765. Determinants of Rotavirus Acquisition in Rotavirus-Vaccinated Guatemalan Infants
Session: Poster Abstract Session: Vaccines: Pediatric
Thursday, October 27, 2016
Room: Poster Hall
Background: Rotavirus vaccination efficacy in low-income countries is variable and frequently lower than in high-income countries, and our understanding of the factors underlying these phenomena is incomplete. As a sub-analysis of a clinical trial for treatment of acute diarrhea, we examined the impact of demographic and socioeconomic factors on risk of rotavirus acquisition in young children in Guatemala. Using a multiplex PCR assay for stool pathogens we analyzed the influence of stool pathogen burden (number and distribution) on rotavirus acquisition.

Methods: Children 6-35 months with acute diarrhea (<72 hours) were enrolled between 3/2015 and 1/2016 in two sites (1 rural, 1 urban). Rotavirus vaccination is routine in Guatemala but uptake is not universal. Stool samples collected at enrollment were analyzed by multiplex PCR (FilmArrayTMGI-Panel, BioFire, Utah, USA) that allows simultaneous identification of 22 viral, parasitic and bacterial diarrheal pathogens including rotavirus. Clinical, vaccination, demographic and stool-test characteristics in subjects with rotavirus positive stools were compared with those that were rotavirus negative.

Results: Among 302 subjects, rotavirus was identified in 21 (7%) of stools. 75.2% of subjects had received 2 or more rotavirus vaccinations, 16.9% one dose and 8.0% no vaccine. Though rates of rotavirus acquisition were higher in subjects who had received no vaccine compared to those with 1 or more dose (12.5% vs. 6.5%) there was no statistically significant difference between any category of vaccination (p=0.49; Chi2 test). Among fully vaccinated children (2+ doses), no differences in age, sex, urban vs. rural, latrine use (proxy for poverty/low hygiene), or number or distribution of additional stool pathogens were noted between rotavirus positive and negative cases.

Conclusion: Rotavirus presence in Guatemalan infants with acute diarrhea was very low. Though numbers in our study were small and statistical significance was not achieved, vaccine effectiveness appeared higher than in previous studies in Latin American infants, perhaps augmented in this population via an effect of herd immunity. Our data suggest that rotavirus vaccine is efficacious in a low-income population across a spectrum of demographic and socioeconomic characteristics.

James Gaensbauer, MD, MScPH, Pediatric Infectious Disease, Denver Health and Hospital Authority, Denver, CO; Center for Global Health, Colorado School of Public Health, Aurora, CO; Pediatric Infectious Disease, Children's Hospital Colorado/University of Colorado School of Medicine, Aurora, CO, Mario Melgar, MD, Infectious Diseases, Unidad Nacional de Oncología Pediátrica, Guatemala, Guatemala, Mirella Calvimontes, MD, Universidad Francisco Marroquin, Guatemala City, Guatemala, Edwin J Asturias, MD, University of Colorado School of Medicine, Aurora, CO, Ingrid Contreras-Roldan, MD, Centro De Estudios En Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala, Samuel R. Dominguez, MD, PhD, Pediatric Infectious Diseases, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, Christine C. Robinson, PhD, Children's Hospital Colorado, Denver, CO, Satoshi Kamidani, MD, Pediatrics, Children's Hospital Colorado/University of Colorado School of Medicine, Aurora, CO and Stephen Berman, MD, Pediatrics, University of Colorado School of Medicine, Aurora, CO

Disclosures:

J. Gaensbauer, None

M. Melgar, Pfizer: Grant Investigator , Grant recipient

M. Calvimontes, None

E. J. Asturias, None

I. Contreras-Roldan, None

S. R. Dominguez, None

C. C. Robinson, None

S. Kamidani, None

S. Berman, None

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