Related articles: Babesiosis
Definition
Babesiosis (or piroplasmosis) is an infectious disease caused by protozoa of the genus Babesia .
This organism is able to parasitize erythrocytes from birds and several mammals, including humans. Babesia enters the red blood cells, matures and divides asexually; in the end, the infected erythrocytes break down and release the microorganisms, which invade other blood cells.
The incidence of babesiosis is greater in the United States, while sporadic cases have been reported in Europe, Asia, Africa, Australia and South America.
In most cases, the infection is contracted following the bite of a tick Ixodes scapularis (in the United States) or Ixodes ricinus (in Europe), especially in summer and late-autumn.
The parasite can also be transmitted to humans through contaminated blood transfusions or blood products, while few cases of transplacental transmission have been reported.
The symptoms of babesiosis usually begin 1-4 weeks after the bite of an infected tick or 1-6 months from a transfusion of contaminated blood.
Most common symptoms and signs *
- Anemia
- Anorexia
- Asthenia
- Chills
- Cachexia
- Coma
- Depression
- Dyspnoea
- Articolar pains
- Muscle pains
- Hepatomegaly
- Temperature
- Fotofobia
- Jaundice
- Leukopenia
- Sore throat
- Headache
- Nausea
- Weight loss
- thrombocytopenia
- Blood in the urine
- splenomegaly
- Sweating
- Night sweats
- Cough
- He retched
Further indications
In immunocompetent people, the infection may be asymptomatic or cause a mild to moderate illness. In the elderly and in immunosuppressed patients, however, babesiosis can cause a febrile illness, with haemolytic anemia, similar to malaria.
When symptomatic, babesiosis most commonly causes fever (even over 40.9 ° C and with splenomegaly), fatigue and general malaise. Other signs include chills, sweating, muscle and joint pain, non-productive cough, hematuria, nausea and anorexia.
Less often, patients have sore throats, photophobia, vomiting, weight loss and depression. These manifestations may resolve within 1-2 weeks, but the asthenia may last for several months.
The disease is more severe in splenectomized and AIDS patients, in whom complications can be observed, including disseminated intravascular coagulopathy, acute respiratory distress syndrome and, more rarely, hepatic, renal or congestive heart failure.
In some cases, babesiosis evolves to coma and results in death.
The diagnosis is performed by identifying the parasites within the erythrocytes of the hosts in a peripheral blood smear, subjected to staining with Giemsa or the Wright method.
For confirmation of the diagnosis and detection of Babesia in the blood, the serological test with indirect immunofluorescence and polymerase chain reaction (PCR) may be useful.
The differential diagnosis must be made with respect to malaria, Lyme disease, ehrlichiosis, typhoid fever and infectious mononucleosis.
When necessary, the treatment is based on the administration of antimicrobial agents, atovaquone and azithromycin. In severe babesiosis, however, oral quinine and intravenous clindamycin are expected.
The prognosis depends on the Babesia species involved and the patient's health; generally, it is good in most immunocompetent subjects.
Standard preventive measures recommend avoiding rodents (main natural reservoirs of infection) and cervids in endemic areas, as well as using protective clothing and repellents for ticks (habitual vectors of Babesia ).
