August 29, 2023: Health advisory
Locally acquired malaria cases identified in the United States: Florida, Texas, and Maryland
Actions requested
- Be aware that locally acquired malaria cases (Plasmodium vivax) have been identified in Florida (7) and Texas (1), and locally acquired Plasmodium falciparum in Maryland (1) within the last 3 months.
- Consider malaria in any person with a fever of unknown origin, regardless of international travel history, particularly if they have been to the areas with recent locally acquired malaria.
- Routinely obtain a travel history and consider malaria in a symptomatic person who traveled to an area with malaria in the weeks to months preceding symptom onset.
- Order microscopic examination of thin and thick blood smears, and a rapid diagnostic test (RDT) if available, to diagnose malaria and confirm species.
- If blood smears or RDT are positive and species determination is not available, antimalarial treatment effective against chloroquine-resistant P. falciparum must be initiated immediately.
- Species determination is important because P. vivax and P. ovale can remain dormant in the liver and require additional anti-relapse treatment; failure to treat the dormant hepatic parasites may result in chronic infection with relapsing episodes.
- If blood smears or RDT are positive and species determination is not available, antimalarial treatment effective against chloroquine-resistant P. falciparum must be initiated immediately.
- Be aware of treatment recommendations for malaria, which vary by species and severity. Please refer to CDC's Malaria Diagnosis and Treatment Guidelines for U.S. Clinicians for specific detailed instructions.
- Malaria is a medical emergency. If not diagnosed and treated promptly, illness may progress to severe disease, a life-threatening stage, where mental status changes, seizures, renal failure, acute respiratory distress syndrome, and coma may occur. An algorithm for diagnosis and treatment of malaria is available.
- Artemether-lumefantrine (Coartem®) is the preferred initial treatment of uncomplicated P. falciparum or unknown species of malaria acquired in areas of chloroquine resistance. Atovaquone-proguanil (Malarone®) is another recommended option. P. vivax infections acquired from regions other than Papua New Guinea or Indonesia should initially be treated with chloroquine (or hydroxychloroquine).
- IV artesunate is the first-line drug for treatment of severe malaria in the United States.
- Malaria is a medical emergency. If not diagnosed and treated promptly, illness may progress to severe disease, a life-threatening stage, where mental status changes, seizures, renal failure, acute respiratory distress syndrome, and coma may occur. An algorithm for diagnosis and treatment of malaria is available.
- Be aware that CDC malaria clinicians are on call 24/7 to provide advice to healthcare providers following infectious disease consultation. Further information can be found online.
- Discuss travel plans with patients. Prescribe a CDC-recommended malaria chemoprophylaxis regimen and discuss mosquito bite prevention for those traveling to an international area with malaria.
- Chemoprophylaxis is not needed domestically at this time
- Chemoprophylaxis is not needed domestically at this time
- Report suspected cases of locally acquired malaria to Public Health 206-296-4774 within 3 business days.
Background
- Be aware that locally acquired malaria cases (Plasmodium vivax) have been identified in Florida (7) and Texas (1), and locally acquired Plasmodium falciparum in Maryland (1) within the last 3 months.
- Consider malaria in any person with a fever of unknown origin, regardless of international travel history, particularly if they have been to the areas with recent locally acquired malaria.
- Routinely obtain a travel history and consider malaria in a symptomatic person who traveled to an area with malaria in the weeks to months preceding symptom onset.
- Order microscopic examination of thin and thick blood smears, and a rapid diagnostic test (RDT) if available, to diagnose malaria and confirm species.
- If blood smears or RDT are positive and species determination is not available, antimalarial treatment effective against chloroquine-resistant P. falciparum must be initiated immediately.
- Species determination is important because P. vivax and P. ovale can remain dormant in the liver and require additional anti-relapse treatment; failure to treat the dormant hepatic parasites may result in chronic infection with relapsing episodes.
- If blood smears or RDT are positive and species determination is not available, antimalarial treatment effective against chloroquine-resistant P. falciparum must be initiated immediately.
- Be aware of treatment recommendations for malaria, which vary by species and severity. Please refer to CDC's Malaria Diagnosis and Treatment Guidelines for U.S. Clinicians for specific detailed instructions.
- Malaria is a medical emergency. If not diagnosed and treated promptly, illness may progress to severe disease, a life-threatening stage, where mental status changes, seizures, renal failure, acute respiratory distress syndrome, and coma may occur. An algorithm for diagnosis and treatment of malaria is available.
- Artemether-lumefantrine (Coartem®) is the preferred initial treatment of uncomplicated P. falciparum or unknown species of malaria acquired in areas of chloroquine resistance. Atovaquone-proguanil (Malarone®) is another recommended option. P. vivax infections acquired from regions other than Papua New Guinea or Indonesia should initially be treated with chloroquine (or hydroxychloroquine).
- IV artesunate is the first-line drug for treatment of severe malaria in the United States.
- Malaria is a medical emergency. If not diagnosed and treated promptly, illness may progress to severe disease, a life-threatening stage, where mental status changes, seizures, renal failure, acute respiratory distress syndrome, and coma may occur. An algorithm for diagnosis and treatment of malaria is available.
- Be aware that CDC malaria clinicians are on call 24/7 to provide advice to healthcare providers following infectious disease consultation. Further information can be found online.
- Discuss travel plans with patients. Prescribe a CDC-recommended malaria chemoprophylaxis regimen and discuss mosquito bite prevention for those traveling to an international area with malaria.
- Chemoprophylaxis is not needed domestically at this time
- Chemoprophylaxis is not needed domestically at this time
- Report suspected cases of locally acquired malaria to Public Health 206-296-4774 within 3 business days.
Resources
- This health advisory is also available in PDF format (245 Kb)
- CDC Malaria information for healthcare providers
- CDC HAN: Locally Acquired Malaria Cases Identified in the United States, June 26, 2023
- CDC HAN: Important Updates on Locally Acquired Malaria Cases Identified in Florida, Texas, and Maryland, August 28, 2023
- CDC Malaria information for International Travelers