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

The effect of buoyancy on upper branch Tollmien-Schlichting waves

We investigate the effect of buoyancy on the upper-branch linear stability characteristics of an accelerating boundary-layer flow. The presence of a large thermal buoyancy force significantly alters the stability structure. As the factor G (which is related to the Grashof number of the flow, and defined in Section 2) becomes large and positive, the flow structure becomes two layered and disturbances are governed by the Taylor-Goldstein equation. The resulting inviscid modes are unstable for a large component of the wavenumber spectrum, with the result that buoyancy is strongly destabilizing. Restabilization is encountered at sufficiently large wavenumbers. For G large and negative the flow structure is again two layered Disturbances to the basic flow are now governed by the steady Taylor—Goldstein equation in the majority of the boundary layer, coupled with a viscous wall layer. The resulting eigenvalue problem is identical to that found for the corresponding case of lower-branch Tollmien—Schlichting waves, thus suggesting that the neutral curve eventually becomes closed in this limit.Eunice W. Mureithi, James P. Denier and Jillian A. K. Stot

Assessment of gestational age at antenatal care visits among Kenyan women to inform delivery of a maternal respiratory syncytial virus (RSV) vaccine in low- and middle-income countries [version 1; peer review: 2 approved]

Background: Maternal respiratory syncytial virus (RSV) vaccines that are likely to be implementable in low- and middle-income countries (LMICs) are in final stages of clinical trials. Data on the number of women presenting for antenatal care (ANC) per day and proportion attending within the proposed gestational window for vaccine delivery, is a prerequisite to guide development of vaccine vial size and inform vaccine uptake in this setting. Methods: We undertook administrative review and abstraction of ANC attendance records from 2019 registers of 24 selected health facilities, stratified by the level of care, from Kilifi, Siaya and Nairobi counties in Kenya. Additional data were obtained from Mother and Child Health (MCH) booklets of women in each of the Health and Demographic Surveillance System (HDSS) areas of Kilifi, Nairobi and Siaya. Data analysis involved descriptive summaries of the number (mean, median) and proportion of women attending ANC within the gestational window period of 28-32 weeks and 24-36 weeks. Results: A total of 62,153 ANC records were abstracted, 33,872 from Kilifi, 19,438 from Siaya and 8,943 from Nairobi Counties. The median (Interquartile range, IQR) number of women attending ANC per day at a gestational age window of 28-32 and 24-36 weeks, respectively, were: 4 (2-6) and 7 (4-12) in dispensaries, 5 (2-9) and 10 (4-19) in health centres and 6 (4-11) and 16 (10-26) in county referral hospitals. In the HDSS areas of Kilifi, Siaya and Nairobi, pregnant women attending at least one ANC visit, within a window of 28-32 weeks, were: 77% (360/470), 75% (590/791) and 67% (547/821), respectively. Conclusions: About 70% of pregnant women across three distinct geographical regions in Kenya, attend ANC within 28-32 weeks of gestation. A multidose vial size with about five doses per vial, approximates daily ANC attendance and would not incur possible wastage in similar settings

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

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

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

A Venue-Based Approach to Reaching MSM, IDUs and the General Population with VCT: A Three Study Site in Kenya

A venue-based HIV prevention study which included Voluntary Counseling and Testing (VCT) was conducted in three diverse areas of Kenya— Malindi, Nanyuki and Rachounyo. Aims of the study were to: 1) assess the acceptability of VCT for the general population, men who have sex with men (MSM), and injecting drug users (IDUs) within the context of a venue-based approach; 2) determine if there were differences between those agreeing and not agreeing to testing; and 3) study factors associated with being HIV positive. Approximately 98% of IDUs and 97% of MSM agreed to VCT, providing evidence that populations with little access to services and whose behaviors are stigmatized and often considered illegal in their countries can be reached with needed HIV prevention services. Acceptability of VCT in the general population ranged from 60% in Malindi to 48% in Nanyuki. There were a few significant differences between those accepting and declining testing. Notably in Rachuonyo and Malindi those reporting multiple partners were more likely to accept testing. There was also evidence that riskier sexual behavior was associated with being HIV positive for both men in Rachounyo and women in Malindi. Overall HIV prevalence was higher among the individuals in this study compared to individuals sampled in the 2008–2009 Kenya Demographic and Health Survey, indicating the method is an appropriate means to reach the highest risk individuals including stigmatized populations

