Cardiac Involvement in Patients with Trichinosis Hospitalized in Western Romania

Introduction

C ardiovascular disturbances are reported as major trichinosis complications (Dupouy-Camet et al., 2002). Myocarditis is the most frequent of them (Bruschi and Murrell, 2006) and occurs in 5%–20% of cases (Dupouy-Camet et al., 2002; Dupouy-Camet and Bruschi, 2007). Findings are not specific and may include chest pain, palpitations, shortness of breath, tachycardia, and electrocardiogram (ECG) anomalies (Schantz and Dietz, 2001; Dupouy-Camet et al., 2002; Dupouy-Camet and Bruschi, 2007; Franco-Paredes et al., 2007). The majority of myocardial changes develop during the invasive phase of the illness (Tint et al., 2009).

Trichinosis is considered the most significant and widespread parasitic disease in Romania. The average yearly incidence was 6.2 cases per 100,000 inhabitants during the period 1990–2007 (Neghina et al., 2010). Previous Romanian surveillances on prevalence of cardiac involvement indicated a rate of 30%–50% in 1960 and 1994 (Olteanu et al., 1999; Enache, 2005).

The aim of the present study was to overview the clinical and the main epidemiological characteristics of persons with trichinosis and cardiac involvement hospitalized in western Romania between 1990 and 2001.

Patients and Methods

Hospitalization documents of 28 patients with trichinosis and cardiac complications admitted at the Hospital of Infectious Diseases in Timisoara, Romania, were retroactively investigated. Patients were residents of three Romanian counties and were hospitalized between 1990 and 2001. The following information was extracted: registration number of the medical record, age, sex, address, date and length of hospital stay, profession, clinical symptomatology, routine laboratory tests, cardiac investigations, and specific therapy. Trichinosis was mainly confirmed by positive muscle biopsy and/or positive serology.

Statistical evaluation was performed using the software package SPSS version 17.0 for Windows (SPSS, Inc., Chicago, IL). Descriptive statistics (percentage, mean, and standard deviation [SD]) were calculated for each variable. Comparisons between patient groups were made by means of standard binomial tests for differences in proportions, and Mann–Whitney U statistics for quantitative data. A p-value of ≤0.05 was regarded statistically significant.

Results

Twenty-eight patients, found to have trichinosis, presented cardiac involvement. Of the study group, six patients (21.4%) died during hospitalization and their necropsy revealed the diagnosis of myocarditis. For the remaining patients, myocarditis was only suspected because myocardial biopsy was not performed. In this latter group, cardiac disturbances were mainly evidenced by electrocardiography (Table 1). Except for two cases (one with essential hypertension and one with cardiac failure), none of the patients had a positive history of cardiac symptoms. The complete symptomatology of the patients is overviewed in Table 2. Increased eosinophil counts (≥5%) were found in 22 cases (78.6%). The mean eosinophil value of the study group was 16.9% (SD, 15.5; range, 2–70). Leukocytes were increased (over 10,000 cells/μL) in 5 patients (17.9%) and erythrocyte sedimentation rate (ESR) was increased (over 10 mm/hour) in 13 patients (46.4%). The average value was 8237 cells/μL (SD, 2512.6; range, 5000–15,800) for leukocytes and 25.8 mm/hour (SD, 30; range, 2–130) in case of ESR. The following antihelminthic drugs were administered: thiabendazole (53.6%, n = 14), mebendazole (21.4%, n = 6), and diethylcarbamazinum (10.7%, n = 3). Corticosteroids were administered in 20 cases (71.4%). The average length of stay in hospital was 18.1 days (SD, 11.4; range, 2–50). Two of the patients (7.1%) developed cardiac complications during a second hospitalization (relapse of the disease).

Regarding the epidemiological aspects of the study group, the mean age of the patients was 38 years (SD, 18.1; range, 3–80). Twenty-five patients (89.3%) were adults and three (10.7%) were children (≤18 years). There were 18 male patients (64.3%) and 10 female patients (35.7%). According to the area of residence, 21 patients (75%) were from urban regions and 7 (25%) from rural regions. Distribution of the adults (n = 25) according to their professions indicated that 10 (40%) were unemployed, 5 (20%) were workers, 5 (20%) were intellectuals and office workers, and 4 (16%) were retired. In the case of one patient, the profession was not specified in the medical document.

