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.
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
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.
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
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
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
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.
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.
43.
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
45.
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
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)
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
54.
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
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
