We will discuss briefly common tropical diseases found in INDIA. The presentation is basic for undergraduate students. we are covering dengue, malaria, chikungunya, and rickettsia in this presentation.

1. TROPICAL DISEASES
DR DEEPAK KUMAR
ASSOCIATE PROFESSOR
DEPTT. OF PEDIATRICS
MAMC AND LNH

2. Tropical Regions

3. Tropical Regions
• In terms of climate - hotter and wetter
• 40% of the Earth's surface area.
• home to 40% of the world's population
• Abundant insects and vectors
• Lack of access to safe water, poor sanitation
• Overcrowding, poor housing, dirty environment
• All --- Transmission of Infections.

6. Tropical Diseases
• Common (India)
Dengue/ Chikungunya
Malaria
Helminthes
Leshminiasis
Leprosy
TB/ TB-HIV
Filariasis
Rickketssia

7. Other-
• Chagas Disease, African Trypniasosis
• STDs, Scabies
• Trachoma, Buruli

8. DENGUE FEVER

9. Dengue
Agent- Dengue Virus
• Single stranded RNA Virus
• Family: Flaviviridae
• Genus: Flavivirus
• 5 serotypes: DENV-1, DENV-2,
DENV-3, DENV-4 ,DENV5
Vector- Mosquito
•Aedes aegypti , Aedes albopictus,
Aedes polynsienses, Aedes scrutella
•Day feeders, Recurrent biter
•Fresh water mosquitoes
•White bands or scale patterns on its
legs and thorax
DENV- Dengue virus

10. Man-Mosquito-Man Cycle
Febrile viremia in
a boy infected
with dengue virus
3-7 days
Mosquito bites and
gets dengue virus
in blood meal
Dengue infected
mosquito bites
healthy person and
transmits the virus
Incubation period
in the infected person
2-7 days
Mosquito
with no
dengue virus
Incubation period
within the mosquito

11. Immune-pathogenesis
The First Dengue Infection
T and B memory cells
Reinfection
B cells- Ab production &
Antibody dependent
enhanced replication
Ag-Ab complex formation with
complement activation
Deposition on various tissues,
vessels and platelets
Thrombocytopenia  bleeding Vasculopathy  capillary leakage
T cell activation
Chemical mediators
Cytokine
Storm/Tsunami
Increased vascular
pathology
Ref: Mongkolsapaya J et al. 2003. Nat Med 9: 921–927
Mathew A et al. 2008. Immunol Rev 225: 300–313

12. CLINICAL PRESENTATION

13. ASYMPTOMATIC
70%

14. Severe Dengue
Death
survive
Dengue fever

15. CLINICAL FEATURES
Three phases-
• Acute Febrile Phase.
High Grade Fever (2-7 Days)
Facial Flushing, Skin Erythema, Petechiae/Mucosal Bleed
Headache, Bodyache, Myalgia, Arthalgia
Nausea, Vomiting.
Tender Hepatomegaly (Risk- Severity)
Thrombocytopenia and Leucopenia

16. • Critical Phase
After 3-7 days of onset of Fever.
Capillary leakage
Thrombocytopenia/ Bleeding
Shock
Multi-Organ Dysfunctions
• Recovery Phase ( After 24-48 hours)
Absorption of extravasated fluids starts
General well bieng, improve in appettite
Heodynamically stabilizes, Urine output improves.
May have- Itching, Bradycardia, Resp. Distress (Pulmonary Edema)
Rashes- Isles of white in the sea of red.

17. Clinical Features
• Maculopapular rash of Dengue
• First appears on the trunk and later extends to the face and extremities

18. Clinical features
• Decreased capillary refilling in Dengue, a very important sign

19. Haemmarhagic manifestations

20. DIFFERENTIAL DIAGNOSIS
Differential diagnosis
Malaria,, pharyngitis, tonsillitis, influenza, leptospirosis, other
hemorraghic fever.
Close differentials
Chikungunya, Zika virus

21. Diagnosis

22. CLINICAL CRITERIA FOR DENGUE
• Acute febrile illness of 2-7 days duration with 2 or more features :
• Headache, Retro-orbital pain,
• Rash, Myalgia, Arthralgia/bone pain,
• Haemorrhagic manifestations,
• Leucopenia (WBC ≤5000 cells/mm3),
• Thrombocytopenia (platelet count <100 000 cells/mm3),
• Rising Haematocrit (5 – 10%);
and at least one of following:
• Supportive serology – Antibody test, Antigen test ( Agglutination, ELISA)
• Occurrence at the same location and time as confirmed cases of dengue fever.

