Thirty-nine HIV-1-infected men were prospectively tested for HIV seminal shedding after the initiation of highly active antiretroviral therapy. HIV RNA drastically decreased in the semen of all men, but low levels remained detectable in three men at month 18. Proviral HIV DNA became undetectable in the seminal cells of all men after 18 months. HIV-infected cells in the male genital compartment may come from the intermittent passage of blood lymphocytes, rather than constituing a major local reservoir.

Background: Many HIV-infected men and women have a strong desire for a child. Assisted reproductive technologies (ART) are an option for HIV-serodifferent couples to reduce the risk of HIV transmission from an infected man to the woman. Potential HIV contamination of selected spermatozoa after semen processing is an important issue in this context. Methods: HIV in processed semen obtained in our laboratory since 1995 were analysed. HIV RNA and DNA detection was performed in the selected spermatozoa of 125 men. HIV RNA was analysed in blood and semen plasma as well as HIV DNA in non-sperm cells. Results: HIV RNA and DNA were detected in the selected spermatozoa of eight and two men (6.4% and 1.6%), respectively. HIV RNA was detected with a median load of 5 copies/106 spermatozoa. Six of the eight men were untreated, one was taking nucleoside analogue therapy and one was on highly active antiretroviral treatment (HAART). HIV RNA detection was more likely to be positive in selected spermatozoa of men with high seminal plasma viral load. HIV RNA was detected in 26% and 11% of selected spermatozoa fractions when the seminal plasma load was > 10 000 copies/ml and 20–10 000 copies/ml, respectively, but in none when the seminal plasma tested negative. Conclusion: Selected spermatozoa may be positive for HIV RNA detection even in treated patients. Viral validation of processed semen is necessary in ART programmes for serodifferent couples, particularly in men with only partially or poorly controlled HIV infection.

Using clinical predictors, we evaluated clinical case definitions of influenza during the 1995-1996 outbreak in France. Thirty-five general practitioners collected virological specimens and clinical data. Predictors of influenza virus infection were selected with logistic regression models. The results varied with the influenza virus subtype: temperature of >38.2 degrees C, stiffness or myalgia, rhinorrhea, and cough were predictive of influenza A/H3N2, whereas fatigue, lacrimation or conjunctival injection, and the absence of stiffness or myalgia were predictive of influenza A/H1N1. On the basis of this analysis and data from the literature, 12 clinical case definitions were evaluated for their abilities to diagnose influenza virus infection. They were associated with positive predictive values of 27% to 40% and negative predictive values of 80% to 91%. We conclude that focused studies evaluating clinical case definitions of influenza with use of subsets of patients should accompany population-based disease surveillance for optimal estimates of the disease burden associated with influenza epidemics.

BACKGROUND:To assess HIV burden in both acellular and cellular fractions of semen in men with different levels of blood plasma HIV RNA by a cross-sectional study. PATIENTS:Fifty-two HIV-1-seropositive men (21 receiving antiretroviral therapy) with CD4 cell counts ranging from 1 to 1170 x 10(6)/l. METHODS:Semen was separated into seminal plasma and fractions enriched in motile spermatozoa or non-spermatozoal cells. HIV RNA was quantified by the HIV-Monitor technique (Roche) in blood plasma, seminal plasma and spermatozoa fractions. HIV DNA or infectious virions in cellular fractions were detected by either PCR or qualitative viral culture. RESULTS:HIV RNA was detected in 86.5% of seminal plasma specimens and in 14.6% of spermatozoa fractions; HIV DNA was detected in 57.1% of non-spermatozoal cell fractions. HIV RNA levels in blood plasma and seminal plasma were correlated (r5 = 0.56, P < 0.0001, Spearman's rank test). A majority of men had lower levels in seminal plasma than in blood plasma: one-third had HIV-positive seminal cell fractions. However, 20 men (38.5%) with HIV RNA levels in seminal plasma (median: 4.65 log10 copies/ml) comparable to or higher than those in blood plasma had all HIV-positive non-spermatozoal cells or spermatozoa fractions with a high frequency of positive cultures. CONCLUSION:A high frequency of men had detectable HIV in semen. We identified a subpopulation demonstrating high levels of HIV RNA in seminal plasma, comparable to or higher than those in blood plasma, frequently associated with a substantial viral shedding in seminal cells, raising the possibility of viral production within the genital tract and suggesting heterogeneity in the potential of HIV sexual transmission among infected men.

Our objective was to evaluate influenza vaccine effectiveness during an influenza epidemic by means of a matched case-control study. The study was performed by 35 general practitioners who collected specimens for influenza virus testing from 610 patients who consulted for infectious syndrome: 168 (28%) were influenza-positive. Two designs were used for selecting controls to take into account the high incidencerate of influenza-like illness and the various possible protective effects of the vaccine. A first disease-free control matched for age and sex was selected during the same week as the case. A second control matched for age and sex was selected at the end of the epidemic period, irrespective of disease history during the epidemic period. Upper and lower bounds of vaccine effectiveness can be derived from these case-control designs. After adjustment for chronic conditions and exposure to an index case, analysis of the matched-pairs whose case was influenza-positive showed, with the first group of controls, an influenza vaccine effectiveness of 68% (95% CI, 10% to 88%) and, in the second group, 53% (95% CI, −19% to 82%). Among the pairs whose case was negative for influenza, vaccine effectiveness was, respectively, 31% (95% CI, −17% to 59%) and 12% (95% CI, −47% to 47%). Vaccine effectiveness was highest for the H3N2 subtype whose vaccine strain was identical to that of the wild-type strain. The results suggest that influenza vaccine is effective in the field in preventing influenza morbidity.

