Malaria must be recognized promptly
in order to treat the patient in time and prevent further spreading of infection in the
community. It should be considered as a
potential medical emergency and
should be treated accordingly, delay in diagnosis and treatment is a leading cause of death in malaria patient. Malaria
can be suspected based on the patients symptoms and physical findings at examination . However for definitive diagnosis to be made laboratory
test must be demonstrated to confirm
malaria parasites or components . The first symptom
of malaria (most often fever, chills, sweat, headaches, muscle pains , nausea and vomiting) are often not specific and can be found in other diseases ( such as ‘Flu’
and common viral infections )
like wise, the physical finding are often not specifically elevated temperature, perspiration, tiredness ). Insevere malaria (caused by p falciparum ) clinical findings (include confusion, coma, neurologic focal signs, severe anaemia and respiratory difficulties ) are more striking and may increase the suspicion index for malaria. Thus, in most cases the early clinical findings in malaria are not typical and need to be confirmed by a laboratory test. The diagnosis of malaria is confirmed by the blood test and can be divided into microscopic and non-microscopic or macroscopic tests (Cheesbrough 2002)
MICROSCOPIC
TEST
For nearly hundred years, the direct
microscopic visualization of the parasite on thick or thin blood
smears has been the accepted
method for the diagnosis of
malaria in most setting from of clinical hematology laboratory to the field surveys. The careful examination
of a well prepared and well stained
blood film currently remains the Gold
Standard for malaria diagnosis. Microscopic test involve staining and
direct visualization of the parasite
under microscope. during staining of
blood film, hemoglobin in the erythrocytes dissolve (dehaemoglobinization) and is removed by
water in these staining solution leaving
the parasite and the leucocytes to be
seen under the microscope
NON-MICROSCOPIC
/MACROSCOPIC TEST
This involves the test that detect parasite
antigen and anti plasmodial antibodies
or the parasite metabolic products. Nucleic acid probes and immune fluorescence for the detection
plasmodia with the erythrocytes get diffusion, counter immune
electrophoresis, radioimmune assay and enzyme
immunoassay for malaria antigens
in the body fluids and haemagglutination
test western blotting for
antiplasmodia antibodies in the
serum have all been developed. The rapid diagnostic test (RDTS ) detect species specific circulating parasite antigens targeting either the Histidine Rich Protein 2 (HRP 2) of p. falciparum it also detect parasite species. Specific lactate dehydrogenate (PLDH) enzyme
and aldolase enzyme (Cheesbrought 2005).
Although the dipstick test may enhance diagnostic speed, microscopic examination remain mandatory in patients with suspected malaria because occasionally dipstick tests are negative in patients with high parastitaemia and their sensitivity below 100 parasite is low. immune chromatographic test for malaria antigen is based on the capture of the parasite antigens from the peripheral blood using either monoclonal or polyclonal antibodies against the parasite antigen targets.
The histidine rich protein to test for p. falciparium is a water soluble protein that is produced by the a sexual stages and young gametocyte of p. falciparium. It is express to remain abandonment in the surface of the red blood cell for at least 28 days after the initiation of antimalaria therapy. Plasmodim aldolase is an enzyme of the parasitic glycolytic pathway express by the blood state of p. falciparum as well as the none falciparum malaria parasite.
Parasite Lactate Dehydrogenase (PLDH) is a soluble glycolytic enzyme produce by sexual and asexual stages of liver parasite. Test base on polymerase chain reaction (PCR) for species. Specific plasmodium genome are more sensitive and specific than other tests.Antibody detection has no value in diagnosis of acute malaria. It is mainly use for epidermological studies. Therefore the simplest and surest rest is the time honoured peripheral Smear study for malaria parasite.
Although the dipstick test may enhance diagnostic speed, microscopic examination remain mandatory in patients with suspected malaria because occasionally dipstick tests are negative in patients with high parastitaemia and their sensitivity below 100 parasite is low. immune chromatographic test for malaria antigen is based on the capture of the parasite antigens from the peripheral blood using either monoclonal or polyclonal antibodies against the parasite antigen targets.
The histidine rich protein to test for p. falciparium is a water soluble protein that is produced by the a sexual stages and young gametocyte of p. falciparium. It is express to remain abandonment in the surface of the red blood cell for at least 28 days after the initiation of antimalaria therapy. Plasmodim aldolase is an enzyme of the parasitic glycolytic pathway express by the blood state of p. falciparum as well as the none falciparum malaria parasite.
Parasite Lactate Dehydrogenase (PLDH) is a soluble glycolytic enzyme produce by sexual and asexual stages of liver parasite. Test base on polymerase chain reaction (PCR) for species. Specific plasmodium genome are more sensitive and specific than other tests.Antibody detection has no value in diagnosis of acute malaria. It is mainly use for epidermological studies. Therefore the simplest and surest rest is the time honoured peripheral Smear study for malaria parasite.
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