Babesiosis
FACTF
FACT
SHEET
SHEET
SH ET 18-077-0317
7 15

Babesiosis is a potentially severe, and sometimes rapidly fatal, ticktick-borne
borne illness caused by a protozoan
parasite that infects and destroys the red blood cells. Babesia microti appears to be responsible for themajority of cases of human babesiosis in the United States. It is the most common species in the easternand Midwestern U. S. where most cases occur. Additional types of Babesia that have been associated with human disedisease
ase in limited areas ofthe U.S., but that have not yet been designated as distinct species, are currently known only as Babesia isolate type WA1 parasites (detected onthe West Coast) and Babesia isolate type MO1 (detected in Missouri). Babesia divergens is the most common species in Europe. Other
Babesia species cause illness in animals
animals..
How does a person get babesiosis?
You can get babesiosis if you are bitten by a tick that is infected with B.. microti
microti,, or lesscommonly, ano
anotherther Babesia species. Protozoa in the tick’s saliva are transmitted to you
while the tick is feeding. An infected tick must be attached to you for at least several hours(usually 2424-48)
48) in order for transmission to take place. Occasionally, cases of babbabesiosis
esiosishave also been acquired via blood transfusion from apparently healthy (asymptomatic,lacking symptoms), but nevertheless infected, individuals.
Do all ticks transmit babesiosis?
No. Only certain species of ticks are capable of transmitting Babesia
Babesia.. There are twovectors (transmitters) of Babesia to humans in the United States. Ixodes scapularis, theblacklegged tick (also known as the “deer tick”), is the primary vector for Babesia in theeast and Midwest, while Ixodes pacificus
pacificus,, the weste
western
rn blacklegged tick, is a presumptive
vector along the West Coast. Ixodes ricinus
ricinus,, sometimes referred to as the sheep tick orEuropean castor bean tick, transmits B. divergens in Europe. Simultaneous infections withboth B. microti and Borrelia burgdorfe
burgdorferi
ri,, the agent of Lyme disease, have been
documented in ticks, and there is evidence that both organisms may be transmitted during
a single tick bite.

Ixodes scapularis (blacklegged tick, a.k.a. ‘deer tick’)is responsible for transmitting most cases of humanbabesiosis in the United States.

