The most potent risk factors in the development of<unk>  are a combined effort between environment and season. Babesia parasites are transmitted via tick bites in tick-populated areas.  Transmission occurs more frequently during the spring and summer in correlation with heightened periods of tick activity. Other risk factors include repeated exposure to the following potential I. scapularis and Ixodes rodent hosts; white-footed deer mice, rats, voles, chipmunks, and field mice.
Further examples of Babesia mammalian hosts also include deer populations. Although unlike the rodent transmission, transmission of Babesia from deer to human populations is likely a result of an infected nymph bite. Reduction tactics therefore include reduced contact and increased proximity from rodent, deer, and tick populations in endemic areas.
Another risk factor, though rare, may be attributed to the transmission of<unk>  via blood transfusion. In certain cases,<unk>  is asymptomatic and contaminated blood may inadvertently be drawn from donors within endemic areas.  Furthermore case reports also indicate rare occurrences of transmission via transplacental and perinatal pathways. 
Age may be an associated risk factor as well. A recent study performed by the Central for Disease Control and Prevention (CDC), identifies 62 years as the median age of reported<unk>  cases in the United States.
Furthermore the study incorporated patients with ages ranging from infantry (less than a year) to individuals of over 100 years. Of the observed cases, 65% were documented as males and 32% as female. However no further determinations were provided about the correlations between age, sex and a heightened risk of contracting the disease.
Babesiosis risk factors
Tularemia risk factors
Brucellosis risk factors
Smallpox risk factors
Ebola risk factors
Malaria risk factors
Chickenpox risk factors
Psittacosis risk factors