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Biomedical subjects

G Rezza

Publications and source records attributed to G Rezza.

At least 145 records · Page 8Linked to original sources
PubMed1995

Use of AIDS surveillance data to describe subepidemic dynamics.

BACKGROUND: Official reports on AIDS surveillance mainly consist of absolute numbers of AIDS cases or cumulative incidence rates. More detailed analyses focusing on the clusters of subepidemics within Italy seemed necessary for a better understanding and more accurate description of the epidemic. METHODS: Age-specific AIDS incidence rates were calculated with reference to resident population by sex, calendar time and geographical area. Age-standardized incidence rates, with the Italian resident population in 1990 as standard, were used to present time trends and geographical distributions. All analyses were repeated for injecting drug users, homosexual/bisexual men, heterosexual contacts and individuals with other or undetermined risk factors. RESULTS: Annual incidence rates for AIDS in Italy increased over the study period. The highest rates were observed in the North and in Sardinia, while Southern regions showed generally lower rates. This heterogeneity was more evident when examining small geographical areas (i.e. provinces). Epidemics in some of the smaller provinces, such as Imperia and Livorno (Northwestern port towns), were shown to be important in that they greatly affect AIDS incidence rates in the regions in which they are located. CONCLUSIONS: According to our analysis, the crude presentation of data from the Italian AIDS Registry is not adequate for understanding the national spread of the AIDS epidemic in terms of several local subepidemics, which may differ by size, temporal trend, and risk group composition. Classifying cases according to their place of residence, which we considered as a good proxy of the place of life, was fundamental for correctly locating these subepidemics. Furthermore, the use of age-standardized rates allowed for unbiased comparisons between regions whose population may have a different age structure and dynamics.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Coinfection of hepatitis C virus with human immunodeficiency virus and progression to AIDS. Italian Seroconversion Study.

To assess the influence of hepatitis C virus (HCV) on the natural history of human immunodeficiency virus (HIV) infection, a longitudinal study was conducted among 416 HIV-positive, AIDS-free persons infected through injecting drug use or homosexual or heterosexual activity and with known seroconversion dates. End points were diagnosis of AIDS and a CD4 cell count of < 100 x 10(6) cells/L. HCV antibodies were detected in 214 persons (51.4%). The crude relative hazard (RH) of progression to AIDS was 0.96 (95% confidence interval [CI], 0.53-1.76) for HCV-coinfected participants compared with those not coinfected. After adjustment for CD4 cell count, the RH was 0.97 (95% CI, 0.52-1.79). Similar RHs were found using a CD4 cell count of < 100 x 10(6) cells/L as the end point. The median CD4 cell loss was 4.83 x 10(6) cells/L per month among coinfected persons and 5.70 x 10(6) cells/L per month among the others. These results suggest that coinfection with HCV does not influence clinical and immunologic progression of HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Clinical characteristics and prognostic value of acute retroviral syndrome among injecting drug users. Italian Seroconversion Study.

OBJECTIVE: To estimate the frequency of acute retroviral syndrome associated with HIV infection among injecting drug users (IDU), and to determine the extent to which acute retroviral syndrome predicts a faster rate of progression to AIDS and immunosuppression in this population. DESIGN: Prospective study of HIV seroconverters (median follow-up, 50.5 months). SETTING: Sixteen clinical centres throughout Italy established to study the natural history of HIV infection. PATIENTS: Three hundred and ninety-one IDU for whom the date of HIV seroconversion was established with a 9-month precision. MAIN OUTCOME MEASURES AND METHODS: Incidence of acute retroviral syndrome with signs and symptoms that included fever (temperature > 38 degrees C) occurring within 6 months prior to the time of first positive HIV test, progression to AIDS, crude and adjusted relative hazard of AIDS using survival analysis techniques, and trajectories of CD4+ cell counts using a piece-wise linear regression model incorporating the degree of dependency of within-person measurements. RESULTS: Of 391 HIV seroconverters, 39 (10.0%) were diagnosed with acute retroviral syndrome. During follow-up, 13 seroconverters with acute retroviral syndrome and 24 asymptomatic seroconverters developed AIDS. The Kaplan-Meier estimates for the cumulative AIDS incidence during 4.5 years of follow-up were 26.8 and 6.5%, respectively; the relative hazard of developing AIDS for acute retroviral syndrome was 5.59 (95% confidence interval, 2.79-11.20) after adjustment for age, sex and year of seroconversion. Although CD4+ level within the first year from seroconversion was similar, the rate of CD4+ cell decline after 1 year from seroconversion was faster in individuals with acute retroviral syndrome than in those without this syndrome (P < 0.001). CONCLUSIONS: Among HIV-infected IDU, a distinct acute retroviral syndrome is apparent and associated with a faster rate of clinical progression to AIDS and HIV-related immunosuppression.