How do ticks acquire Babesia?
Ticks become infected by feeding on an infected animal known as a reservoi
reservoirr host. Reservoir hosts carry Babesia parasites in their bloodstream
for a prolonged period of time, thus causing ticks that feed on them to become infected. Then, when the infected tick feeds on its next host,parasites are passed on to that host and ththee cycle of infection continues. Rodents, especially the white
white--footed
footed mouse ((Peromyscus
Peromyscus leucopusleucopus),),are the reservoir hosts for B. microti
microti,, while in Europe, cattle serve as the reservoir hosts for B. divergens
divergens..
How prevalent is babesiosis?
Within the United States, human babesiosis does not appear to be geographically widespread. It is difficult to assess the trtrue
ue prevalence of thedisease because it has not been designated as a nationally reportable illness to the Centers for Disease ContrControl
ol and Prevention (CDC). Also, it
is suspected that many cases go undiagnosed because of the lack of symptoms in many individuals. Since the first cases were recognized in
California in 1966 (unknown Babesia species) and Massachusetts (Nantucket) in 1969 (Babesia
Babesia microtimicroti),), several hundred cases have been
documented.
documented. TheThe majority
majority ofof these
these cases have occurred in southern New England, especially
especially onon thethe coastal
coastal islands
islands ofof Massachu
Massachusetts
setts(Nantucket, Martha’s Vineyard), Rhode Island (Block Island), and New York (Shelter Island, Long Island). Cases have also been reported in
California, Connecticut, Missouri, New Jersey, Washington, and Wisconsin.
What araree the symptoms of babesiosis
Based on serologic (blood) studies, most infections appear to be asymptomatic. Manifestations of symptomatic disease include fever,headache, chills, sweating, muscle aches (myalgias), fatigue, nausea, vomiting, enlarged spleen and liver (sometimes resultin
resultingg in jaundice), andhemolytic anemia (anemia due to the destruction of red bbloodlood cells). Symptoms usually occur 1 to 4 weeks following an infective tick bite, andcan last for several days, weeks, or months. The disease is more severe, and sometimes fatal, in patients who are immunosup
immunosuppressedpressed (have aweakened immune system), lalack
ck a healthy spleen, or who are elderly. In some cases, parasites may continue to circulate in the blood ofasymptomatic individuals for several months or even years, making transmission of babesiosis by blood transfusion a concern. Because there
have bbeen
een documented cases of transfusiontransfusion-acquiredacquired babesiosis, the American Red Cross does not accept blood donations from anyone who
has ever had babesiosis, even if they have been treated with appropriate antibiotics. CoCo--infection
infection with Lyme disease has been ddocumented
ocumented insome patients. CoCo-infection
infection may complicate diagnosis and treatment, and may result in more severe illness in the individual.
How is babesiosis diagnosed?
Most patients do not remember aa tick
tick bite.
bite. Diagnosis
Diagnosis isis usuallyusually mademade byby examining
examining bloodblood smears
smears under
under aa microscope
microscope andand detect
detectinging Babesia
within the red blood cells. Babesia appear as tetrad (cross(cross-shaped)
shaped) or ring
ring-shaped
shaped forms, but may be very difficult to distinguish from thePlasmodium parasites that cause malaria. Therefore, a combination of diagnostic criteria may be useful. An indirect immunofluorescentantibody assay (IFA) test can be used to detect Babesia
Babesia--specificspecific antibodies in the blood. SerolSerologic
ogic diagnosis is established by a four
four-foldfold orArm
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mological
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Proggram
ram
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Division
5158 Blackhawk Road, APG, MD 21010
21010--5403
5403
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greater rise in the serum titer between the acute (early) phase and the convalescent (late) stage. In addition, patient bloobloodd can be inoculated
into hamsters to observe resultant infection in these animals after 2 to 4 weeks. In some cases, polymerase chain reaction (PCR) may also be
used to detect Babesia DNA in the blood. Because some patients may be coco-infected
infected with Lyme disease (10(10-25%),25%), blood tests should also be
performed for this infection. It is iimportant
mportant to diagnose and treat both infections.
What is the treatment for babesiosis?
There are no standardized treatments for babesiosis. However, the following drug regimens have been found to be useful: quiquinine
nine (650 mg 3times/day) plus clindamycclindamycinin (600 mg 3 times/day or 1.2 g intravenously 2 times/ day) for 7
7-1010 days (the dosages for children are quinine
25mg/kg plus clindamycin 2020-4040 mg/kg, both given in 3 divided oral doses for 7 days), OR azithromycin (600 mg 1 time/day) plus atovaquone(750 mg 2 times/day) for 7
7-1010 days (the dosages for children are azithromycin 12 mg/kg 1 time/day plus atovaquone 20 mg/kg 2 times/day, for7-1010 days). Although all of these drugs are approved, the U.S. Food and Drug Administration currently considers clclindamycin,indamycin, azithromycin, andatovaquone investigational for babesiosis. Patients who exhibit only mild symptoms may require no specific therapy. Severel
Severelyy ill patients with ahigh percentage of infected red blood cells, on the other hand, may benefit from exchange transfusion (removal of the patient’s infected blood,
followed by replacement with clean, donated blood). Dialysis may be required for patients with kidney failure.
What can I do to reduce my risk of becoming infected with babesiosis?
There is no vaccine against babesiosis. Therefore, you can help prevent babesiosis, and other tick
tick--borne
borne diseases, by protecting yourself fromticks. When in tick habitat (tall grass and weeds, scrubby areas, woods and leaf litter), follow these precautions:We
Wear
ar proper clothing as a physical barrier against ticks – long pants tucked into boots or tightly
tightly-woven
woven socks; long sleeve shirt; shirt tucked
into pants; and lightlight-coloredcolored clothing so as to more easily spot ticks.
Check your skin and clothing periodically for ticks.
Use both skin and clothing
clothing repellents
repellents thatthat have been
been approved
approved by thethe Environmental
Environmental Protection Agency
Agency (EPA).
(EPA). They
They areare safe
safe ananddeffective.




