Babesiosis is the most common tick-borne co-infection seen in my chronic Lyme patients. This recent review article discusses the discrepancies in the medical literature regarding symptom severity and chronicity of infections when both organisms are present due to experimental design disparities and subject variability. Dr Peter Krause has published in JAMA on increased severity of symptoms in co-infected patients (P. J.Krause, et al., “Concurrent Lyme disease and babesiosis: evidence for increased severity and duration of illness,” Journal of the American Medical Association, vol. 275, no. 21, pp. 1657–1660, 1996) and my personal experience reflects his observations published in JAMA. My patients with a higher infectious burden (IB), i.e, those with Lyme, Babesia and other associated co-infections such as Bartonella and Mycoplasma species, are definitely sicker than those with low infectious burdens, and once Babesia is effectively treated, the majority of patients improve, as long as overlapping factors on the 16 point MSIDS map (especially those increasing inflammation) have been properly addressed.