Molecular detection of malaria in South punjab with higher proportion of mixed infections

Abstract

Background: Malaria is well known for its fatalities worldwide, Plasmodium vivax and the Plasmodium falciparum are the two important species of malaria reported from Pakistan and creating lots of morbidities across the country.

Method: Study was conducted to determine the Surveillance of malaria in South Punjab by microscopy and Polymerase chain reaction (PCR).

Result: samples out of 100 patients were found positive for malarial parasites. One patient was found with mixed infection, whereas P. falciparum and P. vivax infections were detected in 17 and 22 patients, respectively. In nested PCR, genus-specific primers for Plasmodium species. in round 1 and species-specific primers for P. falciparum and P. vivax in round 2 were used. By the application of PCR 41% were found to be infected by Plasmodium spp. Among Plasmodium positive patients: mixed, P. falciparum and P. vivax infection were detected in 10, 15 and 16 patients, respectively. Thirty nine microscopically positive patients confirmed to have Plasmodium spp. One negative by PCR, 2 microscopically negative patients had shown Plasmodium spp. infection (P. falciparum and P. vivax) by PCR. In total samples, P. falciparum, P. vivax and mixed infection accounted for 36.6%, 39.0% and 24.3%, respectively.

Conclusion: Microscopy was found deficient for interpretation of mixed infections, low parasitaemia, and species specific diagnosis. The sensitivity, specificity and efficacy of nested PCR was calculated 95%, 98% and 97%, respectively, showing PCR as a more effective and efficient diagnostic tool for malaria.

Keywords: Diagnosis; Malaria; Microscopy; PCR; Plasmodium.

Fig 1

Nested PCR results for P. falciparum and P.vivax from 3 malaria patients. M: 50 bp ladder, Lane 1-3 (5, 6, 7 (P. falciparum)); lane 4-6 (5, 6, 7 (P. vivax)) results