17 research outputs found
Within-Compound Versus Public Latrine Access and Child Feces Disposal Practices in Low-Income Neighborhoods of Accra, Ghana.
In crowded urban settlements in low-income countries, many households rely on shared sanitation facilities. Shared facilities are not currently considered "improved sanitation" because of concerns about whether hygiene conditions sufficiently protect users from the feces of others. Prevention of fecal exposure at a latrine is only one aspect of sanitary safety. Ensuring consistent use of latrines for feces disposal, especially child feces, is required to reduce fecal contamination in households and communities. Household crowding and shared latrine access are correlated in these settings, rendering latrine use by neighbors sharing communal living areas as critically important for protecting one's own household. This study in Accra, Ghana, found that household access to a within-compound basic latrine was associated with higher latrine use by children of ages 5-12 years and for disposal of feces of children < 5 years, compared with households using public latrines. However, within-compound access was not associated with improved child feces disposal by other caregivers in the compound. Feces was rarely observed in household compounds but was observed more often in compounds with latrines versus compounds relying on public latrines. Escherichia coli and human adenovirus were detected frequently on household surfaces, but concentrations did not differ when compared by latrine access or usage practices. The differences in latrine use for households sharing within-compound versus public latrines in Accra suggest that disaggregated shared sanitation categories may be useful in monitoring global progress in sanitation coverage. However, compound access did not completely ensure that households were protected from feces and microbial contamination
Production of OSU G5P[7] Porcine Rotavirus Expressing a Fluorescent Reporter via Reverse Genetics
Rotaviruses are a significant cause of severe, potentially life-threatening gastroenteritis in infants and the young of many economically important animals. Although vaccines against porcine rotavirus exist, both live oral and inactivated, their effectiveness in preventing gastroenteritis is less than ideal. Thus, there is a need for the development of new generations of porcine rotavirus vaccines. The Ohio State University (OSU) rotavirus strain represents a Rotavirus A species with a G5P[7] genotype, the genotype most frequently associated with rotavirus disease in piglets. Using complete genome sequences that were determined via Nanopore sequencing, we developed a robust reverse genetics system enabling the recovery of recombinant (r)OSU rotavirus. Although rOSU grew to high titers (~107 plaque-forming units/mL), its growth kinetics were modestly decreased in comparison to the laboratory-adapted OSU virus. The reverse genetics system was used to generate the rOSU rotavirus, which served as an expression vector for a foreign protein. Specifically, by engineering a fused NSP3-2A-UnaG open reading frame into the segment 7 RNA, we produced a genetically stable rOSU virus that expressed the fluorescent UnaG protein as a functional separate product. Together, these findings raise the possibility of producing improved live oral porcine rotavirus vaccines through reverse-genetics-based modification or combination porcine rotavirus vaccines that can express neutralizing antigens for other porcine enteric diseases
Understanding Pediatric Norovirus Epidemiology: A Decade of Study among Ghanaian Children
Understanding the epidemiology of human norovirus infection in children within Ghana and the entire sub-Saharan African region, where future norovirus vaccines would have the greatest impact, is essential. We analyzed 1337 diarrheic stool samples collected from children <5 years from January 2008 to December 2017 and found 485 (36.2%) shedding the virus. GII.4 (54.1%), GII.3 (7.7%), GII.6 (5.3%), GII.17 (4.7%), and GII.5 (4.7%) were the most common norovirus genotypes. Although norovirus GII.4 remained the predominant capsid genotype throughout the study period, an increase in GII.6 and GII.3 capsid genotypes was observed in 2013 and 2014, respectively. The severity of clinical illness in children infected with GII.4 norovirus strains was similar to illness caused by non-GII.4 strains. Since the epidemiology of norovirus changes rapidly, establishment of systematic surveillance within sentinel sites across the country would enhance the monitoring of circulating norovirus strains and allow continuous understanding of norovirus infection in Ghana
Identification of Novel Ghanaian G8P[6] Human-Bovine Reassortant Rotavirus Strain by Next Generation Sequencing
<div><p>Group A rotaviruses (RVAs) are the most important etiological agent of acute gastroenteritis in children <5 years of age worldwide. The monovalent rotavirus vaccine Rotarix was introduced into the national Expanded Programme on Immunization (EPI) in Ghana in May 2012. However, there is a paucity of genetic and phylogenetic data on the complete genomes of human RVAs in circulation pre-vaccine introduction. The common bovine rotavirus VP7 genotype G8 has been sporadically detected in Ghanaian children, usually in combination with the VP4 genotype P[6]. To investigate the genomic constellations and phylogeny of RVA strains in circulation prior to vaccine introduction, the full genomes of two unusual G8P[6] strains, GH018-08 and GH019-08, detected during burden of disease surveillance, were characterized by Illumina MiSeq sequencing. The Ghanaian isolates, GH018-08 and GH019-08, exhibited the unusual, previously unreported genotype constellation G8-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H3. Phylogenetic analyses confirmed that 10 out of the 11 genes of GH018-08 and GH019-08 were identical/nearly identical, with significant variation detected only in their VP1 genes, and clearly established the occurrence of multiple independent interspecies transmission and reassortment events between co-circulating bovine/ovine/caprine rotaviruses and human DS-1-like RVA strains. These findings highlight the contribution of reassortment and interspecies transmission events to the high rotavirus diversity in this region of Africa, and justify the need for simultaneous monitoring of animal and human rotavirus strains.</p></div
Phylograms based on the full-length open reading frame (ORF) nucleotide sequences of VP6, VP1, VP2 and VP3 encoding genome segments of RVA strains GH018-08 and GH019-08 indicating genetic relationships with cognate RVA genes.
<p>See Legend of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100699#pone-0100699-g001" target="_blank">Figure 1</a>.</p
Genotype constellation of GH018-08 and GH019-08 with selected reference RVA strains of known genomic constellation.
a<p>RVA strain names according to proposed nomenclature of new classification system. <b>Boldface</b> font indicates RVA strains sequenced in this study. GenBank accession numbers for reference strains are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100699#pone.0100699.s003" target="_blank">Table S2</a>.</p>b<p>DS-1-like genotypes indicated by <b>boldface</b> font;</p>†<p>Typical bovine-like RVA genotypes.</p>‡<p>AU-1-like genotype.</p
Summary of partial characterization data for GH018-08 and GH019-08.
<p>N/A: Not available; EIA: Enzyme Immunoassay; Neg: Negative; +: positive; L: Long electropherotype by PAGE; H: hospitalization as a measure of severity of rotavirus infection, G?: G-type not available</p
Phylograms based on the full-length open reading frame (ORF) nucleotide sequences of VP7 and VP4 encoding genome segments of RVA strains GH018-08 and GH019-08 indicating genetic relationships with cognate RVA genes.
<p>Neighbour-Joining trees were constructed and rooted with cognate genes of the avian RVA strain PO-13 using MEGA v6.06 software. Only the genotypes in which study strains cluster are shown completely. GH018-08 and GH019-08 are shown in boldface and indicated by a blue, closed circle, animal strains by a black closed box, reported human-artiodactyl reassortant strains by a closed pink box, multiple reassortant bovine-feline/canine-human strains by an open pink circle, and African human strains by an open red triangle. Significant bootstrap values (2000 replicates) of ≥80% are shown. Bar: nucleotide substitutions per site. GenBank Accession numbers for all strains are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100699#pone.0100699.s003" target="_blank">Table S2</a>.</p