Dr. Jack H. Hutto

Dr. Camelo is an infectious disease specialist at Johns Hopkins All Children’s Hospital. She sees patients on the hospital’s campus in St. Petersburg, Florida. She joined the medical staff in 2025. She was previously an attending physician in the Pediatric Infectious Diseases Department at Augusta University and WellStar/Children’s Hospital of Georgia. Dr. Camelo earned her medical degree from Military University Nueva Granada School of Medicine in Bogota DC, Colombia. She completed her residency in pediatrics at Vermont Children’s Hospital/ University of Vermont Larner College of Medicine in Burlington, and completed a fellowship in pediatric infectious diseases at Boston Medical Center/Boston Children’s Hospital and Boston University School of Medicine. She also earned a Master of Public Health from the University of Vermont School of Public Health in Burlington. Her top areas of expertise are Chagas Disease, Pneumonia, Pneumococcal Meningitis, and Urinary Tract Infection in Children.

Dr. Ruiz Holgado specializes in pediatric infectious disease at Johns Hopkins All Children’s. She joined the hospital staff in 2025. She earned her medical degree from Universidad Nacional de Tucuman in Argentina. She completed a pediatric residency at Flushing Hospital Medical Center in Flushing, New York, where she served as pediatric chief resident. She then completed a fellowship in pediatric infectious diseases at NYU Langone Health/Bellevue Hospital in New York. Dr. Ruiz Holgado’s research interests include advancing care for transplant recipients and immunocompromised hosts, with a particular interest in the intersection of tropical medicine and global health to address the needs of diverse and underserved patient populations. She speaks English and Spanish. Her top area of expertise is Osteomyelitis in Children.

Dr. Messina is the chief of the Division of Infectious Disease at Johns Hopkins All Children's Hospital. She joined the pediatric infectious disease program in 2006. She became chief of the medical staff in January 2024. A graduate of Vanderbilt University School of Medicine, she completed her pediatric residency at University of Texas-Southwestern Medical Center/Children's Medical Center, Dallas, followed by a pediatric infectious diseases fellowship at UT/Southwestern Medical Center. She was a staff pediatrician at Children's Medical Center Dallas. In the Johns Hopkins Medicine Clinical Awards, Dr. Messina was named Johns Hopkins All Children’s Hospital physician of the year in 2019 and led a COVID-19 Analytic Response Team that received the Armstrong Award for Excellence in Quality and Safety in 2022. Dr. Messina is a fellow of the American Academy of Pediatrics. She is a member of the Pediatric Infectious Disease Society, the American Society for Microbiology and the Infectious Disease Society of America. Dr. Messina serves as a reviewer for the Pediatric Infectious Disease Journal. Recent News Articles and Media Coverage The Right Vaccine Dose for Kids at the Right Age, Bay News 9 (November 4, 2021) Doctors push for children to get vaccinated before the holidays, WFLA -TV (November 10, 2021) 5 tips for parents as omicron spreads and pediatric hospitalizations rise, ABC News (December 30, 2021) CDC Shortens Isolation Period to Five Days for Asymptomatic Cases, CNN (December 28, 2021) When Can Children Get the COVID-19 Vaccine? Pediatricians Explain What to Expect, Prevention (January 4, 2022) Most Americans — and 75% of children — have gotten COVID, says CDC, Tampa Bay Times (April 28, 2022) Doctors on why Florida’s youngest kids should get COVID vaccine, Tampa Bay Times (June 27, 2022) Got questions about COVID vaccines for babies and toddlers? Here’s the answers, Tampa Bay Times (June 20, 2022) Local health officials monitor rise in RSV cases among children, WTVT - TV (November 8, 2022) Health officials alarmed over rise in RSV cases, St. Pete Catalyst (November 10, 2022) Tampa Bay area doctors give advice on back to school as summer winds down, WFTS -TV (July 27, 2022) Flu admissions spike at Tampa Bay hospitals, Tampa Bay Times (November 24, 2022) How Worried Should We Be About RSV?, Sarasota Magazine (November 10, 2022). Her top areas of expertise are Methicillin-Resistant Staphylococcus Aureus (MRSA) and Infantile Neutropenia.