Multicenter evaluation of the new HIV DUO assay for simultaneous detection of HIV antibodies and p24 antigen.

A multicenter survey was performed to evaluate a new semi-automated human immunodeficiency virus fourth generation antibodies and antigen simultaneous assay. This assay showed a sensitivity of 100% and specificity of 99.6% among sera obtained from hospitalized patients or blood donors. Sera obtained from commercially available as well as in-house seroconversions were tested showing that HIV DUO is able to reveal an infected state in 11 out of 14 cases earlier than conventional tests. This new assay improves old test performances in terms of sensitivity, maintaining specificity at very high levels.

Vertical transmission of HCV.

BACKGROUND: Knowledge about vertical transmission of HCV is still limited. In this study we followed up the virological status of a series of offspring born to anti-HCV positive, anti-HIV negative mothers. METHODS: Between January 1993 and January 1995, 5000 consecutive, anti-HIV negative pregnant women were screened for anti-HCV (ELISA III) and all positive samples were confirmed by RIBA III and analyzed for HCV-RNA by polymerase chain reaction (PCR). Babies born to anti-HCV positive mothers were followed from birth to two years by testing for ALT levels, anti-HCV antibodies and HCV-RNA. RESULTS: Of 5000 mothers 80 (1.6%) were anti-HCV positive (ELISA III) and RIBA III positive. Of these, 56 (70%) were HCV-RNA positive. We examined 80 babies, born to anti-HCV positive mothers: 56 with HCV-RNA positive mothers and 24 with HCV-RNA negative mothers. Two babies (3.6%) of 56 were anti-HCV and HCV-RNA positive, with normal liver function tests. Seventy-eight babies (97.5%) of 80 (54 with HCV-RNA positive mothers and 24 with HCV-RNA negative mothers) were HCV-RNA negative, with normal liver function tests and detectable levels of anti-HCV antibodies that gradually disappeared between 8-12 months. CONCLUSION: Mother-to-infant transmission of HCV is possible only in the case of HCV-RNA positive mothers. In our study the rate of transmission is 3.6%, (2/56 babies with HCV-RNA positive mothers). HCV transmission may occur without evident association with breast-feeding or vaginal delivery.

Cytomegalovirus encephalitis in a non-immunocompromised patient: CSF diagnosis by in situ hybridization cells.

Cytomegalovirus (CMV) encephalitis in immunologically normal patients is rarely reported in the literature. CMV infection was diagnosed by viral DNA probe techniques on CSF cells in a 32-year-old, immunologically normal male presenting with a severe clinical picture due to encephalitis. Administration of ganciclovir was followed by an immediate improvement in the patient's condition. More sensitive techniques for CMV detection could allow to discover more cases of CMV encephalitis in non-immunocompromised patients than previously recognized.

Intrathecal synthesis of anti-HIV antibodies in AIDS patients.

We studied the production within the CNS of anti-HIV antibodies, of non-specific IgG, and the presence of HIV antigens in the serum and CSF of 28 HIV infected patients belonging to group IV in the Center for Disease Control classification. CSF and serum were diluted under optimal conditions to equalize their IgG content, to enable us to better interpret serum and CSF reactivity by means of Western blot and ELISA. Under these conditions, no patient displayed a limited immunological response profile in CSF as compared to serum. On the contrary, there was intrathecal synthesis (ITS) of anti HIV-antibodies in Western blot test in 21 patients for gp160 and ITS was demonstrable for env, gag, and pol products. ITS of anti-HIV antibodies occurred in 17 patients when measured by ELISA. ITS of non specific IgG and HIV-antigens in CSF were less frequent. A marked anti-HIV response is evident in the CSF-CNS compartment in the later phases of the HIV infection.

In-vitro activity of vancomycin, teicoplanin, daptomycin, ramoplanin, MDL 62873 and other agents against staphylococci, enterococci and Clostridium difficile.

