Human babesiosis is a common zoonosis caused by and is attracting an increasing concern worldwide. The natural course of babesiosis infection and how the human immune system changes during the course of babesiosis infection are not clear.
We followed up 1 case infected with for 5 years. The patient was immune-intact and received no standard treatment. Clinical data were obtained from medical records. Microbiological tests, ribonucleic acid (RNA) sequence, and serum cytokines and chemokines were detected at different time points.
The patient was confirmed as infection based on his tick-bite history, clinical manifestations, and positive results of microbiological tests. The parasitemia of the patient persisted for approximately 2 months. With flu-like symptoms aggravating, most cytokines and chemokines in RNA and protein levels increased progressively and reached the peak when fever occurred; and their concentrations decreased to baseline during the same time as clearance of babesia parasites.
infection could take a mild self-limited course in immune-intact individuals. The natural changes of most cytokines and chemokines demonstrated very similar trends, which correlated with blood parasitemia and clinical manifestations. Cytokine profiles involving multiple inflammatory cytokines might be a good indicator of babesia infection.

© The Author(s) 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America.