Molecular Epidemiology of Enteroaggregative Escherichia coli (EAEC) Isolates of Hospitalized Children from Bolivia Reveal High Heterogeneity and Multidrug-Resistance

Enteroaggregative Escherichia coli (EAEC) is an emerging pathogen frequently associated with acute diarrhea in children and travelers to endemic regions. EAEC was found the most prevalent bacterial diarrheal pathogen from hospitalized Bolivian children less than five years of age with acute diarrhea from 2007 to 2010. Here, we further characterized the epidemiology of EAEC infection, virulence genes, and antimicrobial susceptibility of EAEC isolated from 414 diarrheal and 74 non-diarrheal cases. EAEC isolates were collected and subjected to a PCR-based virulence gene screening of seven virulence genes and a phenotypic resistance test to nine different antimicrobials. Our results showed that atypical EAEC (a-EAEC, AggR-negative) was significantly associated with diarrhea (OR, 1.62, 95% CI, 1.25 to 2.09, p < 0.001) in contrast to typical EAEC (t-EAEC, AggR-positive). EAEC infection was most prevalent among children between 7–12 months of age. The number of cases exhibited a biannual cycle with a major peak during the transition from warm to cold (April–June). Both typical and a-EAEC infections were graded as equally severe; however, t-EAEC harbored more virulence genes. aap, irp2 and pic were the most prevalent genes. Surprisingly, we detected 60% and 52.6% of multidrug resistance (MDR) EAEC among diarrheal and non-diarrheal cases. Resistance to ampicillin, sulfonamides, and tetracyclines was most common, being the corresponding antibiotics, the ones that are frequently used in Bolivia. Our work is the first study that provides comprehensive information on the high heterogenicity of virulence genes in t-EAEC and a- EAEC and the large prevalence of MDR EAEC in Bolivia

Impact of rotavirus vaccination on child mortality, morbidity, and rotavirus-related hospitalizations in Bolivia

Background: The public health impact of rotavirus vaccination in countries with high child mortality rates remains to be established. The RV1 rotavirus vaccine was introduced in Bolivia in August 2008. This study describes the trends in deaths, hospitalizations, and healthcare visits due to acute gastroenteritis (AGE) and in rotavirus-related hospitalizations, among children <5 years of age, during the pre- and post-vaccination periods. Methods: Data were obtained from the National Health Information System to calculate vaccine coverage and AGE-related health indicators. Trend reductions in the main health indicators were examined using the pre-vaccine period as baseline. The effect of vaccination on the epidemiology of rotavirus-related AGE was assessed using data from the active surveillance hospitals. Results: Compared with the 2001–2008 pre-vaccine baseline, the mean number of rotavirus-related hospitalizations was reduced by 40.8% (95% confidence interval (CI) 21.7–66.4%) among children <5 years of age in the post-vaccine period (2009–2013). Reductions were most pronounced in children <1 year of age, eligible for vaccination. The mean proportions of AGE-related deaths, AGE-related hospitalizations, and AGE-related healthcare visits during 2009–2014 were reduced by 52.5% (95% CI 47.4–56.3), 30.2% (95% CI 23.5–36.1), and 12.9% (95% CI 12.0–13.2), respectively. The greatest effect in reduction of AGE-related deaths was found during the months with seasonal peaks of rotavirus disease. Over the post-vaccine period, changes in rotavirus epidemiology were observed, manifested by variations in seasonality and by a shift in the mean age of those with rotavirus infection. Conclusions: The significant decrease in main AGE-related health indicators in children <5 years of age after the introduction of rotavirus vaccine provides evidence of a substantial public health impact of rotavirus vaccination in Bolivia, as a measure for protecting children against AGE

Sulfate-Reducing Bacteria in Floating Macrophyte Rhizospheres from an Amazonian Floodplain Lake in Bolivia and Their Association with Hg Methylation