For your skin, use a product that contains 20
20--50%50% DEET (N,N
(N,N-diethyl
diethyl
diethyl-metametameta-toluamide).
toluamide). DEET in higher concentrations is no moreeffective.
Use DEET sparingly on children, and don’t apply to their hands, which they often place in their eyes and mouths.
Apply DEET lightly and evenly to exposed skin; do not use underneath clothing. Avoid contact with eyes, lips, and broken or
irritated skin.
To apply to your face, first dispense a small amount of DEET onto your hands and then carefully spread a thin layer.
Wash DEET off when your exposure to ticks, mosquitoes, and other arthropods ceases.

For yoyourur clothing, use a product that contains permethrin. Permethrin
Permethrin-treatedtreated clothing is especially effective against ticks.
Permethrin is available commercially as 0.5% spray formulations. Clothing that is factory
factory-impregnatedimpregnated with permethrin may also
be purpurchasedchased commercially. Permethrin will withstand numerous launderings.
Permethrin should only be used on clothing, never on skin.

When using any insect repellent, always FOLLOW LABEL DIRECTIONS.

Do not inhale aerosol formulations.

For optimum protection, soldiers should utilize the DOD INSECTREPELLENT SYSTEMSYSTEM.. In addition to proper wear of the military
combat uniform (e.g. ACUs, BDUs) (pants tucked into boots, sleevesdown, undershirt tucked into pants), this system includes thecoconcurrent
ncurrent use of both skin and clothing repellents:Standard military skin repellent: 33% DEET lotion, long
longacting formu
formulation,lation, one application lasts up to 12 hours,
NSN 6840
6840-01
01-284284-3982
3982
3982.
Standard military clothing repellents: either aerosol spray,
0.5% permethrin
permethrin,, one application lasts through 55-6
6 washes,
NSN 6840
6840-01
01-278278-1336
13361336;; or IDA (impregnation kit), 40%
permethrin
permethrin,, one application lasts the life of the uniform(approx. 50 washes), NSN 6840
6840-01
01-345345-0237
0237
0237.. Factory
permethrin
permethrin-treatedtreated ACUs are also availa
available
ble via contract[Contact the Armed Forces Pest Management Board(AFPMB) for details, DSN 295
295-7476;
7476; CM (301) 295
295-7476].
7476].

What should I do if I find a tick attached to my skin?
Remove attached ticks as soon as they are found. Use tweezers to firmly grasp the tick’s mouthparts up against the skin, and pull back firmly
and steadily. Be patient – the tick’s central mouthpart called the hypostome is covered with sharp barbs, sometimes making removal difficult.
Don’t pull back sharply, as this may tear the mmouthparts
outhparts from the body, leaving them embedded in the skin. If the mouthparts do break off, don’t
panic – the mouthparts alone cannot transmit disease because the infective body of the tick is no longer attached. However, to preve
prevent
nt
secondary infection, remove the mouthparts as you would a splinter. Never squeeze the body of the tick or use such things as petroleum jelly,
fingernail polish remover, or a lighted match: these methods could force more infective fluid into the skin. After removal, wash the wound site,
and apply an antiseptic. Preserve the tick by placing it in a clean, dry jar, or other well
well-sealed
sealed container, and keeping it in your freezer. Should
you develop disease symptoms, take the tick with you to the physician’s office; identificati
identification
on of the tick species may assist the physician withyour diagnosis and treatment. [Military clinics can send ticks that have been removed from patients to the A
APH
PHC
C for identification and analysis(contact the address, below)]. You may discard the tick aafter
fter one month; all known tick
tick-borne
borne diseases will generally display symptoms within
this time period.
Use of trademarked name does not imply endorsement by the U.S. Army but is intended only to assist in identification of a specific product.
For more iinformation
nformation please consult the APHC website - http://phc.amedd.army.mil