What to know
- Presentation Day/Time: Thursday, April 24, 2:05–2:25 pm
- Presenter: Mary Moran, PhD, MPH, EIS officer assigned to the National Center for Immunization and Respiratory Diseases, Division of Viral Diseases
What did we do?
- We assessed severe acute gastroenteritis (AGE) transmission in household and among household contacts (HHCs) of medically attended pediatric norovirus-positive index cases.
- We enrolled children aged <11 years with AGE at 7 hospitals as part of the New Vaccine Surveillance Network from December 2011 to June 2016.
- We collected stool samples from children ≤10 days after symptom onset and tested for norovirus.
- We used parent interviews and follow-up questionnaires to assess AGE in HHCs.
What did we find?
- There were 1,993 norovirus-positive and 7,028 norovirus-negative index cases enrolled.
- Among households, those with a norovirus-positive index case were more likely to report AGE transmission (≥1 ill HHCs) in the follow-up period than households with a norovirus-negative index case (32.6% vs 15.3%; OR: 2.67, [95% CI: 2.38–2.99]).
- On the individual level, HHCs of norovirus-positive index cases had an increased odds of reporting AGE symptoms (OR: 3.02 [95% CI: 2.70–3.39]), compared with HHCs of norovirus-negative index cases.
- Index case vomiting (>1 episode) was the greatest risk factor (OR: 2.23, [95% CI: 2.70–3.39]) for AGE symptoms among HHCs of norovirus-positive index cases.
- Among households of norovirus-positive index cases, the attack rate was highest for HHCs aged 0–4 years (22%), but adults aged 18–49 years accounted for the largest proportion of ill HHCs (60.9%).
Why does it matter?
- Norovirus is highly transmissible and is a leading cause of severe acute gastroenteritis (AGE) among children <5 years of age in the United States.
- Norovirus-positive children contribute to significant household transmission of AGE.
- Parents and guardians were the largest proportion of ill HHCs in households of norovirus-positive index cases, indicating that caregiving is a large contributor to transmission.
Abstract Category: Norovirus, Maternal, Child, and Adolescent Health