It is of critical importance to precisely understand the modalities of HIV presence in semen, especially with regard to procreation. In this study, paired blood and semen samples from 31 human immunodeficiency virus type 1 (HIV-1)-positive men were assessed for cell-free HIV-RNA load in blood plasma (BP) and seminal plasma (SP), and for detection of HIV by culture, PCR and RT-PCR in semen cellular fractions separated by centrifugation on Percoll gradient. HIV-RNA was detected in 94% of BP and 84% of SP samples. For 11 men (35%), HIV-RNA load in SP was equal or superior to that observed in blood. HIV-DNA presence was demonstrated (either by PCR or culture positivity) in 39% of the non-spermatozoal cells (NSC)-enriched fractions, and in one Percoll-selected sperm pellet. HIV-RNA was detected in 17% (4/23) of the sperm pellets. This positivity was associated with an HIV-RNA load in SP equal or superior to the HIV-RNA load in blood, a high rate of HIV-DNA detection in the NSC fraction, and a low CD4+ cell count. In such conditions, a significant viral production inside the genital tract is more likely to be present, and a close association between HIV and gametes might occur. Assisted procreation with selected spermatozoa should be preceded by accurate assessments of viral presence in blood, SP and semen cellular fractions.

The predictive value of two methods for measuring HIV RNA concentration in plasma was assessed in relation to CD4 lymphocyte counts during the asymptomatic period of infection, The design was a retrospective longitudinal case-control study for a mean period of 60 months involving 20 asymptomatic patients included in the French National prospective survey. The CD4 counts in these patients during the last 36 months of the study were stable (nonprogressors) or declined (progressors).Plasma RNA concentrations were determined in each subject annually using the AMPLICOR and NASBA techniques. Only AMPLICOR gave RNA titers above the cut-off value for all the patients. The techniques agreed satisfactorily, although there was a difference, median 0.4 log(10), between the AMPLICOR and NASBA values.The non-progressors had low and stable RNA concentrations. The concentration was higher in the progressors, according to the AMPLICOR technique, from their inclusion in the study, and according to the NASBA technique, from 1 year after inclusion. However, only four of ten individual progressors had stable plasma HIV RNA concentrations significantly above those of the non-progressors before the decline in their CD4 counts. These were all and only the patients with a decline in lymphocyte counts more than 100 CD4/mm(3)/year. In each of the other progressors, the RNA concentration was not significantly different from those of the non-progressors.Thus, when making decisions about therapy, plasma HIV RNA determinations cannot be used in place of CD4 counts and may provide valuable additional information. (C) 1998 Wiley-Liss, Inc.

BACKGROUND:There are two types of inflenza surveillance techniques: qualitative laboratory-based surveillance and quantitative medical practice-based surveillance. The former is of great importance in isolating new strains of the virus, which helps in the decision-making process concerning the composition of the vaccine, and the latter provides estimates of morbidity, mortality or economic impact as a result of infection from the influenza virus. Rapid methods such as immunoflourescence (IF) or immunocapture assays (ICA) are now available for diagnosis of influenza infections. However, little is known about the use of these methods for influenza surveillance purposes.AIMS:To evaluate the feasibility of a rapid influenza diagnosis in ambulatory conditions, and to investigate the therapeutical outcomes of patients suffering from influenza-like illness (ILI) in relation to the virological diagnoses.METHOD:During the 1994-1995 influenza season, 130 patients presenting with ILI symptoms (< 36 hours) to 33 general practitioners (GPs) were included in a prospective study. Two nasal swabs and one throat swab per patient were collected and sent to the laboratory within 12 hours. Information concerning therapeutical outcomes was recorded during examination. Specimens were analysed using the immunofluorescence (IF) method and antigen immunocapture assay (ICA).RESULTS:Sixteen influenza A (12%) and 19 influenza B (15%) infections were diagnosed. The overall rate of influenza positive specimens was 17% in the pre-epidemic period and 31% during the epidemic (P = 0.1). The rates of usable specimens for IF assay, nasal ICA and throat ICA were 46%, 100% and 99% respectively. The combination of these three collections ensured a highly sensitive influenza virological diagnosis. There were no differences in therapeutical outcomes between the influenza positive and negative cases. The GPs prescribed antibiotics in 60% of the cases for a mean duration of 7 days (+/- 1.2). The mean duration of sick leave was 3.4 days (+/- 1.6). Twelve patients (four influenza positive, eight influenza negative) had been vaccinated at the beginning of the winter. The practitioner's intuition concerning 'which patient should be tested for influenza virus' did not prove useful in improving the aptness of virological diagnoses in the field of influenza surveillance.CONCLUSION:The only way to estimate the true impact of influenza is to carry out a systematic virological sampling based on a sensitive clinical definition and using sensitive laboratory methods.