Performance of V3-based HIV-1 sero subtyping in HIV endemic areas

HIV-1 serosubtyping based on reactivity to peptides from the V3 region of gp120 is a low-cost and easy to perform procedure often used in geographical areas with high prevalence and incidence of HIV infection. We evaluated the performance of V3-based serotyping on 148 sera from 118 HIV-1-infected individuals living in Uganda, with estimated dates of seroconversion. Of the 148 tested samples, 68 (46.0%) specifically reacted with only one of the V3 peptides included in the test (SP), 64 (43.2%) did not react with any peptide (NR) and 16 (10.8%) reacted with two or more peptides (CR). According to the estimated seroconversion date, the large majority of samples collected early after infection belonged to the NR group. These samples had also a low Avidity Index. In contrast, samples collected later after infection belonged mainly to CR and SP groups and had also a higher avidity index. These results indicate that the performance of V3-based assays depends on maturation of HIV-specific immune response and can be significantly lowered when these tests are carried out on specimens collected from recently infected individuals.

Sexual behaviour reported by a sample of Italian MSM before and after HIV diagnosis

In 2006 we conducted a cross-sectional study involving hospital clinical centres in five Italian cities to compare the sexual behaviour of HIV-positive MSM (men who have sex with men) before and after the diagnosis of HIV infection. Each centre was asked to enrol 30 HIV-positive persons aged ≥ 18 years. The questionnaire was administered to 143 MSM on average 9 years after HIV diagnosis. After diagnosis there was a decrease in the number of sexual partners: the percentage of persons who reported having had more than 2 partners decreased from 95.8% before diagnosis to 76.2% after diagnosis. After diagnosis, there was a significant decrease in the percentage of persons who had never (or not always) used a condom with their stable partner for anal sex from 69.2% before diagnosis to 26.6% after diagnosis and for oral-genital sex from 74.8% before diagnosis to 51.7% after diagnosis. Though at-risk behaviour seems to decrease after diagnosis, seropositive MSM continue to engage in at-risk practices: one fourth of them did not use a condom during sexually transmitted infections (STI) episodes, 12.5% of the participants had had sex for money, and 8.4% had paid for sex. The study shows that our sample of Italian HIV-positive MSM, though aware of being infected, engage in sexual behaviours that could sustain transmission of HIV and other STIs. The results could constitute the first step in implementing national prevention programs for persons living with HIV.

[Genital human papillomavirus (HPV) infection in women in the province of Asti (Italy)]

The aim of this study was to estimate the prevalence of HPV infection in women in the general population and identify associated risk factors. Five hundred women participating in a cervical cancer screening program were included in the study which was performed in Asti between April 2005 and October 2005. The prevalence of HPV infection was 10.6%. The most common genotypes were types 18, 16, 51 and 31. Cigarette smoke and oral contraceptive use were found to be significantly associated with infection.

Avidity Index for anti-HIV antibodies: comparison between third- and fourth-generation automated immunoassays

The development of assays for detecting recent HIV infections has become crucial for analyzing trends in infection in different populations, both for surveillance and prevention activities. The anti-HIV avidity index (AI), measured with third-generation immunoassays (which detect anti-HIV antibody), has been shown to be an accurate tool for discriminating recent HIV infections (<6 months) from established infections (≥ 6 months). We compared a third-generation immunoassay (AxSYM HIV 1/2 gO; Abbott Diagnostics) to a fourth-generation immunoassay (Architect HIV Ag/Ab Combo; Abbott Diagnostics; which detects anti-HIV antibody and p24 antigen) in terms of AI performance in distinguishing between recent and established HIV infections. A total of 142 samples from 75 HIV-infected individuals with an estimated date of seroconversion were assayed. The two assays showed the same accuracy in identifying a recent infection (91.5%), using an AI cutoff of 0.80, although Architect HIV Ag/Ab Combo was slightly more sensitive (89.4% versus 84.8%; P > 0.05) and yet less specific (93.4% versus 97.4%; P > 0.05). The correlation between assays was high (r = 0.87). When 20 specimens falling in the gray zone around the cutoff point (0.75 ≤ AI ≤ 0.84) were excluded, the accuracy of AI with Architect HIV Ag/Ab Combo was 94.7%, and the concordance between the two assays was 99.2%. The anti-HIV AI is a serological marker that accurately discriminates recent from established HIV infections. It can be successfully applied on fully automated fourth-generation HIV Ab/Ag immunoassays, which have several advantages, including increased throughput, high reproducibility, no need for specific technical skills, and easy comparability of results obtained in different settings.

