Technique Overview ...
 

MALARIA OVERVIEW

Approximately 300 million people worldwide are affected by malaria. Between 1 and 1.5 million people die from it every year. Previously extremely widespread, malaria which is now mainly confined to Africa, Asia and Latin America is still one of the most dreaded diseases.
 
Importance of Pathological Diagnosis
Despite the efforts of a global Campaign to roll back Malaria, the number of deaths from Malaria is increasing worldwide. Therefore early and rapid diagnosis of Malaria is gaining increasing importance in response to increasing drug resistance. Improvements in Malaria diagnosis should facilitate early identification of individuals infected with Malaria parasites and faster treatment of such cases with appropriate drugs.

Requirements Of Diagnosis
● Sensitivity: An ability of a test to detect as low parasites as possible in a given blood specimen
● Specificity: An ability of a test to differentiate various plasmodium species and their respective lifecycle stages.
● Easy to perform and interpret.
● Speedy.
● Economical.
 

Diagnostic Techniques Overview

Conventional Microscopy.    
} Thin Smear.
} Thick Smear .
Rapid Diagnostic Tests .    
} Antibody Detection Technique .
} Antigen Detection Technique .
Kapillery Technology .    
Other Techniques .
 

Conventional Peripheral Smear Microscopy.

Technique Overview.
   Conventional microscopy involves observation of blood smear slides stained with geimsa or leishman stains under conventional white light microscope.
 
Advantages:  
● Conventional peripheral thin smear examination is considered to be a gold standard in confirming the diagnosis of malaria
● It is extremely economical .
 
Disadvantages:    
●Very high level of expertise is required to perform the test.     
● Time consuming: In order to report a negative sample, one must observe 100 microscopic fields, usually for 20-30 minutes per case.
● Thin smear technique though being considered to be very good in species identification; its sensitivity is very poor. Often patient suffers from malaria but thin smear
   test comes out negative.
● In the case of Thick smear technique, parasite morphology is not very easy to interpret.
 
Conclusion :      
Thin smear examination is considered as a gold standard for specificity. However; it is not very practical due to very high time and expertise required for executing it. For accurate diagnosis it is necessary to perform thin smear and thick smear both (thick smear for sensitivity and thin smear for species identification) which takes up a lot of time. Though conventional microscopy is used for malaria diagnosis at most places it is mainly due to the relative low cost of operation in absence of any alternative credible technique.
 

Rapid Diagnostic Tests(RDTs)

Technique Overview: Immuno-chromatographic tests popularly also known as RDTs are based on the capture of the parasite antigens from the peripheral blood using either monoclonal or polyclonal antibodies against the parasite antigen targets.

Advantages :    
●  Anyone with little training can perform these tests.  
●  No special equipment or electricity is required.
 
Disadvantages:    
● Parasite index cannot be reported hence severity of the disease cannot be known.    
● Some cards cannot detect gametocyte stages at all.    
● The inability to quantify and differentiate between the sexual and asexual parasitemia could pose problems in the areas of high transmission and in cases of incomplete treatment. The sensitivity and specificity of the RDTs, and hence the diagnosis and treatment of malaria based on the RDTs are influenced by a positive result due to causes other than malaria. The negative results are influenced by causes other than low parasitemia. Therefore; the identification of the colour changes on the RDT strips may look simple but the interpretation of these result would require the knowledge of the malaria dynamics and of the possible errors with the RDTs.
● High chances of false positive results due to cross reactions.    
● Not approved by U.S. FDA.    
● Still very high cost per test.
 
Conclusion :In absence of any dedicated pathological laboratories it can be used only as a primary diagnosis tool and not a complete diagnosis tool.
 

