89. Rheumatic Fever and Rheumatic Heart Disease (RHD)
90. Acute Pericarditis
91. Myocarditis
92. Infective Endocarditis (IE)
93. Congenital Heart Disease
94. Cardiomyopathies
95. Arteriosclerosis
96. Atherosclerosis
97. Inflammatory Disease of Blood Vessels
98. Aneurysms and Dissection
99. Congestive Heart Failure
100. Iron Deficiency Anaemia
101. Megaloblastic anaemia
102. Pancytopenia
103. Leucocytosis and Leucopenia
104. Aplastic anaemia
105. Haemolytic anaemia
106. Hereditary Spherocytosis
107. Haemoglobinipathies
108. Thalassemia syndrome
109. Sickle Cell Disease
110. Leukaemia
111. Leukemoid reaction
112. Lymphadenitits
113. Hodgkin lymphoma
114. Non-hodgkin lymphoma
115. Myeloproliferative disorders
116. Myelofibrosis
117. Multiple myeloma
118. Bleeding disorders
119. Coagulation disorders
120. any
121. Blood grouping
122
Microbiology
122. Introduction of Blood borne infections
123. Infective Endocarditis
124. Brucella
125. Rickettsiae
126. Leishmania donovani
127. Plasmodium
128. Wuchereria bancrofti
129
Biochemistry
129. Metabolism in Blood Cells
130. Iron metabolism
131. Haemoglobin
132. Lipoprotein metabolism
133. Biochemical aspect of MI
134
Microbiology
127. Plasmodium
LABORATORY DIAGNOSIS
Microscopic tests
Peripheral blood smear
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Specimen collection
Specimen
Peripheral blood
Site of collection
Ear lobe or Finger prick → Older children and Adults
Great toes → Infants
Blood film preparation
Directly from the capillary blood.
Anticoagulated blood → Within an hour of collection of blood.
Time for taking blood
Few hours after the height of the paroxysm of fever.
Before taking antimalarial drugs.
Types of Peripheral Blood Smear
Both the smears are made at the same time from capillary blood either on the same or different slides. At least two thick and two thin smears should be made.
Thick smear
A big drop of blood is spread over 1-2 cm square area on a clean glass slide.
The thickness of the film should be such that it allows newsprint to be read.
Thin smear
A small drop of blood is taken on a corner of a slide.
It is spread by another spreader slide at an angle of 45° and then is lowered to an angle of 30° and is pushed gently to the left, till the blood is exhausted.
➢ Surface of good thin film:
Even and uniform
Consists of a single layer of RBCs
Forms a 'feathery tail end' near the center of the slide
Margins of the film don't touch the sides of the slide
Stains
Romanowsky's stains
Leishman's stain
Giemsa and Field's stain
Wright's stain or
JSB (Jaswant Singh and Bhattacharya) stain
Fluorescence microscopy (Kawamoto's technique)
It is fluorescent staining method for demonstrating malaria parasites.
Blood smears are prepared on a slide and are stained with Acridine-orange and examined under a fluorescence microscope.
Nuclear DNA is stained green.
Quantitative buffy coat examination
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It is an advanced microscopic technique for malaria diagnosis and consists of three basic steps.
Steps
Blood (60μL) is collected in a capillary tube coated internally with acridine orange.
Capillary tube is centrifuged, which causes separation of components of blood according to their densities, forming discrete layers as RBCs, WBCs, lymphocytes and platelets.
Examination of capillary tube at the buffy coat region under UV light source.
Interpretation
Acridine orange has a property of staining the nuclear DNA fluorescent brilliant green.
Normal RBCs don't take up the stain (as they are anucleated).
However, parasitized RBCs appear as brilliant green dots.
WBCs also take up the stain.
Advantages
Faster (Entire tube can be screened within minutes)
More sensitive (at least as good as a thick film)
Quantification is possible.
Non-microscopic tests
Antigen detection test
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Rapid Diagnostic Tests
Antigens
Parasite lactate dehydrogenase (pLDH)
Produced by all Plasmodium species.
But currently available test kits can differentiate only two.
⬦ pan-LDH: common to all species and
⬦ Pf-LDH: specific to P. falciparum.
Parasite aldolase
Produced by all Plasmodium species.
Histidine rich protein-2 (HRP-II)
Produced only by P. falciparum.
Principle
Procedure
Interpretation
Advantages
Simple to perform.
Don't require extra equipment.
Don't require trained microscopist.
Sensitivity
More than 90% at > 100 parasites/μL
Markedly reduced at < 100 parasites/μL
Prognosis
pLDH is produced by the viable parasites, hence it is used to monitor the response for treatment.
Pregnancy
HRP-II is a reliable marker to diagnose malaria in pregnancy.
Severity
Intensity of the band is directly proportional to the parasitemia and severity of the disease.
Disadvantages
Antibody detection
Not used because antibodies persists even after the clinical cure.
Culture
Molecular diagnosis
Nested multiplex PCR
Targets 18s rDNA
Detects all five human malaria parasite including P. knowlesi.
