Epidemiology of respiratory pathogen carriage in the homeless population within two shelters in Marseille, France, 2015-2017: cross sectional 1-day surveys.

OBJECTIVES: To assess risk factors for respiratory tract infection symptoms and signs in sheltered homeless people in Marseille during the winter season, including pathogen carriage. METHODS: Data on 479 male participants within two shelters who completed questionnaires and a total of 950 nasal and pharyngeal samples were collected during the winters of 2015-2017. Respiratory pathogen carriage including seven viruses and four bacteria was assessed by quantitative PCR. RESULTS: The homeless population was characterized by a majority of individuals of North African origin (300/479, 62.6%) with a relatively high prevalence of chronic homelessness (175/465, 37.6%). We found a high prevalence of respiratory symptoms and signs (168/476, 35.3%), a very high prevalence of bacterial carriage (313/477, 65.6%), especially Haemophilus influenzae (280/477, 58.7%), and a lower prevalence of virus carriage (51/473, 10.8%) with human rhinovirus being the most frequent (25/473, 5.3%). Differences were observed between the microbial communities of the nose and throat. Duration of homelessness (odds ratio (OR) 1.77, p 0.017), chronic respiratory diseases (OR 5.27, p <0.0001) and visiting countries of origin for migrants (OR 1.68, p 0.035) were identified as independent risk factors for respiratory symptoms and signs. A strong association between virus (OR 2.40, p 0.012) or Streptococcus pneumoniae (OR 2.32, p 0.014) carriage and respiratory symptoms and signs was also found. CONCLUSIONS: These findings allowed identification of the individuals at higher risk for contracting respiratory tract infections to better target preventive measures aimed at limiting the transmission of these diseases in this setting.

Seroprevalence of HSV-1 and HSV-2 infection in the general French population.

BACKGROUND: In spite of the large prevalence and growing incidence of herpes simplex infection (HSV-1 and HSV-2), relatively few large serological surveys are available worldwide and it is still difficult compare frequencies of HSV contaminations in various countries. We present the results of HERPIMAX, the first epidemiological inquiry on HSV prevalence in the general French population. METHODS: Of a cohort of 12,735 presumed healthy adult volunteers included in the prospective study SU.VI.MAX, designed to assess the relation between nutritional supplementations and degenerative diseases, HERPIMAX randomly selected 4412 subjects (females 66.5%, males 33.5%). All serum samples were assessed for HSV-1 and HSV-2 IgG antibodies with a HSV type specific, enzyme immunosorbent assay (EIA). Equivocal result were retested with another HSV type specific immunoblot assay combined with a type common HSV IgG EIA in order to give a definitive interpretation. RESULTS: The mean seroprevalence was 67% for HSV-1 and 17.2% for HSV-2. For HSV-2 the seroprevalence was higher in females (17.9%) compared with males (13.7%) (p<0.001). For both HSV types, there was no significant difference in prevalence as regards age distribution in males and females, whereas prevalence increased significantly with age in females for HSV-1. Univariate analysis showed a significant association between HSV-1 prevalence and education level in males and females (p<0.001) and between HSV-2 prevalence and marital status in both sexes (p<0.001). There were geographical disparities, with a higher HSV-2 prevalence in the south of France as well as in Paris. CONCLUSION: These results confirm a high prevalence of HSV infection in France. They are also in agreement with previous results of other survey carried out in other developed countries as regards higher prevalence of HSV-2 infection in women, the stability of seroprevalence for both HSV types after 35 years of age in females and 45 years of age in males.

[Sensitivity of HIV infection screening assays in 2001]. / Performances des tests de dépistage de l'infection par le VIH en 2001.

Early detection of human immunodeficiency virus (HIV) infection is critical for clinical diagnosis and treatment of patients, as well as for ensuring the safety of blood products. Recently, fourth-generation HIV screening assays have been developed with the objective to offer an increased sensitivity by combining detection of anti-HIV antibodies (Ab) with detection of the p24 viral antigen (Ag). Eight different HIV assays commercially available in France (five fourth-generation HIV screening assays and three third-generation HIV Ab-only assays) were compared in a broad number of seroconversion panels (n = 27). This extensive analysis highlights: 1) the importance of p24 Ag detection for early diagnosis; 2) the improved sensitivity of fourth-generation assays over Ab-only tests. In conclusion, these results emphasize the detection limitations of the different assays and suggest improvements for future HIV screening assays.

