS
DR.K SURENDER ASSOC PROFESSOR
DEPARTMENT OF PEDIATRICS KAKATIYA
MEDICAL COLLEGE WARANGAL

2. INTRODUCTION
• EMERGING INFECTION
• EARLY NON SPECIFIC SIGNS AND SYMPTOMS
• PROGRESSES WITH FATAL OUTCOMES >30%
CASE FATALITY IN UNTREATED OR DELAY
• DIAGNOSTIC DIFFICULTIES
• BETTER OUTCOME WITH EARLY INITIATION OF
TREATMENT

3. ETIOLOGY
• MOTILE GRAM NEGATIVE, NON SPORE
FORMING, PLEOMORPHIC BACTERIA
• OBLIGATE INTRACELLULAR PARASITE
• MAJOR ANTIGENS ARE LPS, LIPOPROTEIN,
OMP-A, OMP-B
• GROWTH IS ENHANCED BY SULPHONAMIDES

4. CLASSIFICATION
SNO DISESASE RICKETSIAL
AGENT
INSECT
VECTOR
MAMMALIAN
RESORVOIR
1 TYPHUS GROUP
EPIDEMIC TYPHUS R. PROWAZEKII LOUSE HUMANS
MURINE TYPHUS R. TYPHI FLEA RODENT
SCRUB TYPHUS R.
TSUTSUGAMUS
HI
MITE RODENT
2 SPOTTED FEVER
GROUP
RMSF R. RICKETTSII TICK DOG/RODENT
INDIAN TICK TYPHUS R. CONORII TICK DOG/RODENT
TICK BORNE
LYMPHADENOPATHY
R. SLOVACA TICK WILD BORE

5. SNO DISESASE RICKETSSIAL
AGENT
INSECT
VECTOR
MAMALLIAN
AGENT
3 TRANSITIONAL
GROUP
RICKETTSIAL POX R. AKARI MITE MICE
CAT FLEA TYPHUS R. FELIS FLEA CAT/DOGS
4 OTHERS
Q FEVER COXIELLA
BURNETTI
NIL SHEEP/CATTLE/
GOAT
TRENCH FEVER ROCHALIMAEA
QUINTANANA
LOUSE HUMANS
EHRLICHIOSIS EHRLICHIA TICK DEER/DOG
ANAPLASMOSIS A
PHAGOCYTOPH
ILO
TICK DOG/DEER

6. METHOD OF TRANSMISSION
• NATURAL HOST/RESERVOIR/VECTORS : TICK,
MITE, FLEA, LOUSE
• RESERVOIR HOST : DOGS AND RODENTS
• TRASOVARIAN & TRANSTADEAL
TRANSMISSION

9. PATHOPHYSIOLOGY
• INNOCULATE INTO DERMIS BY BITE ATTATCH TO
HOST CELL RECEPTORS
• ESCAPE FROM PHAGOSOME BY LYSIS
POLYMERISATION
• ATTACH TO ENDOTHELIAL CELLS OF
MICROVASCULATURE
• CYOKINE MEDIATED DAMAGE TO ENDOTHELIAL
INTEGRITY AND OCCLUSIVE
ENDARTERITIS,MICROINFARCTS “Typhus nodule
of Wolhbach”

10. CLINICAL APPROACH
FEBRILE SUSPECTED CHILD WITH H/O:
• EXPOSURE TO TICKS/MITE/LOUSE
• TRAVEL TO ENDEMIC AREA
• H/O CONTACT WITH PETS
• CLASSICAL TRIAD: FEVER RASH HEADACHE, ABDOMINAL PAIN
• RASH OVER PALMS AND SOLES
• PALPABLE PURPURA
• NECROTIC RASH
• GANGRENE
• ESCHAR
• LYMPHADENOPATHY
• EDEMA OVER DORSUM OF HANDS AND LEGS
• HEPATOSPLENOMEGALY
• ANEMIA LEUCOCYTOSIS THROMBOCYTOPENIA
• PUO
• FEVER NOT RESPONDING TO ROUTINE ANTIBIOTICS

