Controlling Magnetization Reversal and Hyperthermia Efficiency in Core-Shell Iron-Iron Oxide Magnetic Nanoparticles by Tuning the Interphase Coupling.

Magnetic particle hyperthermia, in which colloidal nanostructures are exposed to an alternating magnetic field, is a promising approach to cancer therapy. Unfortunately, the clinical efficacy of hyperthermia has not yet been optimized. Consequently, routes to improve magnetic particle hyperthermia, such as designing hybrid structures comprised of different phase materials, are actively pursued. Here, we demonstrate enhanced hyperthermia efficiency in relatively large spherical Fe/Fe-oxide core-shell nanoparticles through the manipulation of interactions between the core and shell phases. Experimental results on representative samples with diameters in the range 30-80 nm indicate a direct correlation of hysteresis losses to the observed heating with a maximum efficiency of around 0.9 kW/g. The absolute particle size, the core-shell ratio, and the interposition of a thin wüstite interlayer are shown to have powerful effects on the specific absorption rate. By comparing our measurements to micromagnetic calculations, we have unveiled the occurrence of topologically nontrivial magnetization reversal modes under which interparticle interactions become negligible, aggregates formation is minimized and the energy that is converted into heat is increased. This information has been overlooked until date and is in stark contrast to the existing knowledge on homogeneous particles.

Plasma CXCL10 correlates with HAND in HIV-infected women.

HIV-associated neurocognitive disorder (HAND) is characterized by chronic immune activation. We aimed to identify biomarkers associated with HAND and to investigate their association with cognitive function and sex, in a homogenous cohort of HIV-infected (HIV+) young adults, parenterally infected during early childhood. One hundred forty-four HIV+ Romanian participants (51% women) without major confounders underwent standardized neurocognitive and medical evaluation in a cross-sectional study. IFN-γ, IL-1ß, IL-6, CCL2, CXCL8, CXCL10, and TNF-α were measured in plasma in all participants and in cerebrospinal fluid (CSF) in a subgroup of 56 study participants. Biomarkers were compared with neurocognitive outcomes, and the influence of sex and HIV disease biomarkers was assessed. In this cohort of young adults (median age of 24 years), the rate of neurocognitive impairment (NCI) was 36.1%. Median current CD4+ count was 479 cells/mm3 and 36.8% had detectable plasma viral load. Women had better HIV-associated overall status. In plasma, controlling for sex, higher levels of IL-6 and TNF-α were associated with NCI (p < 0.05). Plasma CXCL10 showed a significant interaction with sex (p = 0.02); higher values were associated with NCI in women only (p = 0.02). Individuals with undetectable viral load had significantly lower plasma CXCL10 (p < 0.001) and CCL2 (p = 0.02) levels, and CSF CXCL10 (p = 0.01), IL-6 (p = 0.04), and TNF-α (p = 0.04) levels. NCI in young men and women living with HIV was associated with higher IL-6 and TNF-α in plasma, but not in the CSF. CXCL10 was identified as a biomarker of NCI specifically in women with chronic HIV infection.

Spin-current-mediated rapid magnon localisation and coalescence after ultrafast optical pumping of ferrimagnetic alloys.

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 107 A cm-2. Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.

Beyond the blocking model to fit nanoparticle ZFC/FC magnetisation curves.

We consider the probability of a magnetic nanoparticle to flip its magnetisation near the blocking temperature, and use this to develop quasi-analytic expressions for the zero-field-cooled and field-cooled magnetisation, which go beyond the usual critical energy barrier approach to the superparamagnetic transition. The particles in the assembly are assumed to have random alignment of easy axes, and to not interact. We consider all particles to be of the same size and then extend the theory to treat polydisperse systems of particles. In particular, we find that the mode blocking temperature is at a lower temperature than the peak in the zero-field-cooled magnetisation versus temperature curve, in agreement with experiment and previous rate-equation simulations, but in contrast to the assumption many researchers use to analyse experimental data. We show that the quasi-analytic expressions agree with Monte Carlo simulation results but have the advantage of being very quick to use to fit data. We also give an example of fitting experimental data and extracting the anisotropy energy density K.

Microbial degradation of Cold Lake Blend and Western Canadian select dilbits by freshwater enrichments.

