Front entrance of the Centers for Disease Control and Prevention in Atlanta, Georgia.

In addition to the four classic human species of malaria, there are more than 20 species of malaria parasites that naturally infect non-human primates. It was thought that natural infections of simian malaria in humans were rare and not of public health importance until recent reports from Asia have suggested that P. knowlesi, a simian malaria species, is emerging as a public health problem.

The gold standard for the diagnosis of malaria involves microscopy with visualization of Giemsa-stained parasites in a blood sample. Species determination is made based on morphological characteristics of the four species of human malaria parasites and the infected red blood cells. However, many simian species are largely indistinguishable from the four human species by microscopy. Molecular techniques such as polymerase chain reaction (PCR) and microsatellite testing can assist in definitive species determination.

To accurately assess the burden of simian malaria in humans imported to the United States, molecular testing on all malaria specimens from Asia and non-falciparum specimens from South America is needed. Health-care providers of patients with malaria and laboratories that diagnose a case of malaria imported from Asia or non-falciparum malaria from South America can refer appropriate specimens for species confirmation and assessment for imported simian malaria. CDC Malaria Branch accepts specimens and offers to perform these tests.

Instructions for Submitting Specimens

Please submit specimens along with a completed specimen submission form [PDF, 1 page, 53KB] to your State Health Laboratory for testing and forwarding to CDC if appropriate.

For a listing of State and Territorial Public Health Laboratories, see http://www.aphl.org/AboutAPHL/aboutphls/Pages/MemberLabs.aspx*

Blood smears:

1. Send original slides from which the submitting laboratory made a diagnosis.
2. Send stained or unstained pretreatment slides (if unstained, fix thin smears in methanol as soon as possible after making the smear).
3. Place slides in protective shipping holders to prevent breakage.
4. If you wish the slides to be returned, check the box: Yes, please return the slides.

Blood for PCR or culture:

1. Draw pretreatment whole blood in 3- or 5- ml ethylenediaminetetraacetic acid (EDTA) or acid citrate dextrose (ACD) blood tubes.

Shipping:

1. Label all blood tubes and slides with the patient’s name, collection date, and "SMSCS."
2. Blood tubes must be packed in a primary shipping container with enough absorbent material to contain any leakage.
3. The primary holder of all types of specimens must be placed in a secondary protective container for shipping. Ship at room temperature as a "Clinical Specimen."

Malaria Resources for Health-Care Providers

Health-care providers are encouraged to use CDC resources for malaria diagnosis and management advice. These include a Malaria Hotline, which provides access to CDC malaria experts, Web-based, continuously updated information for clinicians on diagnosis and treatment of malaria, and diagnostic assistance through DPDx.