A PCR method based on 18S rRNA gene for detection of malaria parasite in Balochistan.

OBJECTIVE: To establish a polymerase chain reaction method based on 18S ribosomal ribonucleic acid gene for the detection of plasmodium deoxyribonucleic acid in patients suffering from malaria symptoms.

METHODS: This cross-sectional study was conducted from September 2013 to October 2014 in district Quetta of Pakistan's Balochistan province. Blood samples were collected from patients suffering from general symptoms of malaria. A polymerase chain reaction-based technique was applied for the diagnosis of malaria and detection of responsible species in the patients who were suspected to carry the parasite. Performance of this polymerase chain reaction method was compared against the microscopy results. Parasite number was also calculated for microscopy positive samples.All samples after the genomic deoxyribonucleic acid isolation were subjected to polymerase chain reaction amplification and agarose gel electrophoresis.

RESULTS: Of the 200 samples, 114(57%) were confirmed as positive and 86(43%) as negative for malaria by microscopy. Polymerase chain reaction identified 124(62%) samples as positive and 76(38%) as negative for malaria. The comparative analysis of both diagnostic methods confirmed 109(54.5%) samples as positive by both techniques. Besides, 5(6.58%) samples were identified as false positive and 15(12.1%) samples as false negative by polymerase chain reaction. Sensitivity, specificity and positive predictive values for polymerase chain reaction in comparison to microscopy were 87.98%, 93.42% and 96%, respectively.

CONCLUSIONS: Polymerase chain reaction-based methods in malaria diagnosis and species identification were found to be more effective than other techniques.