1. Babesia microti Ross Boreen and Ellyn Krieg

2. What is Babesia?  Definitive Hosts: Ixodes scapularis (Deer Ticks)  Intermediate Host: White footed mouse (Peromyscus leucopus), deer, humans  Found in the U.S. in the Northeast and Midwest  Several different species but we will be focusing on Babesia microti

3. Interesting Facts  Can be co-infected with Lyme’s Disease and Babesia at the same time  Similar structure to malaria so misdiagnosis can occur  Prior to 1969 human cases were rare since then has been increasing in prevalence  In 2009 a record number of 31 babesiosis cases were reported

5. Life Cycle http://www.youtube.com/watch?v=JOakxoorjoQ

6. Life cycle continued  A Babesia-infected tick bites a mouse and sporozoites enter the mouse’s red blood cycles.  The sporozoites become trophozoites and undergo asexual reproduction (merogony) to produce merozoites.  In the RBC’s the merozoites can become male and female gametes.  Another tick then ingests these gametes when it bites the infected host.  The gametes are fertilized in the gut of the tick and the resulting ookinetes enters the salivary gland.  The ookinetes then mature into sporozoites.  The tick can then bite a human and introduce the sporozoites into human erythrocytes.  Inside of the erythrocytes they become trophozoites again and undergo asexual reproduction.

7. Transmission  Cannot transfer from humans to humans by tick bites only from blood transfusions  159 cases reported from blood transfusions between 1979 and 2009  More than 75% of the cases occurred between 2000- 2009  Mainly in Midwest and Northeast  This makes humans a dead end host  Can be passed from mouse to mouse by tick bite or mouse to human by tick bite

8. Symptoms  Most cases asymptomatic!  Symptomatic patients can have fever, headache, nausea, sweats – closely resembles malaria symptoms  Unlike malaria people with sickle cell can still get it  Hemolytic anemia and thrombocytopenia in severe cases  RBC fragments can block capillaries in liver, kidneys, and CNS  Immunocompromised and splenectomy patients often have more severe disease  Complications include acute respiratory failure, congestive heart failure, and renal failure

9.  Giemsa-stained blood smear although a lot of times there is a low parasite count present  Antibody detection: Indirect fluorescent antibody (IFA) test for donated blood and low parasite count cases  Also can help differentiate between Plasmodium and Babesia if questionable Diagnosis

10. Treatment  Clindamycin plus quinine or atovaquone plus azithromycin  Exchange transfusions for very ill patients

11. Control  DEET  Long, tight clothing when hiking or in areas with lots of brush  Tuck pant legs into boots  Walk on clear trails and avoid leaf litter and overgrown grass where ticks like to be  Do tick checks after being outdoors and remove them right away  Need to be attached 24-36 hours before transmit parasite

12. Proper Tick Removal  When tick is found embedded in the skin, use a fine pointed tweezers at the point of attachment  Using slow, steady, and firm traction pull the tick straight out, some recommend twisting while pulling  Cleanse skin with soap and water  Place tick in alcohol.  If part of tick remains remove like splinter or leave alone.  DO NOT burn the tick  DO NOT squeeze the tick abdomen, it may inject more potential pathogens.

13. Review  What are some of the symptoms of Babesia?  Babesia has a similar structure to which other parasite?  What kinds of reproduction can Babesia undergo?  Where is Babesia found?

14. References  http://vetmedicine.about.com/od/parasites/ht/HT_r emovetick.htm http://vetmedicine.about.com/od/parasites/ht/HT_r emovetick.htm  http://dpd.cdc.gov/dpdx/html/Babesiosis.htm http://dpd.cdc.gov/dpdx/html/Babesiosis.htm  http://www.arupconsult.com/Topics/Babesiamicroti.html http://www.arupconsult.com/Topics/Babesiamicroti.html  http://www.health.state.mn.us/divs/idepc/newslett ers/dcn/sum09/babesiosis.html http://www.health.state.mn.us/divs/idepc/newslett ers/dcn/sum09/babesiosis.html