Oral Transmission of Chagas Disease by Consumption of Açaí Palm Fruit, Brazil

In 2006, a total of 178 cases of acute Chagas disease were reported from the Amazonian state of Pará, Brazil. Eleven occurred in Barcarena and were confirmed by visualization of parasites on blood smears. Using cohort and case–control studies, we implicated oral transmission by consumption of açaí palm fruit

an individual participant data meta-analysis

Background The impact of neuraminidase inhibitors (NAIs) on influenza-related pneumonia (IRP) is not established. Our objective was to investigate the association between NAI treatment and IRP incidence and outcomes in patients hospitalised with A(H1N1)pdm09 virus infection. Methods A worldwide meta- analysis of individual participant data from 20 634 hospitalised patients with laboratory-confirmed A(H1N1)pdm09 (n = 20 021) or clinically diagnosed (n = 613) ‘pandemic influenza’. The primary outcome was radiologically confirmed IRP. Odds ratios (OR) were estimated using generalised linear mixed modelling, adjusting for NAI treatment propensity, antibiotics and corticosteroids. Results Of 20 634 included participants, 5978 (29·0%) had IRP; conversely, 3349 (16·2%) had confirmed the absence of radiographic pneumonia (the comparator). Early NAI treatment (within 2 days of symptom onset) versus no NAI was not significantly associated with IRP [adj. OR 0·83 (95% CI 0·64–1·06; P = 0·136)]. Among the 5978 patients with IRP, early NAI treatment versus none did not impact on mortality [adj. OR = 0·72 (0·44–1·17; P = 0·180)] or likelihood of requiring ventilatory support [adj. OR = 1·17 (0·71–1·92; P = 0·537)], but early treatment versus later significantly reduced mortality [adj. OR = 0·70 (0·55–0·88; P = 0·003)] and likelihood of requiring ventilatory support [adj. OR = 0·68 (0·54–0·85; P = 0·001)]. Conclusions Early NAI treatment of patients hospitalised with A(H1N1)pdm09 virus infection versus no treatment did not reduce the likelihood of IRP. However, in patients who developed IRP, early NAI treatment versus later reduced the likelihood of mortality and needing ventilatory support

Influence of Household Rat Infestation on <i>Leptospira</i> Transmission in the Urban Slum Environment

<div><p>Background</p><p>The Norway rat (<i>Rattus norvegicus</i>) is the principal reservoir for leptospirosis in many urban settings. Few studies have identified markers for rat infestation in slum environments while none have evaluated the association between household rat infestation and <i>Leptospira</i> infection in humans or the use of infestation markers as a predictive model to stratify risk for leptospirosis.</p><p>Methodology/Principal Findings</p><p>We enrolled a cohort of 2,003 urban slum residents from Salvador, Brazil in 2004, and followed the cohort during four annual serosurveys to identify serologic evidence for <i>Leptospira</i> infection. In 2007, we performed rodent infestation and environmental surveys of 80 case households, in which resided at least one individual with <i>Leptospira</i> infection, and 109 control households. In the case-control study, signs of rodent infestation were identified in 78% and 42% of the households, respectively. Regression modeling identified the presence of <i>R. norvegicus</i> feces (OR, 4.95; 95% CI, 2.13–11.47), rodent burrows (2.80; 1.06–7.36), access to water (2.79; 1.28–6.09), and un-plastered walls (2.71; 1.21–6.04) as independent risk factors associated with <i>Leptospira</i> infection in a household. We developed a predictive model for infection, based on assigning scores to each of the rodent infestation risk factors. Receiver operating characteristic curve analysis found that the prediction score produced a good/excellent fit based on an area under the curve of 0.78 (0.71–0.84).</p><p>Conclusions/Significance</p><p>Our study found that a high proportion of slum households were infested with <i>R. norvegicus</i> and that rat infestation was significantly associated with the risk of <i>Leptospira</i> infection, indicating that high level transmission occurs among slum households. We developed an easily applicable prediction score based on rat infestation markers, which identified households with highest infection risk. The use of the prediction score in community-based screening may therefore be an effective risk stratification strategy for targeting control measures in slum settings of high leptospirosis transmission.</p></div

Logistic regression analysis of rodent-related and environmental characteristics associated with <i>Leptospira</i> transmission and scoring system at household level.

a<p>Odds ratios (OR) and 95% confidence intervals (CI) are shown for analyses. Logistic regression was performed to obtain estimates for odds ratios which were adjusted for covariates in the final model.</p>b<p>Assignment of points to risk factors was based on a linear transformation of the corresponding <i>β</i> regression coefficient. The coefficient of each variable was divided by 0.90 (the lowest <i>β</i> value, corresponding to Un-plastered walls), multiplied by two, and rounded to the nearest integer.</p>c<p>Walls composed of exposed bricks without external application of stucco or plastering.</p><p>Logistic regression analysis of rodent-related and environmental characteristics associated with <i>Leptospira</i> transmission and scoring system at household level.</p

Rodent-related and environmental characteristics associated with <i>Leptospira</i> transmission among case and control households at the community study site, Salvador, Brazil.

a<p>Case and control households comprised of households in which cohort subject(s) with evidence of <i>Leptospira</i> infection resided and neighborhood households which were located >30 m of a case household and did not have a member with evidence of <i>Leptospira</i> infection during the study period, respectively.</p>b<p>Median and inter-quartile range (IQR) values are shown for continuous variables.</p>c<p>Values are not shown for non-significant associations.</p>d<p>Categories and variable defined in the CDC form <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0003338#pntd.0003338-CDC1" target="_blank">[22]</a>.</p>e<p>Presence of exposed earth slope (>45°) within 10 m of the household.</p>f<p>Walls composed of exposed bricks without external application of stucco or plastering.</p><p>Rodent-related and environmental characteristics associated with <i>Leptospira</i> transmission among case and control households at the community study site, Salvador, Brazil.</p

Environmental variables related to source of food, water, harborage and access for rodents and rodent active signs in the study area.

<p>(A and B) Photographs of the typical environment at the community study site, which shows a valley in which households are situated and the proximity of households to open sewers, exposed garbage and bushes or shrubbery. (C and D) Rodent burrows. (D and E) Rodent runs. (F) <i>Rattus norvegicus</i> fecal droppings.</p

Receiver operating characteristic (ROC) curve for based logistic regression model score system.

<p>AUC (area under the curve) was 0.78 (95% CI 0.71–0.84).</p