Prevalence of submicroscopic malaria in low transmission state of Punjab: A potential threat to malaria elimination.

The objectives of the study was to explore the prevalence of sub-microscopic infections in low transmission areas of Punjab using highly sensitive molecular tool. Methods: A total of 1114 finger prick blood samples were collected through active surveillance and tested for malaria diagnosis using light microscopy, RDT and PCR. Nested PCR amplification was performed using a pair of Plasmodium genus-specific primers from the 18S rRNA small subunit gene (18S rRNA). The amplified PCR products were analysed using a 2% agarose gel, stained with ethidium bromide and observed under transilluminator. Results: Test positive rate (TPR) by microscopy, RDT and PCR was 4.4, 3.95 and 5.75%, respectively. Microscopy and RDT failed to detect mixed infections whereas 0.26% cases were found to be mixed infection in PCR. Compared to LM and RDT, PCR has detected 1.3% additional positive cases. However, of the total positive cases detected by PCR, 23.4% infections were found to be submicroscopic, which could not be detected by conventional methods of diagnosis. Interpretation & conclusions: The molecular study revealed the existence of submicroscopic malaria cases in the study population which would have remained undetected by conventional methods of diagnosis. This is particularly important because Punjab state is in malaria elimination phase and targeted to achieve elimination in 2021. However, such undetected parasite positive cases may pose bigger problem any time du...
Source: Journal of Vector Borne Diseases - Category: Infectious Diseases Tags: J Vector Borne Dis Source Type: research