23. Clinical Features
• Tourniquet test
• Midpoint between SBP and DBP
• 5 minutes
• positive when 10 or more petechia
per 1 square inch area over forearm
• Definite positive test with > 20 pet.
• 50% cases positive
• Negative in obese and Shock

24. Lab Diagnosis
• Thrombocytopenia (<100,000 cells per mm3)
• Leucocytosis
• Rising Hematocrit

25. Haematocrit
• Normal – 35-45%

26. A) Normal
B) Decreased (Low RBC)
Ex- Anemia, Bleed
A) Increased (Low Plasma)
Ex- Dehydration, Capillary leak “ Dengue “

27. Confirmatory tests
• Direct Methods
NS1 Antigen Detection
PCR
Virus Culture
• Indirect Methods
IgM Detection
IgG Detection

28. Primary Infection
• NS1 antigen :- Day 1 after onset of fever and up to day 9
• IgM antibody :-
• Day 5 of infection
• IgM levels : peaks in 2 weeks, followed by a 2 week rapid decay.
• Low levels of IgG are detected in the early recovery phase, not during
the acute phase.

29. Secondary Infection
• NS1 antigen : day 1 after onset of fever and upto day 9
• IgM response is variable
• appears quite late during the febrile phase
• High levels of IgG are detectable during acute Phase

30. Recommendation for diagnosis
• NS1 for samples collected from day 1 to day 5;
• IgM ( Sn 84% to 98% ,Sp 100%) after Day 5.
• Govt. Of India recommends confirmation of dengue by ELISA based
Antigen detection ( NS1 ) from Day 1 onwards and IgM antibody
ELISA after day 5 onwards.

31. Course of Dengue
Day of illness 0 1 2 3 4 5 6 7 8 9 10
Dehydration
Bleeding
Shock
Reabsorption and
Fluid Overload
Organ Dysfunction
Capillary permeability
Platelet
Hematocrit
WBC
Viremia
IgM/IgG
Febrile Recovery
Critical
40ᴼC
38ᴼC
Temperature
Potential
clinical
problems
Laboratory
parameters
Virology &
Serology
Ref: WHO-TDR Guidelines for diagnosis, management, prevention and control of dengue 2009

32. MANAGEMENT

33. Step I Overall assesment
• History : symptoms, past medical and family history
• Physical examination : full physical and mental assessment
• Investigation : routine labs and dengue specific labs
Step III Management
• Disease notification
• Management decisions, depending on the clinical
manifestations and other circumstances, patients may :
Be sent home
Be referred for in- Hospital management
Require emergency treatment and urgent referral
Step II
• Diagnosis
• Assessment of disease phase and severity
A stepwise approach to the management of dengue

34. WHO CLASSIFICATION (2009)
THREE CATEGORIES-
• Dengue fever
• Dengue fever with warning sign
• Severe dengue

35. WARNING SIGNS
• Severe Abdominal pain
• Recurrent vomiting
• Restlessness, Lethargy
• Decreased urine output
• Cold clammy extremities
• Hepatomegaly >2cm / tenderness
• Bleeding manifestation
• Rise in Hct >20%
• Rapidly falling platelet count.

36. Dengue without warning signs
• HOME CARE
• MONITORING
• EXPLAIN WARNING SIGNS/WHEN TO RETURN

37. Home care advice for patients
• Patient needs to take adequate bed rest.
• Adequate intake of fluids such as milk, fruit juice, isotonic electrolyte
solution, oral rehydration solution (ORS) and barley/rice water.
• Paracetamol & Tepid sponging
• Paracetamol- 10-15mg/kg/d every 6 hrs.
• Aspirin or NSAID is not recommended.
• Follow-up and reassess the patient every day until the patient has no fever
on two consecutive days without the use of paracetamol.

