Alex Welte, PhD

Research Fellow

Research theme: Measuring Infection and Disease

The biggest single issue that has Alex has been engaged with over the last few years is the challenge of defining, and then applying in the field, laboratory based characterizations of ‘recent infection’. This idea, and the SACEMA group’s work in this area, has attracted a lot of interest in recent years as it offers tremendous potential to improve epidemiological surveillance. Tools arising out of this work are available from the Comprehensive R Archive Network, as a package called inctools.

Alex was director of SACEMA from July 2010 to June 2016. Before that, Alex was in the School of Computational and Applied Mathematics at the University of the Witwatersrand, where he was involved with SACEMA projects since the beginning of the centre’s existence. A physicist by training, he is interested in a diverse range of projects involving the mathematical modeling of biological, chemical and population-dynamic processes.

ORCID ID: 0000-0001-7139-7509

Recent publications

Potential for high dynamic range Sedia Limiting Antigen antibody assay to support viral load monitoring during antiretroviral therapy
Sempa JB, Welte A

PLOS ONE

(2024)

https://doi.org/10.1371/journal.pone.0303393
The evolution and interpretation of seroprevalence of SARS-CoV-2 antibodies among South African blood donors from the Beta to Omicron variant-driven waves
Vermeulen M, Mhlanga L, Sykes W, Cable R, Coleman C, Pietersen N, Swanevelder R, Glatt TN, Bingham JL, van den Berg K, Grebe PE, Welte A

Vox Sanguinis

(2024)

https://doi.org/10.1111/vox.13571
Evidence of HIV incidence reduction in young women, but not in adolescent girls, in KwaZulu-Natal, South Africa
Mhlanga L, Welte A, Grebe PE, Ohler L, van Cutsem G, Huerga H, Conan N

IJID Regions

(2023)

https://doi.org/10.1016/j.ijregi.2023.07.004
Coronavirus Disease 2019 Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Infection in the United States Before the Delta- and Omicron-Associated Surges: A Retrospective Cohort Study of Repeat Blood Donors
Grebe PE, Yu AE, Bravo MD, Welte A, Bruhn RL, Stone M, Green V, Williamson PC, Feldstein LR, Jones JM, Busch MP, Custer B

The Journal of Infectious Diseases

(2022)

https://doi.org/10.1093/infdis/jiac318
HIV incidence estimation among female sex workers in South Africa: a multiple methods analysis of cross-sectional survey data
Kassanjee R, Welte A, Otwombe KN, Jaffer M, Milovanic M, Hlongwane KE, Puren A, Hill N, Mbowane V, Dunkle K, Gray G, Abdullah F, Jewkes R, Coetzee J

The Lancet HIV

(2022)

https://doi.org/10.1016/S2352-3018(22)00201-6
Quantitative interpretation of Sedia LAg Assay test results after HIV diagnosis
Sempa JB, Grebe PE, Welte A

PLOS ONE

(2022)

https://doi.org/10.1371/journal.pone.0271763
Estimates of prevalence of anti-SARS-CoV-2 antibodies among blood donors in South Africa in March 2022
Bingham JL, Cable R, Coleman C, Glatt TN, Grebe PE, Mhlanga L, Nyano C, Pieterson N, Swanevelder R, Swarts A, Sykes W, van den Berg K, Vermeulen M, Welte A

medRxiv

(2022)

https://doi.org/10.21203/rs.3.rs-1687679/v2
Estimates of prevalence of anti-SARS-CoV-2 antibodies among blood donors in eight provinces of South Africa in November 2021
Cable R, Coleman C, Glatt T, Grebe PE, Mhlanga L, Nyano C, Pieterson N, Swanevelder R, Swarts A, Sykes W, van den Berg K, Vermeulen M, Welte A

medRxiv

(2022)

https://doi.org/10.21203/rs.3.rs-1359658/v1
Smoothing age/time structure of HIV prevalence, for optimal use in synthetic cohort based incidence estimation
Mhlanga L, Grebe PE, Welte A

medRxiv

(2021)

https://doi.org/10.21203/rs.3.rs-959136/v1
Community-led cross-sectional study of social and employment circumstances, HIV and associated factors amongst female sex workers in South Africa: study protocol
Milovanovic M, Jewkes R, Otwombe KN, Jaffera M, Hopkins K, Hlongwe KE, Mathaludi M, Mbowane V, Graya H, Dunkle K, Huntg G, Welte A, Kassanjee R, Slingersj N, Vanleeuwj L, Pureng A, Kinghorna A, Martinsona N, Abdullahj F, Coetzee J

Global Health Action

(2021)

https://doi.org/10.1080/16549716.2021.1953243