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.

Hepatitis B and C serologic profiles of Canadian organ donors and recipients: retrospective 10-year review at a single center.

BACKGROUND: Hepatitis C virus (HBV) and hepatitis C virus (HCV) are important causes of hepatitis and can be transmitted from organ donor to recipient. This study aimed to determine HBV and HCV serologic profiles of a population of Canadian solid organ transplant (SOT) donors and recipients, including prevalence of recipient HBV immunity. METHODS: Data on age, gender, organ transplanted, and pre-transplant HBV and HCV serology for SOT donors and recipients at a Canadian hospital from 2001 to 2011 were obtained from a transplant database. RESULTS: There were 2455 recipients (2205 adults, 250 children), and 1559 donors. Over 50% of adult and 44% of pediatric recipients were HBV non-immune pre-transplant. Pediatric recipients were more likely to have HBV vaccine immunity than were adult recipients (48.8% vs. 28.9%, P < 0.001). Prevalence of HBV vaccine immunity was highest in renal recipients (48.3% in adult, 63.2% in pediatric recipients). Recipient HBV vaccine immunity increased from 5.8% in 2001 to 44.5% in 2011 (P < 0.001). Of 134 adult recipients with prior HBV infection, 59 (44%) were co-infected with HCV. Only 0.6% of adult non-liver recipients had acute or chronic HBV infection and 3.2% were anti-HCV positive. Only 2 donors had acute or chronic HBV infection, 29 had prior HBV infection, 9 were isolated hepatitis B core antibody positive, and 15 were anti-HCV positive. CONCLUSIONS: The prevalence of HBV vaccine immunity in SOT candidates is low, but increased from 2001 to 2011. Opportunities for quality improvement in pre-transplant HBV immunization exist. HCV co-infection is common in recipients with prior HBV infection. Prevalence of HCV infection in non-liver transplant recipients is low.

Factors associated with vaccine failure and vertical transmission of hepatitis B among a cohort of Canadian mothers and infants.

Mother-to-child transmission of hepatitis B virus (HBV) continues to occur despite immunoprophylaxis. We examined maternal factors contributing to transmission in infants receiving adequate immunoprophylaxis in Alberta, Canada. Prenatal specimens from HBsAg-positive women whose babies developed HBV infection despite immunoprophylaxis (cases) and HBsAg-positive mothers whose babies did not (controls) were tested for HBsAg, HBeAg and HBV DNA. Specimens with detectable DNA underwent HBV genotyping. Routinely collected surveillance data and laboratory test results were compared between cases and controls. Twelve cases and 52 controls were selected from a provincial registry from 2000 to 2005. At the time of prenatal screening, median maternal age was 31 years [interquartile range (IQR): 27.5-34.5], and median gestational age was 12 weeks (IQR 10.0-15.5). Cases were more likely than controls to test positive for HBeAg (77.8% vs. 23.1%; P < 0.05). Of all mothers with detectable viral load (n = 51), cases had a significantly higher median viral load than did controls (5.6 × 10(8) IU/mL vs. 1750 IU/mL, P < 0.0001). Of the two cases who were HBeAg negative, one had an undetectable viral load 8 months prior to delivery and a sP120T mutation. The viral load in the other case was 14,000 IU/mL. The majority of isolates were genotype B (31.3%) and C (31.3%) with no significant differences in genotype between cases or controls. In this case-control study, transmission of HBV to infants was more likely to occur in mothers positive for HBeAg and with high HBV DNA.

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.

Prevalence and estimated incidence of blood-borne viral pathogen infection in organ and tissue donors from northern Alberta.

To determine the potential safety benefit of introducing nucleic acid testing (NAT) in tissue and organ donors, the risk of virus transmission was examined in a Canadian population. Anonymous data on Northern Alberta tissue and organ donors from 1998 to 2004 were used to determine the seroprevalence and estimate the seroincidence and residual risk of HIV, HBV, HCV and HTLV infection. Of the 3372 donors identified, 71.1% were surgical bone, 13.2% were living organ and 15.6% were deceased organ/tissue donors. Seroprevalence was: HIV 0.00%, HBV 0.09%, HCV 0.48% and HTLV 0.03%. Incidence (/100,000 p-yrs) and residual risks (/100,000 donors) could only be estimated for HBV (24.2 and 3.9) and HCV (11.2 and 2.2). Risk estimates were higher for deceased donors than surgical bone donors. HCV had the highest prevalence and HBV had the highest estimated incidence. HIV and HTLV risks were extremely low precluding accurate quantification. In this region of low overall viral prevalence, HCV NAT would be most effective in deceased organ donors. In surgical bone donors the cost of implementing NAT is high without significant added safety benefit.

Herpes simplex virus 2 and syphilis among young drug users in Baltimore, Maryland.

OBJECTIVES: To examine the sex specific seroprevalence and correlates of herpes simplex virus 2 (HSV-2) and syphilis among a cohort of young drug users. METHODS: Drug users aged 15-30 years old who used heroin, cocaine, or crack were recruited between October 1999 and August 2002. Baseline interviews gathered information on sociodemographics, drug use and sexual behaviours. Serum was tested at baseline for HSV-2 and syphilis seroreactivity. For each sexually transmitted infection (STI), infected and non-infected participants were stratified by sex and compared using chi2, Mann-Whitney tests, and logistic regression. RESULTS: Of the 543 participants recruited, 42.4% were female and 39.3% were African-American. The seroprevalence of STIs among females and males, respectively, were HSV-2: 58.7% and 22.0%; syphilis: 4.3% and 0.3%. In multivariate models, older age, African-American race, having over 30 lifetime sex partners, current HIV infection and previous incarceration were independently associated with HSV-2 infection among males. For females, older age, African-American race, sex trade, and daily heroin use were independently associated with HSV-2. For females, only a self reported previous syphilis diagnosis was associated with current syphilis seroreactivity in multivariate analyses. CONCLUSIONS: Examination of this cohort revealed a particularly high seroprevalence of HSV-2 and syphilis, especially among female drug users. Few infected participants had been previously diagnosed with these infections.

Prevalence and determinants of tuberculin reactivity among physicians in Edmonton, Canada: 1996-1997.

BACKGROUND: Health care workers (HCW) have historically borne a heavy burden of tuberculosis (TB) infection and disease. Unfortunately, physicians are rarely included in HCW surveys of tuberculin exposure and infection. METHODS: The prevalence and risk factors for tuberculin reactivity were determined for a sample of the 1732 licensed physicians in Edmonton. Stratified random sampling was used to select 554 specialists and 219 general practitioners. These physicians were contacted by means of an introductory letter and a follow-up telephone call to solicit participation. All eligible physicians were asked to complete a questionnaire and those with either no recorded positive tuberculin test or a previously negative result were two-step tuberculin skin tested. RESULTS: In total, 560 physicians (72.4 %) participated in the study. The overall tuberculin reactivity for this population was 45.9%. Using logistic regression analysis, we determined that risk factors for reactivity were aged over 45 years, of foreign-birth, previous Bacillus Calmette-Guérin (BCG) vaccination, foreign practice experience, and being a respiratory medicine specialist. CONCLUSION: The prevalence of tuberculin reactivity among physicians is considerably higher than estimates for the general Canadian population. This observed excess risk may be associated with factors linked to their medical practice. The high participation rate suggests physician willingness to participate in this type of research, and emphasizes the need to include them in routine HCW surveillance.

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.