Babesiose
Babesiosis is a tick-borne disease carried by domestic and wild animals caused by the protozoan Babesia microti.
Epidemiology
The epidemiology of babesiosis varies depending on the availability of the host, the presence of ticks which act as vectors, and the presence of parasites within the vector. If any of these parameters is missing the transmission of the infection is discontinued.
Babesiosis can be transmitted through:
- The bite of an infected tick (usually occurs in parts of the Northeast and upper Midwest of the United States presenting peaks during warm months).
- Transfusion from a blood donor who has babesia infection but is asymptomatic (rare).
- Congenital transmission during pregnancy or delivery (rare).
Clinical presentation
Babesiosis is typically asymptomatic, but the infection may produce symptoms in immunocompromised, especially asplenic patients.
Symptoms are usually nonspecific in the initial stages, presenting as mild fever, sweats, and myalgias. As more erythrocytes get infected, hemolysis starts to appear developing anemia and hemoglobinuria. In advanced stages, the disease can progress to severe multiorgan failure and death.
Pathology
Etiology
In the United states the infection is usually produced by Babesia microti, in the Pacific Northwest is occasioned by Babesia duncani, and in Europe by Babesia divergens.
Pathophysiology
The nymphal stage of Ixodes is the primary vector, if the tick is carrying the protozoa, the sporozoites enter to erythrocytes where they mature to form merozoites. The merozoites leave the erythrocytes rupturing them and then infecting other erythroid cells repeating the cycle. In the peripheral blood smear, Maltese crosses can be seen, which represent merozoites inside the erythrocyte.
Radiographic features
Few case reports of patients with severe babesiosis have described the development of acute respiratory distress syndrome (ARDS). The radiological findings of severe babesiosis are nonspecific presenting as:
- Ground-glass opacities
- Interlobular septal thickening
Siehe auch:
