Dataset Information

The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960-2006.

ABSTRACT: BACKGROUND: Malaria remains a serious problem in Colombia. The number of malaria cases is governed by multiple climatic and non-climatic factors. Malaria control policies, and climate controls such as rainfall and temperature variations associated with the El Niño/Southern Oscillation (ENSO), have been associated with malaria case numbers. Using historical climate data and annual malaria case number data from 1960 to 2006, statistical models are developed to isolate the effects of climate in each of Colombia's five contrasting geographical regions. METHODS: Because year to year climate variability associated with ENSO causes interannual variability in malaria case numbers, while changes in population and institutional control policy result in more gradual trends, the chosen predictors in the models are annual indices of the ENSO state (sea surface temperature [SST] in the tropical Pacific Ocean) and time reference indices keyed to two major malaria trends during the study period. Two models were used: a Poisson and a Negative Binomial regression model. Two ENSO indices, two time reference indices, and one dummy variable are chosen as candidate predictors. The analysis was conducted using the five geographical regions to match the similar aggregation used by the National Institute of Health for its official reports. RESULTS: The Negative Binomial regression model is found better suited to the malaria cases in Colombia. Both the trend variables and the ENSO measures are significant predictors of malaria case numbers in Colombia as a whole, and in two of the five regions. A one degree Celsius change in SST (indicating a weak to moderate ENSO event) is seen to translate to an approximate 20% increase in malaria cases, holding other variables constant. CONCLUSION: Regional differentiation in the role of ENSO in understanding changes in Colombia's annual malaria burden during 1960-2006 was found, constituting a new approach to use ENSO as a significant predictor of the malaria cases in Colombia. These results naturally point to additional needed work: (1) refining the regional and seasonal dependence of climate on the ENSO state, and of malaria on the climate variables; (2) incorporating ENSO-related climate variability into dynamic malaria models.

SUBMITTER: Mantilla G

PROVIDER: S-EPMC2661091 | biostudies-literature | 2009

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960-2006.

Mantilla Gilma G Oliveros Hugo H Barnston Anthony G AG

Malaria journal 20090108

<h4>Background</h4>Malaria remains a serious problem in Colombia. The number of malaria cases is governed by multiple climatic and non-climatic factors. Malaria control policies, and climate controls such as rainfall and temperature variations associated with the El Niño/Southern Oscillation (ENSO), have been associated with malaria case numbers. Using historical climate data and annual malaria case number data from 1960 to 2006, statistical models are developed to isolate the effects of climate ...[more]

PMID: 19133152

Similar Datasets

Project description:Following the rapid dissemination of COVID-19 cases in Colombia in 2020, large-scale non-pharmaceutical interventions (NPIs) were implemented as national emergencies in most of the country's municipalities, starting with a lockdown on March 20th, 2020. Recently, approaches that combine movement data (measured as the number of commuters between units), metapopulation models to describe disease dynamics subdividing the population into Susceptible-Exposed-Asymptomatic-Infected-Recovered-Diseased and statistical inference algorithms have been pointed as a practical approach to both nowcast and forecast the number of cases and deaths. We used an iterated filtering (IF) framework to estimate the model transmission parameters using the reported data across 281 municipalities from March to late October in locations with more than 50 reported deaths and cases in Colombia. Since the model is high dimensional (6 state variables in every municipality), inference on those parameters is highly non-trivial, so we used an Ensemble-Adjustment-Kalman-Filter (EAKF) to estimate time variable system states and parameters. Our results show the model's ability to capture the characteristics of the outbreak in the country and provide estimates of the epidemiological parameters in time at the national level. Importantly, these estimates could become the base for planning future interventions as well as evaluating the impact of NPIs on the effective reproduction number ([Formula: see text]) and the critical epidemiological parameters, such as the contact rate or the reporting rate. However, our forecast presents some inconsistency as it overestimates the deaths for some locations as Medellín. Nevertheless, our approach demonstrates that real-time, publicly available ensemble forecasts can provide short-term predictions of reported COVID-19 deaths in Colombia. Therefore, this model can be used as a forecasting tool to evaluate disease dynamics and aid policymakers in infectious outbreak management and control.

