2. Clinical Diagnosis
Clinical diagnosis is based on the patient’s symptoms and on physical
findings at examination. Such as:
• Fever
• Chills
• Sweats
• Headaches
• Muscle pains
• Nausea
• Vomiting
3. Clinical Diagnosis
In severe malaria (primarily caused by Plasmodium falciparum), clinical
findings are more striking and may increase the index of suspicion for
malaria. Such as:
• Confusion,
• Coma,
• Neurologic focal signs,
• Severe anemia,
• Respiratory difficulties
4. Laboratory Diagnosis
Clinical findings should always be confirmed by a laboratory test for
malaria.
In addition to ordering the malaria specific diagnostic tests, the health-
care provider should conduct an initial workup and request a:
• Complete blood count
• Routine chemistry panel
In the event that the person does have a positive malaria test, these
additional tests will be useful in determining whether the patient has
uncomplicated or severe manifestations of the malaria infection. Specifically,
these tests can detect severe anemia, hypoglycemia, renal failure,
hyperbilirubinemia, and acid-base disturbances.
5. Laboratory Diagnosis
Malaria parasites can be identified through a variety of methods,
including:
1. Microscopic Diagnosis
2. Antigen Detection
3. Molecular Diagnosis
4. Serology
5. Drug Resistance Tests
6. 1. Microscopic Diagnosis
Malaria parasites can be identified by
examining under the microscope a drop of the
patient’s blood, spread out as a “blood smear” on a
microscope slide.
Prior to examination, the specimen is stained
(most often with the Giemsa stain) to give the
parasites a distinctive appearance.
This technique remains the gold standard for
laboratory confirmation of malaria.
7. Making Thick and Thin Blood Smears
1. Whenever possible, use separate slides for thick
and thin smears.
2. Thin film (a): Bring a clean spreader slide, held at a
45° angle, toward the drop of blood on the
specimen slide.
3. Thin film (b): Wait until the blood spreads along
the entire width of the spreader slide.
4. Thin film (c): While holding the spreader slide at
the same angle, push it forward rapidly and
smoothly.
(a)
(b)
(c)
8. 5. Thick film: Using the corner of a clean slide,
spread the drop of blood in a circle the size of a
dime (diameter 1-2 cm). Do not make the smear
too thick or it will fall off the slide. (You should be
able to read newsprint through it.)
6. Wait until the thin and thick films are completely
dry before staining. Fix the thin film with methanol
(100% or absolute) and let it dry completely before
staining. The thick film should not be fixed.
7. If both thin and thick films need to be made on the
same slide, fix only the thin film with methanol.
The thick film should not be fixed.
Making Thick and Thin Blood Smears
Methanol and its vapours quickly fix thick films and interfere with the
haemolysis of the thick film.
11. Staining
The Giemsa stain is used as the gold standard for the diagnosis of
malaria on blood smears.
Procedure:
1. Using a Pasteur pipette, fix the thin film by carefully dropping methanol
onto the thin film only.
2. Let the blood film dry in air on a drying rack or tray.
3. Place slides for staining blood films face down on a curved staining tray
or face up on a staining rack.
12. Continued….
4. Pour stain slowly on or under the slide until the blood films are covered.
5. Set the timer to 8-10 minutes for the staining.
6. Gently flush all the stain from the slides by dropping clean water over it.
7. Allow the slides to air-dry.
8. Discard the remaining 10% Giemsa solution.
13. Examining Thin Films
1. Place a drop of immersion oil on the
feathered edge of the thin film.
2. Move from the 10x lens to the 100x oil
immersion lens.
3. Examine the feathery end of the edge of the thin film where red cells lay
side by side, and there is minimal overlap. Follow the pattern of
movement shown in figure. Move along the edge of the film, then move
the slide outwards by one field, inwards, returning in a lateral movement,
and so on.
4. Continue examining the thin film until the presence and species of
malaria parasites have been confirmed. Identify and record all species and
stages observed in the malaria microscopy blood register.
16. 2. Antigen-Based Tests
Various test kits are
available to detect antigens derived
from malaria parasites. Such
immunologic
(“immunochromatographic”) tests
most often use a dipstick or
cassette format and provide results
in 2-15 minutes.
These “Rapid Diagnostic Tests” (RDTs) offer a useful alternative to
microscopy in situations where reliable microscopic diagnosis is not available.
Malaria RDTs are currently used in some clinical settings and programs.
17. Procedure:
1. Remove the test device from the sealed pouch and use it as soon as
possible in room temperature.
2. Place the test device on a clean and level surface.
3. For serum or plasma specimen: Hold the dropper vertically and transfer 3
drops of serum or plasma (approximately 100μl) to the specimen well(S)
of the test device, then start the timer.
4. For whole blood specimens: Hold the dropper vertically and transfer 1
drop of whole blood(approximately 35μl) to the specimen well(S) of the
test device, then add 2 drops of buffer (approximately 70μl) and start the
timer.
5. Wait for the colored line(s) to appear. Read results at 15 minutes. Do not
interpret the result after 20 minutes.
18. Interpretation of Results
Positive: Two lines appear. One line should always appear in the control line
region(C), and another one apparent colored line should appear in the test line
region.
Negative: One colored line appears in the control region(C).No apparent
colored line appear in the test line region.
Invalid: Control line fails to appear. Insufficient specimen volume or
incorrect procedural techniques are the most likely reasons for control line
failure.
19. 3. Molecular Diagnosis
Parasite nucleic acids are detected using polymerase chain reaction
(PCR). Although this technique may be slightly more sensitive than smear
microscopy. PCR results are often not available quickly enough to be of value
in establishing the diagnosis of malaria infection.
PCR is most useful for confirming the species of malarial parasite after
the diagnosis has been established by either smear microscopy or RDT.
20. 4. Serologic Tests
Serology detects antibodies against malaria parasites, using:
i. Indirect immunofluorescence (IFA)
ii. Enzyme-Linked Immunosorbent Assay (ELISA).
(Serology does not detect current infection but rather measures past exposure)
21. 5. Drug Resistance Tests
Drug resistance tests are performed in specialized laboratories to
assess the susceptibility to antimalarial compounds of parasites collected from
a specific patient. Two main laboratory methods are available:
1. In vitro tests: The parasites are grown in culture in the presence of
increasing concentrations of drugs; the drug concentration that inhibits
parasite growth is used as endpoint.
2. Molecular characterization: Molecular markers assessed by PCR or
gene sequencing also allow the prediction, to some degree, of
resistance to some drugs. Central Disease Control (CDC) recommends
that all cases of malaria diagnosed in the United States should be
evaluated for evidence of drug resistance.
22. Malaria Reporting System
Malaria reporting in Pakistan, as in many other countries, follows a
specific process to track and manage the disease. The key components of how
malaria is reported in Pakistan include surveillance, data collection, reporting,
and response. Here's an overview of the steps involved:
1. Data Collection and Surveillance
2. Data Reporting
3. Provincial Coordination:
4. National Level Reporting
5. Response and Interventions
6. Monitoring and Evaluation
23. Malaria Reporting System
Form Malaria (FM-1)
Register
OPD Register
Provisional FM-4 Report
Provisional DHIS Report
District FM-3 Report
District DHIS Report
Facility Monthly FM-2
Report
Facility Monthly DHIS
Report
Directorate of Malaria Control
Islamabad
Monthly
Monthly
Monthly
Monthly
District
Health
Information
System
(DHIS)
Malaria
Information
System
(MIS)
Figure. Malaria Surveillance Systems in Pakistan (information flow).
