Mathematical models will be developed for disease control through contact investigation, using individual- based simulations. Realistic contact investigation strategies will be analyzed for pathogens that may be transmissible from asymptomatic carriers as well as transmitted prior to symptoms. It will be determined how extensive or how targeted contact investigation should be, and what information should be systematically collected in future contact investigations. The models also include specific questions regarding the effect of behavior change during a contact investigation. Such models will be applied to tuberculosis transmission (because of the availability of contact investigation expertise and the availability of molecular epidemiogical data at the population level). Such models will also be applied in the setting of community-based trials of trachoma elimination, because such trials provide possibly the only experimental human settings wherein we may monitor the reemergence of an infectious disease. Specific testable predictions are outlined in the proposal.

Public Health Relevance

Our project is designed to improve planning for decision making and emergency preparedness by developing specific operational models to explore the best way to control epidemics using contact investigation (or related methods, including ring vaccination), and to improve data collection during contact investigations. We are proposing to use tuberculosis and trachoma in developing empirical case studies.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project--Cooperative Agreements (U01)
Project #
Application #
Study Section
Special Emphasis Panel (ZGM1)
Program Officer
Sheeley, Douglas
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California San Francisco
Schools of Medicine
San Francisco
United States
Zip Code
Lietman, Thomas M; Worden, Lee; Liu, Fengchen et al. (2018) The distribution of district-level leprosy incidence in India is geometric-stable, consistent with subcriticality. Epidemics 24:21-25
Ramirez, David A; Porco, Travis C; Lietman, Thomas M et al. (2018) Ocular Injury in United States Emergency Departments: Seasonality and Annual Trends Estimated from a Nationally Representative Dataset. Am J Ophthalmol 191:149-155
Grantz, Kyra H; Chabaari, Winnie; Samuel, Ramolotja Kagiso et al. (2018) Spatial distribution of leprosy in India: an ecological study. Infect Dis Poverty 7:20
Ackley, Sarah F; Hacker, Jill K; Enanoria, Wayne T A et al. (2018) Genotype-Specific Measles Transmissibility: A Branching Process Analysis. Clin Infect Dis 66:1270-1275
Worden, Lee; Schwartz, Ira B; Bianco, Simone et al. (2017) Hamiltonian Analysis of Subcritical Stochastic Epidemic Dynamics. Comput Math Methods Med 2017:4253167
Gao, Daozhou; Lietman, Thomas M; Dong, Chao-Ping et al. (2017) Mass drug administration: the importance of synchrony. Math Med Biol 34:241-260
Ramirez, David A; Porco, Travis C; Lietman, Thomas M et al. (2017) Epidemiology of Conjunctivitis in US Emergency Departments. JAMA Ophthalmol 135:1119-1121
Ackley, S F; Mayeda, E R; Worden, L et al. (2017) Compartmental Model Diagrams as Causal Representations in Relation to DAGs. Epidemiol Methods 6:
Deiner, Michael S; Worden, Lee; Rittel, Alex et al. (2017) Short-term leprosy forecasting from an expert opinion survey. PLoS One 12:e0182245
Blok, David J; Crump, Ronald E; Sundaresh, Ram et al. (2017) Forecasting the new case detection rate of leprosy in four states of Brazil: A comparison of modelling approaches. Epidemics 18:92-100

Showing the most recent 10 out of 51 publications