Risk Factors for Infant Intussusception After Introduction of Rotavirus Vaccine

Significant risk factors for intussusception in infants include acute gastroenteritis 2 weeks prior to hospitalization and the use of infant formula with or without breastfeeding; however, the risk related to rotavirus vaccination was undetectable as a result of low vaccine coverage and limited statistical power, according to a study published in Vaccine.

This case-control study investigated the risk of intussusception in infants less than 1 year with systematic inclusion of all suspected intussusception cases in infants in emergency departments in eastern France from April 2008 to March 2012. All level 1 cases (according to the Brighton classification) were matched with 4 hospital controls (115 cases, 457 controls). Exposure windows examined were exposure to first rotavirus vaccine dose in the first 7 days and 14 days prior to intussusception occurrence.

The average rotavirus vaccine coverage rate was 8.6% over the 4 years of the study. The vaccine was not significantly associated with the occurrence of intussusception in the 7 or 14 days after vaccine administration (7 days: odds ratio (OR) not calculated: P =.99; 14 days: OR 1.33, 95% CI, 0.14-12.82). Infant formula given alone or in combination with breastfeeding was associated with a significant risk of intussusception (OR 2.74; 95% CI, 1.10-6.79) as was a history of gastroenteritis within 2 weeks before hospitalization (OR 2.24; 95% CI, 1.07-4.67).

Study limitations included a lack of statistical power as a result of poor vaccine coverage rates and the potential for residual confounding.

Recent gastroenteritis occurrence and infant formula were both significantly associated with increased risk of intussusception in infants. Although a small, insignificant increase in intussusception risk was seen after rotavirus vaccination, study investigators concluded that “[t]he limited statistical power and the low vaccine coverage likely preclude detection of a significant increase in the risk of [intussusception] related to rotavirus vaccination.”

Reference

Fotso Kamdem A, Vidal C, Pazart L, et al. A case-control study of risk factors for intussusception among infants in eastern France after the introduction of the rotavirus vaccine [published online March 7, 2019]. Vaccine. doi: 10.1016/j.vaccine.2019.02.053