Toxocara canis: impact of preweaning nutritional deprivation on the pathogenesis of pneumonia in the mouse

The present study was conducted to better understand the immure response to Toxocara canis pneumonia in mice with preweaning nutritional deprivation. Breast-fed Swiss mice, undernourished due to large litter size (up to 15 pups) and paired controls with only 5-8 pups were used. At 21 days old, both groups were infected with T. canis larvae. Liver retinol, retinyl palmitate, and inflammatory infiltrate in lungs were compared in both groups. Significantly lower levels of retinol and retinyl palmitate in liver tissue confirmed the hypovitaminosis A (P < 0.0001 for both comparisons) in the nutritionally deprived animals. Histological analysis showed similar eosinophilic infiltration in both groups at day 3 but was significantly more severe in undernourished mice at day 20 post-infection (P = 0.01). The present findings indicate that preweaning undernourishment is associated with a more severe inflammation in response to T. canis pneumonia. It suggests that vitamin A deficiency that persists after nutritional rehabilitation, may contribute to the severity of T. canis infection. The authors suggest that nutritional status should be carefully investigated in patients with more severe clinical findings.