Ryan Close, MD, MPH


  •  Medical Officer | Indian Health Service
  •  Dominican Republic | United States
  •   Immunization policy | Iron deficiency | Pediatrics

Languages: English (native), Spanish (basic)

Bio statement

Global Health is an interaction between poverty and morbidity. Particular diseases that afflict the disenfranchised vary geographically, but impoverished persons everywhere share high rates of morbidity and mortality, particularly from illness that is preventable in the “general public”. I focus on novel, sustainable means to address common morbidities in these communities – whether they live in the US or abroad. My interests are less about specific illnesses, and more about finding what impacts communities disproportionately. This led to work on pediatric iron-deficiency anemia in the DR, vaccine-preventable disease in humanitarian crises, and Group A Strep infections in American Indians.

Recent global health projects

1.  Treating and Preventing Iron-deficiency anemia in children < 5 years.I am the co-PI and lead investigator for two randomized control trials in the Dominican Republic that is evaluating the potential of an iron ingot to treat and prevent anemia. Our first RCT randomizes anemic children ages 1-5 years to an iron ingot vs. standard of care, and over the course of 12-months, determines acceptability, feasibility, and effectiveness of iron ingot (vs. SOC) to treat iron-deficiency anemia. The second trial, which is launching June 2018, randomizes mother-newborn dyads to iron ingot vs. SOC, and follows them over a year, but this time assessing if the ingot can prevent iron-deficiency anemia.

2.  Invasive Group A Streptococcus (iGAS) among American Indians (AI). Invasive GAS disproportionately affects indigenous populations around the world, as has been well documented among Aboriginal Australians, First Nation Canadians, and Alaskan Natives. For various reasons, little is known about the impact of iGAS among the 3 million AIs in the continental U.S. After observing high rates of GAS bacteremia and necrotizing fasciitis among my patients where I work in Arizona, I launched an active bacterial surveillance program of all GAS infections (non-invasive and invasive) and to-date our unit has discovered the following: rates of non-invasive GAS pharyngitis is 2-times greater than the general population, rates of non-invasive impetigo is 7-8 times greater than the general population, and most concerning, invasive GAS is > 20-times higher than the general population. We are now in the process of developing protocols for novel point-of-care diagnostics and population-based prevention strategies for GAS.

Selected publications

Myles J. Stone, Ryan M. Close, Christopher K. Jentoft, Katherine Pocock, Gwendena Lee-Gatewood, Brooke I. Grow, Kristen H. Parker, April Twarkins, J. T. Nashio, and James B. McAuley, 0: American Journal of Public Health 0, e1_e3, https://doi.org/10.2105/AJPH.2021.306472

Close RM, Jones TS, Jentoft C, McAuley JB. Outcome Comparison of High-Risk Native American Patients Who Did or Did Not Receive Monoclonal Antibody Treatment for COVID-19. JAMA Netw Open. 2021;4(9):e2125866. doi:10.1001/jamanetworkopen.2021.25866

McKee SG, Close RM, Lowenthal E (2017). Evaluation of screening for, treating, and prevalence of iron-deficiency anemia in infants and children in a peri-rural clinic in the Dominican Republic. Annals of Global Health. 2017. 83:550-56. doi: 10.1016/j.aogh.2017.07.004.

Close RM, Pearson C, Cohn J (2016). Vaccine-preventable disease and the under-utilization of immunizations in complex humanitarian emergencies. Vaccine. 2016;34: 4649-55. Feature article for October 2016. doi: 10.1016/j.vaccine.2016.08.025.  

Close RM, McAuley J (2017). Futility of Centor score for predicating Group A Streptococcal pharyngitis in an adult hyper-endemic Native American population. Poster presented at ID week. October 4-8, 2017. San Diego.

Edmondson E, Close RM (2017). A curious case of chronic thromboembolic pulmonary hypertension, mitral valve stenosis, and nephropathy in a 24-year-old Native American man. Poster presented at American Academy of Pediatrics National Conference. September 16-19, 2017. Chicago.

Dunn M, McKee S, Cordero R, Japa I, Lowenthal E, Close RM (2017). Evaluation of dietary iron intake in preschool-aged children in a resource-limited setting with high burden of iron deficiency anemia. Poster presented at Pediatric Academic Societies. May 6-9, 2017. San Francisco.