#37 Human Toxocariasis: eleven-year experience in a tertiary-care level pediatric hospital in Mexico City

Abstract

Abstract Background In Mexico, human toxocariasis is not subject to continuous epidemiological surveillance. However, some studies that report seroprevalence show a significant association between larva migrans (LM) and pediatric cases (OR 3.2; IC95 2.541-4.279). Data is scarce about infection in animal reservoirs, more specifically dogs, in which there are reports of a 12-18% positivity rate. As for the role of the environment there is evidence to support high contamination levels. Most symptomatic pediatric patients develop ocular presentations that can lead to permanent vision loss, and diagnosis becomes a challenge because serological markers and peripheral eosinophilia can be absent. Method A retrospective, transverse, descriptive study including 17 patients with diagnosis of toxocariasis according to electronic medical records. For categoric variables, frequencies and percentages were analyzed and for discrete variables median and ranges were calculated. Results Nine patients (52.9%) presented with ocular LM of which, 55.6% were female with a median age of 5 years at diagnosis (IQR=9). 44.4% came from the coastal state of Veracruz and 88.9% had close contact with either dogs or cats. Two patients presented with eosinophilia and only one had positive anti-Toxocara antibodies at 2.12 OD. Under suspicion of retinoblastoma, two patients underwent enucleation and diagnosis was made with pathology findings. Eight patients (47.1%) presented with visceral LM of which, 62.5% were female with a median age of 7.5 years at diagnosis (IQR=12). 62.5% of them had close contact with either dogs or cats. In this case, all patients had history of peripheral eosinophilia but it was only in 75% that it was corroborated during initial workup at our institution ranging between 500-9400 cells/mm3 and all of them had positive antibodies that ranged between 1.02-3.2 OD. Five patients received oral treatment with albendazole for 3-7 days. Conclusion Human toxocariasis is a neglected parasitic disease with scarce published data. Pediatric patients are an important vulnerable group specially for ocular presentations. The differential diagnosis of leukochoria should always include retinoblastoma, but as shown in this study, also ocular LM. As new approaches to global health move towards prevention, our study can set a precedent in order to standardize patient care and resource allocation.