38. When to return?
• No clinical improvement
• Persistent vomiting, lack of water intake.
• Severe abdominal pain.
• Lethargy and/or restlessness.
• Bleeding
• Pale, cold and clammy hands and feet.
• Less/no urine output for 4–6 hours

39. Management of patients with WARNING SIGNS
• Hospitalize
• Rule out other common causes - AGE, Surgical Abdomen etc.
• Supportive and symptomatic treatment should be given while under
observation
• IVF
• Monitor Vitals, Platelets and PCV/HCT.

40. Hospitalize
Colloids
10ml/kg/hr
10ml/kg/hr—(2
hrs)—15ml/kg/hr-
--(3 hrs)
Gradually Taper
Fluids (3 Hourly),
By measuring vitals
and PCV/HCT
Improvement
No
Improvement
No
Improvement
NS/RL
7ml/kg/hr
Assess after 1
hr
Dengue with
Warning Signs
Other Causes

41. SEVERE DENGUE
• Shock or fluid accumulation causing Respiratory Distress
• Severe Bleeding
• Impaired consciousness
• Multiple Organ Involvement

42. MANAGEMENT OF Severe Dengue (DHF III)
• Patient is in compensated phase hence can be missed if vitals are not checked
• Hypotension SBP <90 mmHg, pulse pressure < 20 mm Hg, high hct
• iv crystalloids @20 ml/kg/hr over 1 hr.
• If hct falls and vitals improve taper fluid and stop after 24 – 48 hrs.
• If hct increases with no improvement in vitals, give second bolus, still no
improvement, give blood transfusion
• If hct falls with non improving vitals, suspect bleeding.

44. MANAGEMENT OF Severe Dengue (DHF IV)
• Signs of shock, undetectable BP and pulse, high hct
• iv crystalloid @20 ml/kg/hr over 15- 30 minutes
• If hct falls and vitals improve taper fluid and stop after 24 – 48 hrs
• If no improvement, give second bolus over 15- 30 min
• if hct rises give third bolus with either colloid or crystalloid over 1 hour.
• if hct falls after this step or after first bolus with no improvement in vitals,
consider blood transfusion

46. Discharge criteria
All of the following conditions must be present:
• Clinical
• No fever for 24 hours
• Improvement in clinical status (general well-being, appetite, haemodynamic
status, urine output)
• No respiratory distress
• Laboratory
• Increasing trend of platelet count
• Stable haematocrit without intravenous fluids

47. CHIKUNGUNYA

48. Clinical Features
Similar to Dengue Fever.
• Acute onset High grade Fever,
• Headache, Rash, nausea, Vomiting
• Muscle Pain, Joint Pain
• Joint pain- Severe, Polyarticular, Migratory, Small joints of hands and
lower limbs.
• Maculopapular rashes 4-8 day, affecting trunk and limb

49. • Thrombocytopenia not severe.
• Capillary leakage and shock rarely seen
• Diagnosed via
• Virus culture, PCR (2-4 Days)
• ELISA IgM (5-7 Days of illness)

51. Treatment
• Symptomatic treatment
Antipyretics- PCM
Mantain Hydration
Rest.

52. MALARIA

53. ETIOLOGY
CAUSED BY- 4 species if plasmodium genus
P.Vivax
P. Falciparum
P. Ovale
P.Malariae
TANSMITTED BY - female anopheline mosquito
Anopheles stephensi
Anopheles culicifacies

55. Clinical features
•Fever
•Classical cycle of cold, hot and sweating may not be present
•Muscleache
•Bodyache
•Vague abdominal pain
O/E-
•Pallor
•Hepatomegaly
•splenomegaly

