Relana Pinkerton

Giardia duodenalis assemblage, clinical presentation and markers of intestinal inflammation in Brazilian children

Data on the relationship between the two genotypes of Giardia duodenalis that infect humans, assemblages A and B, their clinical presentation and intestinal inflammation are limited. We analyzed 108 stool samples previously collected for a diarrhoeal study among Brazilian children, representing 71 infections in 47 children. Assemblage B was most prevalent, accounting for 43/58 (74.1%) infections, while assemblage A accounted for 9/58 (15.5%) infections and 6/58 (10.3%) infections were mixed (contained both assemblage A and B). There was no significant difference in diarrhoeal symptoms experienced during assemblage A, B or mixed infections. Children with assemblage B demonstrated greater variability in G. duodenalis cyst shedding but at an overall greater level (n=43, mean 3.6 x 10(5), range 5.3 x 10(2)-2.5 x 10(6)cysts/ml) than children infected with assemblage A (n=9, mean 1.4 x 10(5), range 1.5 x 10(4)-4.6 x 10(5)cysts/ml; P=0.009). Children with mixed infections shed more cysts (mean 8.3 x 10(5), range 3.1 x 10(4)-2.8 x 10(6)cysts/ml) than children with assemblage A or B alone (P=0.069 and P=0.046 respectively). This higher rate of cyst shedding in children with assemblage B may promote its spread, accounting for its increased incidence. Additionally, second and third infections had decreasing faecal lactoferrin, suggesting some protection against severity, albeit not against infection, by prior infection.

Early childhood diarrhea predicts impaired school performance.

Objective: Diarrhea is a leading cause of mortality worldwide; however, its long-term morbidity is poorly understood. Recently, early childhood diarrhea (ECD) has been associated with impaired physical fitness, growth and cognitive function 6 to 9 years later. We studied the effects of ECD on school functioning in a shantytown in northeastern Brazil. Design: We administered 77 educational surveys. Complete diarrhea surveillance (ie, >90%) in the first 2 years of life and demographic and anthropometric information were available for 73 children. Age at starting school was calculated for 62 children, whereas age appropriateness for the current grade (AFG) was calculated for all 73 children who were >6 years old. Stepwise regression was used to examine the independent effect of ECD on school functioning after controlling for socioeconomic factors, maternal education, breast feeding, growth and cognitive functioning. Results: ECD correlated with age at starting school (r = 0.55, P = 0.0005) and remained a significant predictor even after controlling for family demographics, days of breast feeding, early growth and TONI-3 test of nonverbal intelligence. This was true despite significant correlations of ECD with growth shortfalls and impaired cognitive functioning. ECD also correlated with AFG (r = 0.38, P = 0.001). Only TONI-3 test scores explained this association, suggesting that ECD may hinder school performance, but only in part school readiness, by impairing cognitive function as measured by performance on the TONI-3 nonverbal intelligence test. Conclusions: These findings document effects of early childhood diarrhea on later school readiness and performance and hence potential long-term human and economic costs of ECD, which warrant further attention and far greater investment for the control of ECD and its consequences.

Prolonged Episodes of Acute Diarrhea Reduce Growth and Increase Risk of Persistent Diarrhea in Children

BACKGROUND & AIMS Prolonged episodes of acute diarrhea (ProD; duration 7-13 days) or persistent diarrhea (PD; duration ≥14 days) are important causes of undernutrition, yet the epidemiology and nutritional impact of ProD are poorly understood. METHODS We conducted a 10-year cohort study of 414 children from a Brazilian shantytown who were followed from birth; data were collected on diarrhea, enteric pathogens, and anthropometry. RESULTS During 1276 child-years of observation, we recorded 3257 diarrheal episodes. ProD was twice as common as PD (12% and 5% of episodes, respectively); ProD and PD together accounted for 50% of all days with diarrhea. ProD was more common in infants whose mothers had not completed primary school (relative risk [RR], 2.1; 95% confidence interval: 1.02-2.78). Early weaning was associated with earlier onset of ProD (Spearman ρ = 0.309; P = .005). Infants with ProD were twice as likely to develop PD in later childhood (log rank, P = .002) compared with infants with only acute diarrhea (AD; duration <7 days), even after controlling for confounders. Childrens growth was more severely stunted before their first episode of ProD, compared with AD (mean height-for-age Z score (HAZ) -0.81 vs -0.51, respectively, P < .05, unpaired t test). Following ProD, HAZ (ΔHAZ = -0.232) and weight-for-age (ΔWAZ = -0.26) significantly decreased (P < .005 in paired t tests). ProD was associated with Cryptosporidium and Shigella infections. CONCLUSIONS ProD accounts for significant morbidity and identifies children at risk of a vicious cycle of diarrhea and malnutrition. Further studies are needed to address the recognition and control of ProD and its consequences in resource-limited settings and assess its role in PD pathogenesis.

