Evolving etiologies, comorbidities, survival, and costs of care in adult encephalitis

Encephalitis is a central nervous system disorder, often caused by infectious agents or aberrant immune responses. We investigated causes, comorbidities, costs, and outcomes of encephalitis in a population-based cohort. ICD-10 codes corresponding to encephalitis were used to identify health services records for all adults from 2004 to 2019. Data were cross-validated for identified diagnoses based on laboratory confirmation using univariate and multivariate statistical analyses. We identified persons with a diagnosis of encephalitis and abnormal cerebrospinal fluid (CSF) results (n = 581) in whom viral genome was detected (n = 315) in a population of 3.2 million adults from 2004 to 2019. Viral genome-positive CSF samples included HSV-1 (n = 133), VZV (n = 116), HSV-2 (n = 34), enterovirus (n = 4), EBV (n = 5), and CMV (n = 3) with the remaining viruses included JCV (n = 12) and HHV-6 (n = 1). The mean Charlson Comorbidity Index (2.0) and mortality rate (37.6%) were significantly higher in the CSF viral genome-negative encephalitis group although the mean costs of care were significantly higher for the CSF viral genome-positive group. Cumulative incidence rates showed increased CSF VZV detection in persons with encephalitis, which predominated in persons over 65 years with a higher mean Charlson index. We detected HSV-2 and VZV more frequently in CSF from encephalitis cases with greater material-social deprivation. The mean costs of care were significantly greater for HSV-1 encephalitis group. Encephalitis remains an important cause of neurological disability and death with a viral etiology in 54.2% of affected adults accompanied by substantial costs of care and mortality. Virus-associated encephalitis is evolving with increased VZV detection, especially in older persons.

HIV non-occupational postexposure prophylaxis in a Canadian province: treatment completion and follow-up testing

Provincial guidelines for HIV non-occupational postexposure prophylaxis (NPEP) were implemented on January 2005 in Alberta, Canada. Human immunodeficiency virus (HIV) NPEP was provided free of charge following approval by a medical officer of health. Between 1 January 2005 and 30 June 2007, 174 individuals were prescribed NPEP; 135 (78%) were women with a median age of 24 years. Sexual assaults accounted for 68% of exposures. NPEP was completed in 49% of cases. Individuals who completed NPEP were less likely to have been exposed by sexual assault ( P = 0.04) and more likely to have received HIV follow-up testing ( P = 0.03).Individuals who received at least one HIV follow-up test were older ( P = 0.03) and more likely to have been exposed percutaneously ( P = 0.003). Those who received no follow-up testing were less likely to have filled an NPEP prescription ( P = 0.0001). New strategies are required to improve follow-up of individuals receiving NPEP, especially younger persons or sexual assault survivors.

Cytoadherence characteristics of Plasmodium falciparum-infected erythrocytes from Malawian children with severe and uncomplicated malaria

Cytoadherence of Plasmodium falciparum-infected erythrocytes to the microvascular endothelium is believed to be a key factor in the development of cerebral malaria. Erythrocyte rosette formation has been correlated with malaria severity in studies from east and west Africa. We cultured fresh isolates from Malawian children with severe (n = 76) or uncomplicated (n = 79) malaria to pigmented trophozoite stage and examined rosette formation and adherence to CD36, intercellular adhesion molecule-1 (ICAM-1), chondroitin sulfate A (CSA), and thrombomodulin (TM). Most (126 of 148) isolates bound to CD36, and 76 of 136 bound to ICAM-1. Fewer bound to CSA (40 of 148) or TM (23 of 148). After controlling for parasitemia, there was an inverse association between binding to CD36 (P = 0.004) or ICAM-1 (P = 0.001) and disease severity. Parasites from children with severe malaria anemia bound least to CD36, whereas ICAM-1 binding was lowest in children with cerebral malaria. There was no difference in rosette formation between any of the groups. In Malawian children, there was no evidence of a positive association between adherence to any of the receptors examined and disease severity. The negative association found raises the possibility that adherence to certain receptors could instead be an indicator of a less pathogenic infection.