Visceral larva migrans in French adults: a new disease syndrome?

Visceral larva migrans is apparently an endemic disease among adults in southwest France. Thirty-seven adults living in the Midi-Pyrenees region of France were confirmed as having visceral larva migrans based on an increased specific antibody titer to Toxocara canis as detected by enzyme-linked immunosorbent assay (ELISA) and by the Western blot method. The disease was characterized clinically by weakness, pruritus, rash, difficulty breathing, abdominal pain, and pathologically by allergic manifestations including eosinophilia and increased serum immunoglobulin (Ig) E levels. Conditional logistic regression analysis using a control group of 37 hospital patients with other conditions who were individually matched to patients with visceral larva migrans by age and sex revealed an increased risk for visceral larva migrans associated with hunting or living in a household with a hunter (odds ratio (OR) = 9.0, p = 0.02) and with living in a village of less than 500 persons (OR = 5.7, p = 0.04). Owning two or more dogs compared with owning one or no dogs increased the risk of visceral larva migrans for hunting or living in a household with a hunter (OR = 9.6 vs. OR = 4.5) and for persons living in nonhunting households (OR = 2.1 vs. OR = 1.0). These findings, however, could not be duplicated when 60 age- and sex-matched neighbors were used as a second control group.

[Larva migrans visceralis--occurrence of ascarid eggs in sandboxes in the East German district city of Cottbus]

Between 1982 and 1985 18 sand-pits were examined for Toxocara canis eggs. Eggs were found in 4 sand-pits. This implies a risk of larva migrans visceralis infection for children playing in these sand-pits. Some measures for diminishing the contamination are recommended.

Zoonotic visceral and ocular larva migrans

Infection of children with the larval stage of the dog roundworm Toxocara canis usually produces few, if any, clinical signs. In some children, however, the disease may be severe, with permanent ocular or neurologic sequelae. Because the prevalence of infection may exceed 10 per cent in some population subgroups, it is important to understand the modes of transmission and risk factors for infection. The clinical presentations of toxocariasis as well as recommendations for their prevention are described.

Clinical features of covert toxocariasis

The clinical features found in 14 children with toxocara ELISA titres of greater than or equal to 0.7 were compared with those found in 34 toxocara negative children. Blood eosinophils were elevated in 7 of the 14 patients and the highest eosinophilia was 14%. There was a highly significant association between hepatomegaly, cough, sleep disturbance and a raised titre (p less than 0.01). Behaviour disturbance, abdominal pain and headache were also significantly associated with a raised titre (p less than 0.05). The combination of abdominal pain, headache and cough was even more significantly associated with a high titre (p less than 0.0005) than were individual clinical features. It is suggested that in addition to the two well recognised clinical conditions of visceral larva migrans and ocular toxocariasis the clinical entity of covert toxocariasis should receive recognition. Eosinophilia may or may not be present in this condition.

Human toxocariasis. Review with report of a probable case

A 23-year-old woman with fever, myalgias, stridor, pelvic cramping, lower abdominal pain, and profound eosinophilia was presumed to have toxocariasis. An enzyme-linked immunosorbent assay titer of 1:64 and an elevated IgE level supported the diagnosis. The patient became asymptomatic without treatment, and the eosinophil count returned to normal over several months. A stool sample from her dog was found to contain Toxocara canis ova, but the patient had no history of geophagia. Presumably, she acquired infection by hand-to-mouth transmission of infectious ova after handling the dog. Toxocariasis from this type of transmission is usually not seen in an adult, but it does occur, as this case demonstrates. Thus, the primary care physician should consider toxocariasis in any patient with a suggestive clinical picture and eosinophilia.

[Larva migrans visceralis--occurrence of Toxocara canis in dogs in the East German district of Cottbus]

Larvae of the nematode genus Toxocara are the main causative agents of the L.m.v. syndrom. 5,002 dogs from the Cottbus district aged between 2 and 36 months were examined. 994 animals (19.9%) were found to be infected with Toxocara canis. Dogs from a rural area have a higher infection rate (25.6%) than dogs from an urban area (15.2%). The relatively high infection rate of dogs, high egg-production and the tenacity of the development stages are factors dangerous to human health.

Visceral larva migrans: a risk assessment in Baton Rouge, Louisiana

Visceral larva migrans, VLM, is a disease of young children. Due to lack of awareness of the disease as well as its non-specific symptomology, a survey of the potential risk of acquiring the disease was conducted in the Baton Rouge, Louisiana area. The greatest number of dogs showing positive results to tests for the presence of the eggs of Toxocara canis were those less than one year of age. Very few of the soil samples collected from twenty different parks/playgrounds were found to contain eggs of T. canis. A higher percentage of soil samples from individual yards proved to be contaminated with the eggs of the parasite. Even though the incidence of VLM in Baton Rouge is reported to be quite low, the potential for the infection certainly is present. Veterinarians must be prepared to take a leading role in the education of their clients as to the potential of the disease for the children associated with new puppies, and the measures parents can take to reduce the exposure potential.