The minimum inhibitory concentrations (MICs) of different antibiotics were determined by a broth microdilution method for staphylococci, enterococci and Clostridium difficile. The antimicrobial agents tested were vancomycin, teicoplanin, daptomycin, ramoplanin, MDL 62873, rifampicin and piperacillin, the latter limited to enterococci. In terms of MIC90S, daptomycin (0.89 mg/l). MDL 62873 (0.99 mg/l), and teicoplanin (1.50 mg/l) were found to be highly active against methicillin-resistant Staphylococcus aureus (MRSA). Daptomycin (MIC90 0.48 mg/l), MDL 62873 (0.95 mg/l) and ramoplanin (1.45 mg/l) were the most active drugs against methicillin-resistant S. epidermidis (MRSE). Teicoplanin (MIC90 0.45 mg/l) was the most active agent against enterococci, followed by MDL 62873 (0.65 mg/l) and daptomycin (1.60 mg/l). MDL 62873 gave the lowest MIC90 (0.17 mg/l) for C. difficile. Teicoplanin (MIC90 0.42 mg/l), daptomycin (0.87 mg/l) and ramoplanin (0.98 mg/l) were also very active. Our results indicate that teicoplanin, daptomycin, ramoplanin and MDL 62873, a teicoplanin derivative, are potentially effective alternative antibiotics for treatment of infections caused by staphylococci, enterococci and C. difficile.

Antimicrobial agent susceptibility patterns of staphylococci isolated in urban and rural areas of Bolivia.

Staphylococcal strains obtained from cutaneous swabs of hospital staff and school students of Camiri and Boyuibe and healthy people living in Javillo, Bolivia, were tested for their in-vitro antimicrobial susceptibility. The highest percentages of resistance to the antibiotics tested were found in staphylococcal strains isolated from hospital personnel. All the S. aureus strains from these subjects were resistant to penicillin. Coagulase-negative staphylococci from hospital personnel evidenced a high rate of multiresistant strains, mainly to penicillin, ampicillin, tetracycline, and chloramphenicol. The staphylococcal strains isolated in the rural population of Javillo were highly susceptible to all the antibiotics tested.

Risk of HIV infection on patients and staff of two dialysis centers: seroepidemiological findings and prevention trends.

In view of the present world-wide diffusion of HIV, we evaluated the possible presence of persons infected by HIV or suffering from AIDS among the patients and staff of two Dialysis Centers. In the past these centers have been found to be at a high risk for HBV infection. The results of this seroepidemiological study, though rather reassuring for the time being, have led the authors to propose specific prevention rules, owing to the nature of activities in these medical structures and in light of the fact that the presence of HIV is beginning to be reported in other such centers.

Screening and confirmatory tests for antibody to HTLV-III/LAV retrovirus in individuals at risk for AIDS.

The prevalence of specific antibodies to HTLV-III/LAV retrovirus was investigated during 1985 in a large group of subjects at risk for AIDS living in the Florence area. Two hundred and thirty-two of 774 (29.9%) intravenous drug users (IDU), 40 of 164 homosexuals (24.3%), 43 of 147 hemophiliacs (29.2%), 7 of 10 children born from IDU mothers and 4 of 88 heterosexual partners of IDU were found to be seropositive using different ELISA kits. The positivity in all serum samples showing low antibody titres and/or discordant results with different sandwich ELISA kits was confirmed by a competition ELISA assay and the Western blot technique. Serum samples from 4 of 210 hemodialyzed and from one of 17 polytransfused patients also showed positive reactions in the assays based on the sandwich principle, but gave negative results in both the competition ELISA assay and the Western blot technique. In addition, all these sera showed positive reactions using immunofluorescence and ELISA procedures that control for reactivity with H9 human cell line material used for culturing the HTLV-III/LAV retrovirus. These data demonstrate that exposure to HTLV-III/LAV retrovirus is widespread in groups of subjects at risk for AIDS living in the Florence area. Furthermore, the results of the present study suggest that, in addition to the Western blot technique, the competition ELISA assay as well as assays that control reactivity with H9 human cell line material may be of value for detecting false positive reactions due to antibody cross-reactive with human cellular components.