Accuracy, acceptability, and feasibility of diagnostic tests for the screening of Strongyloides stercoralis in the field (ESTRELLA): a cross-sectional study in Ecuador.

BACKGROUND: WHO recommends the implementation of control programmes for strongyloidiasis, a neglected tropical disease caused by Strongyloides stercoralis. Specific recommendations on the diagnostic test or tests to be used for such programmes have yet to be defined. The primary objective of this study was to estimate the accuracy of five tests for strongyloidiasis. Secondary objectives were to evaluate acceptability and feasibility of use in an endemic area. METHODS: The ESTRELLA study was a cross-sectional study for which we enrolled school-age children living in remote villages of Ecuador. Recruitment took place in two periods (Sept 9-19, 2021, and April 18-June 11, 2022). Children supplied one fresh stool sample and underwent blood collection via finger prick. Faecal tests were a modified Baermann method and an in-house real-time PCR test. Antibody assays were a recombinant antigen rapid diagnostic test; a crude antigen-based ELISA (Bordier ELISA); and an ELISA based on two recombinant antigens (Strongy Detect ELISA). A Bayesian latent class model was used to analyse the data. FINDINGS: 778 children were enrolled in the study and provided the required samples. Strongy Detect ELISA had the highest sensitivity at 83·5% (95% credible interval 73·8-91·8), while Bordier ELISA had the highest specificity (100%, 99·8-100). Bordier ELISA plus either PCR or Baermann had the best performance in terms of positive and negative predictive values. The procedures were well accepted by the target population. However, study staff found the Baermann method cumbersome and time-consuming and were concerned about the amount of plastic waste produced. INTERPRETATION: The combination of Bordier ELISA with either faecal test performed best in this study. Practical aspects (including costs, logistics, and local expertise) should, however, also be taken into consideration when selecting tests in different contexts. Acceptability might differ in other settings. FUNDING: Italian Ministry of Health. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Use of a "tablet pole" for the administration of ivermectin for strongyloidiasis in a field study in Ecuador.

BACKGROUND: Establishment of efficient control programs for strongyloidiasis, the infection by Strongyloides stercoralis, is among the World Health Organization (WHO) targets for 2030. Ivermectin is a drug of choice for strongyloidiasis, but its weight-based administration can be unfeasible in remote areas. We evaluated a WHO tablet pole for administration of ivermectin in school-age children living in remote villages in Ecuador. METHODS: Children were enrolled in 16 villages in Esmeraldas Province of Ecuador, between July 2021 and June 2022. The pole identified four height intervals corresponding to ivermectin doses going from one to four tablets. For each child, we calculated the dose (µg/kg) administered with both weight-based and pole-based administration. Results were classified as follows: optimal dose, acceptable, overdose, underdose. Agreement between the two methods for estimating the number of tablets was assessed with Cohen's kappa coefficient. Estimations were reported with 95% confidence intervals (CIs). RESULTS: Total of 778 children (47.3% female) were enrolled, with median age of 9.59 years (interquartile range: 7.42‒11.22). Optimal dose was achieved for a higher proportion of children when assessed with weight (37.9%) than with pole (25.7%). Underdose and overdose were more frequent with the pole (8.3% and 19.2% children, respectively) than with the weight-based (3.7% and 6.0%, respectively) administration. Agreement between weight-based and pole-based administration was moderate: 0.56 (95% CI 0.51, 0.61). The two methods indicated the same number of tablets in 71.6% (95% CI 0.684, 0.748) cases. CONCLUSIONS: In our setting, the tablet pole could be a valid alternative. The tool needs further evaluation in different populations.

[I promotori di salute come attori-protagonisti delle cure primarie nel controllo delle malattie comunicabili e non comunicabili e nell' empowerment delle comunità. Esperienza e risultati di lungo periodo in aree marginali in Ecuador dal 1980 al 2018.] / The community health promoters as protagonist actorsof primary health care and community empowerment:a long term field-report from 1980 to 2018.

