Acute Febrile Illness Associated with an Emerging Dengue 4 GIIb Variant Causing Epidemic in León, Nicaragua 2022.

Historically, DENV-4 has been rarely associated with epidemics and has been less well-studied than DENV-1 to -3. Epidemic dengue struck several South and Central American countries in 2022, with Nicaragua reporting the highest incidence. In an acute febrile illness (AFI) cohort enrolled from June to September 2022, 58 (34%) of 172 patients had PCR-confirmed dengue, of which 46 (79%) were serotyped as DENV-4.

Human milk oligosaccharides and Campylobacter jejuni and Campylobacter coli gastroenteritis risk in a Nicaraguan Birth Cohort.

Background: Campylobacter jejuni and C. coli, leading causes of bacterial acute gastroenteritis worldwide, are associated with childhood malnutrition. Human milk oligosaccharides (HMOs) may prevent campylobacteriosis by acting as "decoy receptors" for C.

Dietary plant diversity predicts early life microbiome maturation.

Despite established links between the infant gut microbiome and health, how complementary feeding shapes colonization remains unclear. Using FoodSeq, a DNA-based dietary assessment technique, we surveyed food intake across 729 children (0-3 y) from North and Central America, Africa, and Asia. We detected 199 unique plant food sequences, with only eight staples shared across all countries.

Giardia lamblia risk factors and burden in children with acute gastroenteritis in a Nicaraguan birth cohort.

Background: Giardia lamblia is an intestinal protozoan estimated to cause ~200 million symptomatic infections annually, mainly in children in low- and middle-income countries associated with intestinal damage, increased permeability, and malabsorption.

Methods And Results: We describe here the epidemiology, incidence, clinical characteristics, and risk factors of acute gastroenteritis episodes (AGE) with G. lamblia detection (GAGE) using a birth cohort of 443 Nicaraguan children followed weekly until 36 months of life.

Epidemiology of Pediatric Astrovirus Gastroenteritis in a Nicaraguan Birth Cohort.

Background: Astrovirus is a leading cause of acute gastroenteritis in children worldwide. However, few prospective studies have analyzed astrovirus in community-dwelling pediatric populations in low- and middle-income countries.

Methods: We assessed the incidence, risk factors, clinical characteristics, genotypes, viral coinfections, and time distribution of astrovirus gastroenteritis in 443 healthy Nicaraguan children born in 2017 to 2018 who were followed for 36 months.

Metabolic immaturity and breastmilk bile acid metabolites are central determinants of heightened newborn vulnerability to norovirus diarrhea.

The pathogenic outcome of enteric virus infections is governed by a complex interplay between the virus, intestinal microbiota, and host immune factors, with metabolites serving as a key mediator. Noroviruses bind bile acid metabolites, which are produced by the host and then modified by commensal bacteria. Paradoxically, bile acids can have both proviral and antiviral roles during norovirus infections.

Charting the Impact of Maternal Antibodies and Repeat Exposures on Sapovirus Immunity in Early Childhood From a Nicaraguan Birth Cohort.

Background: Sapovirus is an important cause of acute gastroenteritis in childhood. While vaccines against sapovirus may reduce gastroenteritis burden, a major challenge to their development is a lack of information about natural immunity.

Methods: We measured sapovirus-specific IgG in serum collected between 2017 and 2020 of mothers soon after delivery and at 6 time points in Nicaraguan children until 3 years of age (n = 112 dyads), using virus-like particles representing 3 sapovirus genotypes (GI.

Neurodevelopment in preschool children exposed and unexposed to Zika virus in utero in Nicaragua: a prospective cohort study.

Background: Data on long-term neurodevelopmental outcomes of normocephalic children (born with normal head circumference) exposed to Zika virus in utero are scarce. We aimed to compare neurodevelopmental outcomes in normocephalic children up to age 48 months with and without Zika virus exposure in utero.

Methods: In this prospective cohort study, we included infants from two cohorts of normocephalic children born in León and Managua, Nicaragua during the 2016 Zika epidemic.

Correction: Association between breastfeeding, host genetic factors, and calicivirus gastroenteritis in a Nicaraguan birth cohort.

[This corrects the article DOI: 10.1371/journal.pone.

Transmission Patterns of Norovirus From Infected Children to Household Members in León, Nicaragua.

Norovirus is a common and highly transmissible gastrointestinal pathogen. Among 34 Nicaraguan households with a norovirus-infected child, 48% experienced norovirus transmission within 1 week, infecting 18% of household members; GII norovirus was more commonly transmitted than GI. Pediatric norovirus vaccines could prevent both index cases and transmission to close contacts.

Infant antibody and B-cell responses following confirmed pediatric GII.17 norovirus infections functionally distinguish GII.17 genetic clusters.

Genogroup II (GII) noroviruses are a major cause of diarrheal disease burden in children in both high- and low-income countries. GII.17 noroviruses are composed of distinct genetic clusters (I, II, IIIa, and IIIb) and have shown potential for replacing historically more prevalent GII.

Nonsecretor Phenotype Is Associated With Less Risk of Rotavirus-Associated Acute Gastroenteritis in a Vaccinated Nicaraguan Birth Cohort.

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 reverse-transcription quantitative polymerase chain reaction, and saliva or blood was used to determine HBGA phenotypes.

Visual findings in children exposed to Zika in utero in Nicaragua.

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).

Antibody Immunity to Zika Virus among Young Children in a Flavivirus-Endemic Area in Nicaragua.

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. 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.

Household Surveillance for Norovirus Gastroenteritis in a Nicaraguan Birth Cohort: A Nested Case-Control Analysis of Norovirus Risk Factors.

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.

Timing and genotype distribution of symptomatic and asymptomatic sapovirus infections and re-infections in a Nicaraguan birth cohort.

Objectives: To characterize the timing and genotype distribution of symptomatic and asymptomatic sapovirus infections and re-infections in a Nicaraguan birth cohort.

Methods: Infants (N = 444) were enrolled at 10-14 days of life and observed weekly until 2 years of age. Stool samples were collected for each acute gastroenteritis (AGE) episode, and routine stool samples were collected monthly.

Norovirus Infection in Young Nicaraguan Children Induces Durable and Genotype-Specific Antibody Immunity.

There are significant challenges to the development of a pediatric norovirus vaccine, mainly due to the antigenic diversity among strains infecting young children. Characterizing human norovirus serotypes and understanding norovirus immunity in naïve children would provide key information for designing rational vaccine platforms. In this study, 26 Nicaraguan children experiencing their first norovirus acute gastroenteritis (AGE) episode during the first 18 months of life were investigated.

Immune Imprinting Drives Human Norovirus Potential for Global Spread.

Understanding the complex interactions between virus and host that drive new strain evolution is key to predicting the emergence potential of variants and informing vaccine development. Under our hypothesis, future dominant human norovirus GII.4 variants with critical antigenic properties that allow them to spread are currently circulating undetected, having diverged years earlier.

Gut Microbiome Changes Occurring with Norovirus Infection and Recovery in Infants Enrolled in a Longitudinal Birth Cohort in Leon, Nicaragua.

Noroviruses are associated with one fifth of diarrheal illnesses globally and are not yet preventable with vaccines. Little is known about the effects of norovirus infection on infant gut microbiome health, which has a demonstrated role in protecting hosts from pathogens and a possible role in oral vaccine performance. In this study, we characterized infant gut microbiome changes occurring with norovirus-associated acute gastroenteritis (AGE) and the extent of recovery.

Breadth and Dynamics of Human Norovirus-Specific Antibodies in the First Year of Life.

We measured antibody binding to diverse norovirus virus-like particles over 12 months in 16 children. All had maternal antibodies at 2 months, with estimated lowest levels at 5 months of age. Antibody increases after 3 months suggested natural infections.