13. CASE DEFINITIONS
• SUSPECTED CASE: FEVER MORE THAN 5 DAYS
WITH/WITHOUT ESCHAR ASS WITH RASH
LYMPHADENOPATHY MULTI ORGAN INVOLVEMENT
• PROBABLE CASE: SUSPECTED CASE SHOWING TITERS
1:80 OR ABOVE IN OX2 OX19 OXK ANTIGENS BY WEIL
FELIX TEST OR OPTICAL DENSITY >0.5 IGM BY ELISA
• CONFIRMED CASE: RICETTSIAL DNA DETECTED IN
ESCHAR SAMPLE OR WHOLE BLOOD PCR OR RISING
ANTIBODY TITERS BY 4 FOLDS BY IFA & IPA ELISA

14. INVESTIGATIONS
• LAB: CBP- LEOCOCYTOSIS
THROMBOCYTOPENIA
• HYPONATREMIA
• HYPOPROTENEMIA
• ELEVATED SERUM AMINOTRANSFERASES
• CSF: MONONUCLEAR PLEOCYTOSIS

15. WEIL FELIX TEST
• ANTIGENIC CROSS REACTIVITY BETWEEN
RICKETTSIAL SP AND PROTEUS SP
• PROTEUS ANTIGENS OX2 –REACTS WITH SFG
• OX19- TYPHUS GROUP
• OXK- SCRUB TYPHUS
• BY EDMUND WEIL AND ARTHUR FELIX IN 1916
• SENSTIVITY AND SPECIFICITY 49% & 96% .

16. ELISA FOR IGM ANTIBODIES
• SENSTIVITY 91% AND SPECIFICTY 100%
IMMUNOFLUROSENCE ASSAY FOR IGM AND IGG
• IGM TITERS AFTER 5 DAYS 1:640 SUGGEST
ACUTE INFECTION
• IGG TITES MORE THAN 1:254 SUGGEST ACUTE
INFECTION LESS THAN 1:125 SUGGEST
PREVIOUS INFECTION
IMMUNOPEROXIDASE ASSAY
LATEX AGGLUTINATION TEST
PCR

17. RGA CLINICAL SCORING
RATHI GOODMAN AGHAI SCORING
CLINAL FEATURES SCORE LABORATORY SCORE
RURAL 1 HB LESS THAN 9 1
PETS 1 PLATELETSLESS THAN
1.5LAKH
1
TICK EXPOSURE 2 CRP>50MG/DL 2
TICK BITE 3 SERUM ALBUMIN
<3GM/DL
1
CONJUNCTIVAL
CONGESTION
2 URINE ALBUMIN >2+ 1
MACULOPAPPULAR RASH 1 SGPT >100 2
PURPURA 2 SODIUM <130MEQ/L 2
PALPABLE PURPUR/
ECHYMOSIS/NECROSIS
3 TOTAL 10
RASH AFTER 48-96 HRS
AFTER FEVER
2
PEDAL ODEMA 2
RASH ON PALMS AND
SOLES
3
HEPATOMEGALY 2
LYMPHADENOPATHY 1

18. RGA SCORE CUT OFF SCORE 14
• SENSTIVITY 96.15%
• SPECIFICITY 98.84%
• PPV 98%
• NPV 97.7%
• LR+ 82.7%
• LR- 0.04%
HIGH INDEX OF SUSPICION AND CLINICAL
FEATURES AND EPIDEMILOGICAL FEATURES
AND LABAROTORY FINDINGS ARE IMPORTANT
ADJUVANTS IN DIAGNOSIS

20. TREATMENT
• DOXYCYCLINE : 4.5MG/KG TWO DIVIDED DOSES OR AZITHROMYCIN
10MG/KG FOR 5-7 DAYS
• TERITIARY CARE: Intravenous doxycycline (wherever available)
100mg twice daily in 100 ml normal saline to be administered as
infusion over half an hour initially followed by oral therapy to
complete 7-15 days of therapy.
• Intravenous Azithromycin in the dose of 500mg IV in 250 ml normal
saline over 1 hour once daily for 1-2 days followed by oral therapy
to complete 5 days of therapy OR
• Intravenous chloramphenicol 50-100 mg/kg/d 6 hourly doses to be
administered as infusion over 1 hour initially followed by oral
therapy to complete 7-15 days of therapy
• Doxycycline and/or Chloramphenicol resistant strains have been
seen in South-East Asia. These strains are sensitive to Azithromycin

21. References
• DHR-ICMR 2016 GUIDELINES
• IAP GUIDELINES 2017
• NELSON Text Book of Pediatrics
• Text Book Of Pediatric Infectious Diseases IAP

22. THANK YOU