Authors: Martha Powell, Future Science Group
Research presented at the 27th European Congress of Clinical Microbiology and Infectious Diseases (April 22–25, Vienna), has reported that analyzing the host immune response could be key to accurately diagnosing malaria.
Malaria affects approximately 200 million individuals worldwide, however symptoms are often non-specific. When this is coupled with poor access to testing facilities, malaria can be difficult to distinguish from other diseases.
In this study, presented by Purvesh Khatri (Stanford University, CA, USA) on World Malaria Day, the team examined the immune response to infections with the hope of speeding up diagnosis and treatment for malaria. The researchers combined data from 40 previous studies, including a total of 3000 blood samples from patients; some with confirmed malaria, some with other common tropical diseases and others were healthy volunteers.
The group analysed 2100 of the samples, studying the activity of more than 6000 genes and identifying patterns in gene expression. They discovered a group of seven genes that displayed a different pattern of expression in patients with malaria, compared with both healthy patients and those with other diseases.
Khatri explained: “We know that the immune system is able to deploy different tactics for fighting different infections such as bacteria, viruses and the malaria parasite. This research shows that we can detect signs of these differences by looking at which genes are being expressed, and we think it is possible to use this knowledge to speed up diagnosis and treatment.”
The team then tested this pattern in the remaining 900 samples, investigating whether it could be utilized to distinguish malaria from other diseases. They discovered the expression pattern could be utilized to distinguish malaria with 96% accuracy in these samples.
Khatri commented: “The early signs of malaria include fever, headache and nausea, which can also be signs of common viruses such as the flu or of tropical diseases such as dengue.
The gold-standard for diagnosing malaria involves examining blood under a microscope, but that option is not always available, for example in parts of sub-Saharan Africa. This research suggests that it’s possible to develop a fast and accurate blood test for malaria that could be used even in areas where medical facilities are very basic. And if that’s the case, more patients can be given life-saving treatment straight away.”
Work is still required; the team hope to carry out a further trial, testing the activity of these genes in additional patient samples with suspected malaria. In addition, the researchers are working on a device to measure gene expression that could be utilized in a low-resource setting, hoping the test could be available in the next 3 – 5 years.