Treatability experiments were conducted to determine the biodegradation of diluted bitumen (dilbit) at 5 and 25 °C for 72 and 60 days, respectively. Microbial consortia obtained from the Kalamazoo River Enbridge Energy spill site were enriched on dilbit at both 5 (cryo) and 25 (meso) ºC. On every sampling day, triplicates were sacrificed and residual hydrocarbon concentrations (alkanes and polycyclic aromatic hydrocarbons) were determined by GCMS/MS. The composition and relative abundance of different bacterial groups were identified by 16S rRNA gene sequencing analysis. While some physicochemical differences were observed between the two dilbits, their biodegradation profiles were similar. The rates and extent of degradation were greater at 25 °C. Both consortia metabolized 99.9% of alkanes; however, the meso consortium was more effective at removing aromatics than the cryo consortium (97.5 vs 70%). Known hydrocarbon-degrading bacteria were present in both consortia (Pseudomonas, Rhodococcus, Hydrogenophaga, Parvibaculum, Arthrobacter, Acidovorax), although their relative abundances depended on the temperatures at which they were enriched. Regardless of the dilbit type, the microbial community structure significantly changed as a response to the diminishing hydrocarbon load. Our results demonstrate that dilbit can be effectively degraded by autochthonous microbial consortia from sites with recent exposure to dilbit contamination.

Increasing incidence of HIV- associated tuberculosis in Romanian injecting drug users.

BACKGROUND: A high prevalence of tuberculosis (TB) among HIV-positive injecting drug users (IDUs) may fuel the TB epidemic in the general population of Romania. We determined the frequency and characteristics of TB in HIV-infected IDUs referred to a national centre. METHODS: Prospective observational cohort study of all newly-diagnosed HIV-positive IDUs admitted to Victor Babes Hospital, Bucharest, between January 2009 and December 2014. Socio-demographics, clinical characteristics and outcomes of HIV/TB co-infected IDUs were compared to HIV-positive IDUs without TB. RESULTS: 170/598 (28.5%) HIV-infected IDUs were diagnosed with TB. The prevalence increased from 12.5% in 2009 to 32.1% in 2014 (P < 0.001). HIV/TB co-infected individuals had lower median CD4 cell counts 75 (vs. 450/mm3 , P < 0.0001) and higher median HIV viral loads 5.6 log10 (vs. 4.9 log10 , P < 0.0001) when presenting to healthcare services. 103/170 (60.6%) HIV/TB co-infected IDUs were diagnosed with pulmonary TB. Resistant Mycobacterium tuberculosis strains were common, with 18/105 (17.1%) of patients having Multi-Drug Resistant (MDR) disease. Higher mortality rate was associated with TB co-infection (P < 0.0001), extra-pulmonary TB (P = 0.0026) and extensively drug resistant TB (P = 0.024). CONCLUSIONS: Tuberculosis (TB) is an increasing problem in HIV-infected IDUs in Romania. Presentation is often with advanced HIV, significant TB drug resistance and consequent outcomes are poor.

Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection.

We evaluated the impact of latent toxoplasmosis (LT) on neurocognitive (NC) and neurobehavioural functioning in young adults with and without chronic HIV infection, using a standardised NC test battery, self-reported Beck Depression Inventory, Frontal System Behavior Scale, MINI-International Neuropsychiatric Interview and risk-assessment battery. 194 young adults (median age 24years, 48.2% males) with chronic HIV infection (HIV+) since childhood and 51 HIV seronegative (HIV-) participants were included. HIV+ individuals had good current immunological status (median CD4: 479 cells/µl) despite a low CD4 nadir (median: 93 cells/µl). LT (positive anti-Toxoplasma IgG antibodies) was present in one third of participants. The impairment rates in the HIV- with and without Toxo were not significantly different (p=0.17). However, we observed an increasing trend (p<0.001) in impairment rates with HIV and LT status: HIV-/LT- (6.1%); HIV-/LT+ (22%), HIV+/LT- (31%), HIV+/LT+ (49%). In a multivariable analysis using the entire study group there were main effects on cognition for HIV and also for LT. Within the HIV+ group LT was associated with worse performance globally (p=0.006), in memory (p=0.009), speed of information processing (p=0.01), verbal (p=0.02) and learning (p=0.02) domains. LT was not associated with depressive symptoms, frontal systems dysfunction or risk behaviors in any of the groups. HIV participants with lower Toxoplasma antibody concentration had worse NC performance, with higher GDS values (p=0.03) and worse learning (p=0.002), memory (p=0.006), speed of information processing (p=0.01) T scores. Latent Toxoplasmosis may contribute to NC impairment in young adults, including those with and without chronic HIV infection.

