Frequency and determinants of use of antiretroviral and prophylactic therapies against Pneumocystis carinii Pneumonia (PCP) before AIDS diagnosis in Italy

Impact of chemorophylaxis policy for AIDS-immunocompromised patients on emergence of bacterial resistance

Chemoprophylaxis (antibiotic prophylaxis) is a long relied-upon means of opportunistic infection management among HIV/AIDS patients, but its use represents an evolutionary tradeoff: Despite the benefits of chemoprophylaxis, widespread use of antibiotics creates a selective advantage for drug-resistant bacterial strains. Especially in the developing world, with combined resource limitations, antibiotic misuse, and often-poor infection control, the emergence of antibiotic resistance may pose a critical health risk. Extending previous work that demonstrated that this risk is heightened when a significant proportion of the population is HIV/AIDS-immunocompromised, we work to address the relationship between HIV/AIDS patients' use of antibiotic chemoprophylaxis and the emergence of resistance. We apply an SEIR compartmental model, parameterized to reflect varying percentages of chemoprophylaxis use among HIV/AIDS+ patients in a resource-limited setting, to investigate the magnitude of the risk of prophylaxis-associated emergence versus the individual-level benefits it is presumed to provide. The results from this model suggest that, while still providing tangible benefits to the individual, chemoprophylaxis is associated with negligible decreases in population-wide morbidity and mortality from bacterial infection, and may also fail to provide assumed efficacy in reduction of TB prevalence.

The association of perceived health, clinical status, and initiation of HAART (highly active antiretroviral therapy) in adolescents

PURPOSE

To examine factors associated with the initiation of highly active antiretroviral therapy (HAART) in adolescents to understand better how current National Institutes of Health (NIH) Guidelines are being used in practice.

METHODS

HIV infected and HAART-naive adolescents seen at 15 REACH clinical sites were selected. Repeated measures methodology using generalized estimating equations was applied to identify associations between subject demographic characteristics, risk behaviors, perceived health, and clinical status with the outcome measure of HAART initiation during the first 24 study months.

RESULTS

A total of 219 subjects were eligible for analysis; HAART was prescribed in 115 (53%). Significant univariate associations with HAART prescription included lower CD4(+) T cell counts (OR = 1.7, 95% CI: 1.1-2.6), higher viral loads (OR = 2.7, 95% CI: 1.5-5.0), and calendar year of HAART prescription (OR as high as 2.4, 95% CI: 1.1-5.2). Multivariate results showed that after controlling for CD4(+) T cell counts below 500 cells/mm(3), higher plasma HIV-1 RNA (<or=10,000 copies per ml), and temporal factors, having a high school diploma/GED but no further education (OR = 2.7, 95% CI: 1.3-5.5) and subject's perception of poor health status (OR = .987; 95% CI: .975- .999) were independently associated with prescription of HAART. HAART was most likely to be prescribed during the first half of 1998 in this cohort (OR = 10.8; 95% CI: 4.0-29.0).

CONCLUSIONS

In this first ever study of HAART prescription in adolescents infected with HIV, perception of poor health status and having a high school diploma/GED were independently associated with prescription of HAART suggesting that the personal decision to accept therapy is related to the belief that one's health is deteriorating and that the decision to prescribe therapy may be linked in some fashion to the prescriber's assessment of the patient's ability to master the regimen as well as clinical status.

Sexual behaviour of heterosexual individuals with HIV infection naive for antiretroviral therapy in Italy

BACKGROUND

Specific information about determinants of sexual behaviour of HIV infected heterosexuals, like injecting drug use (IDU), are essential to design interventions aimed at promoting safer sex practices.

METHODS

We analysed data on sexual behaviour collected, between March 1997 and March 1999, through a self administered questionnaire among 1050 IDUs and 642 non-IDU heterosexuals enrolled in a prospective multicentre cohort study on the natural history of HIV infection.

RESULTS

Among non-IDU heterosexuals, more women (48.5%) than men (25.1%) (p<0.001) reported that they were infected by HIV positive regular partners whose HIV status they were not aware of. Among the 1119 heterosexual males, one fifth reported having had more than 25 sexual partners during their lifetime. Condom use in the last sexual intercourse was more common among heterosexual IDUs (64.9%) than among non-IDU heterosexual males (58.3%) (p=0.05). Heterosexual IDU males were more likely (66.7%) than non-IDU heterosexuals (50.6%) to have an HIV negative partner (p<0.001). Of the 573 heterosexual females studied, 10.2% reported having had more than 25 lifetime sex partners. This proportion was higher among heterosexual IDUs (18.8%) than among non-IDU heterosexuals (4.3%) (p<0.001). Nearly 50% of the women in both groups reported having used a condom in the last intercourse. Almost 57% of heterosexual IDUs had a current HIV negative partner, compared with 34.9% non-IDU heterosexuals (p<0.001). In both sexes, the findings from univariate analysis were confirmed by multiple logistic regression analysis.

CONCLUSIONS

This study identified some important differences, in both males and females, in sexual lifestyles according to injecting drug use (for example, in terms of HIV negative partners). This observation indicates the need to tailor HIV prevention messages according to history of injecting drug use.

Increasing survival time after AIDS in Italy: the role of new combination antiretroviral therapies. Tuscany AIDS Study Group

BACKGROUND

In Italy, antiretroviral combination therapy was adopted in mid-1995 and protease inhibitors in mid-1996.

OBJECTIVE

To conduct a prospective, population-based, observational study to evaluate the effect of these therapies on the survival of persons with AIDS (PWA).

METHODS

PWA living in the Tuscany region diagnosed between 1985 and 31 March 1997 (National AIDS Registry) were studied. Information on antiretroviral drugs, prophylactic treatment, CD4 cell count, and AIDS-defining illnesses was collected for PWA still alive at 1 January 1996 and those diagnosed thereafter (analysis cut-off date, 30 November 1997). Kaplan-Meier curves were calculated by year of diagnosis. A Cox model was then used to estimate the adjusted (by sex, age, HIV exposure category, CD4 cell count, type and number of AIDS-defining illnesses) relative hazard (RH) of death by year of diagnosis and calendar date (considered as a time-dependent variable). Similar analyses were repeated for PWA diagnosed after 1989, having been stratified by disease-specific AIDS condition. A final analysis was performed for PWA still alive at 1 January 1996 or diagnosed thereafter for estimating the effect of single, double and triple combination therapy (time-dependent variables), having adjusted for the above variables and for prophylactic treatment.

RESULTS

A total of 1683 (79.5%) out of 2118 PWA died before 1 December 1997. Use of more potent combination therapies, including protease inhibitors, greatly increased during 1997. Median survival was 2.9, 12.3, 13.4, 11.4 and 17.6 months for diagnoses before 1987, in 1987-1990, 1991-1993, 1994 and 1995, respectively; an estimated 62% of those diagnosed in 1996-1997 had survived 15 months after diagnosis. The Cox model showed a trend of decrease of RH for calendar time starting in the first half of 1996, compared with 1994. When stratifying by specific AIDS-defining disease there was no statistically significant evidence that the improved overall survival was due to increased survival only for certain diseases. The final multivariate analysis for the 771 PWA still alive at 1 January 1996 or diagnosed thereafter estimated significant RH < 1.0 for double and triple therapy (RH, 0.61 and 0.36, respectively) compared with no therapy.

CONCLUSIONS

A significant reduction in risk of death after AIDS was observed from the second half of 1996, apparently due to the widespread use of antiretroviral combination therapies.