Severe Sepsis in Two Ugandan Hospitals: a Prospective Observational Study of Management and Outcomes in a Predominantly HIV-1 Infected Population

Background Sepsis likely contributes to the high burden of infectious disease morbidity and mortality in low income countries. Data regarding sepsis management in sub-Saharan Africa are limited. We conducted a prospective observational study reporting the management and outcomes of severely septic patients in two Ugandan hospitals. We describe their epidemiology, management, and clinical correlates for mortality. Methodology/Results Three-hundred eighty-two patients fulfilled enrollment criteria for a severe sepsis syndrome. Vital signs, management and laboratory results were recorded. Outcomes measured included in-hospital and post-discharge mortality. Most patients were HIV-infected (320/377, 84.9%) with a median CD4+ T cell (CD4) count of 52 cells/mm3 (IQR, 16–131 cells/mm3). Overall mortality was 43.0%, with 23.7% in-hospital mortality (90/380) and 22.3% post-discharge mortality (55/247). Significant predictors of in-hospital mortality included admission Glasgow Coma Scale and Karnofsky Performance Scale (KPS), tachypnea, leukocytosis and thrombocytopenia. Discharge KPS and early fluid resuscitation were significant predictors of post-discharge mortality. Among HIV-infected patients, CD4 count was a significant predictor of post-discharge mortality. Median volume of fluid resuscitation within the first 6 hours of presentation was 500 mLs (IQR 250–1000 mls). Fifty-two different empiric antibacterial regimens were used during the study. Bacteremic patients were more likely to die in hospital than non-bacteremic patients (OR 1.83, 95% CI = 1.01–3.33). Patients with Mycobacterium tuberculosis (MTB) bacteremia (25/249) had higher in-hospital mortality (OR 1.97, 95% CI = 1.19–327) and lower median CD4 counts (p = 0.001) than patients without MTB bacteremia. Conclusion Patients presenting with sepsis syndromes to two Ugandan hospitals had late stage HIV infection and high mortality. Bacteremia, especially from MTB, was associated with increased in-hospital mortality. Most clinical predictors of in-hospital mortality were easily measurable and can be used for triaging patients in resource-constrained settings. Procurement of low cost and high impact treatments like intravenous fluids and empiric antibiotics may help decrease sepsis-associated mortality in resource-constrained settings.

Cryptosporidium Infection Causes Undernutrition and, Conversely, Weanling Undernutrition Intensifies Infection

Abstract Cryptosporidium parvum is a leading pathogen in children in developing countries. To investigate whether early postnatal malnutrition leads to heavier C. parvum infections, we assessed intestinal adaptation and parasite load in suckling mice during the first 2 wk of life, analogous to the first postnatal yr in humans. Undernutrition was induced by daily C57BL6J pup separation from lactating dams. Half of the pups were separated daily, for 4 hr on day 4, 8 hr on day 5, and for 12 hr from day 6 until day 14. On day 6, each pup received an oral inoculum of 105 to 107 parasites in 10–25 μl of PBS. Littermate controls received PBS alone. Stools were assessed from days 8, 11, and 14 for oocyst counts. Mice were killed on day 14, 8 days postinoculation, at the peak of the infection. Ileal and colon segments were obtained for histology, real-time and reverse transcriptase PCR, and immunoassays. Villus and crypt lengths and cross-sectional areas were also measured. Undernourished and nourished mice infected with excysted 106 or 107 oocysts exhibited the poorest growth outcomes compared with their uninfected controls. Nourished 106-infected mice had comparable weight decrements to uninfected undernourished mice. Body weight and villi were additively affected by malnutrition and cryptosporidiosis. Hyperplastic crypts and heavier inflammatory responses were found in the ilea of infected malnourished mice. Undernourished infected mice exhibited greater oocyst shedding, TNF-α and IFN-γ intestinal levels, and mRNA expression compared to nourished mice infected with either 105 or 106 oocysts. Taken together, these findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.

