Outbreak of Locally Acquired Mosquito-Transmitted (Autochthonous) Malaria

Florida and Texas, May-July 2023

Dawn Blackburn, BVMS; Michael Drennon, MSPH, MPA; Kelly Broussard, MPH; Andrea M. Morrison, PhD; Danielle Stanek, DVM; Elizabeth Sarney, MA; Christina Ferracci, MPH; Steve Huard; Wade Brennan; John Eaton; Sara Nealeigh; Natalie Barber; Rebecca A. Zimler, PhD; Jeremy N. Adams, PhD; Carina Blackmore, DVM; Manuel Gordillo, MD; Robert Mercado, MD; Harold Vore, MS; Kelly Scanlan; Ian Motie, MD; Leslie Stanfield; Ahmed Farooq, MD; Kimberly Widel, MBA; Kelly Tomson, MS; Nancy Kerr; John Nasir; Marshall Cone, MPH; Connor Rice, MPH; Thomas Larkin; Edwin Hernandez, MD; Jennifer Bencie, MD; Christopher R. Lesser, MS; Max Dersch; Samantha Ramirez-Lachmann, MPH; Marah Clark; Susan Rollo, DVM, PhD; Amira Bashadi, MPH; Ronald Tyler, DVM; Bethany Bolling, PhD; Brent Moore, DVM; Brendan Sullivan, DVM; Eric Fonken, DVM; Raquel Castillo, MPH; Yaziri Gonzalez, MS; Gustavo Olivares; Kimberly E. Mace, PhD; Dean Sayre, MD; Audrey Lenhart, PhD; Alice Sutcliffe, MS; Ellen Dotson, DSc; Claudia Corredor; Emma Rogers, MS; Brian H. Raphael, PhD; Sarah G. H. Sapp, PhD; Yvonne Qvarnstrom, PhD; Alison D. Ridpath, MD; Peter D. McElroy, PhD


Morbidity and Mortality Weekly Report. 2023;72(36):973-978. 

In This Article

Abstract and Introduction


Eight cases of locally acquired, mosquito-transmitted (i.e., autochthonous) Plasmodium vivax malaria, which has not been reported in the United States since 2003, were reported to CDC from state health departments in Florida and Texas during May 18–July 17, 2023. As of August 4, 2023, case surveillance, mosquito surveillance and control activities, and public outreach and education activities continue in both states. U.S. clinicians need to consider a malaria diagnosis in patients with unexplained fever, especially in areas where autochthonous malaria has been recently reported, although the risk for autochthonous malaria in the United States remains very low. Prompt diagnosis and treatment of malaria can prevent severe disease or death and limit ongoing transmission to local Anopheles mosquitoes and other persons. Preventing mosquito bites and controlling mosquitoes at home can prevent mosquitoborne diseases, including malaria. Before traveling internationally to areas with endemic malaria, travelers should consult with a health care provider regarding recommended malaria prevention measures, including potentially taking malaria prophylaxis. Malaria is a nationally notifiable disease; continued reporting of malaria cases to jurisdictional health departments and CDC will also help ensure robust surveillance to detect and prevent autochthonous malaria in the United States.