gems: An R Package for Simulating from Disease Progression Models.

Mathematical models of disease progression predict disease outcomes and are useful epidemiological tools for planners and evaluators of health interventions. The 𝖱 package is a tool that simulates disease progression in patients and predicts the effect of different interventions on patient outcome. Disease progression is represented by a series of events (e.

Cost-effectiveness of different strategies to monitor adults on antiretroviral treatment: a combined analysis of three mathematical models.

Background: WHO's 2013 revisions to its Consolidated Guidelines on antiretroviral drugs recommend routine viral load monitoring, rather than clinical or immunological monitoring, as the preferred monitoring approach on the basis of clinical evidence. However, HIV programmes in resource-limited settings require guidance on the most cost-effective use of resources in view of other competing priorities such as expansion of antiretroviral therapy coverage. We assessed the cost-effectiveness of alternative patient monitoring strategies.

Impact of viral load and the duration of primary infection on HIV transmission: systematic review and meta-analysis.

Objectives: HIV 'treatment as prevention' (TasP) describes early treatment of HIV-infected patients intended to reduce viral load and transmission. Crucial assumptions for estimating TasP's effectiveness are the underlying estimates of transmission risk. We aimed to determine transmission risk during primary infection, and describe the relation of HIV transmission risk to viral load.

Virologic response in children treated with abacavir-compared with stavudine-based antiretroviral treatment: a South African multi-cohort analysis.

Background: Initiation criteria and pediatric antiretroviral treatment regimens have changed over the past few years in South Africa. We reported worse early virological outcomes associated with the use of abacavir (ABC)-based regimens at 1 large site: here, we expand this analysis to multiple sites in the IeDEA-Southern Africa collaboration.

Methods: Data for 9543 antiretroviral treatment-naïve children <16 years at treatment initiation started on either stavudine/lamivudine (d4T/3TC) or ABC/3TC with efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r) treated at 6 clinics in Johannesburg and Cape Town, South Africa, were analyzed with χ tests and logistic regression to evaluate viral suppression at 6 and 12 months.

Tracing of patients lost to follow-up and HIV transmission: mathematical modeling study based on 2 large ART programs in Malawi.

Objective: Treatment as prevention depends on retaining HIV-infected patients in care. We investigated the effect on HIV transmission of bringing patients lost to follow-up (LTFU) back into care.

Design: Mathematical model.

Cost-effectiveness of point-of-care viral load monitoring of antiretroviral therapy in resource-limited settings: mathematical modelling study.

Background: Monitoring of HIV viral load in patients on combination antiretroviral therapy (ART) is not generally available in resource-limited settings. We examined the cost-effectiveness of qualitative point-of-care viral load tests (POC-VL) in sub-Saharan Africa.

Design: Mathematical model based on longitudinal data from the Gugulethu and Khayelitsha township ART programmes in Cape Town, South Africa.

Missed opportunities to prevent mother-to-child-transmission: systematic review and meta-analysis.

Objectives: To determine magnitude and reasons of loss to program and poor antiretroviral prophylaxis coverage in prevention of mother-to-child transmission (PMTCT) programs in sub-Saharan Africa.

Design: Systematic review and meta-analysis.

Methods: We searched PubMed and Embase databases for PMTCT studies in sub-Saharan Africa published between January 2002 and March 2012.

[Factors of virulence associated with enteropathogenicity in strains of Aeromonas spp. isolated from children with diarrhea in Mérida, Venezuela].

The feces of 397 patients with acute diarrheal disease (ADD) and of other 121 patients without diarrea (control group) were studied in the state of Mérida, Venezuela, from June 1993 to December 1994. The genus Aeromonas was identified in patients with ADD in 11.83% and in 5.