The Follow-Up of Treatment Process of Malaria by Real-Time Polymerase Chain Reaction: In Vivo Model

Abstract

Microscopic methods are accepted as the gold standard in the diagnosis of malaria and in the followup of treatment. However, as the microscopical methods require experienced personnel, it is important to confirm the diagnosis with a different method for accurate diagnosis and treatment follow-up. In our study, we aimed to investigate the utility of the use of real time reverse transcriptase polymerase chain reaction (rRT-PCR), as well as microscopic methods for malaria treatment follow-up. In our study, we formed five groups each consisting of five male Balb/c mice. Each mouse was injected intraperitoneally with 107/ml Plasmodium berghei parasites. After 48 hours following the injection, the mice in the first, second and third groups received 50 mg/kg/day of chloroquine treatment for one, two and three days, respectively. The fourth group was not treated and the fifth group of mice received saline for three days. The parasitemia was monitored for 21 days by blood smears prepared from the end of tail of the mice and searching the presence of the target gene region of the parasite by rRT-PCR. Both the blood smears and rRT-PCR results were positive for groups I, II, IV and V. Both blood smears and rRT-PCR results of mice in groups other than the third group were found to be positive. Blood smears of the mice in third group were found to be positive on the 5th and 7th days of the infection, and the subsequent preparations were evaluated as negative. rRT-PCR results showed positivity on day seven, but no presence of the target gene region of the parasite was detected on the other days. The comparison of microscopy and rRT-PCR methods, had shown parallel results. Apart from the microscopic examination method, it was concluded that the rRT-PCR method is important in the diagnosis of malaria and in the follow-up of the patient during the treatment process, and that different methods that support each other should be used.