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.

West nile virus surveillance in Romania: 1997-2000.

In response to the 1996 West Nile (WN) fever epidemic that occurred in Bucharest and southeastern Romania, a surveillance program was established. The surveillance system detected 39 clinical human WN fever cases during the period 1997-2000: 14 cases in 1997, 5 cases in 1998, 7 cases in 1999, and 13 cases in 2000. Thirty-eight of the 39 case-patients lived in the greater Danube Valley of southern Romania, and 1 case-patient resided in the district of Vaslui, located on the Moldavian plateau. The estimated annual case incidence rate for the surveillance area during the period 1997-2000 was 0.95 cases per million residents. Thirty-four cases were serologically confirmed, and 5 cases were classified as probable. Twenty-four case-patients presented with clinical symptoms of meningitis (62%), 12 with meningoencephalitis (31%), 1 with encephalitis (3%), and 2 with febrile exanthema (5%). Five of the 39 cases were fatal (13%). Fourteen case-patients resided in rural areas, and 25 in urban and suburban areas, including 7 case-patients who resided in Bucharest. The ages of case-patients ranged from 8 to 76 years with a median age of 45 years. Twenty-four case-patients were males and 15 were females. Dates of onset of illness occurred from May 24 through September 25, with 82% of onset dates occurring in August and September. Limited entomological surveillance failed to detect WN virus. Retrospective sampling of domestic fowl in the vicinity of case-patient residences during the years 1997-2000 demonstrated seroprevalence rates of 7.8%-29%. Limited wild bird surveillance demonstrated seroprevalence rates of 5%-8%. The surveillance data suggest that WN virus persists focally for several years in poorly understood transmission cycles after sporadic introductions or that WN virus is introduced into Romania at relatively high rates, and persists seasonally in small foci.

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.

Phagocytic function of monocytes in children with human immunodeficiency virus type 1 infection.

We investigated the phagocytic function of monocytes in 7- to 10-year-old children horizontally infected with human immunodeficiency virus type 1 (HIV-1) in comparison to that in healthy sex- and age-matched controls. CR3-mediated phagocytosis was increased in patients with HIV-associated pulmonary tuberculosis, independently of CD4 counts and p24 antigenemia.

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.

Subversion of monocyte functions by coxiella burnetii: impairment of the cross-talk between alphavbeta3 integrin and CR3.

Several intracellular pathogens exploit macrophages as a niche for survival and replication. The success of this strategy requires the subversion or the avoidance of microbicidal functions of macrophages. Coxiella burnetii, the agent of Q fever, is a strictly intracellular bacterium that multiplies in myeloid cells. The survival of C. burnetii may depend on the selective use of macrophage receptors. Virulent C. burnetii organisms were poorly internalized but survived successfully in human monocytes, whereas avirulent variants were efficiently phagocytosed but were also rapidly eliminated. The uptake of avirulent organisms was mediated by leukocyte response integrin (alphavbeta3 integrin) and CR3 (alphaMbeta2 integrin), as demonstrated by using specific Abs and RGD sequence-containing peptides. The phagocytic efficiency of CR3 depends on its activation via alphavbeta3 integrin and integrin-associated protein. Indeed, CR3-mediated phagocytosis of avirulent C. burnetii was abrogated in macrophages from integrin-associated protein-/- mice. In contrast, the internalization of virulent C. burnetii organisms involved the engagement of alphavbeta3 integrin but not that of CR3. The pretreatment of monocytes with virulent C. burnetii organisms prevented the CR3-mediated phagocytosis of zymosan particles and CR3 activation assessed by the expression of the 24 neo-epitope. We conclude that the virulence of C. burnetii is associated with the engagement of alphavbeta3 integrin and the impairment of CR3 activity, which probably results from uncoupling alphavbeta3 integrin from integrin-associated protein. This study describes a strategy not previously reported of phagocytosis modulation by intracellular pathogens.

Dynamics of the HIV-1 variability in adults from Bucharest, 1992-1998.

Variability is a hallmark of HIV viruses both at the genetic and the phenotypic level. Viral sequencing and phylogenetic analysis of many isolates revealed specific distribution of HIV-1 subtypes according to the geographic location and route of transmission. In Romania, the currently available data coming from the study of pediatric HIV infection suggest the predominance of subtype F. However, there are few data concerning the distribution of HIV-1 subtypes among adults. We investigated the changes in the distribution of different HIV-1 subtypes among HIV-1 infected adult patients from Bucharest over a 6 years period (1992-1998) by means of V3 binding assays. The analysis of the relative incidence of different HIV-1 serotypes revealed the steady predominance of serotype F (50-75%) among the adults from Bucharest and a small but constant increase of the number of samples with serotype B- from 5% in 1994 to 14% in 1998. In contrast, the serotype E is either absent or weakly represented (4%) during the period of the study. All over the years there was a relatively high proportion (6-30%) of non-reactive samples. This could be an indication for the possible emergence of new or recombinant HIV-1 subtypes.

An outbreak of aseptic meningitis due to ECHO 30 virus in Romania during the 1999 summer.

Between April-September 1999 an unusually high number of acute aseptic meningitis was reported in six North Eastern counties of Romania. At the end of 1999 summer the epidemic area extended in South Romania including the Capital City Bucharest. The total number of cases surpassed 5500. The majority of confirmed cases were young children under 15 years of age. More than 1800 cases were registered in the same interval in the neighboring Republic of Moldavia. We report the isolation of ECHO 30 virus from 12 CSF samples of 52 tested on RD and human diploid cells. A small case control study identified high seroneutralization titers confirming a recent ECHO 30 infection in 74% of patient's samples and in 54% of samples from control children tested. The time spent outdoors and poor hygiene practices were prominent risk factors for transmission.