Agricultural Information Worldwide, vol. 6, 2014

Agricultural Information Worldwide, Volume 6, 2014In this issue: FROM THE EDITOR’S DESK / Jim Morris-Knower (3); Conference Reflections / Antoinette Paris Greider (4). ARTICLES: Keynote Address: The State of Information Literacy Policy: A Global Priority / Sharon Weiner (5); Framing of Climate Change News in Four National Daily Newspapers in Southern Nigeria / Agwu Ekwe Agwu, Chiebonam Justina Amu (11); Access and Use of Information Communication Technologies by Women Staff of Public Extension Service in the North Central Zone of Nigeria / Agwu Ekwe Agwu, Elizabeth Ene Ogbonnah (18); Providing User Preferred Information Resources for a New Faculty of Agriculture, Nnamdi Azikiwe Univeristy, Awka, Nigeria / Chinwe V. Anunobi, Andrew U. Ogbonna (25); Diffusion of Scientific Knowledge in Agriculture: The Case for Africa / Shimelis Assefa, Daniel Gelaw Alemneh, Abebe Rorissa (34); The Use of Social Media in Agricultural Research Workflows in Ghana and Kenya / Justin Chisenga, Richard Kedemi, Joel Sam (48); Towards Mobile Agricultural Information Services in Zimbabwean Libraries: Challenges and Opportunities for Small Sacle Farmers in Utilizing ICTs for Sustainable Food Production / Collence Takaingenhamo Chisita, Thembani Malapela (58); Agriculture and Natural Resource Scientists' Biodiversity Information Needs: Barriers and Facilitators to Use and Access in the U.S. Southeast / Miriam L.E. Steiner Davis, Carol Tenopir, Suzie Allard (66); French Agricultural Research Institute Paves the Way to Open Access: Feedback from CIRAD / Marie-Claude Deboin, Cécile Fovet-Rabot (77); Exploring Relevance of Agro Input Dealers in Disseminating and Communicating of Soil Fertility Management Knowledge: The Case of Siaya and Trans Nzoia Counties, Kenya / T. B. Etyang, J. J. Okello, S. Zingore, P. F. Okoth, F. S. Mairura, A. Mureithi, B. S. Waswa (82); Plantwise Knowledge Bank: Building Sustainable Data and Information Processes to Support Plant Clinics in Kenya / Cambria Finegold, MaryLucy Oronje, Margo C. Leach, Teresia Karanja, Florence Chege, Shaun L.A. Hobbs (96); Innovation in Extension Services for Improved Farmer Access to Agricultural Information in Uganda / Patrick Kasangaki (102); Managing a Web Portal Adapting to New Technologies / Soonho Kim, Kathryn Pace Kincheloe, Yuan Gao, Valdete Berisha (107); Library Outreach to University Farm Staff / Emily MacKenzie, Natalie Waters (114); Enhancing Access to Research in Institutional Repositiories through API / Ryan Miller, Indira Yerramareddy (118); Building Capacity of Smallholder Farmers in Agribusiness and Entrepreneurship Skills in Northern Uganda / Basil Mugonola, Callistus Baliddawa (122); The Data Landscpe of the Coral Triangle / Jeanette Norris (127); Agricultural Information Access Among Smallholder Farmers: Comparative Assessment of Peri-Urban and Rural Settings in Kenya / Dorine Odongo (133); From Local to Global: Launching the New Rangelands West Portals and Database / Jeanne L. Pfander, Barbara S. Hutchinson, Valeria Pesce, Matt Rahr (138); Seed Village Programme: An Innovative Approach for Small Farmers / Dheeraj Singh, M. K. Chaudhary, M. L. Meena, M. M. Roy (143); Transformation of Indian Agricultural Libraries in a Digital and Collaborative Era: A Case Study / Neena Singh, Anil Chikate (147); Collaboration for Impact / Indira Yerramareddy, Luz Marina Alvaré, Katarlah Taylor (157