. INTRODUCTION: Against the increasing recognition of the critical importance of a direct participation of community members to assure effective health care in peripheral areas of Middle and Low Income Countries (MLIC), representative field experiences of their essential role are only occasionally available. AIMS AND METHODS: We report a narrative, factual documentation of a spectrum of projects covering the basic and specific health needs of the disperse communities in Ecuador, a model MLIC, and discuss the broader implications of the role and performance of HPs over a long period, 1980-2018, in the project activation, implementation and monitoring. RESULTS: The role of 60 HPs, with the coordination of a small core group of professionals of the Centro de Epidemiologia Comunitaria y Medicina Tropical (CECOMET) is documented through their main achievements which include: infectious diseases and in particular Neglected Tropical Diseases (eradication of onchocerciasis and yaws; virtual elimination of malaria and of strongyloidiasis; identification and control of a new focus of Chagas Disease; control of tuberculosis), mother and child health, reproductive health, hypertension (as model of the emergence of non-transmissible, chronic diseases). The most effective and sustainable strategies and methods are discussed also in terms of their more general transferability, already partially tested in programs in Bolivia, Burkina Faso, undeserved areas of Argentina. CONCLUSIONS: The systematic availability of non-professional, trained HPs should be recommended as a sustainable and reliable component of health care strategies and interventions targeted to marginalized settings, to assure a concrete accessibility to the fundamental human right to life.

Mapping the Prevalence of Strongyloides stercoralis Infection in Ecuador: A Serosurvey.

Data on the prevalence of strongyloidiasis in Ecuador are patchy. The aim of this study was to document the presence of Strongyloides stercoralis infection in rural communities of different provinces of Ecuador. We tested 1,418 serum samples stored at the biobank of the Central University of Ecuador, Quito, with an ELISA test for Strongyloides. The samples had been collected in eight different provinces of Ecuador. Two hundred ninety-four samples (20.7%) were positive, and Jipijapa, Manabí Province, was the site with the largest proportion of positive samples (66.7%). Further surveys aimed at estimating the prevalence of the infection should be carried out in areas where the infection seems highly prevalent, and ad hoc control measures should be adopted.

Long-Term Outcomes of a Cohort of Hypertensive Subjects in Rural Ecuador.

BACKGROUND: In contrast with the abundance of global epidemiological descriptive data on cardiovascular diseases and their risk factors, information on the outcomes of real populations prospectively followed up in their life and care settings is much rarer, especially in low-income countries. OBJECTIVES: This study sought to evaluate the feasibility and the overall results of a hypertension control program, based mainly on a network of community nonprofessional health promoters, in the poor rural region of Borbon (Ecuador). METHODS: This is a prospective cohort study describing the results of a program of hypertension diagnosis, treatment and follow-up from 2004 to 2015 in the area, carried out mainly by the health promoters. RESULTS: The number of hypertensive patients identified and followed over the years increased from 1,024 in 2004 to 1,733 in 2015. The percentage of patients with no visits during a year was reduced to <10%, whereas the proportion of hypertensive subjects attending all 4 scheduled annual checks approached and, in some years, exceeded 50%. From 2004 to 2015, the proportion of patients at high or very high cardiovascular risk progressively decreased from 26.6% in 2004 to 17.5% in 2015 (p for trend <0.01), whereas the proportion of hypertensive patients at low or very low risk increased from 30.4% in 2004 to 45.0% in 2015 (p for trend <0.01). CONCLUSIONS: In a poor, disadvantaged area, a strategy of control mainly based on the involvement and responsibility of community health promoters (with health professionals as supporters more than direct actors) can achieve adequate follow-up of the population of hypertensive patients and improve their global cardiovascular risk level.

Community Epidemiology Approach to Parasitic Infection Screening in a Remote Community in Ecuador.