Five subgroups of sulfate-reducing bacteria (SRB) were detected by PCR in three macrophyte rhizospheres (Polygonum densiflorum, Hymenachne donacifolia, and Ludwigia helminthorriza) and three subgroups in Eichhornia crassipes from La Granja, a floodplain lake from the upper Madeira basin. The SRB community varied according to the macrophyte species but with different degrees of association with their roots. The rhizosphere of the C(4) plant Polygonum densiflorum had higher frequencies of SRB subgroups as well as higher mercury methylation potentials (27.5 to 36.1%) and carbon (16.06 ± 5.40%), nitrogen (2.03 ± 0.64%), Hg (94.50 ± 6.86 ng Hg g(−1)), and methylmercury (8.25 ± 1.45 ng Hg g(−1)) contents than the rhizosphere of the C(3) plant Eichhornia crassipes. Mercury methylation in Polygonum densiflorum and Eichhornia crassipes was reduced when SRB metabolism was inhibited by sodium molybdate

Diarrheal bacterial pathogens and multi-resistant enterobacteria in the Choqueyapu River in La Paz, Bolivia.

Water borne diarrheal pathogens might accumulate in river water and cause contamination of drinking and irrigation water. The La Paz River basin, including the Choqueyapu River, flows through La Paz city in Bolivia where it is receiving sewage, and residues from inhabitants, hospitals, and industry. Using quantitative real-time PCR (qPCR), we determined the quantity and occurrence of diarrheagenic Escherichia coli (DEC), Salmonella enterica, Klebsiella pneumoniae, Shigella spp. and total enterobacteria in river water, downstream agricultural soil, and irrigated crops, during one year of sampling. The most abundant and frequently detected genes were gapA and eltB, indicating presence of enterobacteria and enterotoxigenic E. coli (ETEC) carrying the heat labile toxin, respectively. Pathogen levels in the samples were significantly positively associated with high water conductivity and low water temperature. In addition, a set of bacterial isolates from water, soil and crops were analyzed by PCR for presence of the genes blaCTX-M, blaKPC, blaNDM, blaVIM and blaOXA-48. Four isolates were found to be positive for blaCTX-M genes and whole genome sequencing identified them as E. coli and one Enterobacter cloacae. The E. coli isolates belonged to the emerging, globally disseminated, multi-resistant E. coli lineages ST648, ST410 and ST162. The results indicate not only a high potential risk of transmission of diarrheal diseases by the consumption of contaminated water and vegetables but also the possibility of antibiotic resistance transfer from the environment to the community

The burden of pediatric diarrhea: a cross-sectional study of incurred costs and perceptions of cost among Bolivian families

Background: Worldwide, acute gastroenteritis represents an enormous public health threat to children under five years of age, causing one billion episodes and 1.9 to 3.2 million deaths per year. In Bolivia, which has one of the lower GDPs in South America, an estimated 15% of under-five deaths are caused by diarrhea. Bolivian caregiver expenses related to diarrhea are believed to be minimal, as citizens benefit from universal health insurance for children under five. The goals of this report were to describe total incurred costs and cost burden associated with caregivers seeking treatment for pediatric gastroenteritis, and to quantify relationships among costs, cost burden, treatment setting, and perceptions of costs. Methods: From 2007 to 2009, researchers interviewed caregivers (n=1,107) of pediatric patients (<5 years of age) seeking treatment for diarrhea in sentinel hospitals participating in Bolivia’s diarrheal surveillance program across three main geographic regions. Data collected included demographics, clinical symptoms, direct costs (e.g. medication, consult fees) and indirect costs (e.g. lost wages). Results: Patient populations were similar across cities in terms of gender, duration of illness, and age, but familial income varied significantly (p < 0.05) when stratified on appointment type. Direct, indirect, and total costs to families were significantly higher for inpatients as compared to outpatients of urban (p < 0.001) and rural (p < 0.05) residence. Consult fees and indirect costs made up a large proportion of total costs. Forty-five percent of patients’ families paid ≥1% of their annual household income for this single diarrheal episode. The perception that cost was affecting family finances was more frequent among those with higher actual cost burden. Conclusions: This study demonstrated that indirect costs due to acute pediatric diarrhea were a large component of total incurred familial costs. Additionally, familial costs associated with a single diarrheal episode affected the actual and perceived financial situation of a large number of caregivers. These data serve as a baseline for societal diarrheal costs before and immediately following the implementation of the rotavirus vaccine and highlight the serious economic importance of a diarrheal episode to Bolivian caregivers