Seven human immunodeficiency virus (HIV) antigen-antibody combination assays: evaluation of HIV seroconversion sensitivity and subtype detection.

In this study, we evaluated the performance of two prototype human immunodeficiency virus (HIV) antigen-antibody (Ag-Ab) combination assays, one from Abbott Laboratories (AxSYM HIV Ag-Ab) and the other from bioMerieux (VIDAS HIV Duo Ultra), versus five combination assays commercially available in Europe. The assays were Enzygnost HIV Integral, Genscreen Plus HIV Ag-Ab, Murex HIV Ag-Ab Combination, VIDAS HIV Duo, and Vironostika HIV Uniform II Ag-Ab. All assays were evaluated for the ability to detect p24 antigen from HIV-1 groups M and O, antibody-positive plasma samples from HIV-1 groups M and O, HIV-2, and 19 HIV seroconversion panels. Results indicate that although all combination assays can detect antibodies to HIV-1, group M, subtypes A to G, circulating recombinant form (CRF) A/E, and HIV-1 group O, their sensitivity varied considerably when tested using diluted HIV-1 group O and HIV-2 antibody-positive samples. Among combination assays, the AxSYM, Murex, and VIDAS HIV Duo Ultra assays exhibited the best antigen sensitivity (at approximately 25 pg of HIV Ag/ml) for detection of HIV-1 group M, subtypes A to G and CRF A/E, and HIV-1 group O isolates. However, the VIDAS HIV Duo Ultra assay had a lower sensitivity for HIV-1 group M and subtype C, and was unable to detect subtype C antigen even at 125 pg of HIV Ag/ml. The HIV antigen sensitivity of the VIDAS HIV Duo and Genscreen Plus combination assays was approximately 125 pg of HIV Ag/ml for detection of all HIV-1 group M isolates except HIV-1 group O while the sensitivity of Vironostika HIV Uniform II Ag-Ab and Enzygnost HIV Integral Ag-Ab assays for all the group M subtypes was >125 pg of HIV Ag/ml. Among the combination assays, the AxSYM assay had the best performance for detection of early seroconversion samples, followed by the Murex and VIDAS HIV Duo Ultra assays.

Early detection of human immunodeficiency virus infection using third- and fourth-generation screening assays.

Early detection of infection with human immunodeficiency virus (HIV) is critical for clinical diagnosis and treatment of patients, as well as for ensuring the safety of blood transfusion products. Recently, a number of fourth-generation HIV screening assays have been developed that offer increased sensitivity over earlier tests by combining detection of anti-HIV antibodies with detection of the p24 viral antigen. Previously, six different HIV assays were compared against a broad range of 30 seroconversion panels. In the present study, three of the newer fourth-generation assays were tested together with three of the third-generation HIV antibody-only assays. This extensive analysis highlights (i) the importance of p24 antigen detection for early diagnosis, (ii) the improved sensitivity of fourth-generation assays over antibody-only tests, and (iii) the superior performance of the Vidas Duo assay, which allows reduction of the diagnostic window by up to 2 weeks. Finally, the results emphasize the detection limitations of the different assays and suggest improvements for future HIV screening assays.

Antiviral resistance of biologic HIV-2 clones obtained from individuals on nucleoside reverse transcriptase inhibitor therapy.

