Prevalence of asymptomatic malaria in patients of a secondary care hospital presenting with non-febrile symptoms

Background: Malaria remains a major public health problem in endemic regions such as Odisha, India, where asymptomatic infections can sustain transmission and hinder elimination efforts. This study assessed the prevalence of asymptomatic malaria among afebrile patients in a secondary care hospital and compared the diagnostic performance of peripheral blood smear (PBS) and rapid diagnostic tests (RDT). Methods: An observational cross-sectional study was conducted at a secondary care hospital in Gopalpur, Odisha, from January 2021 to March 2022. A total of 300 OPD and inpatient cases from Medicine, Surgery, and Obstetrics & Gynecology departments were enrolled. Inclusion criteria included residence in Odisha for ≥10 years, absence of fever in the preceding month, and no malaria diagnosis in the previous six months. All participants underwent PBS and RDT testing. Positive cases were reconfirmed externally, and treatment was provided as per national guidelines. Results: Of the 300 participants (171 males, 129 females), none were positive on PBS, while 46 cases (15.3%) were detected by RDT. Plasmodium vivax accounted for 59% of cases, P. falciparum for 30%, and mixed infections for 11%. Although 44% reported previous malaria treatment, only 30% completed the full regimen, and radical therapy with primaquine was administered in 10.8% of cases. Conclusions: A substantial burden of asymptomatic malaria was observed in this hospital-based population. The poor sensitivity of PBS and inadequate treatment adherence highlight the need for sensitive diagnostic tools, active surveillance, and improved therapeutic compliance to support malaria elimination in endemic regions.