Emerging pathogens associated with tick-borne infections

In recent years, several microbial agents have been identified that result in significant morbidity and mortality. The newly recongnized tick borne infections, babesiosis and ehrlichiosis, may be transmitted by the same tick that transmits Borrelia burgdorferi and simultaneous infections may occur. Babesia are intraerythrocytic protozoa that may cause severe hemolytic anemia, whereas Ehrlichia, depending on the species, may infect either monocytes or granulocytes, with associated leukopenia, thrombocytopenia and anemia. Improved laboratory surveillance is urgently needed to assess the prevalence of these worldwide pathogens in order to institute appropriate infection control efforts.