Author Archives: Steven Bellan

ICI3D Teaching Materials live on Figshare!

The 2017 Clinic on the Meaningful Modeling of Epidemiological Data (MMED) has come and gone, and left a wake of clinic faculty and participants happy to have spent two weeks together in beautiful Muizenberg, South Africa. This year we made a big push to help disseminate ICI3D teaching materials to a wider audience online. As part of this, we professionally recorded two days of MMED 2017. These video lectures, slides for all MMED 2017 lectures, and links to our R Tutorials Github repository can now be found on the ICI3D Figshare Collection. This provides resources lovingly polished by the ICI3D faculty (including many by Steve) over 8+ years in an open access, citable way.

We encourage those teaching or learning infectious disease ecology and epidemiology, or statistics to check these resources out! Please do cite us and let us know if you use them so we can keep records on their impact.

New lab publication: Antiretroviral therapy and HIV resistance in San Francisco

In a new paper in Proceedings of the Royal Society B, we investigated under what circumstances earlier initiation of antiretroviral therapy could decrease both the number of total new HIV infections and of new drug-resistant HIV infections amongst men who have sex with men (MSM) in San Francisco. Using a transmission model fit to data from this population, we find that this goal occurs when the second-line drug effectiveness (combination of resistance monitoring, biomedical drug efficacy, and adherence) exceeds 80%. However, these dual decreases in the number of new infections may misleadingly and seemingly paradoxically be accompanied by an increase in the proportion of new infections that are drug resistant. This work was led by Mingwang Shen, a PhD student visiting from Xi’an Jiaotong University, in close collaboration with Steve during Mingwang’s 2 year scholar exchange in Lauren Ancel Meyers’ Lab at The University of Texas at Austin.

Shen M, Xiao Y, Rong L, Meyers LA, and Bellan SE (2017). Early antiretroviral therapy and potent second-line drugs could decrease HIV incidence of drug resistance. Proc R Soc B. (postprint PDF, journal PDF) (Appendix)

New lab publication: Analysis of the Tanzanian National Database

Many studies have characterized the immune system recovery of HIV-infected patients following antiretroviral treatment, as evidenced by CD4+ cell count increases over time. Such analyses rarely have large enough samples to examine how patterns vary by sex and age.

In Means et al. 2016, published in PLOS ONE, we analyzed >200,000 observations of >30,000 individuals recorded by the outpatient monitoring system of the National AIDS Control Program in Tanzania. We found that older patients started treatment at higher CD4+ counts (i.e. earlier in disease progression) but experienced slower CD4+ recovery. We also found that earlier treatment initiation led to greater eventual CD4+ cell counts regardless of age or sex (figure below).

This publication arose from a group project initiated during the 2014 Clinic on the Meaningful Modeling of Epidemiological Data.



September 2016

At the beginning of September Dr. Bellan began his appointment as an Assistant Professor in the Department of Epidemiology and Biostatistics, College of Public Health at the University of Georgia. He is very excited to join the fantastic infectious disease research community at UGA!