Estimating the distribution of the window period for recent HIV infections: a comparison of statistical methods

In the past few years a number of antibody biomarkers have been developed to distinguish between recent and established Human Immunodeficiency Virus (HIV) infection. Typically, a specific threshold/cut-off of the biomarker is chosen, values below which are indicative of recent infections. Such biomarkers have attracted considerable interest as the basis for incidence estimation using a cross-sectional sample. An estimate of HIV incidence can be obtained from the prevalence of recent infection, as measured in the sample, and knowledge of the time spent in the recent infection state, known as the window period. However, such calculations are based on a number of assumptions concerning the distribution of the window period. We compare two statistical methods for estimating the mean and distribution of a window period using data on repeated measurements of an antibody biomarker from a cohort of HIV seroconverters. The methods account for the interval-censored nature of both the date of seroconversion and the date of crossing a specific threshold. We illustrate the methods using repeated measurements of the Avidity Index (AI) and make recommendations about the choice of threshold for this biomarker so that the resulting window period satisfies the assumptions for incidence estimation.

Excess mortality for non–AIDS-defining cancers among people with AIDS

During the period 1999–2006, non–AIDS-defining cancers accounted for 7.4% of deaths among Italian people with AIDS. The risk of death was 6.6-fold higher than in the general population, being particularly elevated for virus-related cancers. The study findings highlighted the importance of monitoring the cancer burden on mortality for people with AIDS.

[Epidemiology and management of patients with ano-genital warts in Italy]

PURPOSE

Overview of the impact of ano-genital warts in Italy.

COMMENTS

In Italy, the HPV infection is not subject to mandatory reporting, the available epidemiological data come from sentinel surveillance of STIs and show a high spread among young people under 25 years and an increase in reports after 2004. Although ano-genital warts are a benign disease, nonetheless they are characterized by a big relational and psycho-sexual impact, due also to high recurrence rates.

CONCLUSIONS

It is extremely useful to promote information activities, education in safe sex, early diagnosis and treatment of genital warts. In this context, primary prevention through vaccination represents a valid tool of protection.

Social and behavioural characteristics of a sample of AIDS Help-Line users never tested for HIV in Italy

BACKGROUND

We conducted an anonymous cross-sectional telephone survey among persons who had never undergone HIV testing to determine their socio-demographic characteristics, behaviour, risk perception and reasons for not being tested.

METHODS

A questionnaire was administered to adult callers to the Italian National AIDS Help-Line who reported that they had never been tested for HIV.

RESULTS

The study sample consisted of 539 individuals. The individual who does not undergo testing is young (median age 30 years), male (85.5%), unmarried (79.0%), employed (70.1%) and with a high educational level (81.6%). More than two-thirds of the respondents had little or no perception of risk. Among persons who had more than one sexual partner, 47.0% do not use a condom. When dividing the respondents into two groups (i.e. high risk and lower risk), the results showed that the proportion of respondents with a high risk was higher among women (73.1%), among persons >35 years (76.3%) and among persons with a low educational level (77.8%). Individuals who had hadbeen seen in health-care facilities also reported high-risk behaviour.

CONCLUSIONS

The results indicate the socio-demographic characteristics, behaviours, risk perception and reasons for not being tested among a sample of callers to Italy's National AIDS Help-Line, and they confirm the necessity of gearing prevention activities towards heterosexuals and young adults with a low perception of risk.

