Prevalence of Malaria at a Tertiary Care Hospital in Mumbai, India

Background: Malaria is caused by parasites of genus Plasmodium. It remains a major public health concern around the world. Though various diagnostic tools are available, there is an urgent need to use a more sensitive diagnostic method for early diagnosis to prevent unwanted outcomes.

Objectives: (i) To assess the prevalence of malaria in a tertiary care hospital in Mumbai (ii) To detect and speciate Plasmodium by Peripheral Blood Smear (PBS), Rapid Diagnostic Test (RDT) and real-time Polymerase Chain Reaction (PCR) and to compare their performance characteristics.

Methodology: A hospital-based diagnostic study was carried over a period of 18 months. A total of 550 non-duplicated blood samples from clinically suspected cases of malaria were collected and subjected to three tests- PBS by Field’s staining, RDT and PCR to detect Plasmodium species. The agreement and the differences between the three tests were analyzed and the statistical significance was assessed using Chi-square test.

Results: Out of the 550 samples, 166 (30.2%) were positive for malaria by either of the three tests, of which 92 (55.42%), 119 (71.69%) and 161 (96.99%) samples were positive by PBS, RDT and PCR, respectively. P. vivax was the predominant Plasmodium species. The most significant finding was PCR detected mixed infections in 8.43% of cases whereas PBS and RDT could detect 0% and 1.20% of mixed infection, respectively. Considering PBS as gold standard, sensitivity of RDT and PCR was 100% and 97.83% and specificity was 94.10% and 84.50% respectively.

Conclusions: In this study, 30% of the population was infected with malaria with P. vivax being the predominant Plasmodium species. PCR helped identify more mono and mixed infections than conventional methods and would be a helpful adjunct for malaria diagnosis in tertiary care setup.