Six patients died of cardiopulmonary arrest, of which five (83.3%) were females. The mean age of the deceased patients was 39.5 years (SD, 15.6; range, 25–66), and four of them (66.7%) were unemployed. It is noteworthy that three (50%) of these patients did not present any ECG disturbances or cardiac symptoms. Average values of the routine laboratory tests were as follows: 7.3% (SD, 7; range, 2–21) for eosinophil counts, 7950 cells/μL (SD, 2082.1; range, 5000–10,800) for leukocyte counts, and 5 mm/hour (SD, 3.6; range, 2–10) for ESR. Three of them received combination therapy using an antiparasitic drug (either thiabendazole or diethylcarbamazinum) and a corticosteroid, one patient received an antiparasitic drug only (thiabendazole), and another one was treated with a corticosteroid alone. The two patients with a positive cardiac history belonged to this group.

Discussion

Although all of the patients from the study group were suspected of myocarditis caused by Trichinella, diagnosis was confirmed only in the deceased ones by postmortem examination. For the remaining cases, cardiac disturbances were evidenced especially by electrocardiography. ECG modifications represent the most common sign of cardiac involvement in nonfatal trichinosis (Tint et al., 2009). Nevertheless, this investigation has a sensitivity of 47% in myocarditis (Cooper, 2009). Repolarization disturbances predominated in the present study and similar findings were supported by other reports (Siwak et al., 1994; Puljiz et al., 2005). The biomarkers of cardiac injury (troponin I, creatine kinase muscle-brain isoenzyme [CK-MB isoenzyme]) could not be assessed because the financial resources of the hospital are strictly limited. Moreover, echocardiography was not available in the early period of the study. The predominant symptom was myalgia, a finding also noticed in the extensive surveillances performed in the same region (Neghina et al., 2009a, 2009b) and in other studies (Cortes-Blanco et al., 2002; Roy et al., 2003; Shimoni et al., 2007; Jansen et al., 2008; Kennedy et al., 2009). Two patients developed cardiac complications during a relapse of the illness, similar to former patients with trichinosis from Brasov County, Romania (Nemet et al., 2009).

Regarding the average value of the routine laboratory tests, noteworthy is that eosinophil counts and ESR were significantly lower in patients who died (p = 0.039 and p = 0.015, respectively). Thiabendazole, although not recommended anymore by experts because of its adverse effects (Dupouy-Camet et al., 2002; Dupouy-Camet and Bruschi, 2007), was used in most of patients, either survivors (50%, n = 11) or deceased (66.7%, n = 4), because of its hospital availability.

The mean age of our study group (38 years) was found to be similar to the mean age observed in Croatian patients with myocarditis due to trichinosis (35.6 years) (Puljiz et al., 2005). Most studies of acute myocarditis evidenced a slightly male predominance probably because of the protective effect of the natural hormone variations on immune responses in women (Cooper, 2009). The supposition was strengthened by the present study (64.3%—males) as well as the Croatian one (65.6%—males) (Cooper, 2009). Despite female patients represented the majority (83.3%) of the fatal cases, this number was comparable to the female cases who survived (p = 1.000). The largest number of patients were unemployed, generally individuals with limited formal education and low incomes. This could explain that the infection occurred by ingestion of poorly heated or raw pork originating from illegal sources or from backyard pigs (Neghina et al., 2010).

Cardiac involvement represented and still continues to be a major complication of trichinosis in Romanian patients. Besides the reported cases, many cases may have been misdiagnosed. Studies on exhumed bodies showed that deaths previously considered to be caused by different cardiac disorders were actually complications of trichinosis (Olteanu et al., 1999; Enache, 2005).

Conclusions

Because of its potentially lethal outcome, myocarditis must be considered in patients with trichinosis even when specific symptoms are missing (Lachkar et al., 2008). Dosage of serum cardiac troponin I in these patients should be implemented for a timely diagnosis (Lachkar et al., 2008). Prophylactic measures are also very important and should be based especially on health education programs for the masses.