Examining the Role of Network Structure in HIV Transmission among People who Inject Drugs in the Philippines: A Tale of Two Cities

While HIV growth has slowed globally, new HIV epidemics among people who inject drugs (PWID) continue to emerge [1-4]. These epidemics are marked by periods of unusually rapid growth, where HIV increases from virtually 0% to 20-50% within 3-6 years [5-6]. In concentrated epidemics, HIV epidemics among PWID could precipitate larger-scale heterosexual epidemics [7-10], which further underscores the urgent need to find effective ways to reach and deliver prevention services to PWID. We studied the emergence of HIV among PWID in two cities in the Philippines. The epidemic began in Cebu City, where HIV prevalence grew from 0.6% in 2009 to 50% in 2010 [11]. Expanded surveillance in neighboring Mandaue City found more limited spread of infection, with HIV prevalence reaching only 3.5% in 2011[12], rising to 38% in 2013 [13]. We used exponential random graph models (ERGMs) to simulate network structures and assess whether differences in network structure could explain variation in HIV prevalence patterns in the two cities. We further analyzed genetic sequencing data to consider the extent of overlap or linkage between networks. Simulated networks showed distinct differences between the two cities. We found smaller network components in Mandaue than in Cebu (1082 v 2980), which may explain the limited spread of HIV there. We also found that Cebu networks exhibited higher degree (21.5 v 10.8), lower clustering (0.29 v 0.39), and shorter average paths (3.3 v 3.8), all of which would facilitate rapid spread of infection across the network. A phylogenetic tree showed high bootstrap support for a large cluster of HIV infections (N = 172), predominantly from PWID from Cebu and Mandaue (85%), which suggests that HIV infection in the two cities arose from a common source infection. This work suggests that the emergence of a rapidly growing epidemic among PWID in Cebu City spread to Mandaue City, but network structures initially prevented growth of infection. The fragmented network in Mandaue initially prevented penetration of infection into the connected portion of the network. Future work applying transmission modeling to these networks may offer important insights to the role of networks on HIV in these populations.Doctor of Philosoph

Comparing acne follow-up: teledermatology versus outpatient dermatology visits

The application of teledermatology for evaluating acne patients has yielded comparable therapeutic outcomes with traditional face-to-face evaluation, but follow-up compliance between these modalities is not well-studied. Our objective is to compare the rate and duration of follow-up between acne patients initially evaluated by teledermatology versus in-person outpatient consultation. Electronic medical review of acne patients, 18-35 years-old seen via teledermatology and face-to-face evaluation at the University of Pittsburgh Medical Center between 2010-2018 was performed. Teledermatology patients were less likely to follow-up in the first 90 days (13.0% versus 31.0%, P<0.001) compared to patients seen face-to-face with overall follow-up rates of 22% among both modalities. The median time to follow-up was 45.5 days (IQR: 13/57) in the teledermatology group compared to 64 days (IQR: 56/77) in the face-to-face group (P<0.001). Teledermatology patients were more likely to be treated with oral antibiotics (43.0% versus 28.5%) or oral spironolactone (18.5% versus 12.5%) compared to patients seen face-to-face (P<0.001). Teledermatology poses a promising solution to extend dermatologic care with earlier access to follow-up. Our data demonstrates a need to improve teledermatology follow-up education to improve follow-up care

Differences between self-reported and electronically monitored adherence among patients receiving antiretroviral therapy in a resource-limited setting

Measurement of adherence to antiretroviral therapy (ART) by patient self-report is common in resource-limited settings but widely believed to overstate actual adherence. The extent to which these measures overstate adherence has not been examined among a large patient population

New Survey Questions and Estimators for Network Clustering with Respondent-Driven Sampling Data

Clustering coefficient estimation in respondent-driven samplin

Comparing acne follow-up: teledermatology versus outpatient dermatology visits

The application of teledermatology for evaluating acne patients has yielded comparable therapeutic outcomes with traditional face-to-face evaluation, but follow-up compliance between these modalities is not well-studied. Our objective is to compare the rate and duration of follow-up between acne patients initially evaluated by teledermatology versus in-person outpatient consultation. Electronic medical review of acne patients, 18-35 years-old seen via teledermatology and face-to-face evaluation at the University of Pittsburgh Medical Center between 2010-2018 was performed. Teledermatology patients were less likely to follow-up in the first 90 days (13.0% versus 31.0%, P<0.001) compared to patients seen face-to-face with overall follow-up rates of 22% among both modalities. The median time to follow-up was 45.5 days (IQR: 13/57) in the teledermatology group compared to 64 days (IQR: 56/77) in the face-to-face group (P<0.001). Teledermatology patients were more likely to be treated with oral antibiotics (43.0% versus 28.5%) or oral spironolactone (18.5% versus 12.5%) compared to patients seen face-to-face (P<0.001). Teledermatology poses a promising solution to extend dermatologic care with earlier access to follow-up. Our data demonstrates a need to improve teledermatology follow-up education to improve follow-up care