Transcript [ Malaria Diagnosis]

Malaria Diagnosis
Sachin Kale, MD (Pathology).
Approaches
 Clinical
 Microsopy
 RDTs
Microscopy
Microscopy
 Sensitive
 5 – 10 parasites/ul
 100 parasites/ul (in field conditions.)
 Informative
 Species
 Inexpensive
Microscopy
 Permanent record
 Quality control
 Disadvantages
 Labour intensive
 Exacting
Photomicrography
 Nikon Coolpix 3700
 Vision 2000
 Camera mode: Manual
 White Balance: Auto
 Size: 1024x780
Conflict of Interest Statement: No association with any of above brands.
Vivax
Falciparum
Vivax
Falciparum
Rapid Diagnstic Tests
Antigens
 HRP-2
 p-LDH
Suspected cases
RDT/PS
Severe
T/t
+ve
-ve
P.f
High Suspicion
Uncomplicated
T/t
Low Susp
T/t, exclude
Other diseases
Other diseases,
Review/refer
Species-specific PCR
diagnosis of malaria
 5 parasites or less/ul
 Species identified
Other Approaches
 Quantitative buffy coat
 Fluorescence Microscopy
 Sensitivity: 41 to 93 % (0.002%
parasitemia)
 Specificity: 93%(P.f)
 No species identification
Ancillary Tests
 Hb, PCV
 Blood glucose
 WBC, Platelet Count
 Coagulation tests; FDPs, Fibrinogen
 Urine for free Hb
 Blood Urea/ Creatinine
 Urine Protein
 G6PD
Poor Prognosis
 Heavy parasitemia >5% RBC
 Presence Malarial pigment, schizonts and
mature trophs
 WBC > 12,000/cmm
 Creatinine: > 2.9 mg/dl
 BUN: 128 mg/dl
 PCV: < 20%, Hb: < 7.0 gm/dl
 Blood glucose: < 40
 Riased transaminases
 Iqbal et al. (J. Clin. Microbiol. 39:3644–3646. )
looked at pLDH detection compared to microscopy
and PCR in 550 immigrants from malaria-endemic
areas who were entering Kuwait, where malaria is
not endemic. They concluded that for parasite levels
of >100 parasites/µl , the sensitivity obtained for
OptiMAL was 97%. However, because half of the
samples with <50 parasites/µl detected by
microscopy were not detected, the authors
recommended that the test should be used with
great caution and should not replace
conventional microscopy in the diagnosis of
malaria.
Diagnostic and Prognostic Utility of Rapid Strip
(Optimal and Paracheck) Versus Conventional Smear
Microscopy in Adult Patients of Acute,
Uncomplicated P. falciparum Malaria in Mumbai, India
NJ Gogtay*, SS Dalvi**, D Rajgor***, AR Chogle#, DR Karnad+++, M Ramdas+, U Aigal##,
NA Kshirsagar++
 Thrombocytopenia in malaria
 Patel U, Gandhi G, Friedman S, Niranjan S.
 The study found the sensitivity of platelet count
for diagnosing malaria was 100%, and the
specificity was 70%.
 The negative predictive value was 100% and the
positive predictive valve was 86%.
 J Natl Med Assoc. 2004 Sep;96(9):1212-4
Clinical Microbiology Reviews, January 2002, p. 66-78, Vol. 15, No. 1
References
 Treatment of Malria www.cdc.gov
 The use of Malaria Rapid Diagnstic Tests. WHO, Roll Back
Malaria
 REPORT OF A JOINT WHO/USAID INFORMAL
CONSULTATION
25–27 OCTOBER 1999 New Perspectives Malaria Diagnosis
 http://japi.org/August2003/O-762.pdf?malaria
 Clinical Microbiology Reviews,
January 2002, p. 66-78, Vol. 15, No. 1
Thank You !
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