Mosquitoes are vectors of many human diseases. In particular, Aedes ægypti (Linnaeus) is the main vector for Chikungunya, Dengue, and Zika viruses in Latin America and it represents a global threat. Public health policies that aim at combating this vector require dependable and timely information, which is usually expensive to obtain with field campaigns. For this reason, several efforts have been done to use remote sensing due to its reduced cost. The present work includes the temporal modeling of the oviposition activity (measured weekly on 50 ovitraps in a north Argentinean city) of Aedes ægypti (Linnaeus), based on time series of data extracted from operational earth observation satellite images. We use are NDVI, NDWI, LST night, LST day and TRMM-GPM rain from 2012 to 2016 as predictive variables. In contrast to previous works which use linear models, we employ Machine Learning techniques using completely accessible open source toolkits. These models have the advantages of being non-parametric and capable of describing nonlinear relationships between variables. Specifically, in addition to two linear approaches, we assess a support vector machine, an artificial neural networks, a K-nearest neighbors and a decision tree regressor. Considerations are made on parameter tuning and the validation and training approach. The results are compared to linear models used in previous works with similar data sets for generating temporal predictive models. These new tools perform better than linear approaches, in particular nearest neighbor regression (KNNR) performs the best. These results provide better alternatives to be implemented operatively on the Argentine geospatial risk system that is running since 2012.

Introduction: Chagas disease, caused by infection with the parasite Trypanosoma cruzi, represents a huge public health problem in the Americas, where millions of people are affected. Despite the availability of two drugs against the infection (benznidazole and nifurtimox), multiple factors impede their effective usage: (1) gaps in patient and healthcare provider awareness; (2) lack of access to diagnosis; (3) drug toxicity and absence of treatment algorithms to address adverse effects; (4) failures in drug supply and distribution; and (5) inconsistent drug efficacy against the symptomatic chronic stage. Areas covered: We review new approaches and technologies to enhance access to diagnosis and treatment to reduce the disease burden. We also provide an updated picture of recently published and ongoing anti-T. cruzi drug clinical trials. Although there has been progress improving the research and development (R&D) landscape, it is unclear whether any new treatments will emerge soon. Literature search methodologies included multiple queries to public databases and the use of own-built libraries. Expert opinion: Besides R&D, there is a major need to continue awareness and advocacy efforts by patient associations, local and national governments, and international agencies. Overall, health systems strengthening is essential to ensure vector control commitments, as well as patient access to diagnosis and treatment.

There is a clinical need to test new schemes of benznidazole administration that are expected to be at least as effective as the current therapeutic scheme but safer. This study assessed a new scheme of benznidazole administration in chronic Chagas disease patients. A pilot study with intermittent doses of benznidazole at 5 mg/kg/day in two daily doses every 5 days for a total of 60 days was designed. The main criterion of response was the comparison of quantitative PCR (qPCR) findings prior to and 1 week after the end of treatment. The safety profile was assessed by the rate of suspensions and severity of adverse effects. Twenty patients were analyzed for safety, while qPCR was tested for 17 of them. The average age was 43 ؎ 7.9 years; 55% were female. Sixty-five percent of treated subjects showed detectable qPCR results prior to treatment of 1.45 (0.63 to 2.81) and 2.1 (1.18 to 2.78) parasitic equivalents per milliliter of blood (par.eq/ml) for kinetoplastic DNA (kDNA) qPCR and nuclear repetitive sequence satellite DNA (SatDNA) qPCR, respectively. One patient showed detectable PCR at the end of treatment (1/17), corresponding to 6% treatment failure, compared with 11/17 (65%) patients pretreatment (P ‫؍‬ 0.01). Adverse effects were present in 10/20 (50%) patients, but in only one case was treatment suspended. Eight patients showed mild adverse effects, whereas moderate reactions with increased liver enzymes were observed in two patients. The main accomplishment of this pilot study is the promising low rate of treatment suspension. Intermittent administration of benznidazole emerges a new potential therapeutic scheme, the efficacy of which should be confirmed by long-term assessment posttreatment.

Chagas disease, caused by the parasite Trypanosoma cruzi, is the neglected tropical disease with a highest burden in Latin America. Its acute stage is mostly asymptomatic and goes unnoticed. Symptoms appear at the chronic stage, which is when diagnosis is usually made. This is based on the agreement of two conventional serological tests such as Enzyme-Linked Immunosorbent Assays (ELISAs). There are commercial kits with good sensitivity and specificity but their use is impractical in many highly endemic regions with poorly equipped laboratories. Luckily, several rapid diagnostic tests (RDTs) are available for the detection of anti-T. cruzi immunoglobulins. They are easy to operate, require no cold storage, provide fast turnaround of results, and some can work with a tiny volume of whole blood as sample. With the aim to field validate their use we compared an alternative algorithm based on a combination of RDTs with the standard based on ELISAs. In both cases a third test was available in case of discordance. RDTs were implemented by mobile teams in field campaigns to detect chronic T. cruzi-infections in the Chaco region of Bolivia. ELISAs were made in the reference laboratories located in the main hospitals of Yacuiba and Villa Montes, two major cities of the region. We enrolled 685 subjects who voluntarily participated in the study and had not been treated against the disease before. The agreement between the two main RDTs was 93.1% (638/685) (kappa index = 0.86; CI 95% 0.83–0.90). In comparison to the ELISAs algorithm, the combined use of the RDTs provided a sensitivity of 97.7% and a specificity of 96.1%. These results support the use of RDTs for the diagnosis of chronic Chagas disease in the studied region, and encourage their evaluation in other regions of Bolivia and other endemic countries.

BackgroundRecommendations for soil-transmitted helminth (STH) control give a key role to deworming of school and pre-school age children with albendazole or mebendazole; which might be insufficient to achieve adequate control, particularly against Strongyloides stercoralis. The impact of preventive chemotherapy (PC) against STH morbidity is still incompletely understood. The aim of this study was to assess the effectiveness of a community-based program with albendazole and ivermectin in a high transmission setting for S. stercoralis and hookworm.MethodologyCommunity-based pragmatic trial conducted in Tartagal, Argentina; from 2012 to 2015. Six communities (5070 people) were enrolled for community-based PC with albendazole and ivermectin. Two communities (2721 people) were re-treated for second and third rounds. STH prevalence, anemia and malnutrition were explored through consecutive surveys. Anthropometric assessment of children, stool analysis, complete blood count and NIE-ELISA serology for S. stercoralis were performed.Principal findingsSTH infection was associated with anemia and stunting in the baseline survey that included all communities and showed a STH prevalence of 47.6% (almost exclusively hookworm and S. stercoralis). Among communities with multiple interventions, STH prevalence decreased from 62% to 23% (p<0.001) after the first PC; anemia also diminished from 52% to 12% (p<0.001). After two interventions S. stercoralis seroprevalence declined, from 51% to 14% (p<0.001) and stunting prevalence decreased, from 19% to 12% (p = 0.009).ConclusionsHookworm’ infections are associated with anemia in the general population and nutritional impairment in children. S. stercoralis is also associated with anemia. Community-based deworming with albendazole and ivermectin is effective for the reduction of STH prevalence and morbidity in communities with high prevalence of hookworm and S. stercoralis.