Human (Granulocytic) Anaplasmosis (HGA ... - Allina Health

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MDH recommends at least two of the following three tests for diagnosis: Test LAB 6607/MAL Malaria/Parasite Stain Specially prepared smear identifies parasites within infected red blood cells. Turnaround Time Same day Performed at Allina Medical Laboratories Sensitivity Highly sensitive during acute illness. Cannot differentiate between Babesia species. Comments A negative examination does not rule out the diagnosis. LAB 8076 Babesia microti PCR Detects Babesia DNA in whole blood. 1-3 days Test Referred to Mayo Medical Laboratories Highly sensitive May be helpful in cases of low parasitemia and can differentiate between species. LAB 994/MSO Babesia microti Abs IgG, IgM 1-3 days Test Referred to Focus Labs via- Mayo Medical Laboratories 88-96% sensitivity for B. microti IgM antibody first appears 2 weeks after the onset of illness. IgG titers often exceed 1:1024 during the first weeks of illness, and then decline gradually over 6 months to titers of 1:16 to 1:256 Does not detect Babesia WA1 species (B. duncani) found on the west coast. A positive Babesia IFA test for IgM is insufficient for diagnosis. If IgM is positive but the IgG result is negative, a follow-up blood specimen drawn at least one week after the first should be tested. If the IgG result remains negative in the second specimen, the IgM result was likely a false positive result. 8
TRANSFUSION-TRANSMITTED DISEASE Cases of transfusion-transmitted HGA and babesiosis do occur. Anaplasma can survive for more than one week in refrigerated blood. Leukoreduction reduces but does not eliminate the risk of transmission for HGA. Babesia organisms may also survive in refrigerated blood, and the transfusion-transmitted rate of babesiosis, thought to be higher than that of transfusiontransmitted HGA, may be as high as 1 in 1800 red cell units. American Red Cross reports that 50% of recipients receiving Babesia-infected cellular products will demonstrate seroconversion. There is sharing of blood products nationally, so the packed red cells your patient receives may theoretically have come from anywhere in the United States. Some of the reasons why it is so hard to eliminate the risk of an infected blood product include: It is difficult to identify those donors who are infected before they become symptomatic or if they have subclinical infection; some donors infected with Babesia may harbor the parasite for months without overt symptoms; deferring donors during peak tick activity as potentially infected just because they are from disease-endemic areas would severely limit blood supply with little potential gain; and PCR testing of donors for HGA is cost prohibitive and felt to be of low yield. Transfusion-transmitted HGA and/or Babesiosis should be considered in patients who develop fever and thrombocytopenia post-transfusion. The incubation period before manifestation of symptoms in HGA appears to be 7-10 days, similar to that of HGA disease transmitted by tick bites. Symptom onset for Babesiosis is 1-9 weeks following the instigating tick bite; symptom onset for Babesiosis due to an infected blood product is also thought to be 1-9 weeks, although it may be shorter than for tick bites, presumably because more organisms are being introduced. Please contact the associated Blood Bank and MDH immediately about any suspected cases so that investigation can be undertaken. As always, please be vigilantly mindful of risks versus benefits when prescribing blood products, and make sure that you obtain informed consent from your patients. Also, be aware that the American Red Cross (ARC) is currently undertaking a look-back study to evaluate by IFA and PCR representative blood donations from high, moderate and low endemic areas. 10,000 total blood donations from Minnesota/Wisconsin/upper Midwest (considered a moderately endemic area by ARC) are reportedly going to be evaluated this year. Donors whose products test positive will be notified, and recipient tracing will be undertaken. If your patient is a recipient of one of these positive blood products, expect notification through ARC or via the blood bank/pathologist. 9
Page 1 and 2: July 2012 Human (Granulocytic) Anap
Page 3 and 4: Morules in neutrophils indicated by
Page 5 and 6: BABESIOSIS Babesiosis (originally c
Page 7: Infected individuals may be asympto
Page 11: REFERENCES K. Annen, D.O., et al. T

Human (Granulocytic) Anaplasmosis (HGA ... - Allina Health

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