Acquired Immunodeficiency Syndrome↗
PubMed1995

The classification of AIDS cases: concordance between two AIDS surveillance systems in Italy.

This study assessed the concordance between the transmission classification of 725 acquired immunodeficiency syndrome (AIDS) cases by the Italian AIDS Registry (the national surveillance system) and the classification of the same cases by the Italian Cooperative Group on AIDS-Related Tumors. A high degree of concordance emerged for intravenous drug users in both sexes (kappa = 0.88; 95% confidence interval [CI] = 0.84, 0.92), for homosexual men (kappa = 0.83; 95% CI = 0.79, 0.87), and for persons infected through contaminated blood or blood derivatives (kappa = 1.00). The concordance was lower among heterosexual men (kappa = 0.51; 95% CI = 0.37, 0.65) and especially among men whose risk group was not determined (kappa = 0.28; 95% CI = 0.12, 0.44). The discrepancies observed among heterosexual men indicate a need for continuing and accurate monitoring of AIDS reporting by transmission category.

Acquired Immunodeficiency Syndrome↗
PubMed1995

[Not Available].

The authors briefly report the epidemiological status of HIV-1 and HIV-2 infections among patients affected by tuberculosis in Guinea Bissau and evaluate the therapeutic follow up in 177 patients contemporarily affected by TBC and HIV-2 infection. The evaluation of the surviving times has been done according to the Kaplan-Meier curve by considering the following determinants: 1) sex; 2) sputum positive for acid-fast bacilli; 3) age range: A) 10-30 years - B) 31-45 years - C) more than 45 years. The total number days/person was 1417. The drop out was moderate. The serum prevalence for HIV-2 in patients affected by tuberculosis in Guinea Bissau is about 20% but in the last two years HIV-1 infection is increasing. There is no significant difference in the surviving curves due to the sex. Tbc-HIV-2+ patients have a longer survival than tbc-HIV-1+ patients reported by European and North America epidemiological data. The present epidemiological data were obtained in an African environment and, due to the low financial support, it was not possible to correlate them with the immunological and microbiological ones.

English Abstract↗
PubMed1995

[Prevalence of HIV infection in Italian drug users attending drug treatment centers in the years 1990-92].

Repeated cross-sectional surveys have been conducted to collect information on the trend of HIV prevalence among drug users attending drug treatment centers in Italy in the years 1990-92. Annual HIV prevalence was 31.5% in 1990, 29.1% in 1991, and 24.6% in 1992, showing a declining trend. HIV prevalence was higher in the North than in the South of the country, and among females than in males. Drug users entering treatment for the first time during the study period were less likely to be infected than old clients.

Female↗
PubMed1994

HIV disease progression in 854 women and men infected through injecting drug use and heterosexual sex and followed for up to nine years from seroconversion. Italian Seroconversion Study.

