Clinical and laboratory characteristics of Toxocara canis infection among children in Ho Chi Minh City, Vietnam.

BACKGROUND: This study determines the clinical and paraclinical characteristics of children with Toxocara canis infection and serum eosinophil cut-off values for predicting toxocariasis in the group displaying symptoms of itching, urticaria and erythema. METHODS: A cross-sectional study was conducted during March and April 2023 with a sample size of 986 children aged 3-15 y. RESULTS: In total, 140 (14.2%) of the 986 participants had anti-T canis antibodies. The most frequently experienced symptoms in this group were itching (10.1%), abdominal pain (8.2%) and urticaria (3.3%). The rate of IgE increased (37%), and the rates of mild and high eosinophilia were 38% and 2.2%, respectively. There were significant differences in IgE concentration and eosinophil count, and for both IgE concentration and eosinophil count between the two groups with and without toxocariasis. The optimal threshold for eosinophil to predict toxocariasis was 0.38 K/µL, with itching, urticaria and erythema resulting in a sensitivity of 61.5%, a specificity of 82.1% and a receiver operating characteristic curve (area under the curve) of 0.71. CONCLUSIONS: This study confirmed a positive association between IgE concentration, eosinophil count and positive serology for T. canis. A general blood count, including eosinophils, is a simple test that can be performed in hospitals. Clinicians should target and screen for T.oxocara canis infection when children display clinical symptoms of itching, urticaria, erythema and eosinophilia. CLINICAL TRIAL REGISTRATION NUMBER: NCT05208333.

The seroprevalence of toxocariasis and related risk factors in children in Ho Chi Minh City, Vietnam: results from a school-based cross-sectional study.

BACKGROUND: Children are especially vulnerable to Toxocara infection and its severe complications; however, there have not been any published data on the disease prevalence and treatment effectiveness in the population of Vietnamese children. This study was conducted to determine the prevalence of toxocariasis and explore factors associated with Toxocara infection in children aged 3-15 y in Ho Chi Minh City, Vietnam. METHODS: We conducted a cross-sectional study using a multistage cluster sampling approach in public schools. Blood samples were collected, and toxocariasis cases were confirmed, based on a history of contact with dogs/cats and positive anti-Toxocara antibody detection via ELISA. We calculated the percentage of seropositive children across gender, grade levels, districts and caregiver education. Multiple regression models were employed to identify potential risk factors. RESULTS: Anti-Toxocara antibodies were found in 14.2% of the 986 children studied. Significant variations in seropositivity were observed across grade levels, districts and caregiver education levels. Multivariable analysis identified caregiver education, contact with dogs/cats and improper handling of pet feces as seropositivity risk factors. CONCLUSION: This was the first community-based prevalence study of toxocariasis in a pediatric population in Vietnam. Implementation of preventive measures such as public education, routine fecal examinations and chemotherapeutic treatment of animals is highly recommended.