This is a combined synopsis/solicitation for commercial items prepared in accordance with the format in Subpart 12.6, as supplemented with additional information included in this notice. This announcement constitutes the only solicitation: proposals are being requested and a written solicitation will not be issued.

The solicitation number is 2010-Q-12086 and this is a request for quotes.

The solicitation document and incorporated provisions and clauses are those in effect through Federal Acquisition Circular 2005-37.

Period of Performance
The period of performance shall be July 1, 2010 to June 30, 2012. A one year (12 months) option period following the base period is possible.

Line Items

ITEM SUPPLIES / SERVICES QTY / UNIT UNIT PRICE EXTENDED PRICE
0001 HIV Incidence Assay Validation
1 Each

Description/Work Statement

Background and Need
HIV incidence is defined as the rate at which new HIV infections occur, per unit of time. In contrast, HIV prevalence is defined as the proportion of persons infected with HIV or testing HIV positive at a single point in time. Whereas HIV prevalence is a measure of the burden of disease in a population at a given time, HIV incidence indicates the extent to which transmission of the virus is occurring over a defined period (e.g. a year). It is therefore the crucial epidemiological indicator of both the need for preventive interventions, and of their outcome.

A variety of laboratory assays have been developed to estimate HIV incidence using cross-sectional data. The advantage of these assays is that their use does not require following participants longitudinally nor collecting serial blood samples, but rather can be used on one blood sample collected at one point in time.

The BED capture enzyme immunoassay (hereafter termed the BED assay) measures the increasing proportion of HIV-1 IgG to total IgG after seroconversion to estimate HIV-1 incidence in cross-sectional settings. In 2005, the UNAIDS Reference Group on Estimates, Modeling and Projections issued a statement in response to preliminary data on the application of the BED-CEIA in HIV surveillance settings and selected validation studies which demonstrated that the assay overestimated HIV-1 incidence by misclassifying a number of individuals with long-term infection as recent infection in cross-sectional settings. This misclassification effect is particularly severe in settings with high HIV prevalence and may vary by HIV-1 subtype. UNAIDS called for further validation of the assay to improve specificity.

The recommended design for incidence assay validation is the application of the assay in cohorts of persons at risk for HIV infection, with additional follow-up of HIV positive persons, for at least one year or twice the length of the window period of the assay. This design enables the comparison of HIV incidence estimated by the assay at various cross-sectional time points after enrollment against directly observed incidence. Additionally this design enables one to quantify the proportion of persons known to be infected for longer than 1 year (false-recent rate). When this design cannot be conducted, the incidence assay can also be applied to a large cross-sectional sample of HIV-infected specimens from persons who had their prior HIV-positive test ≥ 1 year ago and who are not on treatment, to determine the proportion that misclassify as a recent infection on the assay. Care should be taken to ensure that the validation sample is representative of the non-recently infected individuals in the population in which the incidence survey will ultimately be carried out. At the minimum, the validation sample should have data on ART use, AIDS status, and HIV testing history to distinguish between true long-term infections and recent infections in the sample. Further, the validation sample should be appropriately powered in order to estimate the false-recent rate with an acceptable level of precision. The resulting false-recent rate from these validation studies can then be used to calibrate the incidence estimate for an improved estimate in the population of interest.

Project Objective
The primary objectives of this project are:

• To determine the proportion of samples from individuals in select populations in Eastern and Southern Africa with known HIV positive status of greater than 12 months that misclassify as recent infection on the assay (otherwise known as the "false-recent" rate).
• To estimate assay-derived incidence using the observed false-recent rate in similar cross-sectional sites in Eastern and Southern Africa where the incidence assay(s) have been or will be applied.
• To compare assay-derived incidence to other measures of incidence in the same population.

Scope of Work
There are ongoing cohort studies for HIV incidence in multiple sites in Africa to identify candidate sites for HIV prevention research among populations at risk for HIV infection. We propose to integrate incidence assay validation studies within these cohorts, particularly those in Eastern and Southern Africa for settings where false-recent rates have not been established (e.g. Ethiopia and Mozambique) but where assay-based incidence surveys have been conducted or currently being planned. Validation studies will: 1) quantify the level of misclassification among HIV-infected persons with > 12 months of infection on the various assays; 2) estimate assay-derived incidence in cross-sectional sites that are representative to the sample in which the false-recent rate is derived; 3) compare assay-based incidence to other measures of incidence (e.g. comparisons against directly observed incidence, other assays).

Technical Requirements
Task 1: Conduct a false recent calibration study for HIV-1 incidence assays to determine the percentage of false recent samples from individuals with known HIV positive status of greater than 12 month duration

• Develop protocol incorporating a false recent calibration study at the site
• Assist local staff to conduct data collection
• Assist local laboratory staff to conduct incidence assay testing on entire sample of known long-term infections using:
o BED capture enzyme immunoassay
o New developmental assays (such as: the rIDR-M avidity index assay, the rIDR-M limiting antigen avidity assay, and the rapid incidence prevalence assay).
• Assist local staff to conduct data analysis, including development of the local false-recent rate for HIV-1 incidence assays
• Assist local staff to develop a draft report on findings

Task 2: Estimate assay-derived incidence in a cross-sectional sample of HIV-infected persons at the study site and, where possible, compare to other measures of incidence (e.g. directly observed cohort incidence).
• Develop protocol incorporating incidence estimation in a cross-sectional samples at the site or proxy population
• Assist local laboratory staff to conduct incidence assay testing on a cross-sectional samples at the site or proxy populations using:
o BED capture enzyme immunoassay
o New developmental assays (such as: the rIDR-M avidity index assay, the rIDR-M limiting antigen avidity assay, and the rapid incidence prevalence assay)
• Assist local staff to conduct data analysis for incidence estimation
• Assist local staff to develop a draft report on findings

Reporting and Delivery Schedule

The following deliverables shall be delivered to the Contracting Officer's Technical Representative (COTR):

Description Copies Due Date
Draft report 2 December 30, 2011
Final report 2 June 30, 2012

Submission of Application:
Responses may be emailed to the attention of Terren Grimble at [email protected] by COB 7 June 2010. The solicitation number must be included on all documents submitted with the application package, as well as any other correspondence regarding this solicitation.