Showing papers by "Filemon Bucardo published in 2023"
TL;DR: In this paper , the rotavirus-associated acute gastroenteritis (AGE) was assessed in 444 Nicaraguan children followed from birth until 3 years of age, followed by RT-qPCR and saliva or blood were used to determine the HBGAs phenotypes.
Abstract: BACKGROUND
Histo-blood group antigens (HBGAs) have been associated with rotavirus vaccine take; but the effect of these HBGAs on rotavirus incidence and risk remains poorly explored in vaccinated populations.
METHODS
Rotavirus-associated acute gastroenteritis (AGE) was assessed in 444 Nicaraguan children followed from birth until 3 years of age. AGE episodes were tested for rotavirus by RT-qPCR and saliva or blood were used to determine the HBGAs phenotypes. Cox proportional hazards models were used to estimate the relative hazard of rotavirus AGE by HBGA phenotypes.
RESULTS
Rotavirus was detected in 109 (7%) stool samples from 1,689 AGE episodes over 36 months of observation between June 2017 and July 2021. Forty-six samples were successfully genotyped. Of these, 15 (35%) were rotavirus vaccine strain G1P[8], followed by G8P[8] or G8P[nt] (11, 24%) and equine-like G3P[8] (11, 24%). The overall incidence of rotavirus-associated AGE was 9.2/100 child-years, and was significantly higher in secretor compared to non-secretor children (9.8 vs. 3.5/100 child-years, P = 0.002).
CONCLUSION
The non-secretor phenotype was associated with decreased risk of clinical rotavirus vaccine failure in a vaccinated Nicaraguan birth cohort. These results show the importance of secretor status on rotavirus risk, even in vaccinated children.
TL;DR: In this paper , the authors studied the dynamics of Zika virus (ZIKV)-specific antibody immunity in children born to mothers in a flavivirus-endemic region during and after the emergence of ZIKV in the Americas.
Abstract: Objective: To understand the dynamics of Zika virus (ZIKV)-specific antibody immunity in children born to mothers in a flavivirus-endemic region during and after the emergence of ZIKV in the Americas. Methods: We performed serologic testing for ZIKV cross-reactive and type-specific IgG in two longitudinal cohorts, which enrolled pregnant women and their children (PW1 and PW2) after the beginning of the ZIKV epidemic in Nicaragua. Quarterly samples from children over their first two years of life and maternal blood samples at birth and at the end of the two-year follow-up period were studied. Results: Most mothers in this dengue-endemic area were flavivirus-immune at enrollment. ZIKV-specific IgG (anti-ZIKV EDIII IgG) was detected in 82 of 102 (80.4%) mothers in cohort PW1 and 89 of 134 (66.4%) mothers in cohort PW2, consistent with extensive transmission observed in Nicaragua during 2016. ZIKV-reactive IgG decayed to undetectable levels by 6–9 months in infants, whereas these antibodies were maintained in mothers at the year two time point. Interestingly, a greater contribution to ZIKV immunity by IgG3 was observed in babies born soon after ZIKV transmission. Finally, 43 of 343 (13%) children exhibited persistent or increasing ZIKV-reactive IgG at ≥9 months, with 10 of 30 (33%) tested demonstrating serologic evidence of incident dengue infection. Conclusions: These data inform our understanding of protective and pathogenic immunity to potential flavivirus infections in early life in areas where multiple flaviviruses co-circulate, particularly considering the immune interactions between ZIKV and dengue and the future possibility of ZIKV vaccination in women of childbearing potential. This study also shows the benefits of cord blood sampling for serologic surveillance of infectious diseases in resource-limited settings.
TL;DR: In this paper , the authors performed ophthalmic examination between 16 and 21 months and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the Zika virus epidemic in Nicaragua (2016-2017).
Abstract: Knowledge regarding the frequency of ocular abnormalities and abnormal visual function in children exposed to Zika virus (ZIKV) in utero but born without congenital Zika syndrome (CZS) is limited. We hypothesized that children exposed to ZIKV in utero born without CZS may have visual impairments in early childhood. We performed ophthalmic examination between 16 and 21 months of age and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the ZIKV epidemic in Nicaragua (2016–2017). ZIKV exposure status was defined based on maternal and infant serological testing. Visual impairment was defined as abnormal if the child had an abnormal ophthalmic exam and/or low visual reception score in the MSEL assessment. Of 124 children included in the analysis, 24 (19.4%) were classified as ZIKV-exposed and 100 (80.6%) unexposed according to maternal or cord blood serology. Ophthalmic examination showed that visual acuity did not differ significantly between groups, thus, 17.4% of ZIKV-exposed and 5.2% of unexposed had abnormal visual function (p = 0.07) and 12.5% of the ZIKV-exposed and 2% of the unexposed had abnormal contrast testing (p = 0.05). Low MSEL visual reception score was 3.2-fold higher in ZIKV-exposed than unexposed children, but not statistically significant (OR 3.2, CI: 0.8–14.0; p = 0.10). Visual impairment (a composite measure of visual function or low MESL visual reception score) was present in more ZIKV-exposed than in unexposed children (OR 3.7, CI: 1.2, 11.0; p = 0.02). However, the limited sample size warrants future investigations to fully assess the impact of in utero ZIKV exposure on ocular structures and visual function in early childhood, even in apparently healthy children.
TL;DR: In a case-control study nested in a birth cohort study in Nicaragua between June 2017 and January 2022, the authors followed children weekly for acute gastroenteritis (AGE) episodes, and collected stool specimens from symptomatic children as discussed by the authors .
Abstract: Norovirus causes a large proportion of pediatric acute gastroenteritis (AGE) worldwide, and no vaccines are currently available. To inform public health measures against norovirus gastroenteritis, we assessed risk factors in a case–control study nested in a birth cohort study in Nicaragua. Between June 2017 and January 2022, we followed children weekly for AGE episodes, and collected stool specimens from symptomatic children. Risk factors for AGE were collected during routine weekly visits. Norovirus was detected in stools using real-time reverse transcriptase polymerase chain reaction and positive specimens were genotyped using Sanger sequencing. We included 40 norovirus-positive AGE children matched 1:2 to controls and conducted bivariate and multivariable analyses of norovirus AGE risk factors. Among typeable norovirus infections, GII.4 were more severe than non-GII.4 (four/twenty-one vs. one/nine) and accounted for all emergency visits and hospitalizations. Adjusted conditional logistic regression found that female sex and higher length-for-age Z score were protective against norovirus AGE; a dirt floor in the home, sharing cups or bottles, and recent contact with someone with AGE symptoms were associated with norovirus AGE, though estimates were highly imprecise. Reducing contact with symptomatic persons and with saliva or other bodily fluids on cups or floors could reduce infant norovirus incidence.