Differences in the availability of diagnostics and treatment modalities for chronic hepatitis B across Europe.

The prevalence and management of chronic hepatitis B virus (HBV) infection differ among European countries. The availability and reimbursement of diagnostics and drugs may also vary, determining distinct treatment outcomes. Herein, we analyse differences in medical facilities for the care of patients with chronic HBV infection across Europe. A survey was sent to the members of the ESCMID Study Group for Viral Hepatitis, all of whom are experts in chronic HBV infection management. The comprehensive survey asked questions regarding hepatitis B surface antigen (HBsAg) prevalence, the availability of diagnostics and drugs marketed, and distinct clinical practice behaviours in the management of chronic HBV infection. World Bank data were used to assess the economic status of the countries. With 16 expert physicians responding (69%), the HBsAg prevalence rates were <1% in France, Hungary, Italy, The Netherlands, Portugal, Spain, and the UK, intermediate (1-5%) in Turkey, Romania, and Serbia, and high (>5%) in Albania and Iran. Regarding the availability and reimbursement of HBV diagnostics (HBV DNA and liver stiffness measurement), HBV drugs (interferon, lamivudine, tenofovir, and entecavir), HBV prophylaxis, and duration of HBeAg-positive and HBeAg-negative HBV infection, the majority of high-income and middle-income countries had no restrictions; Albania, Iran and Serbia had several restrictions in diagnostics and HBV drugs. The countries in the high-income group were also the ones with no restrictions in medical facilities, whereas the upper-middle-income countries had some restrictions. The prevalence of chronic HBV infection is much higher in southern and eastern than in western European countries. Despite the availability of European guidelines, policies for diagnostics and treatment vary significantly across European countries.

Unified model of hyperthermia via hysteresis heating in systems of interacting magnetic nanoparticles.

We present a general study of the frequency and magnetic field dependence of the specific heat power produced during field-driven hysteresis cycles in magnetic nanoparticles with relevance to hyperthermia applications in biomedicine. Employing a kinetic Monte-Carlo method with natural time scales allows us to go beyond the assumptions of small driving field amplitudes and negligible inter-particle interactions, which are fundamental to the applicability of the standard approach based on linear response theory. The method captures the superparamagnetic and fully hysteretic regimes and the transition between them. Our results reveal unexpected dipolar interaction-induced enhancement or suppression of the specific heat power, dependent on the intrinsic statistical properties of particles, which cannot be accounted for by the standard theory. Although the actual heating power is difficult to predict because of the effects of interactions, optimum heating is in the transition region between the superparamagnetic and fully hysteretic regimes.

Hepatitis B virus compartmentalization in the cerebrospinal fluid of HIV-infected patients.

We detected hepatitis B virus (HBV) DNA in the cerebrospinal fluid (CSF) of 26 adolescents co-infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) with neurological disease and studied compartmentalization of HBV in the CSF. More than half of the subjects with positive HBV DNA plasma also had CSF positive for HBV. CSF HBV DNA was found in subjects with preserved blood-brain barrier integrity. In a subgroup of these subjects, compartmentalized evolution of HBV was demonstrated by distinct profiles of resistance mutations. Future studies are warranted to determine the clinical significance of HBV presence in the CSF and its contribution to HIV-associated neurological disease.

