Aggressive Antipyretics in CNS Malaria: A Randomized-Controlled Trial Assessing Antipyretic Efficacy and Parasite Clearance Effects

Despite ongoing eradication efforts, malaria remains a major public health challenge in Africa where annually, ~250,000 children with malaria experience a neurologic injury with subsequent neurodisability. In other central nervous system (CNS) disorders, fever is a recognized cause of worsening secondary neurologic injury and ex-tensive efforts are made to avoid hyperthermia or induce hypothermia for neuroprotection. Evidence indicates that among children with CNS malaria a higher temperature during the acute illness is a risk factor for post-infectious neurologic sequelae. As such, aggressive antipyretic therapy may be warranted, at least among children with complicated malaria who are at substantial risk of brain injury. Previous clinical trials conducted primarily in children with uncomplicated malaria and using only a single antipyretic medication have shown limited benefits in terms of fever reduction; however, no studies to date have examined malaria fever management using dual therapies. Enthusiasm for aggressive fever reduction measures among clinicians caring for children with malaria has been curbed by in vitro findings that malaria parasite replication slows at higher temperatures and a single clinical trial in which peripheral parasite clearance was slower in children receiving treatment for fever. However, the relationship between temperature and malaria parasite behavior is complex. Additional in vitro data suggest that at febrile temperatures uninfected red blood cells (RBCs) are more likely to adhere to infected RBCs, worsening the process of sequestration, increasing the parasite burden obstructing microvascular cerebral blood flow, and perhaps contributing to ongoing immunopathogenesis in CNS malaria. In this exploratory clinical trial of aggressive antipyretic therapy, children hospitalized with CNS malaria will be randomized to usual care (acetaminophen every 6 hours for a temperature ≥ 38.5ºC) vs. prophylactic acetaminophen and ibuprofen every 6 hours for 72 hours. This proof-of-concept study will determine whether aggressive antipyretic therapy results in a lower mean maximum temperature relative to usual care. Serial quantitative levels of histidine rich protein 2 (HRP2), a P. falciparum-specific protein that facilitates estimates of whole body parasite burden and CNS parasite sequestration, will also be collected to clarify the relationship between antipyretic use and in vivo parasite behavior. Findings from this study will determine whether a Phase III clinical trial of aggressive antipyretics for neuroprotection in pediatric CNS malaria should be undertaken. This study will take place in Zambia and Malawi, where prior NIH-funded collaborations have assisted in developing the substantial infrastructure needed to undertake a clinical trial of this nature.