A Filter Paper Method for the Detection of Plasmodium falciparum

Malaria kills approximately one of the 250 million that infects every year. This disease endemic of tropics is most common in regions of little economic development like Sub-Saharan Africa. Nowadays, blood film microscopy, the most common ─and seemingly effective─ diagnosis procedure for malaria diagnosis involves the preservation of blood. Interestingly, the most malaria-ridden regions in the world are not exactly the places where you will find the means to do so. In these cases, "dipsticks " or rapid malaria-diagnosis paper tests are used. However this procedure has a few disadvantages. First, it is not a quantitative method, since it only detects if malaria antigens are present in the blood. The other downside of these tests is that they only detect the infection when the malaria parasite (Plasmodium falciparum) is mature; thus carriers of the immature forms of the parasite cannot be treated, so the disease keeps spreading. A few years ago, a new method for the diagnosis called RT-PCR (Reverse Transcription-Polymerase Chain Reaction) appears to have solved the two later problems, and it is even more accurate than microscopy. Sadly, it still requires specialized equipment and the preservation of blood.

Consequently, researchers like David Sullivan and Nirbhay Kumar at the John Hopkins Malaria Research Institute have experimented with the application of the RT-PCR method using dried blood instead frozen samples. They utilized blood-soaked filter paper to collect the samples. There study showed that malaria parasites can be detected from these sun-dried paper samples with a similar detection limit to that of frozen blood samples. Also, the process will cost less since there is no need for RNAlater treatment (part of the RT-PCR method) of the sample and cold chain transportation if filter paper is used.

In sum, this article is an example that sometimes cutting edge & complex solutions do not apply to all cases, and alternative and more practical pathways can make the difference in effective diagnosis and treatment.

Reference:

Godfree Mlambo, Yessika Vasquez, Ralph LeBlanc, David Sullivan, AND Nirbhay Kumar. "A Filter Paper Method for the Detection of Plasmodium falciparum Gametocytes by Reverse Transcription–Polymerase Chain Reaction." The American Society of Tropical Medicine and Hygiene 78(1), 2008, pp. 114-116. PubMed.gov. Web. 29 September. 2010

Source:

http://www.ajtmh.org.lib-ezproxy.tamu.edu:2048/cgi/content/full/78/1/114