The Spectrum projection package: improvements in estimating mortality, ART needs, PMTCT impact and uncertainty bounds.

BACKGROUND: The approach to national and global estimates of HIV/AIDS used by UNAIDS starts with estimates of adult HIV prevalence prepared from surveillance data using either the Estimation and Projection Package (EPP) or the Workbook. Time trends of prevalence are transferred to Spectrum to estimate the consequences of the HIV/AIDS epidemic, including the number of people living with HIV, new infections, AIDS deaths, AIDS orphans, treatment needs and the impact of treatment on survival. METHODS: The UNAIDS Reference Group on Estimates, Modelling and Projections regularly reviews new data and information needs and recommends updates to the methodology and assumptions used in Spectrum. The latest update to Spectrum was used in the 2007 round of global estimates. RESULTS: Several new features have been added to Spectrum in the past two years. The structure of the population was reorganised to track populations by HIV status and treatment status. Mortality estimates were improved by the adoption of new approaches to estimating non-AIDS mortality by single age, and the use of new information on survival with HIV in non-treated cohorts and on the survival of patients on antiretroviral treatment (ART). A more detailed treatment of mother-to-child transmission of HIV now provides more prophylaxis and infant feeding options. New procedures were implemented to estimate the uncertainty around each of the key outputs. CONCLUSIONS: The latest update to the Spectrum program is intended to incorporate the latest research findings and provide new outputs needed by national and international planners.

Lack of effect of chemokine receptor CCR2b gene polymorphism (64I) on HIV-1 plasma RNA viral load and immune activation among HIV-1 seropositive female workers in Abidjan, Côte d'Ivoire.

The prevalence of the CCR2b-V64I mutation among human immunodeficiency virus (HIV)-seropositive and -seronegative female workers and the potential effect of heterozygosity of this mutation on HIV-1 plasma RNA viral load and markers of immune activation were assessed. CCR2b-V64I was detected by polymerase chain reaction, followed by restriction enzymes analysis; plasma viral load was measured by the Amplicor HIV-1 monitor assay and CD4(+) T-cell counts and markers of immune activation by standard three-color FACscan flow cytometry. Of the 260 female workers, 56 (21.5%) were heterozygous for CCR2b-V64I, and 8 (3%) were homozygous. Of the 99 HIV-seronegative female workers, 19 (19.2%) were heterozygous for the CCR2b-V64I mutation compared with 37 (23%) of the 161 HIV-seropositive FSW (P = 0.47). In a univariate analysis of viral load among HIV-seropositive FSW, no difference was noted between those heterozygous for or without the mutation; both groups had plasma viral loads of 5.0 log(10) copies/ml. After controlling for the effects of CD4(+) T-cell counts in a multivariate analysis, no significant difference was observed between the groups in viral load or in markers of immune activation. The data suggest that the presence of the CCR2b mutation has no effect on HIV-1 plasma viral load and markers of immune activation in our study population. The finding that the frequency of this mutation is similar in HIV-seropositive and -seronegative female workers suggests that its presence is not associated with increased risk of HIV infection.