Identification and Management

1. ANTIBIOTICS FOR TROPICAL
INFECTIONS IN ICU
Dr Jay Prakash
Assistant Professor (Dept. of Critical Care Medicine)
RIMS, Ranchi

2. Defined as infections (Fever) that are prevalent in or are
unique to tropical and sub-tropical regions due to climatic
conditions.
Introduction

3. Do we need this topic for discussion !!

7. Pioneer researchers on tropical infections in
Indian ICUs

8. Prevalence of tropical infections in India
Singhi S, Rungta N, Nallasamy K, et al. Tropical Fevers in Indian
Intensive Care Units: A Prospective Multicenter Study. Indian J Crit
Care Med. 2017;21(12):811-818. doi:10.4103/ijccm.IJCCM_324_17

10. • Causative organism: Orientia tsutsugamushi
• Vector: Chiggers (larva of Trombiculid mite)
• Incubation period: 6-20 days
• Eastern + Southern India ►
• Pathophysiology: Infects vascular endothelium with
subsequent vascular injury in organs like skin, liver, kidney,
meninges and brain
Scrub Typhus

11. • Clinical features: Fever, headache, myalgia,
breathlessness, delirium, vomiting, cough,
jaundice
• Eschar (pathognomonic) ►
• Causes of ICU admission: ARDS, Hepatitis,
Encephalitis, Aseptic Meningitis, Myocarditis
and DIC
• Main diagnostic tests: Weil Felix,
IFA (gold standard) and ELISA

12. • Doxycycline is the first line drug (100 mg BD for a duration
of 7 days).
Intravenous (IV) antibiotics may be administered
to patients who are seriously ill and unable to
swallow pills.
• Azithromycin (500 mg OD for five days) is the drug
of choice in pregnant women as doxycycline is
contraindicated.
Alternative: Rifampicin (600 mg-900 mg OD PO) or
Chloramphenicol
• Rifampicin and Azithromycin should be reserved for resistant
cases
Centers for Disease Control and Prevention. Scrub typhus.
www.cdc.gov/typhus/healthcare‐providers/index.html (accessed 13 March 2018).

14. • Causative organism: Leptospira interrogans
• Incubation period: 5-14 days
• Source of infection: Direct contact of skin
or mucosa with water contaminated with urine or body
fluid of infected animal
• Widespread in Southern, Eastern
and Western India.
Seen in Northern India as well !
Leptospirosis

15. • Pathophysiology: multiply in small blood vessel
endothelium, resulting in damage and vasculitis
• Peaks during rainy season.
• Clinically:
– Anicteric
– Icteric (Weil’s): Jaundice, Anuria, ARDS and Myocarditis
• Serology: ELISA for IgM, Microscopic agglutination test and
PCR

16. • No FDA-approved drugs for the treatment of leptospirosis.
• Antimicrobial therapy is indicated for the severe form of
leptospirosis, but its use is controversial for the mild form of
leptospirosis.
Antibiotics shorten duration of clinical illness by two to four days and also
reduces shedding of the organism in the urine
Brett‐Major DM, Coldren R. Antibiotics for leptospirosis. Cochrane Database of Systematic Reviews.
2012(2)

17. Jarisch-Herxheimer reaction
• It occurs following the treatment
with antimicrobial therapy for leptospirosis.
• An acute inflammatory response
to the clearance of spirochetes from the
circulation.
• Characterized by fever, rigor, and hypotension.
• In one series including 262 patients with leptospirosis, a
Jarisch-Herxheimer reaction occurred in 21 % of cases.
Guerrier G, Lefèvre P
, Chouvin C, D’Ortenzio E. Jarisch-Herxheimer reaction among patients
with leptospirosis: incidence and risk factors. Am J Trop Med Hyg. 2017;96:791-794.

18. • Causative organism: Dengue virus ( Flavivirus serotype 1-4)
• Vector: Aedes mosquitoes ►
• Incubation period: 4-10 days
• Pathogenesis:
• Non-neutralizing cross-reactive anti-dengue antibodies from
previous infection
• Amplified cascade of cytokines and complement activation
• Endothelium dysfunction, platelet destruction and consumption
of coagulation factors
Dengue

19. • Clinical features:
– Dengue fever
– Dengue hemorrhagic fever
– Dengue shock syndrome
– Expanded dengue syndrome
Diagnosis: NS1 antigen and IgM, IgG serology
• Treatment is only Supportive.
• No antibiotics required unless patient develops secondary
infections in ICU.