Effect of infant feeding practices on iron status in a cohort study of Bolivian infants

Abstract Background Iron deficiency (ID) is the most common micronutrient deficiency worldwide, with potentially severe consequences on child neurodevelopment. Though exclusive breastfeeding (EBF) is recommended for 6 months, breast milk has low iron content. This study aimed to estimate the effect of the length of EBF on iron status at 6 – 8 months of age among a cohort of Bolivian infants. Methods Mother-infant pairs were recruited from 2 hospitals in El Alto, Bolivia, and followed from one through 6 – 8 months of age. Singleton infants > 34 weeks gestational age, iron-sufficient at baseline, and completing blood draws at 2 and 6 – 8 months of age were eligible for inclusion (N = 270). Ferritin was corrected for the effect of inflammation. ID was defined as inflammation-corrected ferritin  6 months) was assessed for ID, IDA, and anemia (logistic regression) and ferritin (Fer) and hemoglobin (Hb, linear regression). Results Low iron status was common among infants at 6 – 8 months: 56% of infants were ID, 76% were anemic, and 46% had IDA. EBF of 4 months and above was significantly associated with ID as compared with EBF  6 months: 3.3 [1.0 – 12.3]), but not with IDA (4 – 6 months: OR 1.4 [0.8 – 2.4]; > 6 months: 2.2 [0.7 – 7.4]), or anemia (4 – 6 months: OR 1.4 [0.7 – 2.5]; > 6 months: 1.5 [0.7 – 7.2]). Fer and Hb concentrations were significantly lower with increasing months of EBF. Conclusions Results suggest a relationship between prolonged EBF and ID, but are not sufficient to support changes to current breastfeeding recommendations. More research is needed in diverse populations, including exploration of early interventions to address infant IDA

The burden of pediatric diarrhea: A cross-sectional study of incurred costs and perceptions of cost among Bolivian families

Background: Worldwide, acute gastroenteritis represents an enormous public health threat to children under five years of age, causing one billion episodes and 1.9 to 3.2 million deaths per year. In Bolivia, which has one of the lower GDPs in South America, an estimated 15% of under-five deaths are caused by diarrhea. Bolivian caregiver expenses related to diarrhea are believed to be minimal, as citizens benefit from universal health insurance for children under five. The goals of this report were to describe total incurred costs and cost burden associated with caregivers seeking treatment for pediatric gastroenteritis, and to quantify relationships among costs, cost burden, treatment setting, and perceptions of costs. Methods. From 2007 to 2009, researchers interviewed caregivers (n=1,107) of pediatric patients (\u3c5 years of age) seeking treatment for diarrhea in sentinel hospitals participating in Bolivia\u27s diarrheal surveillance program across three main geographic regions. Data collected included demographics, clinical symptoms, direct costs (e.g. medication, consult fees) and indirect costs (e.g. lost wages). Results: Patient populations were similar across cities in terms of gender, duration of illness, and age, but familial income varied significantly (p\u3c0.05) when stratified on appointment type. Direct, indirect, and total costs to families were significantly higher for inpatients as compared to outpatients of urban (p\u3c0.001) and rural (p\u3c0.05) residence. Consult fees and indirect costs made up a large proportion of total costs. Forty-five percent of patients\u27 families paid ≥1% of their annual household income for this single diarrheal episode. The perception that cost was affecting family finances was more frequent among those with higher actual cost burden. Conclusions: This study demonstrated that indirect costs due to acute pediatric diarrhea were a large component of total incurred familial costs. Additionally, familial costs associated with a single diarrheal episode affected the actual and perceived financial situation of a large number of caregivers. These data serve as a baseline for societal diarrheal costs before and immediately following the implementation of the rotavirus vaccine and highlight the serious economic importance of a diarrheal episode to Bolivian caregivers. © 2013 Burke et al.; licensee BioMed Central Ltd