56. Complicated / severe malaria
Defined as symptomatic malaria with signs of severity or evidence of vital organ
dysfunction
• Cerebral malaria -Unrousable coma / multiple convulsions in last 24 hrs
• Severe normocytic anemia - Hb <5 g/dL, hct < 15%
• Renal failure (Serum creatinine >3 mg/dl, UO < 0.5 ml/kg/hr)
• Hypoglycemia (<40 mg/dl)
• Circulatory collapse/ Shock (Systolic blood pressure less than 50 mmHg in
children below 5 years)
• Respiratory distress due to metabolic acidosis- pH < 7.35 / s. bicarbonate < 15
mmol/l

57. • Spontaneous bleeding/Disseminated intravascular coagulopathy
• Pulmonary edema
• Hemoglobinuria
• Jaundice- S. bil > 3mg/dl or clinical jaundice
• Hyperparasitemia (>5% RBC infected)

58. Microscopic diagnosis
• Light microscopy of well stained thick and thin films by a skilled
microscopist has remained the "gold standard" for malaria
diagnosis.
• Thick films are nearly 10 times more sensitive
• larger amount of blood are there in a given area as compared to
thin films.
• Species identification is better with thin films as morphology of
the parasite and RBC are well preserved.

59. Collection of blood Sample
• As soon as malaria is suspected.
• Any time irrespective of fever
• Before administration of antimalarials.
• Smears prepared soon after collection cause minimal
distortion of parasites and red cells.

60. Examination of blood film
• Smear should be examined with 100X
oil immersion objective.
• A minimum of 100 fields should be
examined before concluding the slide to
be negative.
• Once negative, samples may be
examined for at least three consecutive
days where clinical suspicion of malaria
persists.

61. Advantage of microscopy
• Species identification along with characterization of the
stage of parasite is possible thereby helping in adequate
treatment and prognostication.
• Determining the parasite density. The parasite load is
utilized to determine the severity of malaria along with
prognosis and assessing the response to treatment.

62. Rapid diagnostic tests (RDTs)
• These are immunochromatographic test
(ICT) to detect plasmodium specific
antigens in blood sample. Test employ
monoclonal antibodies directed against
targeted parasite antigens.
• Histidine rich protein II (HRP-II) is actively
secreted by asexual stages and young
gametocytes of P. falciparum but not by
mature gametocytes.

63. • A metabolic enzyme Parasite lactate dehydrogenase (pLDH) is
produced by all four species of plasmodia, both asexual and
sexual (gametocytes) stages provided they are viable.

64. • HRP-II tests can remain positive for
7-14 days following successful
malaria treatment even when blood
doesn't show parasitemia by
microscopy.
• On the other hand as pLDH is
produced by only viable parasite so
the tests detecting this antigen
becomes negative within 3-5 days
of treatment.

65. Advantages of RDTs in comparison to
Microscopy
• Simple
• Objective
• less time consuming
• requiring no special equipment or skill/training.
• They can detect P. falciparum infection even when the parasite
is sequestered in the deep vascular compartment.

66. Polymerase chain reaction PCR
• Highly sensitive and specific for detecting all
species of malaria.
• Not commercially available and hence limited
practical utility.

67. Tests for disease management and
assessing severity
• Blood counts and culture,
• PT, PTT, Blood glucose, electrolytes, pH, bicarbonate and
lactate.
• Chest X-ray for respiratory distress syndrome,
• Serum bilirubin, transaminases and creatinine.
• Urine Hb,
• Lumbar puncture.

68. Management of uncomplicated malaria
in children
• Presumptive-
A case of fever treated for malaria without parasitological diagnosis
with an aim to prevent mortality and morbidity due to delay in
treatment.
• Curative-
Treatment given after diagnosis but without 8-aminoquinolines
because of contraindication.
• Radical-
Therapy after parasitological confirmation to eliminate all the forms
of parasite from all possible host tissues

69. Uncomplicated P. vivax
Recommended treatment
•Chloroquine 10 mg base/kg stat followed by 5 mg/kg at 6, 24 and 48
hours
OR
•Chloroquine 10 mg base/kg stat followed by 10 mg/kg at 24 hours and
5 mg/kg at 48 hours. (Total dose 25 mg base/kg)
AND
primaquine- 0.25 mg/kg/day for 14 days.

