Integrated diagnostic and host biomarker assessment of plasmodium infections in malaria-endemic Peshawar, Pakistan

Abstract

Malaria remains a major public health problem in Pakistan, where Plasmodium vivax and P. falciparum are predominant. Accurate diagnosis and characterization of malaria-associated hematological and biochemical alterations are essential for effective disease control. This cross-sectional study was conducted in District Peshawar, Khyber Pakhtunkhwa, during peak malaria transmission months. A total of 2500 suspected patients were screened. Capillary and venous blood samples were collected for microscopy, hematological and biochemical analyses, and PCR. Microscopy was performed on Giemsa-stained blood smears, while PCR targeting the 18S rRNA gene was used for genus- and species-specific detection. Diagnostic performance was evaluated using PCR as the reference standard. Multivariate and logistic regression analyses were conducted exploratorily to examine demographic, seasonal, and host-response associations. PCR detected significantly more malaria cases than microscopy (p = 0.001), confirming underestimation by the latter. Microscopy showed moderate sensitivity but perfect specificity, with an overall accuracy of 86.4 %, substantial agreement (κ = 0.692), and good discriminatory power (AUC = 0.823). Infection prevalence peaked in September, with higher rates among males aged 21–30 years (p = 0.04). Malaria-positive individuals exhibited significant hematological abnormalities, including reduced hemoglobin, hematocrit, and red blood cell indices, alongside leukocyte alterations. Biochemical analysis revealed elevated ALT, AST, bilirubin, and ALP levels with reduced albumin. Parasite density showed negative correlations with hemoglobin, hematocrit, and platelet counts, and positive correlations with liver enzymes and bilirubin. Overall, this integrated diagnostic and host-response assessment highlights the substantial malaria burden in Peshawar and supports the added value of PCR-based detection combined with hematological and biochemical markers for improved surveillance and disease management.