20. • Causative organism: Salmonella
typhi (serovar paratyphi A, B or C)
• Incubation period: 1-14 days
• Pathophysiology: Spread throughout
the reticulo-endothelium system
• Most prevalent in urban areas, with
high incidence in children 15 years
of age and younger
Typhoid/Enteric fever

21. • Manifestations:
• 1st week - fever, headache, relative bradycardia
• 2nd week - Abdominal pain, diarrhea, constipation,
hepatosplenomegaly, encephalopathy
• 3rd week - Intestinal bleeding, perforation, MODS.
• Cause of ICU admission:
• Intestinal bleeding
• Perforation and
• MODS (3rd week)

22. • Diagnosis:
– Typhidot (RDT) – Sensitivity 95-97%, Specificity > 90%
– Widal test- non-specific
– Bone marrow culture - Sensitivity 80-95%
– Blood culture (Gold standard)

23. • The main options are third- generation cephalosporin,
fluoroquinolones, and azithromycin.
• Fluoroquinolones are more effective than beta-lactams
against susceptible organisms.
• Ceftriaxone is first line drug – 50-75 mg/Kg/day for 10-14
days. (risk of relapse with shorter durations)
• Carbapenems are reserved for suspected infection with
extensively drug-resistant (XDR) strains.

24. ANTIMICROBIAL RESISTANCE to S. enterica is increasing
to ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones
and chloramphenicol

25. • Severe malaria accounted for 8% of tropical fever
admissions to ICU
• Main species causing severe malaria is Plasmodium
falciparum (90%), but Plasmodium vivax and recently by
Plasmodium knowlesi
• ICU admission: Signs of organ dysfunction +
Hyperparasitemia (>5%)
• Death can occur within hours of presentation
Severe malaria

26. Pathophysiology
• Mechanical microcirculatory obstruction caused by
cytoadherence to the vascular endothelium of parasitized RBC
and sequestration
• Intra-vascular hemolysis

27. Clinical features
• Paroxysm of fever, shaking
chills and sweats occur
every 48 or 72 h,
depending on species.
• Cerebral malaria
(sometimes with coma)
• Hepatosplenomegaly
• Severe anemia
• Hypoglycemia
• Metabolic acidosis
• Acute renal failure (serum
creatinine > 3 mg/dl)
• ARDS
• Shock
• DIC
• Hemoglobinuria

28. Diagnosis
• Microscopy: Thick smears – parasite detection; Thin
smears- species identification
• Quantitative buffy coat test
• Rapid diagnostic tests (RDTs) – histidine rich protein,
lactate dehydrogenase antigen based immune-
chromatography: Sensitivity and specificity > 95%
• Malaria ruled out if two negative RDTs

30. Presentation:
Sudden onset of convulsions with clenching of teeth and
loss of consciousness, mostly in the early morning, with no
prodrome or sequelae.
Hypoglycemia is a common finding
Prevalent in Southern, central
and North-Eastern Indian
states such as Uttar Pradesh,
Haryana, Bihar, Maharashtra,
Andhra Pradesh and
Tamilnadu

31. Pathophysiology: Virus reaches the central nervous
system through leukocytes and affects various parts of
the brain to cause vascular congestion, microglial
proliferation, formation of gliomesenchymal nodules, focal
or confluent areas of cystic necrosis and cerebral edema.
Diagnosis:
IgM capture ELISA Serum:
sensitivity(85-93%),
Specificity (96-98%),
CSF: Sensitivity 65-80%,
Specificity 89-100%.
Treatment:
Supportive-
Airway management,
seizure control and
management of raised
intracranial pressure.

32. • 2009-10: pandemic
• High risk groups: elderly people,
pregnant female in late stage of
pregnancy, postpartum period,
obesity (body mass index >30),
and presence of chronic
underlying medical conditions,
including immunosuppression
• Cause for ICU admission:
hypoxemic respiratory failure
MC symptoms
Fever and breathlessness
N Am J Med Sci. 2012 Sep; 4(9): 394–398.
Swine flu (H1N1)

33. Antibiotic management
• Start Oseltamivir within 48 h of
onset of influenza symptoms
• Dosage: enteral 75 mg twice
daily for 5 days
• In critically ill, 150 mg twice daily
and longer duration of treatment until clinical
improvement or sequentially negative results for virus in
respiratory tract is achieved.

34. • Zanamivir in case of Oseltamivir resistance
• Two inhalations (5 mg per
inhalation for a total dose of
10 mg) 2 times daily for 5 days.

35. Flow chart

38. Take home message
 Initial antibiotics for tropical sepsis are mostly empirical
 Aware of local resistance pattern of particular antibiotic
 Always de escalate
 Avoid under or over treatment
 Take help from ID specialist if available

39. THANK YOU