Dynamics of multi-stage infections on networks

This paper investigates the dynamics of infectious diseases with a nonexponentially distributed infectious period. This is achieved by considering a multistage infection model on networks. Using pairwise approximation with a standard closure, a number of important characteristics of disease dynamics are derived analytically, including the final size of an epidemic and a threshold for epidemic outbreaks, and it is shown how these quantities depend on disease characteristics, as well as the number of disease stages. Stochastic simulations of dynamics on networks are performed and compared to output of pairwise models for several realistic examples of infectious diseases to illustrate the role played by the number of stages in the disease dynamics. These results show that a higher number of disease stages results in faster epidemic outbreaks with a higher peak prevalence and a larger final size of the epidemic. The agreement between the pairwise and simulation models is excellent in the cases we consider

Eroding Gains in Safe Sex Behavior, HIV/AIDS Knowledge, and Risk Perceptions Among Royal Thai Navy Conscripts After 28 Years of the AIDS Epidemic in Thailand

Despite extensive early prevention efforts, recent surveys suggest that sexual risk taking may again be on the rise in Thailand. The present cross-sectional study surveyed 3,299 recruits in the Thai Navy in 2010, to examine their rates and correlates of consistent condom use. Most participants were aged 21-22 years, unmarried, and had a secondary education. Almost half were employed in labor/agriculture. Only 17 % of sexually experienced recruits were consistent condom users, and 53 % reported multiple sex partners in the past 3 months. In multiple logistic regression, residence in the Northeast (AOR 1.47), age (AOR 1.43), being single (AOR 2.13), non-MSM status (AOR 1.41), voluntary testing (AOR 1.24), and condom use at first sex (AOR 4.29) were significantly associated with consistent condom use. These findings suggest gaps in Thailand's condom campaign targeting both sexually experienced and inexperienced youth. Interventions targeting naval recruits may benefit from including sex education in the training curriculum, building drillmasters' capacities to facilitate sex education/counseling, and creating a supportive environment with better access to condoms