Toxocara antibodies in patients with visceral or ocular disorder in Slovenia

Seroprevalence of human toxocarosis in Europe: A review and meta-analysis

Toxocarosis is distributed worldwide and represents the most prevalent zoonotic helminth infection in industrialized countries, thereby posing a substantial risk for public health. Thus, toxocarosis is one of CDC's Neglected Parasitic Infections that has been targeted for public health action. This systematic review and meta-analysis summarizes Toxocara seroprevalence in general populations from Europe, populations suspected of Toxocara infection and defined risk groups. Random-effects meta-analysis of proportions based on 41 publications resulted in an overall seroprevalence of 6.2% (95% CI: 4.7-8.3%) in the general population of Europe. Subgroup analysis according to decades (1970-2010s) revealed a significant increase in seroprevalence, with the highest value (12.4%; 95% CI: 6.5-22.3%) in the 2010s (χ²=17.87, df=4, P=0.001). There were no significant differences between pooled prevalence rates of European sub-regions (χ²=3.01, df=3, P=0.389). Furthermore, meta-analysis of seroprevalence according to age groups, based on data from 22 publications, indicated a significantly higher pooled seroprevalence of 14.9% (95% CI: 8.5-24.8%) in people more than 50 years of age than in younger age cohorts (χ²=8.33, df=2, P=0.016). Occupational groups exposed to contaminated soil and infected animals bear substantial risk for acquiring Toxocara infection. Due to the close link between animal infection and human Toxocara exposure, a "One Health" approach for the prevention of Toxocara infection in both humans and animals is required.

Developmental age, physical fitness andToxocaraseroprevalence amongst lower-secondary students living in rural areas contaminated withToxocaraeggs

Scarce and inconclusive information on general biological impact ofToxocarainvasion on paratenic hosts, and people in particular, has led us to undertake a comprehensive study of the problem. The study has been conducted in a rural environment, which is considered a toxocarosis risk factor. In total 200 soil samples have been screened forToxocaraeggs by flotation, of which 14·5% were positive. Backyards close to households were most heavily contaminated with infectious eggs – 21·7% of positive samples. ELISA serological tests performed on 242 lower-secondary students found 14·5% of the studied population to be definitely positive – 16·5% of boys and 12·8% of girls, respectively. The odds of being infected withToxocarawere 2 times (CI: 1·15–3·85) more likely for individuals who owned a cat than those who did not own a cat. Strong significant correlation between seropositivity and the presence of a dog in a household was found with boys. The level of developmental age was significantly higher in seropositive than in seronegative students. No significant correlation has been observed between the motor abilities and seropositivity of students. Seropositive boys had significantly lower end-of-year grades than their seronegative counterparts.

Experimental toxocariosis in BALB/c mice: effect of the inoculation dose on brain and eye involvement

Ocular toxocarosis (OT) is a well-established disease. However, our understanding of the migratory route, time and circumstances that produce ocular invasion are not clear. To improve our knowledge of factors related to ocular invasion, BALB/c mice were inoculated with simple doses (SD) of 6, 12, 50, 100, 200 and 1000 embryonated eggs (EE) and multiple doses (MD) of 200 and 1000 EE. Brains and eyes were studied for the presence of larvae in animals sacrificed on days 3, 5, 7, 9, 11, 13, 15, 17, 19, 40, 80 and 120 in SD and on days 28, 30, 32, 34, 36, 38, 40, 42, 46, 87 and 127 in MD. The humoral immune responses were studied by ELISA using excretory-secretory antigen. Due to the considerable number of days tested, results showed are based on one set of experiments. However, each point studied represents the result obtained from a group of five mice. We have shown that the eye involvement with Toxocara canis larvae is a phenomenon mainly produced once larvae have reached the brain. There is a direct relationship between the parasitic load and the number of ocular larvae. Moreover, the arrival of larvae to the eye is an independent event, unrelated to the kind of administered dose (SD, MD), although the number of the brain larvae was higher in the cases of MD. High levels of specific antibodies were observed but they did not prevent the arrival of the larvae to the brain and the eye.

Larval toxocariasis and its clinical manifestation in childhood in the Slovak Republic

Results are presented of 90 children aged 1–15 years hospitalized with toxocariasis. Blood count analysis and laboratory examination were done by routine clinical laboratory methods. Anti-Toxocara antibodies were detected in the serum of patients using an ELISA method. Demographic analysis of the children's families exposed to the risk of disease allowed estimation of age-specific rates for clinical toxocariasis. The probability of toxocaral infection and the intensity of its clinical manifestations in children are determined by the epidemiology of this zoonosis and by the risk factors in the family. The presence of high titres of specific IgG antibodies in all age categories correlates with the clinical manifestations of toxocariasis. The highest admission rate is in the age categories of 3–5 years (43.3%) and 6–10 years (36.7%). Laboratory findings show that the most conspicuous changes occur in the age category 1–5 years. The high percentage of seropositive dog-keeping and puppy-breeding families and the possibility of infection with repeated doses of larvae stimulate eosinophilia, which prevails in children under the age of five years. We present the percentage of patients whose parameters showed deviations from the reference values for a particular age category. Analyses of laboratory indices and of clinical manifestations will contribute to the accuracy of diagnosis and effectiveness of treatment of this disease.

Manifestation of toxocariasis in children with neuroblastoma treated with autologous hematopoietic transplants

Toxocariasis was diagnosed in 3 out of 22 children (14%) treated in our center with high-dose chemotherapy and autologous hematopoietic stem cell transplantation (HSCT). The patients were coming from rural areas in the southeastern Poland and did not present any clinical symptoms of toxocariasis upon admission to the hospital. Although no neurological and ophthalmological abnormalities were noticed, the atypical form of toxacariasis was diagnosed based on elevated eosinophils counts, positive serological tests, and biochemical symptoms of liver damage. The authors conclude that toxocariasis should be taken into consideration in the differential diagnosis of eosinophilia in children undergoing high-dose chemotherapy and HSCT, especially if they are coming from rural areas.

Seroprevalence of Toxocara antibodies among patients suspected of ocular toxocariasis in Slovenia

Ocular toxocariasis named also ocular larva migrans is caused by larvae of the roundworm Toxocara spp. The purpose of this study was to find out the seroprevalence of Toxocara antibodies in patients suspected of ocular toxocariasis. Between January 2001 and December 2003, sera from 239 ocular patients, aged 3 to 80 years, were examined by ELISA and confirmed by Western blot test. Out of the 239 patients, 172 (72%) were seronegative and 67 (28%) were Toxocara seropositive; 95% CI (22-34%). The median age of Toxocara seropositive patients was 37.6 years. There was no significant difference in the number of Toxocara positive sera between the younger age group (< or = 14 years) and the older age group (> 14 years), p > 0.05. A high rate of Toxocara seropositivity in ocular patients should alert the ophthalmologists in Slovenia to include toxocariasis in the differential diagnosis of eye diseases more frequently.