Healthcare Policy & Research Residents, Fellows, and Postdoctoral Associates


Rami Hani Mohammad Al Rifai

Houssein Ayoub, Ph.D. (+974-4492-8422,, is a mathematical modeler who currently holds the position of Postdoctoral Associate in the Infectious Disease Epidemiology Group (IDEG) at Weill Cornell Medical College in Qatar. He is currently involved in studies to understand the population dynamics of infectious diseases. Dr. Ayoub focuses his research on the development of mathematical models to examine aspects of hepatitis C virus (HCV) epidemiology and assessing the public health impact of HCV vaccination.

Prior to joining IDEG, Dr. Ayoub was a lecturer and research assistant at Bordeaux University. His research for the doctoral dissertation focused on understanding T cell proliferation in lymphopenia conditions using mathematical modeling. Subsequently, he studied optimal control of the fisheries system in French Guiana using also mathematical modeling. Dr. Ayoub completed his Ph.D. in applied mathematics and computational science at Bordeaux University.

Karima Chaabna, Ph.D. (+974-4492-8936,, is an epidemiologist and postdoctoral associate at the Infectious Disease Epidemiology Group (IDEG) at Weill Cornell Medical College in Qatar. Her research focuses on characterization of the disease burden of sexually transmitted infections (STIs) and the role of sexual networks in the epidemiology of STIs. Her research aims to understand the drivers and scale of STI transmission in the Middle East and North Africa (MENA).

Prior to joining IDEG, Dr. Chaabna's main research interests were in the fields of descriptive and analytic cancer and infectious disease epidemiology in MENA and Africa. Her research focused primarily on assessing the patterns and trends of AIDS-related cancers such as Kaposi sarcoma, non-Hodgkin lymphoma and cervical cancer using data from the cancer registries of Setif (Algeria), Sousse (Tunisia), Gharbiah (Egypt), Kyadondo County (Uganda) and Harare (Zimbabwe). Karima was also the principal investigator for a retrospective study that assessed HIV/AIDS prevalence and mortality time trends, HIV/AIDS patient profile, as well as hepatitis C virus (HCV) and hepatitis B virus (HBV) prevalence in lymphoma patients. The study was conducted in collaboration with the infectious disease and hematological services of the Regional Teaching Hospitals in Algeria. Furthermore, she was involved in another retrospective study that aimed to assess HCV genotype geographical distribution in Algeria, and was also involved in two clinical trials assessing the variability in antibody response to influenza immunization. Karima completed her Ph.D. in Epidemiology at Claude Bernard University, France, in 2013.

Maroun Sfeir, M.D. (646-962-7645,, a resident in general preventive medicine, attended the Lebanese University School of Medicine where he completed his residency in internal medicine and started his fellowship in infectious disease. He moved to Florida and started over his residency at University of Miami/Jackson Memorial Hospital. He joined Weill Cornell Medical College in 2015 as an infectious disease fellow which he will complete concomitantly with his preventive medicine residency. His clinical and research interests include the epidemiology and microbiological diagnosis of multidrug resistant bacteria. In his free time, Dr. Sfeir enjoys playing tennis, running and biking.


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