One of most important aspect of the malaria detection is the clinical diagnosis which is based on patient’s clinical symptoms and on physical examination.
Most common physical symptoms include; often fever, chills, sweats, headaches, muscle pain, nausea and vomiting.
In falciparum malaria these clinical symptoms may get severe. Confusion, coma, neurological focal signs, rerspiratory difficulties and anemia are some of them.
But the physical findings are often non specific. And you have to keep in mind , that the clinical findings should always be confirmed by laboratory tests to indicate positivity for malaria.
So, Let’s talk about laboratory tests available for malaria detection. For the diagnosis of malaria, patient’s blood sample which is collectted at any time during their course of illness , is required.
1. Microscopic diagnosis
The gold standarad method for malaria confirmation is the microscopic examination of thin and thick blood smears, which stained with a Romanowsky stain. The thick blood smear enable the laboratory preson to determine the presence of malaria in patient’s blood ,while thin smear allow to speciation of malaria type and detection of parasitemia. Blood smear examination is relatively simple and available in medical laboratories as routine hematological test.
2. Antigen detection
Tests for malarial antigen detection are available as Rapid Diagnostic Tests(RDT), which can be used as alternatives to the microscopy. Mainly these kit methosds are based on the Immunochromatographic assay format and provide results in 2 -15 minutes. But once the RDT gives positive results it is necessary to carry out the microscopic examination for confirmation and to detect parasitemia. However, these RDTs are easy to handle and quick , compare to other methods available.
3. Molecular diagnosis
Molecular diagnosis is mainly based on the polimerase chain reaction(PCR) which detect the parasitic DNA. This enable to detect very low number of parasitemia which occur in acute phase of disease. Therefore, the sensitivity is high. Also this can be used to confirm the species of malaria, to which is responsible for the disesase , as it gives high specificity as well. But molecular diagnosis is costly and time consuming than other methods.
4. Serological tests
Antibody detection methods for malaria are available as indirect immunofluorescence assay (IFA) or enzyme linked immuno sorbant assay(ELISA).But currently these tests are not used for the diagnosis of malaria. We can use serological tests to detect past exposure history especially in case of surveillance programme.
5. Drug resistancy tests
In-vitro diagnosis techniques and molecular tests are available in special laboratories to carry out the antimalarial susceptibility tests. In-vitro tests are culture based, while the molecular tests are based on PCR or gene sequencing techniques to detect molecular markers. However these methods are highly sophisticated and rarely performed.