OBJECTIVE: To compare the progression of HIV-1 infection in men and women followed up for up to nine years after an accurately estimated date of seroconversion. DESIGN: Prospective observational study. SETTING: 16 HIV outpatient clinics across Italy. SUBJECTS: 321 women and 533 men infected with HIV through injecting drug use or heterosexual sex and with accurately estimated dates of seroconversion. MAIN OUTCOME MEASURES: Progression to severe CD4 lymphocytopenia (CD4 lymphocyte count < 200 x 10(6)/l), development of AIDS defining diseases, and death from AIDS. RESULTS: Thirty two women and 67 men developed AIDS at Kaplan-Meier progression rates of 25% (95% confidence interval 13.8% to 35.5%) and 23% (15.6% to 30.4%), respectively, 7 years after seroconversion. In a Cox proportional hazards model the relative hazard was 0.93 (that is, a slightly lower hazard in women) before and 1.10 (0.70 to 1.72) after adjusting for age, HIV exposure group, and year of seroconversion. When CD4 lymphocytopenia and death from AIDS were used as end points the results were similar, with adjusted relative hazards of 0.95 (0.63 to 1.42) and 0.72 (0.48 to 1.79) respectively. In both women and men the risk of developing AIDS before the CD4 lymphocyte count had declined below 200 x 10(6)/l was small (3% in women, 6% in men). The estimated median count at which AIDS developed in women (34 x 10(6)/l; 10 x 10(6) to 44 x 10(6)) was similar to that for men (44 x 10(6)/l; 22 x 10(6) to 60 x 10(6)). CONCLUSION: There seems to be little evidence for appreciable differences in the natural course of HIV infection between men and women followed up from the time of seroconversion.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Assessing HIV prevention among injecting drug users in European Community countries: a review.

By September 30th 1991, 19,579 cases of AIDS among injecting drug users had been reported in Europe. HIV seroprevalence rates among drug injectors vary from less than 5% in some cities, to over 50% in others. Since the estimated number of drug injectors in Europe is between 750,000 and 1,000,000, HIV is a considerable threat to drug injectors, their sex partners and their off-spring, affecting large numbers of citizens in the European region. This paper gives an overview of the magnitude of the drugs/AIDS problem in the European region, and the concrete measures that have been taken to prevent HIV infection among drug users. Data from the evaluation of methadone programmes, needle and syringe exchange schemes and data on sexual behaviour change of drug users are critically reviewed. Limitations of the methods used for the evaluation of prevention activities are also discussed. Based on all the material reviewed, the main conclusions are the following: AIDS is a greater threat to public health than problem drug use, more accurate and reliable evaluation methods need to be utilized at European Community level, a combination of prevention measures should be used in order to reduce the further spread of HIV infection among injecting drug users.

AIDS Serodiagnosis↗
PubMed1994

Methadone treatment as a determinant of HIV risk reduction among injecting drug users: a nested case-control study.

In order to evaluate the protective effect of methadone treatment on HIV infection, we performed a nested case-control study on seroconverters (cases) who were part of a cohort of HIV-negative injecting drug users (IDUs) (controls). Controls were matched with cases by sex, age, duration of drug use and follow-up time. Information on methadone treatment in the year prior to seroconversion was collected using clinical registries. Univariate and multivariate conditional logistic regression were used to identify variables related to HIV-seroconversion. The study included 40 cases and 40 controls. Univariate analysis showed the following variables to be associated to HIV seroconversion: number of cycles of treatment, daily dose and time out of treatment. After performing multivariate analysis, daily dose remained protective with a linear effect noted even at low doses and time out of treatment was the most important risk factor. The risk increased 1.5 times for every 3 months spent out of treatment. Long-term methadone treatment protects against HIV infection. Its effect may be attributable to a reduction in the frequency of injecting drug use or to an increased knowledge of risk factors following counselling in drug centres.

Adolescent↗
PubMed1994

Impact of HIV infection on non-AIDS mortality among Italian injecting drug users.