Does Childhood Diarrhea Influence Cognition Beyond the Diarrhea-Stunting Pathway?

Background Diarrhea is a leading cause of morbidity among children under 5 years of age in low- and middle-income countries yet the additional effects and sequelae, such as cognitive impairment associated with diarrhea, have not been quantified. Methods We quantified the association between diarrhea prevalence and cognitive outcomes while controlling for linear growth in 4 study populations. Cognition was assessed using different methods across sites and was expressed in standardized units. We built linear regression models for each study with standardized cognitive score as the outcome and diarrhea prevalence as the main predictor variable. We then conducted meta-analyses of the regression coefficients to generate pooled estimates of the association between diarrhea prevalence and cognition whilst controlling for anthropometric status and other covariates. Results Diarrhea was not a significant predictor of cognitive score in any site in the regression models or in the meta-analyses (Coefficient = 0.07; 95% CI: −0.1, 0.2). The length for age Z- score was negatively related to cognition in all sites (0.18; 95% CI: 0.14, 0.21), with coefficients remarkably similar across sites (Coefficient Range: 0.168–0.186). Conclusions We did not demonstrate an association between diarrhea and cognition with stunting included in the model. The links between diarrhea, stunting, and cognition provide additional rationale for accelerating interventions to reduce diarrhea.

Biomarkers of environmental enteropathy, inflammation, stunting, and impaired growth in children in Northeast Brazil

Critical to the design and assessment of interventions for enteropathy and its developmental consequences in children living in impoverished conditions are non-invasive biomarkers that can detect intestinal damage and predict its effects on growth and development. We therefore assessed fecal, urinary and systemic biomarkers of enteropathy and growth predictors in 375 6–26 month-old children with varying degrees of malnutrition (stunting or wasting) in Northeast Brazil. 301 of these children returned for followup anthropometry after 2-6m. Biomarkers that correlated with stunting included plasma IgA anti-LPS and anti-FliC, zonulin (if >12m old), and intestinal FABP (I-FABP, suggesting prior barrier disruption); and with citrulline, tryptophan and with lower serum amyloid A (SAA) (suggesting impaired defenses). In contrast, subsequent growth was predicted in those with higher fecal MPO or A1AT and also by higher L/M, plasma LPS, I-FABP and SAA (showing intestinal barrier disruption and inflammation). Better growth was predicted in girls with higher plasma citrulline and in boys with higher plasma tryptophan. Interactions were also seen with fecal MPO and neopterin in predicting subsequent growth impairment. Biomarkers clustered into markers of 1) functional intestinal barrier disruption and translocation, 2) structural intestinal barrier disruption and inflammation and 3) systemic inflammation. Principle components pathway analyses also showed that L/M with %L, I-FABP and MPO associate with impaired growth, while also (like MPO) associating with a systemic inflammation cluster of kynurenine, LBP, sCD14, SAA and K/T. Systemic evidence of LPS translocation associated with stunting, while markers of barrier disruption or repair (A1AT and Reg1 with low zonulin) associated with fecal MPO and neopterin. We conclude that key noninvasive biomarkers of intestinal barrier disruption, LPS translocation and of intestinal and systemic inflammation can help elucidate how we recognize, understand, and assess effective interventions for enteropathy and its growth and developmental consequences in children in impoverished settings.

Point-of-Care Lactate Testing Predicts Mortality of Severe Sepsis in a Predominantly HIV Type 1– Infected Patient Population in Uganda