Identification of recent HIV infections and of factors associated with virus acquisition among pregnant women in 2004 and 2006 in Swaziland

BACKGROUND

HIV continues to spread at high rates in sub-Saharan Africa. In particular, Swaziland is one of the countries most affected by the HIV/AIDS pandemic. Monitoring of HIV infection in Swaziland is being made by periodical investigations on HIV prevalence in pregnant women. However, knowledge of proportion of recent HIV infections is important for epidemiologic purposes to assess HIV transmission patterns.

OBJECTIVES

To evaluate the proportion of recent HIV infections among pregnant women and its change overtime and to analyze factors associated with recent HIV infection in Swaziland.

STUDY DESIGN

HIV-positive sera from pregnant women were collected during the 2004 and 2006 National HIV Serosurveys conducted in Swaziland and tested for the HIV antibody avidity, in order to identify recent HIV infections. Socio-demographic and clinical information was also collected. A multivariate analysis was conducted to assess the association between recent HIV infection and socio-demographic and clinical factors.

RESULTS

A total of 1636 serum samples were tested for HIV antibody avidity. The overall proportion of recent infections was 13.8%, with no significant difference between 2004 and 2006 (14.6% vs. 13.1%, P>0.05, respectively). At the multivariate analysis, the younger age [14-19 vs. >or=20 years; adjusted odds ratio (aOR) 2.17, 95% CI: 1.45-3.24], as well as being at first pregnancy (1 vs. >or=2; aOR 1.61, 95% CI: 1.10-2.35) was independently associated with recent HIV infection.

CONCLUSIONS

This study shows no significant difference in the proportion of recent infections between 2004 and 2006 and suggests that young women and women at their first pregnancy are currently high-risk groups for HIV acquisition, highlighting the importance of developing targeted youth programmes to reduce the spread of HIV infection in the country.

Continued high prevalence of HIV, HBV and HCV among injecting and noninjecting drug users in Italy

We estimated the prevalence of HIV, HBV and HCV infections among injecting and noninjecting drug users treated within public drug-treatment centres in Italy to determine the correlates of infection. In the sample of 1330 drug users, the prevalence of HIV was 14.4% among drug injectors and 1.6% among non-injectors; the prevalence of HBV was 70.4% among injecting drug users and 22.8% among non-injectors and of HCV was 83.2% among injecting drug users and 22.0% among non-injectors. Old age, unemployment, and intravenous drug use were significantly correlated with each of the infections, as well as a longer history of injecting drug use. The results indicate that these infections continue to circulate among drug users, highlighting the need for monitoring of this group in Italy.

HIV virology and pathogenetic mechanisms of infection: a brief overview

Studies on HIV virology and pathogenesis address the complex mechanisms that result in the HIV infection of the cell and destruction of the immune system. These studies are focused on both the structure and the replication characteristics of HIV and on the interaction of the virus with the host. Continuous updating of knowledge on structure, variability and replication of HIV, as well as the characteristics of the host immune response, are essential to refine virological and immunological mechanisms associated with the viral infection and allow us to identify key molecules in the virus life cycle that can be important for the design of new diagnostic assays and specific antiviral drugs and vaccines. In this article we review the characteristics of molecular structure, replication and pathogenesis of HIV, with a particular focus on those aspects that are important for the design of diagnostic assays.

Laboratory diagnostics for HIV infection

Laboratory diagnosis of human immunodeficiency virus (HIV) infection is fundamental for detecting and monitoring infection. Many diagnostic tools are available that are based on both detection of HIV-specific antibodies and virus antigen, or nucleic acid. As technology evolves, HIV testing assays are being improved providing better sensitivity and specificity. In this short review, we summarize the common and new methodologies that are being used in laboratories, from the HIV antibody-based assays to the new tests for the detection of HIV nucleic acids.