Project description:BackgroundCervical cancer (CC) promotion and prevention (P&P) programmes' challenge lies in guaranteeing that follow-up strategies have a real impact on reducing CC-related mortality rates. CC P&P programme compliance and coverage rates are relevant indicators for evaluating their success and good performance; however, such indicators' frequency rates are considerably lower among women living in rural and border areas. This study was aimed at identifying factors associated with CC screening programme attendance for women living in Colombia's Amazon region.MethodsThis study (qualitative and quantitative phases) was carried out between September 2015 and November 2016; women residing in the border towns of Leticia and Puerto Nariño participated in it. The first phase (qualitative) involved interviews and focus group discussions; this led to establishing factors related to CC P&P programme attendance which were used in the quantitative phase for designing a survey for determining the strength of association in a logistic regression model. The terms attendance and compliance were considered to apply to women who had followed the 1-1-3 scheme throughout their lives, i.e. a cytology examination every 3 years after receiving two consecutive negative annual cytology results.ResultsInclusion criteria were met by 309 women (≥18-year-olds having an active sexual life, having resided in the target community for at least one year); 15.2% had suitable P&P programme follow-up. Screening programme attendance was positively associated with first intercourse after becoming 20 years-old (aOR: 3.87; 1.03-9.50 95%CI; p = 0.045), frequent contraceptive use (aOR: 3.11; 1.16-8.33 95%CI; p = 0.023), awareness of the age to participate in P&P programmes (aOR: 2.69; 1.08-6.68 95%CI; p = 0.032), awareness of cytology's usefulness in identifying cervical abnormalities (aOR: 2.43; 1.02-5.77 95%CI; p = 0.043) and considering cytology important (aOR: 2.64; 1.12-6.19 95%CI; p = 0.025). Women living in rural areas had a lower probability (aOR 0.43: 0.24-0.79 95%CI; p = 0.006) of adhering to CC P&P programmes.ConclusionsThis study's findings suggested the need for including novel strategies in screening programmes which will promote CC P&P activities going beyond hospital outpatient attendance to reach the most remote or widely scattered communities, having the same guarantees regarding access, opportunity and quality. Including education-related activities and stimulating the population's awareness regarding knowledge about CC prevention could be one of the main tools for furthering the impact of attendance at and compliance with P&P programmes.

Project description:Malaria community case management (CCM) can improve timely access to healthcare, and CCM programmes in sub-Saharan Africa are expanding from serving children under 5 years (CU5) only to all ages. This report characterizes malaria case management in the setting of an age-expanded CCM programme in Chadiza District, Zambia. Thirty-three households in each of 73 eligible communities were randomly selected to participate in a household survey preceding a trial of proactive CCM (NCT04839900). All household members were asked about fever in the prior two weeks and received a malaria rapid diagnostic test (RDT); those reporting fever were asked about healthcare received. Weighted population estimates were calculated and mixed effects regression was used to assess factors associated with malaria care seeking. Among 11,030 (98.6%) participants with RDT results (2,357 households), parasite prevalence was 19.1% by RDT; school-aged children (SAC, 5-14 years) had the highest prevalence (28.8%). Prior fever was reported by 12.4% of CU5, 7.5% of SAC, and 7.2% of individuals ≥ 15 years. Among those with prior fever, 34.0% of CU5, 56.0% of SAC, and 22.6% of individuals ≥ 15 years had a positive survey RDT and 73.7% of CU5, 66.5% of SAC, and 56.3% of individuals ≥ 15 years reported seeking treatment; 76.7% across all ages visited a CHW as part of care. Nearly 90% (87.8%) of people who visited a CHW reported a blood test compared with 73.5% seen only at a health facility and/or pharmacy (p < 0.001). Reported malaria treatment was similar by provider, and 85.9% of those with a reported positive malaria test reported getting malaria treatment; 66.9% of the subset with prior fever and a positive survey RDT reported malaria treatment. Age under 5 years, monthly or more frequent CHW home visits, and greater wealth were associated with increased odds of receiving healthcare. Chadiza District had high CHW coverage among individuals who sought care for fever. Further interventions are needed to increase the proportion of febrile individuals who receive healthcare. Strategies to decrease barriers to healthcare, such as CHW home visits, particularly targeting those of all ages in lower wealth strata, could maximize the benefits of CHW programmes.

Dataset Information

The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960-2006.

Publications

The role of ENSO in understanding changes in Colombia's annual malaria burden by region, 1960-2006.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets