National Autonomous University of Nicaragua

About: National Autonomous University of Nicaragua is a education organization based out in Managua, Nicaragua. It is known for research contribution in the topics: Population & Public health. The organization has 775 authors who have published 715 publications receiving 9791 citations.

Intracluster correlation coefficients from the 2005 WHO Global Survey on Maternal and Perinatal Health: Implications for implementation research.

Abstract: Cluster-based studies involving aggregate units such as hospitals or medical practices are increasingly being used in healthcare evaluation. An important characteristic of such studies is the presence of intracluster correlation, typically quantified by the intracluster correlation coefficient (ICC). Sample size calculations for cluster-based studies need to account for the ICC, or risk underestimating the sample size required to yield the desired levels of power and significance. In this article, we present values for ICCs that were obtained from data on 97,095 pregnancies and 98,072 births taking place in a representative sample of 120 hospitals in eight Latin American countries. We present ICCs for 86 variables measured on mothers and newborns from pregnancy to the time of hospital discharge, including 'process variables' representing actual medical care received for each mother and newborn. Process variables are of primary interest in the field of implementation research. We found that overall, ICCs ranged from a minimum of 0.0003 to a maximum of 0.563 (median 0.067). For maternal and newborn outcome variables, the median ICCs were 0.011 (interquartile range 0.007-0.037) and 0.054 (interquartile range 0.013-0.075) respectively; however, for process variables, the median was 0.161 (interquartile range 0.072-0.328). Thus, we confirm previous findings that process variables tend to have higher ICCs than outcome variables. We demonstrate that ICCs generally tend to increase with higher prevalences (close to 0.5). These results can help researchers calculate the required sample size for future research studies in maternal and perinatal health.

Assessment of groundwater vulnerability in the Rio Artiguas basin, Nicaragua

Abstract: The Rio Artiguas basin in central Nicaragua shows a distinctive case of environmental deterioration due to anthropogenic activities. Heavy metals used in gold mining and other wastes are continuously released into the rivers, representing a threat to the water quality. This article aims to evaluate the groundwater intrinsic vulnerability in the Rio Artiguas basin and to provide information for sustainable use of water resources. The DRASTIC and GOD methods were used to analyse the relative pollution potential within the basin. DRASTIC was modified to include the degree of influence that geological structures have on the vulnerability. Moderate vulnerability areas cover most of the basin along stream valleys and lowlands, increasing downstream in the basin. The resulting vulnerability maps show that the limited groundwater resources are susceptible to surface water pollution as high vulnerability areas converge along the river valleys.

Modeling human enteric dysbiosis and rotavirus immunity in gnotobiotic pigs

Abstract: Rotavirus vaccines have poor efficacy in infants from low- and middle-income countries. Gut microbiota is thought to influence the immune response to oral vaccines. Thus, we developed a gnotobiotic (Gn) pig model of enteric dysbiosis to study the effects of human gut microbiota (HGM) on immune responses to rotavirus vaccination, and the effects of rotavirus challenge on the HGM by colonizing Gn pigs with healthy HGM (HHGM) or unhealthy HGM (UHGM). The UHGM was from a Nicaraguan infant with a high enteropathy score (ES) and no seroconversion following administration of oral rotavirus vaccine, while the converse was characteristic of the HHGM. Pigs were vaccinated, a subset was challenged, and immune responses and gut microbiota were evaluated. Significantly more rotavirus-specific IFN-γ producing T cells were in the ileum, spleen, and blood of HHGM than those in UHGM pigs after three vaccine doses, suggesting HHGM induces stronger cell-mediated immunity than UHGM. There were significant correlations between multiple Operational Taxonomic Units (OTUs) and frequencies of IFN-γ producing T cells at the time of challenge. There were significant positive correlations between Collinsella and CD8+ T cells in blood and ileum, as well as CD4+ T cells in blood, whereas significant negative correlations between Clostridium and Anaerococcus, and ileal CD8+ and CD4+ T cells. Differences in alpha diversity and relative abundances of OTUs were detected between the groups both before and after rotavirus challenge. Alterations in microbiome diversity and composition along with correlations between certain microbial taxa and T cell responses warrant further investigation into the role of the gut microbiota and certain microbial species on enteric immunity. Our results support the use of HGM transplanted Gn pigs as a model of human dysbiosis during enteric infection, and oral vaccine responses.