Suggested strategies for the laboratory diagnosis of HIV infection in Italy

HIV/AIDS surveillance data indicate that, in 2008, approximately one-fourth of all HIV infections in adults remain undiagnosed in Italy and that close to 60% of AIDS diagnosed individuals discovered their seropositivity at the diagnosis of AIDS. Late diagnosis of HIV infection is associated with increased mortality and morbidity and increased cost to healthcare services. From a public health perspective, knowledge of HIV status is associated with a reduction in risk behaviour. Thus, a routine screening for HIV infection is important for both a better prognostic outcome, and control of HIV spreading in the population. In Italy there are not shared guidelines for the laboratory diagnosis. In this paper, we suggest two algorithms that can be adopted for the diagnosis of HIV infection in individuals undergoing HIV testing.

Elevated risks of death for diabetes mellitus and cardiovascular diseases in Italian AIDS cases

After the introduction of highly active antiretroviral therapies (HAART), an increased incidence of insulin resistance, diabetes mellitus (DM), and cardiovascular diseases has been described. The impact of such conditions on mortality in the post-HAART era has been also assessed in various modes in the literature. In this paper, we report on the death risks for DM, myocardial infarction, and chronic ischemic heart diseases that were investigated among 9662 Italian AIDS cases diagnosed between 1999 and 2005. Death certificates reporting DM, myocardial infarction, and chronic ischemic heart diseases were reviewed to identify the underlying cause of death, and to compare the observed numbers of deaths with the expected ones from the sex- and age-matched, general population of Italy. Person-years at risk of death were computed from date of AIDS diagnosis up to date of death or to December 31, 2006. Standardized mortality ratios (SMR) and their 95% confidence intervals (CI) were computed. DM and cardiovascular diseases were the cause of death for 43 out of 3101 deceased AIDS cases (i.e., 1.4% of all deaths). In comparison with the general population, the risks of death were 6.4-fold higher for DM (95% CI:3.5-10.8), 2.3-fold higher for myocardial infarction (95% CI:1.4-3.7) and 3.0 for chronic ischemic heart diseases (95% CI: 1.5-5.2).

The impact of Kaposi sarcoma and non-Hodgkin lymphoma on mortality of people with AIDS in the highly active antiretroviral therapies era

BACKGROUND

Kaposi sarcoma (KS) and non-Hodgkin lymphoma (NHL) have strongly diminished in the HAART era, but their impact on life expectancy of people with AIDS (PWA) needs to be monitored. We aimed at quantifying the burden of KS and NHL on mortality of PWA in the HAART period in Italy.

METHODS

Death certificates of 3209 PWA diagnosed in 1999-2006 who died as of December 2006 were reviewed to identify those deaths in which KS or NHL was the underlying cause. Standardized mortality ratios (SMR) were computed.

RESULTS

KS or NHL appeared in 4.3% and 14.6% death certificates, respectively; they were the underlying cause of death in 3.1% and 13.4% of cases. SMR were 8698-fold higher for KS and 349-fold higher for NHL, and tended to decline over the study period.

CONCLUSION

KS and NHL caused about 16% of deaths of PWA in the HAART era, with 100-fold higher risks of death compared to the Italian general population also in recent years. Clinicians and public health officials should be aware of the persisting negative impact of these cancers on life expectancy of PWA.

The epidemic of HIV infection and AIDS, promotion of testing, and innovative strategies

In Europe, the incidence of new diagnoses of HIV infection in 2008 was 86.7 cases per one million population, and most cases were attributable to sexual transmission. In Italy, in 2007, the incidence was 60.0 cases per one million population (in the areas in which surveillance exists), and 73.7% of the cases were attributable to sexual transmission. At present, there are an estimated 170,000-180,000 persons living with HIV/AIDS in Italy, some of whom are unaware of being infected. Based on available epidemiological data and taking into consideration the level of risk of exposure to HIV, we describe several proposals for promoting access to HIV testing in diverse population groups and contexts, including some innovative approaches. The promotion of HIV testing is fundamental for public health and human rights and must be associated with treatment, care and prevention activities, which must be guaranteed for the entire population.