OBJECTIVE: To study phenotypic and genotypic resistance of HIV-2 against nucleoside reverse transcriptase inhibitors (NRTI). METHODS: Biologic HIV-2 clones were generated from 3 patients before and after initiation of antiretroviral therapy with zidovudine (AZT) in patient RH2-7, AZT and didanosine (ddI) in patient PH2-1, and after addition of lamivudine (3TC) to AZT monotherapy in patient RH2-5. The sensitivity to NRTI of the virus clones, as defined by the 50% inhibitory concentration (IC(50)), was determined in vitro. The predicted amino acid sequences of the reverse transcriptase proteins from these clones were determined. RESULTS: Comparing the sensitivity of the biologic HIV-2 clones obtained after start of therapy with those from antiviral naive patients, resistance had developed to AZT (patients RH2-7 and RH2-5) and 3TC (patient PH2-1 and RH2-5). No resistance to AZT was observed in the biologic clone from PH2-1 obtained after start of therapy. The resistant clones from RH2-5 and PH2-1, but not RH2-7, contained amino acid mutations at positions where HIV-1 has been shown to mutate after AZT and 3TC treatment. CONCLUSIONS: Phenotypic resistance of HIV-2 to nucleoside analogues, which developed in HIV-2-infected patients treated with NRTIs, was associated with genotypic changes. Some of the mutations at amino acid positions in the HIV-2 reverse transcriptase gene corresponded with those involved in HIV-1 resistance, although no conventional mutations associated with resistance to AZT were observed.

Evaluation of the Nuclisens HIV-1 QT assay for quantitation of human immunodeficiency virus type 1 RNA levels in plasma.

Nuclisens HIV-1 QT is a new version of the NASBA HIV-1 QT assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma. The specificity of this assay was 100% in one laboratory and 99%-with nonrepeatability of the initial false positive-in another. The test was linear between 2.0 and 6.0 log RNA copies per ml. According to the input HIV-1 RNA concentration, accuracy varied from -0.11 to +0.10 log RNA copy per ml and precision varied from 0.66 to 0.14 log RNA copy per ml. Reproducibility decreased when the HIV-1 RNA level was near the lower limit of quantitation of the test. HIV-1 RNA could be quantitated by Nuclisens HIV-1 QT in 36% (laboratory 1) and 24% (laboratory 2) of clinical samples with HIV-1 RNA levels lower than the lower limit of quantitation by NASBA HIV-1 QT. Nuclisens HIV-1 QT was not suitable for measurement of RNA from clade G and group O HIV-1 strains.

HIV-2 infection in 12 European residents: virus characteristics and disease progression.

OBJECTIVE: To assess the disease progression rate among 12 HIV-2-infected West European residents (nine of West African descent), compared with the disease progression rate among HIV-1-infected individuals of the same population, and the characteristics of the HIV-2 strains involved. METHODS: HIV-2-infected individuals were identified by commercially available serological assays, their clinical status and CD4+ cell counts were monitored, and HIV-2 was isolated from their peripheral blood mononuclear cells. T-cell-line tropism and syncytium-inducing capacities of the isolated viruses were determined and their phylogenetic relationships were analysed by comparing polymerase chain reaction-amplified nucleotide sequences of reverse transcriptase (RT) gene segments. RESULTS: Eight of the 12 HIV-2-infected individuals presented with progressive disease and one of them progressed from Centers for Disease Control and Prevention group A1 to A3 within 36 months after seroconversion. The ratios of asymptomatic versus symptomatic individuals among residents of the Rotterdam region of West African descent were 2:7 for HIV-2 and 8:9 for HIV-1-infected individuals. HIV-2 was isolated from six of the nine individuals with progressive disease. The time required for virus isolation correlated inversely with the individuals' CD4+ cell counts. Five of the HIV-2 isolates replicated in immortalized T-cell lines, and two isolates from patients with AIDS were syncytium-inducing. Five HIV-2 isolates from patients born in the Cape Verdian Isles grouped together within subtype A. The HIV-2 isolate from a patient of Ghanese origin belonged to subtype B. Mutations were identified in the RT genes from HIV-2 isolates of two zidovudine-treated patients, one of which has also been shown to be involved in zidovudine resistance in HIV-1. CONCLUSION: Disease progression in HIV-2 infection may be as rapid as in HIV-1. HIV-2 isolation and viral phenotype were related to disease status, and mutations identical to those observed in HIV-1 zidovudine resistance were observed in patients treated with zidovudine.

Variability of human immunodeficiency virus type 1 group O strains isolated from Cameroonian patients living in France.

