toxocara canis ( t. canis ) , a common dog roundworm , is one of the causative agents of visceral larva migrans ( vlm ) .
when infective eggs of t. canis reach the human gastrointestinal tract , they enter the portal system and reach the liver .
some larvae then migrate from the liver to the lung and the heart through the systemic circulation .
myocarditis may occur in 10 - 15% of cases of vlm , and in those cases , myocarditis is accompanied by an increased level of circulating eosinophils . there have been approximately 10 cases of myocarditis associated with toxocara infection and only 2 cases were found in english publication since the year 2000 .
this is the first report in korea . here , we present case of myocarditis associated with eosinophilia caused by t. canis vlm .
a 41-year - old woman presented at our hospital complaining of chest discomfort and pain .
she had been healthy with no significant preceding symptoms , allergic history or past medical history .
the initial examination showed the following findings ; body temperature 37.8 , blood pressure 94/60 mmhg , heart rate 100 beats / min and a cardiac gallop rhythm . laboratory data on admission revealed decrease in the total white blood cell count ( 1040/mm ) , elevated enzymes ( creatinine phosphokinase 236 iu / l , aspartate aminotransferase 112 iu / l , alanine aminotransferase 87 iu / l , lactic dehydrogenase 588 iu / l , troponin - i 4.070 ng / ml , ck - mb 12.32 ng / ml and probnp 8760 pg / ml ) . electrocardiogram ( ecg ) showed a regular sinus rhythm with low voltage in all limb and precordial leads ( fig .
transthoracic echocardiogram ( tte ) showed marked edematous left ventricular ( lv ) myocardium and global hypokinesis ( fig .
2a ) , resulted in mild left ventricular systolic dysfunction ( lv ejection fraction = 48% ) ( fig .
there was no significant valvular dysfunction and small pericardial effusion without tamponade physiology was noted .
empirical treatment such as intravenous antibiotics injection , bed rest , pain control and close vital sign monitoring were performed . on the tenth day of admission ,
total white blood cell count ( 17160/mm ) and eosinophil count ( 8430/mm ) markedly increased ( 49% of her total white blood cell count ) .
we started oral administration of prednisolone 1 mg / kg for 3 days and performed ventricular endomyocardial biopsy .
the antibody test against parasitic infection demonstrated that toxocara immunoglobulin g ( igg ) was positive . taken together , we diagnosed that she had myocarditis caused by t. canis vlm .
we started oral administration of albendazol 400 mg twice a day for two weeks after oral prednisolone 1 mg / kg administration for 3 days .
tte finding showed that echogenicity of lv myocardium was markedly decreased and wall thickness was normalized ( fig . 2c ) .
after the completion of the treatment , physical examination , laboratory tests , ecg and echocardiogram showed no abnormal findings and she was able to return to work .
human toxocariasis is a helminthozoonosis due to the migration of toxocara species larvae through human organism .
many reviews from western countries indicated that children under 12 years old , who often play outside , are the most affected age group for toxocariasis.1)2 ) they are accidentally infected with t. canis eggs , which expelled in feces puppies and fully develop in the surrounding environment within two to four weeks .
human become infected by ingesting either embryonated eggs from soil ( geophagia , pica ) , dirty hands or raw vegetables , or larvae from undercooked giblets . when embryonated eggs of t. canis reach the human gastrointestinal tract , they hatch and enter the portal system , reaching the liver .
some larvae then migrate to the lungs and heart through the systemic circulation.3 ) in this case , we could not find obvious source for t. canis infection .
we assumed that she infected by ingesting embryonated eggs or larvae from raw vegetables , such as lettuce .
a definitive laboratory diagnosis of human toxocaral infection can be achieved by pathology examination of various organ specimens .
however , such a direct parasitologic assessment is awkward and uncommon , serologic methods are the mainstay for the diagnosis .
the most commonly utilized diagnostic serologic test is the enzyme - linked immunosorbent assay with toxocara excretory secretory antigen .
but when interpreting a serologic result , it should be kept in mind that the numerous seropositive individuals detected through screening of large populations in epidemiological surveys probably represent past rather than recent infection .
immunologic testing therefore , should be accompanied by a blood eosinophil count and if possible , by determination of serum total immunoglobulin e.4 ) a finding of both a peripheral eosinophilia and a positive serologic test result is indicative of active toxocariasis.5 ) myocarditis in vlm may result from direct larval invasion to the myocardium and/or hypersensitivity reactions to the parasites.6 ) it has been suggested that there are 3 clinical stages of eosinophilic myocarditis : acute necrotizing phase , thrombotic phase and endomyocardial fibrosis phase .
loffler 's endomyocarditis is considered to correspond to the second stage of eosinophilic endomyocardial disease .
the third stage probably corresponds to restrictive myocarditis.7 ) differential diagnoses include other types of myocarditis , churg - strauss syndrome , hypersensitivity reaction , malignant diseases , parasitic infection or hypereosinophilic syndrome .
tte finding shows diverse feature including diffuse severe hypokinesia or left ventricular focal asynergy.8 ) in our case , lv diastology did not showed significant dysfunction except abnormal relaxation .
we think mild decreased lv systolic function , ( left ventricle ejection fraction = 48% ) was the reason .
thrombus also can occur and according to its characteristics , not only anticoagulation therapy but also surgical removal of the thrombus should be considered to prevent systemic embolism.9)10 ) therapy is primarily based upon administration of anthelmintics .
currently , 5 days or more use of albendazole 800 mg / day or 10 mg / kg / day are recommended for treatment of t. canis infection .
the mechanism of its anthelmintic action is inhibition of tubulin polymerization and microtubule - dependent glucose uptake inhibition . in this case , for the control of aggravated eosinophilia , we started administration of prednisolone . because she did n't have cardiac tamponade , cardiogenic shock or pulmonary edema , prednisolone was administered at 1.0 mg / kg / day.8 ) and as soon as we confirmed toxocara igg positive , albendazole was added to the medication .
when a patient who has myocarditis with eosinophilia occurs , toxocara infection should be considered for possible cause .
 a 41-year - old woman who was diagnosed with myocarditis presented eosinophilia . since the antibody against toxocara canis ( t. canis ) was positive , we diagnosed that she had visceral larva migrans due to t. canis associated with myocarditis . 
 she was treated with oral albendazole and prednisolone for two weeks , eosinophil count and hepatic enzymes were normalized after completion of treatment . 
 this is the first report of myocarditis caused by t. canis infection in korea . 