Background: Babesiosis is an intraerythrocytic parasitic infection caused by protozoa of the genus Babesia and transmitted through the bite of the Ixodes tick. The disease most severely affects patients who are elderly, immunocompromised, or have undergone splenectomy. In the United States, Babesiosis is usually an asymptomatic infection in healthy individuals. Pathophysiology: The parasite only infects red blood cells (RBCs). This significantly affects the hematological system, causing hemolytic anemia, thrombocytopenia, and atypical lymphocyte formation. Alterations in RBC membranes cause decreased conformability and increased red cell adherence, which can lead to development of acute respiratory distress syndrome (ARDS) among those severely affected.
Frequency:
In the US: Babesiosis is limited to those who live in, or have recently traveled to, the northeastern United States. Few cases have been reported in California, Washington, Wisconsin, and Georgia. Hundreds of cases have been reported since the first domestic case of human babesiosis was reported in 1966. An increasing trend over the past 30 years may be the result of restocking of the deer population, curtailment of hunting, and an increase in outdoor recreational activities. Although the most life-threatening cases occur in patients who are elderly, immunocompromised, HIV infected, or have undergone splenectomy, most patients with babesiosis are asymptomatic, which may result in underreporting of the disease across all age groups.
Internationally: Babesiosis in Europe, caused by a different species of Babesia, is a more devastating disease. Although rare, it is symptomatic and often fatal. Like its US counterpart, babesiosis in Europe is also seen in patients who have undergone splenectomy. Anecdotal reports of babesiosis in China, Mexico, South Africa, and Egypt have been documented.
Mortality/Morbidity: The US mortality rate is low.
Most cases are asymptomatic and improve spontaneously without treatment.
Approximately 25% of patients with babesiosis are co-infected with Lyme disease. ( I am.) These patients experience more severe symptoms for a longer duration than those with either disease alone.
In Europe, babesiosis is a life-threatening disease.
Of patients with babesiosis, 84% are asplenic, and 53% become comatose and die.
Of those rare reported cases of subclinical infection, all patients were infected by the same Babesia species that affects patients in the northeastern United States.
Sex: The male-to-female ratio is about 1:1.
Age: Babesiosis affects all age groups with similar frequency; however, patients older than 50 years are at increased risk for severe infection and death.
No difference in seropositivity exists among age groups.
Adequate reporting is a major problem, especially in children, because of masking by other infections and the disease's history of occurrence in elderly patients.
CLINICAL
History: Patients report a history of travel to an endemic area between the months of May and September. This is the period during which the Ixodes tick is in its infectious nymph stage; however, most do not recall being bitten by a tick. Incubation period is from 1-4 weeks.
Symptoms
Fatigue
Anorexia
Arthralgia and myalgia
Depression
Dark urine
Nausea and vomiting
Cough
Dyspnea
Physical:
Fever
Shaking chills
Hepatosplenomegaly
Jaundice
Myalgia
Malaise
Causes: The causative agent of babesiosis varies according to geographical region.
In the northeastern United States, infections are caused by Babesia microti, transmitted by the same Ixodes tick that transmits Lyme disease.
In California and Washington, WA-1, which is similar to Babesia gibsoni, is the causative agent. The arthropod vector has yet to be identified.
In Europe, the Ixodes tick transmits the infectious agent, Babesia divergens.
Occasionally, cases of infection via blood transfusion from a donor who lived in or traveled to an endemic area are reported.
I have no idea what I do now....the doctor is gone until Monday....
Tick Chick
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