Therapy and Screening for Malaria

Presumptive therapy for refugees has been shown to decrease malaria prevalence and be a cost-effective public health intervention [1, 2].  Presumptive therapy is meant both to improve the health of the individual refugee and to protect public health since mosquitoes are present in much of the US and can spread malaria [3].

In 2007, pre-departure presumptive therapy was changed to artemether-lumafantrine (AL) [2]. This presumptive treatment is currently limited to refugees originating from sub-Saharan Africa (SSA) and is focused on addressing P. falciparum malaria. AL is not considered effective therapy for the non-blood stages of relapsing malaria (P. vivax and P. ovale). Guidelines for pre-departure presumptive treatment and directed treatment of malaria for all refugees from sub-Saharan Africa are available from the CDC.

Currently all SSA refugees receive pre-departure treatment of AL with the exception of special populations such as pregnant/lactating women and children less than 5 years old at time of departure. After arrival in the US, the CDC recommends screening these special populations for symptoms of malaria, targeted testing, or presumptive treatment once the contra-indication has resolved (e.g. the child is now over 5 years of age).

If choosing to utilize presumptive treatment, the most effective and well-tolerated medications available in the US include atovaquone-proguanil (trade name Malarone) or artemether-lumafantrine (AL, trade name Riamet and Coartem). Please note that no refugees are treated for the relapsing form of malaria, and refugees originating outside of SSA do not receive presumptive treatment for malaria.

Testing for Malaria
All refugees from malaria endemic areas, including those who have been presumptively treated for P. falciparum, should be tested for malaria if they develop clinical signs or symptoms of the disease. Common signs and symptoms include fever, chills, headache, splenomegaly (enlargement of the spleen), signs of anemia (e.g. pallor), nausea, or vomiting.

Typical laboratory findings may include one or more of the following: thrombocytopenia (low platelet count), anemia, low white blood cell count, increased liver enzymes, and elevated inflammatory markers such as C-reactive protein. The tests of choice for those with clinical signs or symptoms of malaria disease include traditional thick and thin blood films and rapid antigen detection testing (RDT). The RDT should always be used concurrently with a traditional blood film because it has sub-optimal sensitivity for non-falciparum malaria. Additionally, RDT cannot determine the quantity of malaria in the blood and it may not effectively distinguish the species of malaria. When initial blood smear and RDT are not diagnostic, multiple blood films over a period of time may be necessary to detect infection. To screen for asymptomatic or sub-clinical malaria, the most sensitive and specific test is polymerase chain reaction (PCR).

Healthcare providers needing assistance with diagnosis or management of suspected cases of malaria may call the CDC Malaria Hotline: (770) 488-7788 or (855) 856-4713 toll-free, Monday through Friday from 9am to 5pm Eastern Time. For emergency consultation after hours, call (770) 488-7100 and request to speak with a CDC Malaria Branch clinician.

Contributed by William Stauffer M.D., M.S.P.H., University of Minnesota

1. Collinet-Adler S, Stauffer WM, Boulware DR, Larsen KL, Rogers TB, Williams DN. Financial implications of refugee malaria: the impact of pre-departure presumptive treatment with anti-malarial drugs. Am J Trop Med Hyg 2007; 77:458-63.
2. Phares CR, Kapella BK, Doney AC, et al. Presumptive treatment to reduce imported malaria from East Africa resettling in the United States. Amer J Trop Med Hyg 2011;85(4):612-615.
3. Zucker JR. Changing patterns of autochthonous malaria transmission in the United States: a review of recent outbreaks. Emerg Infect Dis 1996; 2:37-43.