70. • Chloroquine should not be given in empty stomach and in high
fever. Bring down the temperature first.
• If vomiting occurs within 45 minutes of a dose of chloroquine that
particular dose is to be repeated after taking care of vomiting by
using Domperidone/Ondansetron.
• As primaquine can cause hemolytic anemia in children with G6PD
deficiency they should be preferably screened for the same prior
to starting treatment.

71. • As infants are relatively G6PD deficient it is not
recommended in this age group and children with 14 days
regime should be under close supervision to detect any
complication.
• In cases of borderline G6PD deficiency once weekly dose of
primaquine 0.6 - 0.8 mg/kg is given for 6 weeks.

72. Uncomplicated P. falciparum
Recommended treatment
•Artesunate 4 mg/kg of body weight once daily for 3 days
AND
•sulfadoxine/pyrimethamine (SP) as 25 mg/kg of sulfadoxine and 1.25 mg/kg of
pyrimethamine as a single dose ON DAY 1
OR
•Mefloquin 25 mg/kg divided in two(15 + 10) doses on day 2 and 3
OR
• ARTEMETHER + LUMIFANTRINE FOR 3 DAYS.
AND
•A single dose of Primaquine (0.75 mg/kg) is given for
gametocytocidal action.

73. TREATMENT OF COMPLICATED / SEVERE
MALARIA
• Artesunate2.4 mg/kg IV (loading dose), f/by 1.2 mg/kg at 12 and
24 hours, then 1.2 mg/kg daily for 6 days.
OR
• Artemether 3.2 mg/kg (loading dose) IM, f/by 1.6 mg/kg daily for 6 days.
• If the patient is able to swallow, then the daily dose can be given orally.
AND
• At the end of the therapy
a single dose of SP
OR
Mefloquine

74. QUININE BASED
Recommended treatment
•Quinine, 10 mg salt/kg/dose3 times daily for 7-10 days.
•In case of cinchonism,
•Quinine, 10 mg salt/kg/dose 3 times daily for 3-5 days
+
•Tetracycline (if age >8 yrs) 4 mg/kg/dose 4 times daily for 7-10 days OR
•Doxycycline (if age >8 yrs) 3 mg/kg/day 2 times daily for 7-10 days OR
•Clindamycin 20mg/kg/day divided 3 times daily for 7-10 days.
•A single dose of primaquine above 1 year age (0.75mg/kg) is given for gametocytocidal
action.

75. SUPPORTIVE MANAGEMENT
Clinical Monitoring
Repeat the necessary investigations
Intravenous fluid therapy
Oxygen therapy
PCV Transfusion Cautiously if Hb< 4, with use of Furosemide.
Nursing care

76. RICKETTSIAL INFECTIONS

77. • Caused by Intracellular obligate gm –ve bacteria
• Transmitted to man by arthropod
• Classified-
Typhus Group – Epidemic/Endemic/Scrub
Spotted Fever Group- Indian Spotted/ Rocky Mountain
Q Fever
Trench Fever
Ehrlichiosis

78. Found in INDIA
• Scrub typhus – R. Tsutsugamushi
• Indian spotted Fever- R. conorii
• Q Fever- C Brunetii

79. Clinical Manifestations
• Triad – Fever, Rash and Headache
• GI symptoms
• Rash in spotted fever – after 4-5 days of fever macular or
maculopapular, pink to red in color, initially over extremeties then
entire body.
• Rash in scrub typhus- painless eschar (where the tick attaches can be
seen, rashes can be seen over trunk.
• Complications – hepatic, renal, myocardial, brain

81. Diagnosis
• Leukopenia
• Thrombocytopenia
• Serological
IgM and IgG
Weil-Felix test (low sensitivity)

82. Treatment
• Supportive- Antipyretics, maintain hydration, rest
• Doxycycline (5-7 days)
• Azithromycin (5 days)

83. Attendance !!!