BACKGROUND Prediction of mortality may improve management and outcomes of patients with sepsis in resource-limited settings. Therefore, we evaluated the ability of a hand-held portable whole-blood lactate (PWBL) analyzer to predict mortality of patients who are admitted to the hospital with severe sepsis. METHODS A prospective observational study enrolled 253 patients at a national referral hospital in Uganda. Inclusion criteria required (1) >or=2 systemic inflammatory response syndrome criteria or thermodysregulation, (2) hypotension, and (3) suspected infection. A subset of 72 patients had PWBL and standard laboratory serum lactate measured. The primary measured outcome was in-hospital mortality. RESULTS Fifty-nine (81.9%) of 72 evaluated patients were infected with human immunodeficiency virus type 1. The in-hospital mortality rate was 25.7% (18 of 70), and the in- and outpatient mortality at 30 days was 41.6% (30 of 72). PWBL was positively associated with in-hospital but not outpatient mortality (P=.001). The receiver operating characteristic area under the curve for PWBL was 0.81 (P=.081). The optimal PWBL concentration for predicting in-hospital mortality (sensitivity, 88.3%; specificity, 71.2%) was >or=4.0 mmol/L. Patients with a PWBL concentration >or=4.0 mmol/L died while in the hospital substantially more often (50.0%) than did those with a PWBL concentration <4.0 mmol/L (7.5%) (odds ratio, 12.3; 95% confidence interval, 3.5-48.9; [P=.001). Standard laboratory serum lactate results were inconsistent and less predictive of mortality than were those of PWBL in a multiple logistic regression model. CONCLUSION A PWBL concentration >or=4.0 mmol/L predicts with 81% accuracy a 7-fold higher mortality of patients with sepsis than does a PWBL concentration <4.0 mmol/L. PWBL testing would be useful in places where clinical decisions are limited by lack of laboratory infrastructure and poor reliability.

Urinary N -methylnicotinamide and β-aminoisobutyric acid predict catch-up growth in undernourished Brazilian children

Enteric infections, enteropathy and undernutrition in early childhood are preventable risk factors for child deaths, impaired neurodevelopment, and later life metabolic diseases. However, the mechanisms linking these exposures and outcomes remain to be elucidated, as do biomarkers for identifying children at risk. By examining the urinary metabolic phenotypes of nourished and undernourished children participating in a case-control study in Semi-Arid Brazil, we identified key differences with potential relevance to mechanisms, biomarkers and outcomes. Undernutrition was found to perturb several biochemical pathways, including choline and tryptophan metabolism, while also increasing the proteolytic activity of the gut microbiome. Furthermore, a metabolic adaptation was observed in the undernourished children to reduce energy expenditure, reflected by increased N-methylnicotinamide and reduced β-aminoisobutyric acid excretion. Interestingly, accelerated catch-up growth was observed in those undernourished children displaying a more robust metabolic adaptation several months earlier. Hence, urinary N-methylnicotinamide and β-aminoisobutyric acid represent promising biomarkers for predicting short-term growth outcomes in undernourished children and for identifying children destined for further growth shortfalls. These findings have important implications for understanding contributors to long-term sequelae of early undernutrition, including cognitive, growth, and metabolic functions.

Systemic inflammation, growth factors, and linear growth in the setting of infection and malnutrition.

Objectives Deficits in weight gain and linear growth are seen frequently among children in areas where malnutrition and recurrent infections are common. Although both inflammation and malnutrition can result in growth hormone (GH) resistance, the interrelationships of infection, inflammation, and growth deficits in developing areas remain unclear. The aim of this study was to evaluate relationships between low levels of systemic inflammation, growth factors, and anthropometry in a case–control cohort of underweight and normal weight children in northern Brazil. Methods We evaluated data from 147 children ages 6 to 24 mo evaluated in the MAL-ED (Interactions of Malnutrition and Enteric Disease) case–control study following recruitment from a nutrition clinic for impoverished families in Fortaleza, Brazil. We used nonparametric tests and linear regression to evaluate relationships between current symptoms of infections (assessed by questionnaire), systemic inflammation (assessed by high-sensitivity C-reactive protein [hsCRP]), the GH insulin-like growth factor-1 (IGF-1) axis, and measures of anthropometry. All models were adjusted for age and sex. Results Children with recent symptoms of diarrhea, cough, and fever (compared with those without symptoms) had higher hsCRP levels; those with recent diarrhea and fever also had lower IGF-1 and higher GH levels. Stool myeloperoxidase was positively associated with serum hsCRP. hsCRP was in turn positively associated with GH and negatively associated with IGF-1 and IGF-binding protein-3 (IGFBP-3), suggesting a state of GH resistance. After adjustment for hsCRP, IGF-1 and IGFBP-3 were positively and GH was negatively associated with Z scores for height and weight. Conclusions Infection and inflammation were linked to evidence of GH resistance, whereas levels of GH, IGF-1, and IGFBP-3 were associated with growth indices independent of hsCRP. These data implicate complex interrelationships between infection, nutritional status, GH axis, and linear growth in children from a developing area.