Estimating HIV Incidence among Adults in Kenya and Uganda: A Systematic Comparison of Multiple Methods

CITATION: Kim, A. A. et al. 2011. Estimating HIV incidence among adults in Kenya and Uganda : a systematic comparison of multiple methods. PLos ONE, 6(3): e17535, doi:10.1371/journal.pone.0017535.The original publication is available at http://journals.plos.org/plosoneBackground: Several approaches have been used for measuring HIV incidence in large areas, yet each presents specific challenges in incidence estimation. Methodology/Principal Findings: We present a comparison of incidence estimates for Kenya and Uganda using multiple methods: 1) Epidemic Projections Package (EPP) and Spectrum models fitted to HIV prevalence from antenatal clinics (ANC) and national population-based surveys (NPS) in Kenya (2003, 2007) and Uganda (2004/2005); 2) a survey-derived model to infer age-specific incidence between two sequential NPS; 3) an assay-derived measurement in NPS using the BED IgG capture enzyme immunoassay, adjusted for misclassification using a locally derived false-recent rate (FRR) for the assay; (4) community cohorts in Uganda; (5) prevalence trends in young ANC attendees. EPP/Spectrum-derived and survey-derived modeled estimates were similar: 0.67 [uncertainty range: 0.60, 0.74] and 0.6 [confidence interval: (CI) 0.4, 0.9], respectively, for Uganda (2005) and 0.72 [uncertainty range: 0.70, 0.74] and 0.7 [CI 0.3, 1.1], respectively, for Kenya (2007). Using a local FRR, assay-derived incidence estimates were 0.3 [CI 0.0, 0.9] for Uganda (2004/2005) and 0.6 [CI 0, 1.3] for Kenya (2007). Incidence trends were similar for all methods for both Uganda and Kenya. Conclusions/Significance: Triangulation of methods is recommended to determine best-supported estimates of incidence to guide programs. Assay-derived incidence estimates are sensitive to the level of the assay's FRR, and uncertainty around high FRRs can significantly impact the validity of the estimate. Systematic evaluations of new and existing incidence assays are needed to the study the level, distribution, and determinants of the FRR to guide whether incidence assays can produce reliable estimates of national HIV incidence.http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0017535Publisher's versio

Trends in HIV prevalence among young women aged 15–24 years attending antenatal clinics in Kenya, 2000–2005.

<p>Trends in HIV prevalence among young women aged 15–24 years attending antenatal clinics in Kenya, 2000–2005.</p

Trends in HIV incidence by estimation method, adults aged 15–49 years, Uganda, 2000–2007.

<p>Trends in HIV incidence by estimation method, adults aged 15–49 years, Uganda, 2000–2007.</p

HIV Incidence and Prevalence Rates in the Year of the National Survey, by Estimation Method, Kenya and Uganda.

<p>*Among adults aged 15–49 years.</p><p>†Uganda 2000–2005.</p><p>‡Kenya 2003–2007.</p><p>a. All assay-derived estimates were weighted to account for unequal probability of selection and adjusted for non-response, where necessary. For the 2007 Kenya estimate, any participant that reported current ARV use was excluded from the incidence analysis.</p><p>b. The Uganda FRR was generated from: (1) pooled data from 699 ARV naive long-term specimens from Rakai (76/473) and rural Tororo districts (28/226) in Uganda that classified as false-recent on the BED assay.</p><p>c. Statistically significant difference observed in assay-derived estimate and the EPP/Spectrum estimate in Uganda 2005.</p><p>d. No data published on community cohort incidence in Kenya.</p><p>e. 95% confidence intervals not reported.</p><p>f. All participants that that reported current ARV use were excluded from the 2007 Kenya HIV prevalence estimate.</p

Trends in HIV prevalence among young women aged 15–24 years attending antenatal clinics in Uganda, 2000–2007.

<p>Trends in HIV prevalence among young women aged 15–24 years attending antenatal clinics in Uganda, 2000–2007.</p