Introducing KAPILLERYTM

How it works:    
Kapillery tube is a high precision glass haematocrit tube pre-coated with acridine orange fluorescent stain. It is filled with approximately 65 micro-liters of blood specimen from a finger puncture. Kapillery is than sealed using a specially designed tube plug. A precision cylindrical suspender is than inserted inside the open end of the tube. The tube is then centrifuged at 12,000 RPM for 5 minutes in a specially designed centrifuge machine. Components of the blood get separated according to their densities to form discreet bands.

The Kapillery tube is then placed on the Kapillery holder and examined using a fluorescent microscope. Malaria parasite if present in the specimen absorbs the acridine orange and fluoresces bright green with characteristic morphology. Parasites are usually observed at RBC and WBC interface.

 

KAPILLERY TECHNOLOGY
Technique Overview:     Key feature of the technology is concentration of large numbers of RBCs by centrifugation in a predictable area of the Kapillery tube making detection fast and easy.

 

KAPILLERY TECHNOLOGY

Advantages:

● Very high level of sensitivity due to large quantity of blood specimen and concentration. (It has been reported to detect 1 parasite per 2microlitre of blood)  
● High specificity: Kapillery technique can differentiate all four plasmodium species along with their sexual and asexual parasitemia.  
● Ease of use-very easy to use and perform. Factory pre-coated Kapillery tubes provide consistent and uniform staining; providing predictable results every time.
   time.  
● Requires only1 minute for reporting positive and maximum of 3-5 minutes for reporting of a negative specimen. (Parasites can be detected at predictable areas    making detection easier).
● Complete process from blood specimen collection to reporting can be achieved within 10 minutes.
● Kapillery technology can be learnt in few days even by non-clinical staff/technicians.  
● Chances of false positive are negligible or non-existent.  
● Kapillery technology can detect microfilaria as well.

 

KAPILLERY TECHNOLOGY 

Disadvantages:
● Artifacts may be reported as positive by not so well trained technicians.  
● Requires fluorescent microscope and electricity which is expensive compared to conventional microscope. Although efforts are on to reduce the cost; this technology is still not as economical to perform as a conventional smear.  

Conclusion:  
● Kapillery technology is highly sensitive, very specific, easy to perform, fast and quick technique for diagnosis of malaria.  
● Technique has been approved by the U.S. FDA and WHO technical committee on malaria.  
● Criticized worldwide only for the lack of availability and cost but considered to be very good in all other aspects of malaria diagnosis.

 
COMPARISON CHART SUMMARY
 

COMPARISON CRITERIA

CONVENTIONAL

KAPILLERY

KAPILLERY BENEFITS

Blood Quantity

4-5 micro litres'

65 micro litres'

more blood, more
No. of parasites

Staining

Staining required.

Pre-coated vials

Easy, fast & uniform
Used. staining

Sensitivity

100 parasites per
2 micro litre  

1 parasite per
2 micro litre

almost 100 times
more sensitive

Concentration

Parasites are spread in
Preparation of smears.

Parasites are concentrated By   centrifugation.

Easy to detect

Reading time
For negatives

10-15 min. each

less than 3 min.

Quick and fast.

 

COMPARISON WITH RAPID CARD TEST
Although, Rapid card provides instant and easy malaria diagnosis, its use as a “complete pathological diagnostic tool” is limited. (Kapillery: Complete diagnosis) Cards cannot detect all parasite stages. (Kapillery detects all malaria stages) Cards cannot provide parasite index. Hence severity of disease cannot be reported. (Kapillery: Parasite index can be reported which helps in correctly administering drug dosage). Due to ‘cross reactivity’ chances of false positives are more with Rapid. (Kapillery: Chances of false positives are less to nil.)

It is evident that Kapillery technology fulfills most of the requirement needed for malaria diagnosis effectively. Advantages of this efficient technique could not be exploited for all this time only due to the high costs involved.

 
FLOROTEK BIOSYSTEMS intends to revolutionize the way malaria diagnosis is performed by making this technology accessible and economical.
 
LETS CREATE A MALARIA FREE WORLD TOGETHER