Human Babesiosis in Europe

Abstract

Babesiosis is attracting increasing attention as a worldwide emerging zoonosis. The first case of human babesiosis in Europe was described in the late 1950s and since then more than 60 cases have been reported in Europe. While the disease is relatively rare in Europe, it is significant because the majority of cases present as life-threatening fulminant infections, mainly in immunocompromised patients. Although appearing clinically similar to human babesiosis elsewhere, particularly in the USA, most European forms of the disease are distinct entities, especially concerning epidemiology, human susceptibility to infection and clinical management. This paper describes the history of the disease and reviews all published cases that have occurred in Europe with regard to the identity and genetic characteristics of the etiological agents, pathogenesis, aspects of epidemiology including the eco-epidemiology of the vectors, the clinical courses of infection, diagnostic tools and clinical management and treatment.

The New Human Babesia sp. FR1 Is a European Member of the Babesia sp. MO1 Clade

“…Sporadic cases were reported in Asia, Africa, and South America, with diverse and often partially characterized etiological agents [48]. In Europe, human babesiosis is rare and B. divergens is the main causal agent [43,49]. The most impacted countries are France, Ireland and Great Britain, and in France, Western regions and Normandy are most affected [10], due to substantial farming of bovines, the natural host of B. divergens [50].…”

“…This is the most probable place of tick acquisition by the patient, as it is close to a forest, where the abundance of the potential vector I. ricinus is high, increasing the risk of contracting tick-borne pathogens [51]. The patient was asplenic, which is also a major risk factor for severe or fatal babesiosis [10,43,49]. However, the symptoms in this patient developed slowly (two to three weeks between the onset of symptoms and admission to hospital) despite aspleny, while B. divergens' course of infection in such cases is usually fulminant [42].…”

“…In splenectomized patients, babesiosis due to B. divergens is fulminant with symptoms that appear within 1-3 weeks post infection, with persistent high fevers and headaches, followed by severe intravascular hemolysis, hemoglobinuria, and jaundice. Babesiosis in splenectomized patients is often fatal in Europe, as diagnosis and therefore adequate treatment are often delayed due to uncharacteristic flu-like symptoms and the infrequency of cases [42,43]. Severe symptoms and fatal cases also occur in non-splenectomized patients with known or unknown predispositions such as splenic dysfunction or a rudimentary spleen [18,19].…”

Ticks, Human Babesiosis and Climate Change

“…), another host that can feed all tick stages and thus maintain small populations of I. ricinus, could theoretically maintain zoonotic B. microti in the absence of large hosts [26,27]. As yet there are no reports of such foci, partly no doubt because zoonotic B. microti genotypes are rare in Europe [8].…”

“…The predominant vectors of human babesiosis are Ixodes scapularis transmitting Babesia microti in the USA, and Ixodes ricinus, transmitting Babesia divergens and Babesia venatorum in Europe [7]. Babesia microti also occurs in Europe, but human cases are extremely rare [8].…”