[Visceral larva migrans in childhood: report of 2 cases]

Reports of Visceral larva migrans (VLM) are not frequent in Brazil, but the prevalence of this disease may be more common due to poor environmental conditions to which most of the children are exposed. The most common infectious agent is Toxocara canis, a parasite of the intestinal tract of dogs. Children get infected eating contaminated material with feces of dogs. The ova are swallowed and reach the intestinal lumen of the children. Systemic migration occurs by lymphatic or portal circulation to several organs, most frequently, to the liver and lungs, causing hepatosplenomegaly and/or bronchospasm.

[Toxocara canis as a cause of visceral larva migrans. Survival and development of eggs in the environment and potential ways of transmission to man: a review]

A review is given on the occurrence of Toxocariasis, the prevalence of T. canis among dogs and investigations on the prevalence of infective ova in soil- and sandsamples. The resistance of ascarid eggs and larvae against different environmental influences, including various sewage treatment-effects is discussed. The eggs are destroyed in 7 minutes when kept at 55 degrees C in a high humidity, slower when the humidity is lowered. When the temperature is -32 degrees C T. canis eggs are inactivated after 8 hours. Complete embryonation is reached in 4 days when the temperature is 30 degrees C. Potential ways of transmission to man are outlined (pica, vegetables, bathing etc.) and recommendations in order to prevent the disease are given such as deworming of dogs, methods to decimate occurrence of eggs in wastewater and sludge etc.

Toxocariasis in an institution for the mentally retarded

A seroepidemiologic investigation was conducted in order to determine the cause of an apparent increase in rates of eosinophilia among 1400 institutionalized children during 1976-1977. The annual serologic survey during this period revealed 283 (20%) individuals with eosinophilia that exceeded 600 cells/cu mm of blood. During a five-month period in 1977, five patients who were hospitalized in adjacent wards developed acute pneumonia with eosinophilia. Because laboratory tests of sputum, bone marrow, and stool failed to identify the etiologic agent, it was thought that these pneumonia cases might be related to the increased rates of eosinophilia. Analyses of random samples of sera from patients with eosinophilia revealed seroprevalence rates of 12% for Ascaris, 20% for Toxocara canis, 24% for Strongyloides stercoralis, and 32% with increased antibody to Entamoeba histolytica. Further investigation showed a statistically significant positive association between occurrence of eosinophilia and pica behavior, and eosinophilia and contact with dogs. Although the serologic survey showed patients to have had previous exposure to a variety of parasites, we hypothesize that a principal cause of eosinophilia among institutionalized children may be Toxocara infestation, due to their frequent pica behavior and, in this case, contact with resident animals. We recommend that children in similar facilities have limited contact with pet dogs, and only after frequent and vigorous examination of the animals for infectious parasites.

Pica patterns, toxocariasis, and elevated blood lead in children

Blood samples were obtained during a lead screening program from 100 children aged 1-6 years in Allegheny County, Pennsylvania, to determine whether there was any association between specific forms of pica and infection with Toxocara canis, the principal cause of visceral larva migrans in the United States, or elevated blood lead levels. Significant associations were found between: 1) feces, soil, or grass pica and Toxocara infection; 2) paint or plaster pica and elevated blood lead; and 3) dog ownership and Toxocara infection. These findings suggest that an accurate pica history may be useful in identifying potential health problems in children.

Risk factors for toxocaral ocular larva migrans: a case-control study

Twenty-four patients with serologically confirmed toxocaral ocular larva migrans (OLM) and 24 age- and sex-matched controls were the subjects of an epidemiologic study. Information on the exposure to dogs and other factors possibly associated with transmission of toxocariasis was obtained by contacting the parents of the subjects. The odds of having had a dog present in the household within the year previous to onset of illness were 3 to 1 for cases vs controls. An association of pups (< 3 months) in the households of OLM patients within one year of onset was statistically significant (P < .05). Twenty-three of 24 OLM patients had had dogs in their homes some time before their illness, and the twenty-fourth patient had a history of geophagia, a behavioral pattern previously identified as a risk factor for toxocariasis. Exposure to cats and other animals in or outside the home did not differ for patients and controls. Infected dogs, especially pups, in the patients' homes were the most probably sources of infection for this group of OLM patients.

An outbreak of toxoplasmosis linked to cats

Clinical, serologic, and epidermiologic evidence documents an outbreak of toxoplasmosis involving ten of 30 members of an extended family. The index patient had unusual clinical manifestations including brain abscesses, progressive chorioretinitis, seizures, neurologic deficits, hepatosplenomegaly, pneumonitis, and eosinophilia. Toxoplasmosis was confirmed by demonstrating the organism in brain tissue and cerebrospinal fluids; clinical and serologic evidence also indicated infection with Toxocara (viscd children. Of the 11 such children, seven (68%) were seropositive, six of whom had high acute-phase titers (greater than or equal to 1024) to Toxoplasma and a disease consistent with acute toxoplasmosis. All six of the latter group required specific chemotherapy. Geophagia was associated statistically with acute toxoplasmosis among the children; it also increased the risk of infection with Toxocara and enteroparasites. Two school-aged children and two adults had serologic evidence of acute toxoplasmosis, but only one of the group was symptomatic. Epidemiologic evidence indicates that this outbreak was probably caused by ingesting oocysts from cat feces. We suggest that the severe and unusual clinical manifestations of the index patient resulted from simultaneous infection with Toxoplasma and Toxocara.

Prevalence of Toxocara canis in babies and in adults as determined by the ELISA test

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