Estudio piloto sobre correlación clínica, radiológica y ecográfica en pacientes con artritis reumatoidea / Pilot study on clinical, radiographic and ecographic correlation in patients with rehumatoid arthritis

El objetivo de este estudio piloto fue evaluar la correlación entre las evaluaciones clínicas, radiológica y ecográfica en pacientes con AR. Material y métodos: Estudio de corte transversal realizado en el marco de un taller de clinimetría y ecografía para médicos reumatólogos. Se incluyeron pacientes ≥ a 18 años de edad, con diagnóstico de AR. Los pacientes fueron evaluados a través de autocuestionarios validados: actividad de la enfermedad (RADAI), capacidad funcional (HAQ-A y HAQ-II) y RAPID-3; escala visual análoga (EVA) para dolor, evaluación global de la enfermedad y rigidez matinal (RM) y recuento articular (28) por dos médicos reumatólogos. Estos dos médicos también determinaron la evaluación global de la enfermedad de los pacientes (EVA). Se consignó valor de eritrosedimentación (ERS) dentro de la semana previa al examen. Se calculó el índice compuesto DAS28. Radiografías de manos y pies (en posición frente) efectuadas dentro de la semana previa al examen fueron leídas por otros dos médicos reumatólogos mediante método de Sharp modificado por van der Heijde (SvdH) y método SENS (Simplified Erosion and Narrowing Score). A todos los pacientes se les realizó ecografía articular Modo B y Doppler de poder (PD) de 12 por 5 médicos experimentados. Se determinó presencia de derrame de líquido sinovial (DS), hipertrofia sinovial (HS) y señal (PD). A la presencia de cada uno de estos hallazgos se les asignaba 1 punto y el índice ecográfico total resultaba de la suma de los puntos positivos (rango 0-36).

The aim of this pilot study was to evaluate the correlation betweenclinical, radiological and ultrasound assessments in patients withRA.Material and methods: Cross-sectional study conducted in theframework of a clinimetric and ultrasound workshop for rheumatologists.We included patients with rheumatoid arthritis (ACR1987) ≥ 18 years of age. Patients were evaluated using validatedquestionnaires: disease activity (RADAI), functional capacity (HAQ-Aand HAQ-II) and RAPID-3; visual analog scale (VAS) for pain, globalassessment of disease and morning stiffness (MS) and joint count(28) by two rheumatologists who also determined the global assessmentof the patient’s disease (VAS). Sedimentation rate (ESR)in the week before the exam was recorded. DAS28 composite indexwas calculated. Radiographs of hands and feet (front position) performedwithin one week before the examination were read by tworheumatologists using the Sharp method modified by van der Heijde(SvdH) and SENS (Simplified Erosion and Narrowing Score) method.All patients underwent joint ultrasonography B Mode and PowerDoppler (PD) of 12 joints by 5 experienced physicians. Presence ofeffusion of synovial fluid (SF), synovial hypertrophy (SH) and signal(PD) were determined. To the presence of each of these findingswere assigned 1 point and the total ultrasound index was the sumof the positive points (range 0-36).

Remission criteria and activity indices in psoriatic arthritis.

Remission criteria and activity indices used in rheumatoid arthritis (RA) are often applied in psoriatic arthritis (PsA). Some new indices have been specifically developed for PsA. Our objective was to evaluate the performance of different remission criteria and activity indices in PsA. This is a cross-sectional study that includes consecutive patients with PsA. Information necessary to complete the following indices was captured: Composite Psoriatic Disease Activity Index (CPDAI), Psoriatic Arthritis Screening and Evaluation (PASE), Disease Activity Index for Psoriatic Arthritis (DAPSA), Disease Activity Score in 28 Joints (DAS28), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), and American College of Rheumatology and European League Against Rheumatism (ACR/EULAR) Boolean RA remission criteria. Patients were classified according to activity categories (remission, low, medium, or high disease activity). Correlation between indices was established. Fifty-five patients were included. Mean age was 53 years (SD = 12), and 35 (63.6 %) were males. Mean PsA disease duration was 5.9 years (SD = 8.5), and mean psoriasis duration was 15.9 (SD = 12.6). We found important differences in the percentage of patients classified as in remission by applying different remission criteria: DAS28 = 33 % (95 % confidence interval (CI) 20-45) vs ACR/EULAR = 4 % (95 % CI 1-17). Particularly, DAS28 and minimal disease activity seemed to be less stringent in PsA than the other indices. Of the specific PsA indices evaluated, CPDAI showed the poorest correlation with all the other activity measurements, although differences were not statistically significant in most cases. Disease activity in PsA is measured by many different indices. In spite they all showed good correlations between them, they classified different patients in different disease status.

Major HIV resistance mutations in untreated Romanian patients.

Drug resistance mutations are frequently detected in antiretroviral-naive HIV positive patients, however the data on transmitted resistance in non-B subtypes are limited. As HIV1 subtype F is prevalent in Romania, our goal is to analyze resistance mutations in the pol gene of HIV-1 isolates from drug-naive Romanian patients. HIV-1 pol gene from 12 untreated patients, newly diagnosed (n = 6) and chronically infected (n=6), with detectable HIV RNA viral load was genotyped and the viral subtype was determined by using the Stanford database algorithm. 8/12 strains belonged to the F subtype, 1/12 to the G subtype, and the rest of the studied strains appeared to be K/F, A/F and J/F inter-subtype recombinant forms. The prevalence of HIV-1 strains with at least one major drug resistance mutation in the studied group was unexpectedly high. Major mutations associated with NRTI, NNRTI and PI resistance were detected in 6/12 patients, 2/12 patients and 3/12 patients, respectively; in addition all viral strains had minor mutations in the protease gene. Newly diagnosed patients harbored resistant variants more often than chronically infected ones (4/6 vs. 2/6) did. These data support the use of genotypic resistance testing in treatment-naive HIV positive patients, in order to guide the selection of the first line of antiretrovirals, due to the fact that persons with transmitted drug resistance have a higher risk for both virologic failure and development of resistance at treatment initiation.

How much do antiretroviral drugs penetrate into the central nervous system?

The central nervous system can act as a compartment in which HIV can replicate independently from plasma, and also as a sanctuary in which, under suboptimal drug pressure, HIV antiretroviral genetic variants can occur. Continuous replication of HIV in brain can contribute to neurocognitive impairment. Therefore, reaching adequate concentrations of antiretrovirals in the central nervous system might be essential in providing neuroprotection and improving neurocognition. Antiretrovirals have a restricted entry into the brain, due to several factors: the unique structure of the blood-brain barrier, and the existence of efficient efflux mechanisms. However, there is a high variability of antiretrovirals in reaching therapeutic drug concentrations in cerebrospinal fluid, that depend on the characteristics of the antiretrovirals (molecular weight, lipophilicity, protein binding) and on their capacity to be substrate for efflux transporters. The review aims to discuss the main mechanisms that interfere with antiretroviral penetration into central nervous system, and to summarize the current data concerning the penetrability of different antiretrovirals into the cerebrospinal fluid.

Primer estudio argentino de correlación en ecografía musculoesquelética / First argentine study of musculoskeletal ultrasonography correlation

Si bien existe evidencia de la potencial aplicación de la ecografía musculoesquelética en la evaluación de las articulaciones con artritis, sonlimitados los datos acerca de su exactitud y reproducibilidad. El objetivo de este estudio es conocer la correlación interobservador e intermáquinas de un grupo de radiólogos y reumatólogos ecografistas de diferentes centros del país. Métodos: Seis reumatólogos y 1 radiólogo se reunieron para definir los lineamientos a ser usados para la lectura e interpretación de imágenes. Las articulaciones evaluadas fueron: carpo (radiocarpiana, intracarpiana), 2 MCF dorsal, ventral y lateral, 3 MCF dorsal, ventral, 2 PIF. Se consignó sinovitis cuando se detectó al menos una de las siguientes lesiones ecográficas: presencia de derrame articular (DA), hipertrofia sinovial (HS) o señal Doppler+. Se vieron 36 imágenes en 2 oportunidades con 1 mes de diferencia para determinar la correlación interobservador de las imágenes de banco. Se evaluaron 3 pacientes para determinar correlación interobservador en tiempo real y uno de los observadores evaluó al mismo paciente en las 3 máquinas para determinar la correlación intermáquinas. Resultados: En las correlaciones de lectura de imágenes de banco, el valor de kappa fue regular a moderado siendo el coeficiente de correlación intraclase (CCI) para señal doppler 0,91. Las correlaciones en tiempo real mostraron un kappa moderado tanto para la detección de líquido como para la hipertrofia sinovial con valores de 0,51 y 0,46, respectivamente, siendo (CCI) para señal doppler en tiempo real de 0,68.

Phase I study of the botanical formulation PHY906 with capecitabine in advanced pancreatic and other gastrointestinal malignancies.

PURPOSE: The botanical formulation, PHY906, has been used widely in Eastern countries to treat gastrointestinal symptoms including diarrhea, nausea and vomiting. PHY906 may also have anti-tumor properties and may potentiate the action of several chemotherapeutic agents based on pre-clinical studies. We conducted a Phase I study using PHY906 in combination with capecitabine in patients with advanced pancreatic and gastrointestinal malignancies to determine the maximum tolerated dose (MTD) of capecitabine in combination with PHY906. PATIENTS AND METHODS: This study was a single institution, open-label, Phase I study of PHY906 800mg BID on days 1-4 in combination with escalating doses of capecitabine (1000, 1250, 1500, and 1750mg/m(2)) orally twice daily on days 1-7 of a 14-day cycle (7/7 schedule). Capecitabine was increased until the appearance of dose limiting toxicities (DLTs). Measurements of efficacy included tumor response by Response Evaluation Criteria in Solid Tumors (RECIST). RESULTS: Twenty-four patients with a median age of 67 years (range 40-84) with pancreatic cancer (15), colon cancer (6), cholangiocarcinoma (1), esophageal cancer (1) and unknown primary (1) received a total of 116 cycles (median 5 cycles; range 1-17 cycles) over 4 dose levels of capecitabine. One DLT (Grade 4 AST/ALT, Grade 3 hyponatremia) was observed in the 1000mg/m(2) cohort of patients. No further DLT was observed in the subsequent cohorts and doses of capecitabine were escalated to 1750mg/m(2) BID. There were no DLTs at the maximum dose level of 1750mg/m(2), however, the delivered dose-intensity of capecitabine was similar at the 1750mg/m(2) dose level as the 1500mg/m(2) dose level. Therefore, the MTD was defined at 1500mg/m(2) of capecitabine in this dosing schedule with PHY906. One patient achieved a partial response, and 13 patients had stable disease that lasted more than six weeks. CONCLUSION: The MTD of capecitabine was determined to be 1500mg/m(2) BID administered in a 7/7 schedule, in combination with PHY906 800mg BID on days 1-4. This combination was well tolerated and warrants further study.

Evaluation of immunoglobulin M (IgM) and IgG enzyme immunoassays in serologic diagnosis of West Nile Virus infection.

A unique urban encephalitis epidemic in Romania signaled the emergence of neurological infection due to West Nile (WN) virus as a novel public health threat in Eastern Europe and provided an opportunity to evaluate patterns of immunoglobulin G (IgG) and IgM reactivity in IgM capture and IgG enzyme-linked immunosorbent assays (ELISAs). WN virus infection was diagnosed serologically in 236 of 290 patients from whom acute serum or cerebrospinal fluid (CSF) samples were available. In 37% of serum samples and in 25% of CSF samples collected in the first week of illness, anti-WN virus IgM antibody was detected in the absence of virus-specific IgG. The switch to an IgG antibody response occurred after 4 to 5 days of illness and earlier in CSF than in serum. A specific humoral immune response was detected in the CSF before the serum in some patients for whom paired CSF and serum samples from the same day were available. IgM antibody in convalescent serum samples persisted beyond 2 months after the onset of illness in more than 50% of patients. ELISA optical density values and antibody concentrations were well correlated for both IgM and IgG immunoassays. Anti-WN virus IgM antibody in acute-phase samples did not cross-react significantly with flaviviruses in other antigenic groups.

Continued transmission of West Nile virus to humans in southeastern Romania, 1997-1998.

After an epidemic of West Nile (WN) virus neurologic infections in southeastern Romania in 1996, human and animal surveillance were established to monitor continued transmission of the virus. During 1997 and 1998, neurologic infections were diagnosed serologically as WN encephalitis in 12 of 322 patients in 19 southeastern districts and in 1 of 75 Bucharest patients. In addition, amid a countrywide epidemic of measles, the etiology of the febrile exanthem in 2 of 180 investigated cases was determined serologically to be WN fever; 1 case was complicated by hepatitis. Sentinel chickens placed in Bucharest seroconverted to WN virus during the summer months, indicating their potential value in monitoring transmission. The continued occurrence of sporadic WN infections in southeastern Romania in consecutive years after the 1996 epidemic is consistent with local enzootic transmission of the virus.