Human immunodeficiency virus type 1 (HIV-1) nucleotide sequences encoding p24Gag and the Env C2V3 region were obtained from seven patients who were selected on the basis of having paradoxical seronegativity on a subset of HIV enzyme-linked immunosorbent assay detection kits and having atypical Western blot (immunoblot) reactivity. Sequence analyses showed that all of these strains were more closely related to the recently described Cameroonian HIV isolates of group O (HIV-1 outlier) than to group M (HIV-1 major). All seven patients had Cameroonian origins but were living in France at the time the blood samples were taken. Characterization of a large number of group M strains has to date revealed eight distinct genetic subtypes (A to H). Genetic distances between sequences from available group O isolates were generally comparable to those observed in M intersubtype sequence comparisons, showing that the group O viruses are genetically very diverse. Analysis of sequences from these seven new viral strains, combined with the three previously characterized group O strains, revealed few discernable phylogenetic clustering patterns among the 10 patients' viral sequences. The level of diversity among group O sequences suggests that they may have a comparable (or greater) age than the M group sequences, although for unknown reasons, the latter group dispersed first and is the dominant lineage in the pandemic.

Different patterns of HIV-1-specific cytotoxic T-lymphocyte activity after primary infection.

OBJECTIVE: To analyse the HIV-1-specific cytotoxic T-lymphocyte (CTL) responses of nine HIV-seropositive subjects in relation with primary infection. METHODS: Anti-HIV CTL were generated by in vitro stimulation of peripheral mononuclear cells obtained from HIV-seropositive donors at various times after primary infection. They were tested against several structural or regulatory HIV-1 proteins, using autologous target cells infected with recombinant vaccinia viruses expressing one of the HIV-1LAI proteins. RESULTS: An important CTL activity was found during the first month following seroconversion only in those donors who showed clinical symptoms during primary infection. The temporal evolution of this response differed for each subject; one remained a non-responder even 30 months after seroconversion. The structural proteins were recognized particularly early, while the antigenicity of regulatory proteins appeared later. CONCLUSION: Different patterns of HIV-specific CTL response can be observed after primary infection. The evolution of infection in these different HIV-seropositive subjects will be particularly interesting to analyse.

HIV-1/HIV-2 seronegativity in HIV-1 subtype O infected patients.

Nine patients with atypical HIV-1 western blot profiles were diagnosed as having HIV-1 subtype O infection. All the patients were living in France; eight originated from Cameroon and one from France. Lymphocyte DNA amplification by the polymerase chain reaction was only positive when HIV-1 subtype O specific primers were used. Preliminary sequence analysis of amplified products and serological reactivity against a specific subtype O synthetic env peptide confirmed HIV-1 subtype O infection. HIV-1/HIV-2 enzyme-linked immunosorbent assays, especially those based on env peptides or on the sandwich format, can be negative in HIV-1 subtype O infection.

[Statement: The evaluation of the Serodia-HIV and Serodia-ATLA FUJIREBIO-MILES kits]. / Communiqué: étude des trousses Sérodia-HIV et Sérodia-ATLA FUJIREBIO-MILES.

A new test, based on agglutination of gelatin particles (PA), sensitized with viral antigens of HIV, was applied on detection of the human immunodeficiency virus (HIV 1) antibody. Sensitivity compared to the ELISA tests (Organon, Dupond de Nemours and/or Elavia 2) was the same during the screening test (97.7 p. cent). Specificity was also acceptable when compared to the same tests (94 p. cent). This specificity remains acceptable with African sera (96 p. cent). During screening, 11.8 p. cent of tested sera were declared falsely positive by the Elisa classical techniques, against only 1.96 p. cent with the PA assay. The six sera remained positive with ELISA (false positives), whereas this positivity was not confirmed with the PA assay. Moreover, all the positive sera were confirmed with the Western blot HIV 1 assay (55.84 p. cent), HIV 1 + 2 (31.17 p. cent) or HIV 2 (13.0 p. cent). Amongst the five false positives pointed out in the european sera, all of them have shown in the Western blot the presence of one or two bands of the GAG protein. In this case, the assay whose easy use is attractive, can be adopted in screening serology and could be useful in African regions, as no further equipment is needed.