The Awa indigenous people of Ecuador live in remote areas and were included in health programs only recently. The first screening for parasitic infections in the Awa communities was implemented in the context of community epidemiology. During the site visits in each community, the health-care staff collected the samples for stool microscopy and serology for Strongyloides. A total of 705 individuals consented for the study, representing 40% of the Awa population living in the targeted communities; 184 (26%) participants supplied a stool sample. Giardia intestinalis was found in about 11% of samples. Prevalence of Ascaris lumbricoides and Trichuris trichiura was 54.9% and 36.9%, respectively. No hookworm eggs were found. In addition, Strongyloides stercoralis larvae were found in eight individuals (4.3%), whereas serology was positive in 22.7% of the individuals tested. The community-based approach resulted in an impressive participation. There was a high prevalence of parasites associated with relevant morbidity.

Comparison of S. stercoralis Serology Performed on Dried Blood Spots and on Conventional Serum Samples.

Background: Dried blood spots (DBS) are used for epidemiological surveys on infectious diseases in settings where limited resources are available. In fact, DBS can help to overcome logistic difficulties for the collection, transport and storage of biological specimens. Objective: To evaluate the accuracy of Strongyloides stercoralis serology performed on DBS. Methods: A survey was proposed to children attending a school in the village of Borbon, Ecuador, and to their parents/guardians. Each participant gave consent to the collection of both serum and DBS specimens. DBS absorbed on filter papers were analyzed with a commercially available ELISA test for S. stercoralis antibodies, as well as with standard serology. The agreement between the two methods was assessed through the Cohen's kappa coefficient. Results: The study sample was composed of 174 children and 61 adults, for a total of 235 serum and 235 DBS samples. The serology was positive in 31/235 (13%) serum samples, and in 27/235 (11%) DBS: 4 samples resulted discordant (positive at standard serology). Cohen's kappa coefficient was 0.921 (95% CI 0.845 - 0.998), indicating a high rate of concordance. Conclusion: DBS are suitable for in field-surveys requiring serological testing for S. stercoralis.

Mass Administration of Ivermectin for the Elimination of Onchocerciasis Significantly Reduced and Maintained Low the Prevalence of Strongyloides stercoralis in Esmeraldas, Ecuador.

OBJECTIVES: To evaluate the effect of ivermectin mass drug administration on strongyloidiasis and other soil transmitted helminthiases. METHODS: We conducted a retrospective analysis of data collected in Esmeraldas (Ecuador) during surveys conducted in areas where ivermectin was annually administered to the entire population for the control of onchocerciasis. Data from 5 surveys, conducted between 1990 (before the start of the distribution of ivermectin) and 2013 (six years after the interruption of the intervention) were analyzed. The surveys also comprised areas where ivermectin was not distributed because onchocerciasis was not endemic. Different laboratory techniques were used in the different surveys (direct fecal smear, formol-ether concentration, IFAT and IVD ELISA for Strongyloides stercoralis). RESULTS: In the areas where ivermectin was distributed the strongyloidiasis prevalence fell from 6.8% in 1990 to zero in 1996 and 1999. In 2013 prevalence in children was zero with stool examination and 1.3% with serology, in adult 0.7% and 2.7%. In areas not covered by ivermectin distribution the prevalence was 23.5% and 16.1% in 1996 and 1999, respectively. In 2013 the prevalence was 0.6% with fecal exam and 9.3% with serology in children and 2.3% and 17.9% in adults. Regarding other soil transmitted helminthiases: in areas where ivermectin was distributed the prevalence of T. trichiura was significantly reduced, while A. lumbricoides and hookworms were seemingly unaffected. CONCLUSIONS: Periodic mass distribution of ivermectin had a significant impact on the prevalence of strongyloidiasis, less on trichuriasis and apparently no effect on ascariasis and hookworm infections.

First description of Trypanosoma cruzi human infection in Esmeraldas province, Ecuador.