OBJECTIVES: To estimate the excess mortality of injecting drug users (IDU) stratified by HIV serostatus compared with the general population in Italy. To compare total and cause-specific mortality in HIV-positive versus HIV-negative IDU, in order to identify possible HIV-related non-AIDS causes of death in this population. METHODS: All IDU attending two drug-treatment centres in Rome who underwent HIV testing between 1985 and 1991 were enrolled into a prospective study. The end-point of the study was death from any cause by 31 December 1991. Mortality rates were compared using age-adjusted standardized mortality ratios and person-time techniques. RESULTS: Of the 2431 IDU, 1661 (68.3%) were HIV-seronegative and 82 seroconverted. Of 181 deaths, comprising 89 from AIDS and 92 from other causes, the mortality rate was 4.5 and 0.8 per 100 person-years in HIV-seropositives and HIV-seronegatives, respectively. For non-AIDS mortality in HIV-seropositives, the overall rate was 1.7 per 100 person-years. Deaths from overdose and endocarditis/embolus tended to be higher in HIV-seropositive than HIV-seronegative IDU, although there was no difference in the rate of deaths due to pneumonia by HIV serostatus. CONCLUSIONS: These data are consistent with other studies demonstrating a higher frequency of mortality among HIV-seropositive IDU. The excess in overdose mortality among HIV-seropositives is disturbing and merits further investigation.

Adult↗
PubMed1994

CD4 lymphocyte count as a determinant of the time from HIV seroconversion to AIDS and death from AIDS: evidence from the Italian Seroconversion Study.

OBJECTIVES: It is well established that a low CD4 lymphocyte count is strongly associated with an increased risk of AIDS in HIV infection. We attempted to determine whether the link is sufficiently strong that the wide inter-person variability in times from HIV infection to AIDS can be explained solely by differences in CD4 count experience. METHODS: We followed 1090 HIV-infected individuals for up to 12.8 years from seroconversion (median, 3.5 years; 25% for more than 5.2 years). The median interval between last negative and first positive anti-HIV tests was 9 months. A median of four CD4 counts per subject were measured. RESULTS: Individuals with CD4 lymphocyte counts above 250 x 10(6)/l cells experienced an AIDS incidence rate of one per 339 years (0.3 per 100 years; 10 cases in 3394 person-years), compared with one per 6 years in those whose count had declined below this level (17.2 per 100 years; 96 cases in 559 person-years) and one per year in those whose count had declined below 50 x 10(6)/l (100.0 per 100 years; 41 cases in 41 person-years). The AIDS rate increased by an average of 33% [relative rate, 1.33; 95% confidence interval (CI), 1.20-1.49; P = 0.0001] with every year from seroconversion; one per 46 years (2.2 per 100 years) for people seropositive for less than 5 years compared with one per 14 years (7.3 per 100 years) for those seropositive for more than 5 years. After adjusting for the tendency for CD4 lymphocyte counts to be higher soon after seroconversion, the relative rate declined to 1.07 (95% CI, 0.94-1.22) per year from seroconversion (P = 0.32). This result was similar when those infected through sharing injecting equipment, homosexual sex, and other routes were considered separately. The relative rate per year from seroconversion for death due to AIDS fell from 1.41 (P = 0.0001) to 1.00 (P = 0.99) after adjusting for CD4 count. CONCLUSIONS: Most of the inter-person variability in time from HIV infection to AIDS appears to result from differences in CD4 lymphocyte counts. HIV infection appears to cause AIDS and death largely by its ability to induce CD4 lymphocytopaenia or some closely correlated abnormality.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Understanding the dynamics of the HIV epidemic among Italian intravenous drug users: a cross-sectional versus a longitudinal approach.

We studied annual human immunodeficiency virus (HIV) seroprevalence and incidence in a large number of intravenous drug users attending drug treatment centers in three Italian urban areas. We also evaluated risk factors for HIV seropositivity and for HIV seroconversion. The results showed that HIV prevalence and incidence are declining. HIV prevalence declined dramatically in study participants that were < 25 years old. Prevalent HIV cases were associated with older age and longer duration of intravenous drug use; however, short duration of drug use increased the risk of seroconversion. The findings of our study suggest that comparing cross-sectional and longitudinal data contributes to a better understanding of the dynamics of the HIV epidemic among intravenous drug users.

Adult↗