Publications by authors named "Alberto Narvaez"
Objective: The present study seeks to analyse sociodemographic determinants related to severe acute respiratory infections (SARI) and calculate the priorization index in the cantons of Ecuador to identify areas probably most vulnerable to COVID-19 transmission.
Design: This descriptive ecological observational study.
Setting: 224 cantons (geographical area) of Ecuador with secondary data sources of hospital information.
Article Synopsis
- Cryptic species pose challenges in systematic and biogeographic studies, especially when they are invasive or transmit diseases.
- The research focuses on the genus Galba, a group of invasive freshwater snails that reproduce mainly through self-fertilization and can carry liver flukes harmful to humans and livestock.
- Using an integrative approach involving morphology, molecular data, and broad sampling, the study reveals that Galba has six species or complexes, with significant variations in shell shape and genetic diversity, and emphasizes the necessity of molecular markers for accurate species identification.
Article Synopsis
- A new molecular tool uses multiplex PCR to quickly and accurately differentiate between three species of freshwater snails (Galba) that transmit fasciolosis, an infectious disease affecting humans and animals.* -
- The method works by targeting unique microsatellite loci for each species, allowing them to be identified based on the size of DNA fragments produced in a single reaction, even when all three species are present.* -
- This affordable and efficient technique has been validated against other species identification methods and can be scaled for large samples, aiding in monitoring snail populations and controlling fasciolosis transmission.*
Chagas disease is a parasitic disease caused by the protozoan parasite Trypanosoma cruzi and about 230,000 persons are estimated to be infected in Ecuador. However, limited studies have been performed in the Amazon region, on the eastern side of the country. We evaluated here the seroprevalence of Trypanosoma cruzi infection in 12 rural villages of the Loreto canton, Orellana Province in schoolchildren aged 5-15 years and in pregnant women.
View Article and Find Full Text PDFBackground: We report the main findings of the WHO Multicountry Survey on Maternal and Newborn Health (WHOMCS), which aimed to assess the burden of complications related to pregnancy, the coverage of key maternal health interventions, and use of the maternal severity index (MSI) in a global network of health facilities.
Methods: In our cross-sectional study, we included women attending health facilities in Africa, Asia, Latin America, and the Middle East that dealt with at least 1000 childbirths per year and had the capacity to provide caesarean section. We obtained data from analysis of hospital records for all women giving birth and all women who had a severe maternal outcome (SMO; ie, maternal death or maternal near miss).
Background: Caesarean section rates continue to increase worldwide with uncertain medical consequences. Auditing and analysing caesarean section rates and other perinatal outcomes in a reliable and continuous manner is critical for understanding reasons caesarean section changes over time.
Methods: We analyzed data on 97,095 women delivering in 120 facilities in 8 countries, collected as part of the 2004-2005 Global Survey on Maternal and Perinatal Health in Latin America.
Rationale: Bedside use of Bayes' theorem for estimating probabilities of diseases is cumbersome. An alternative approach based on five categories of powers of tests from 'useless' to 'very strong' has been proposed. The performance of clinicians using it was assessed.
View Article and Find Full Text PDFCluster-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.
View Article and Find Full Text PDFObjective: To assess the risks and benefits associated with caesarean delivery compared with vaginal delivery.
Design: Prospective cohort study within the 2005 WHO global survey on maternal and perinatal health.
Setting: 410 health facilities in 24 areas in eight randomly selected Latin American countries; 123 were randomly selected and 120 participated and provided data
Participants: 106,546 deliveries reported during the three month study period, with data available for 97,095 (91% coverage).
Background: Caesarean delivery rates continue to increase worldwide. Our aim was to assess the association between caesarean delivery and pregnancy outcome at the institutional level, adjusting for the pregnant population and institutional characteristics.
Methods: For the 2005 WHO global survey on maternal and perinatal health, we assessed a multistage stratified sample, comprising 24 geographic regions in eight countries in Latin America.