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they seek out and penetrate the erythrocytes (red blood <br />cells). <br />Transfusion -associated malaria can only be acquired if <br />intact red cells are present in the blood product. How- <br />ever, only a few parasites are necessary to transmit <br />malaria. In 1949, Boyd documented the transmission of <br />malaria with a dose of 10 parasites. Transmission by <br />accidental needlestick has been described in a few cases. <br />The incubation period for transfusion -transmitted <br />malaria varies from about 8 days to 3 months (range of 1 - <br />110 days). The viability of malaria organisms in blood, and <br />hence their potential infectivity, declines after refriger- <br />ated storage for more than 7 days. <br />There is no practical serologic test to screen donors <br />for malaria. The only effective tool to minimize bloodborne <br />malaria transmission is accurate donor history. It is <br />important for all physicians to be aware that transfusion <br />does carry a potential risk of malaria transmission, how- <br />ever slight this may be. If this is common knowledge, the <br />rare cases that are observed will not be misdiagnosed, and <br />appropriate therapy will be quickly instituted. <br />Bacterial and Fungal Infections J <br />Transmission of bacterial or fungal infections by blood <br />transfusion occurs rarely in the US because of several fac- <br />tors. Our initial line of defense is the care with which <br />the donor's arm is prepared for venipuncture. Skin contami- <br />nants are removed by adherence to the arm scrub protocol and <br />the blood is collected under sterile conditions into a <br />closed system including sterile disposable plastic <br />containers and tubing. Second, the universal storage of <br />blood at refrigerated temperatures markedly decreases the <br />count of viable bacteria even in units that have been con- <br />taminated. The likelihood of clinical infection following <br />transfusion of viable organisms depends on the number of <br />organisms -transfused, the condition of the host and the <br />pathogenicity of the organism. <br />After careful donor screening, it is unlikely that <br />anyone suffering from bacteremia due to a pathogenic <br />organism would be accepted as a blood donor. Therefore, the <br />risk of cntracting a significant bacterial, fungal or even <br />rickettsial disease by accidental needlestick or splash <br />exposure in the blood bank is extremely small. <br />From: Rosenschein SE: Handling infectious agents in the <br />blood bank, in Gibbs FL and Kasprisin CA (eds) Environmental <br />safety in the blood bank. AABB, Arlington, Va, 1987. <br />BIOSAFETY - INFAGT - 0491 - PAGE 7 <br />