Chagas disease was described in Ecuador in 1930 in the province of Guayas and thereafter in various provinces. Triatomine were reported in the province of Esmeraldas but no human infection has been described. Here we report the first evidence that the disease does exist in the province of Esmeraldas. In indigenous Awá communities located in the northwest jungle of the Esmeraldas province, 144 individuals were tested using ELISA and PCR for T.cruzi of which 5 (3.47%) were positive. Twenty eight triatomine were collected, 27 were Triatoma dispar and 1 Pastrongylus rufotuberculatus, T.cruzi was detected in 11 (42.3%) of 26 insects.

Diagnostic evaluation of people with hypertension in low income country: cohort study of "essential" method of risk stratification.

OBJECTIVES: To explore the predictive power of a risk stratification method for people with hypertension based on "essential" procedures (that is, available in economically less developed areas of the world), comparing it in the same population with the results given by the method suggested by the 1999 World Health Organization-International Society of Hypertension (WHO-ISH) guidelines. DESIGN: Prospective cohort study of outcomes according to cardiovascular risk profile at baseline. SETTING: Primary care in a poor rural area of the Ecuadorian forest. PARTICIPANTS: 504 people with hypertension prospectively monitored for a mean of 6.7 (SD 2.3) years. INTERVENTIONS: Essential data included blood pressure, medical history, smoking, age, sex, and diagnosis of diabetes; the WHO-ISH methods additionally included measurement of fasting blood glucose, total cholesterol, and creatinine, urinalysis, and electrocardiography. MAIN OUTCOME MEASURES: Cardiovascular events and total deaths. RESULTS: With both methods there was a highly significant association between the level of predicted risk and the incidence of cardiovascular events and of total deaths: up to three quarters of all cardiovascular events and two thirds of all deaths were reported among people classified as at high or very high risk with either method. The predictive discrimination of the essential method is comparable with the WHO-ISH with C statistics (95% confidence interval) of 0.788 (0.721 to 0.855) and 0.744 (0.673 to 0.815), respectively, for cardiovascular events and 0.747 (0.678 to 0.816) and 0.705 (0.632 to 0.778) for total mortality. CONCLUSIONS: The risk stratification of patients with hypertension with an essential package of variables (that is, available and practicable even in the economically less developed areas of the world) serves at least as well as the more comprehensive method proposed by WHO-ISH.

[Community participation as a strategy of hypertension control in a health district of Ecuador]. / Una comunità del sud del mondo partecipa al controllo dell'ipertensione arteriosa: i protagonisti raccontano.

The results of a program for the treatment and control of arterial hypertension in a rural community of the northern area of Ecuador are reported through the voices and the posters used for patients education, by nurses and health promoters (non professional representatives of the community, with a nursing role) of the district. The steps of the program, from the awareness of the problem because of its high impact on mortality; to the organization of the screening for hypertension of 4284 adults (half of the local adult population); to the systematic collection of data on mortality are described. One of the strategies adopted is the discussion of patients' stories with the local communities: the death of a young patient who refused the treatment and died had a strong influence in convincing at risk patients to enter the program. Treatments were available for 1 dollar a month. Nurses and community health promoters have a pivotal role in guaranteeing pressure control and in identifying at risk patients with the help of community adapted risk tables. From the analysis of data of the first 18 months of follow-up some improvements can be observed: grade II hypertensive patients shifted from 34% to 25%; grade III from 35% to 29%. Lack of compliance with the drug therapy is still one of the main problems.

Treatment and control of arterial hypertension in a rural community in Ecuador.

Cardiovascular diseases are widespread in developing countries, but little is known about cardiovascular risk profiles in rural communities. To assess the importance of arterial hypertension in a rural district of Ecuador, we screened 4284 of the 8876 adults who lived in the area. 1542 (36%) individuals had hypertension, only four (0.3%) of whom were well controlled by treatment. We monitored all deaths for 2.5 years, and noted that cardiovascular diseases were the primary cause of death in the adult population. Furthermore, of the individuals who died of a cardiovascular disease, four out of five had a history of hypertension. Our findings indicate that in this rural area of Ecuador the high prevalence of uncontrolled hypertension is a major cause of total mortality.