Assessment of the anti-hepatitis B vaccination efficacy in high risk children.

In October 1995, The Ministry of Health has initiated the national immunization program of newborns against hepatitis B. Owing to the frequency of asymptomatic Hepatitis B clinical forms in children, as well as the deficiencies in the surveillance system, the assessment of the vaccination efficacy can be performed objectively only by the detection of the prevalence of anti HBs antibodies in children to whom the complete three doses of immunization schedule have been administered (at 0, 2 and 6 months of age). We report in this study the results of a seroprevalence research carried out on a group of 272 children from orphanages who have been vaccinated. A protective anti HBs titer (> 10 mIU) was recorded only in 66.3% of cases; other 10 samples contained antibodies at a titer lower than the protective level. In the 80 children without seroconversion the presence of anti HBc antibodies (marker for the natural infection) was investigated. 30% of the seronegative children have anti HBc antibodies from which 54.2% have also HbsAg. Significant differences were recorded in the seroconversion level and in the geometric mean of titers between the various units in which sera were collected. In four orphanages (district Arad, Jassy, Sibiu and Teleorman) the seroconversion exceeded 90%, in 5 orphanages it was over 80% and in the others it ranged from 30% to 70%. The lowest seroconversions were recorded in the orphanages in Bucharest, Botosani, Galati and Olt. The possible causes of the low immunogenicity are analyzed: non-vaccination or incomplete vaccination; low immunoreactivity of children, many of whom are premature; high HbsAg carriage rate among the mother's etc. Although the evolution of the post vaccinal seroconversion is not a routine practice in the appraisement of Hepatitis B vaccine immunogenicity, our results require the extension of the study in order to adopt the most effective vaccinal strategy.

A high number of severe neurologic clinical forms during an epidemic of West Nile virus infection.

The serologic confirmation of more than 800 cases hospitalized during the viral meningoencephalitis epidemic caused by the West Nile virus (WNV) that affected the South-East of Romania during the summer of 1996 consolidated the case definition in over 80% of the patients admitted to the hospital with neurological impairments. Other clinical forms of the WN infection were reported only scarcely during the epidemic and were seroconfirmed at a lower rate (60%). IgM capture ELISA (MAC-ELISA) is a test of choice for the rapid diagnosis. The major advantage of MAC-ELISA procedure is the high probability of accurate diagnosis of WN infection when the test is performed only with acute serum or cerebrospinal fluid (CSF) specimens obtained while the patient is still hospitalized. Rapid diagnosis by MAC-ELISA is important for the institution of public health control, but the results obtained have also some predictive values. We report the serological patterns of 65 pairs of CSF and serum samples collected in the early days of neuroinfection for diagnostic purposes. An unexpected onset of the intrathecal specific humoral immune response before serum immunoglobulins synthesis was recorded in 25% of cases. For 14 patients with intrathecal onset of IgM synthesis, their records evaluated retrospectively showed a severe evolution. The presence of only IgM antibodies in CSF is a characteristic which matched with other laboratory variables described which predict poor evolution in viral encephalitis: pleocytosis, elevated protein concentration in CSF (> 100 mg per deciliter), hyponatremia (< 130 mmol per liter).

Upregulation of tumor necrosis factor alpha and interleukin-1 beta in Q fever endocarditis.

The occurrence of Q fever endocarditis likely involves some alterations in the responses of monocytes, the in vivo targets of Coxiella burnetii. To test this hypothesis, the production of the inflammatory cytokines tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 was assessed in monocytes from patients with Q fever endocarditis. Spontaneous transcription and secretion of tumor necrosis factor and interleukin-1 were significantly higher in patient monocytes than in healthy controls. The interleukin-6 transcripts were also upregulated in patient cells. Moreover, in patients with recent endocarditis exhibiting high titers of immunoglobulin G directed to C. burnetii in phase I, monocytes released significantly higher levels of tumor necrosis factor and interleukin-1 than in patients with stabilized endocarditis. Immunoglobulin G titers and the overproduction of tumor necrosis factor and interleukin-1 were significantly correlated. Hence, the overproduction of inflammatory cytokines might be a marker of disease activity.

[A seroprevalence study of the hepatitis C virus among multiply transfused patients]. / Etudes sur la séroprévalence du virus de l'hépatite C chez les polytransfusés.

A study was conducted on 61 polytransfused patients, 24 patients submitted to long lasting parenteral treatments, 116 blood donors and 132 controls. Immuno-enzymatic tests were used for detection of antibodies against hepatitis C virus (HCV). They were found in 56 (91.8%) out of the 61 polytransfused patients, in 5 (4.3%) of the donors, in 5 (20.8%) of the patients with multiple treatments and in 5 (3.7%) controls. The VHB markers were detected at variable rates in all investigated groups. The high rate of seropositivity indicates that hepatitis C is becoming an important public health problem in Romania.

[Seroprevalence of hepatitis C virus among the multiply transfused]. / Etudes sur la séroprévalence du virus de l'hépatite C chez les polytransfusés.

A study was conducted on 61 polytransfused patients, 24 patients submitted to long lasting parenteral treatments, 116 blood donors and 132 controls. Immuno-enzymatic tests were used for detection of antibodies against hepatitis C virus (HCV). They were found in 56 (91.8%) out of the 61 polytransfused patients, in 5 (4.3%) of the donors, in 5 (20.8%) of the patients with multiple treatments and in 5 (3.7%) controls. The VHB markers were detected at variable rates in all investigated groups. The high rate of seropositivity indicates that hepatitis C is becoming an important public health problem in Romania.