Control of dengue virus (DenV) transmission, primarily based on strategies to reduce populations of the principle vector Stegomya aegypti (= Aedes aegypti) (Diptera: Culicidae), is difficult to sustain over time. Other potential strategies aim to manipulate characteristics such as vector competence (VC), the innate capacity of the vector to transmit the virus. Previous studies have identified genetic factors, including differential expression of apoptosis-related genes, associated with the refractory and susceptible phenotypes in selected strains of S. aegypti from Cali, Colombia. The present study was designed to evaluate the variability of VC in selected strains against different DenV serotypes and to determine whether field-collected mosquitoes respond similarly to selected laboratory strains in terms of enhanced or reduced expression of apoptosis-related genes. Vector competence differed between strains, but did not differ in response to different DenV serotypes. Differences in VC were observed among mosquitoes collected from different localities in Cali. The overexpression of the pro-apoptosis genes, caspase 16 and Aedronc, was conserved in field-collected refractory mosquitoes and the selected laboratory refractory strain. The results suggest that the apoptosis response is conserved among all refractory mosquitoes to inhibit the development of all DenV serotypes.

Background Detection and management of neglected tropical diseases such as cutaneous leishmaniasis present unmet challenges stemming from their prevalence in remote, rural, resource constrained areas having limited access to health services. These challenges are frequently compounded by armed conflict or illicit extractive industries. The use of mobile health technologies has shown promise in such settings, yet data on outcomes in the field remain scarce. Methods We adapted a validated prediction rule for the presumptive diagnosis of CL to create a mobile application for use by community health volunteers. We used human-centered design practices and agile development for app iteration. We tested the application in three rural areas where cutaneous leishmaniasis is endemic and an urban setting where patients seek medical attention in the municipality of Tumaco, Colombia. The application was assessed for usability, sensitivity and inter-rater reliability (kappa) when used by community health volunteers (CHV), health workers and a general practitioner, study physician. Results The application was readily used and understood. Among 122 screened cases with cutaneous ulcers, sensitivity to detect parasitologically proven CL was >95%. The proportion of participants with parasitologically confirmed CL was high (88%), precluding evaluation of specificity, and driving a high level of crude agreement between the app and parasitological diagnosis. The chance-adjusted agreement (kappa) varied across the components of the risk score. Time to diagnosis was reduced significantly, from 8 to 4 weeks on average when CHV conducted active case detection using the application, compared to passive case detection by health facility-based personnel. Conclusions Translating a validated prediction rule to a mHealth technology has shown the potential to improve the capacity of community health workers and healthcare personnel to provide opportune care, and access to health services for underserved populations. These findings support the use of mHealth tools for NTD research and healthcare.

BackgroundClinical manifestations of cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) range from asymptomatic infection to self-limited, or chronic (non-healing) cutaneous lesions. Given the critical role of the immune response in the clinical outcome of CL, it is plausible that functional polymorphisms in immune-related genes contribute to define the clinical manifestations of human infection.MethodsDNA samples from a retrospective cohort of individuals from an endemic area of L. V. panamensis transmission in Colombia were used to determine the frequency of SNPs in TNFα, IL-10 and TLR4 genes. DNA samples were obtained from 74 adult participants: 38 patients presenting chronic cutaneous leishmaniasis (CCL) and 36 individuals with asymptomatic infection. Genotyping of TNFα-308G/A, IL-10-819C/T, and TLR4 Asp299Gly and Thr399Ile SNPs, was conducted by PCR-restriction fragment length polymorphisms. Allele, genotype frequencies and associations between SNPs and clinical groups were evaluated.ResultsThe A allele in TNFα-308G/A SNP was found more frequently in individuals with asymptomatic infection (16% vs 7%), whereas the CC genotype in IL-10-819 C/T SNP was more frequent in patients with CCL (34% vs. 27% in asymptomatic individuals). No differences in allele frequencies for TLR4 SNPs were found among groups.ConclusionThis study provides a reference base for statistical power calculation and design of association studies of genetic polymorphisms in immune response related-genes and the pathogenesis of infections caused by L. V. panamensis.

Introducción. Para la prevención de la transmisión materno-infantil de la sífilis en Colombia, se promueve el diagnóstico y el tratamiento en una sola consulta mediante el uso de pruebas de diagnóstico rápido, así como programas de eliminación conjunta de la transmisión materno-infantil de la sífilis y el HIV.Objetivo. Detectar los vacíos de capacitación del personal de salud en torno a la prevención de la transmisión materno-infantil de la sífilis y el HIV, y hacer recomendaciones para mejorar los programas.Materiales y métodos. Se hizo un estudio descriptivo mediante 306 encuestas hechas al personal de salud de 39 instituciones de Cali. Se indagó sobre la planeación, la gestión y la ejecución de los servicios ofrecidos a las mujeres gestantes, los conocimientos clínicos sobre la sífilis, el HIV y las pruebas rápidas, así como sobre las capacitaciones recibidas.Resultados. Se encontraron deficiencias en el conocimiento del manejo de la sífilis gestacional entre el personal de salud, incluidos los médicos. Las pruebas de diagnóstico rápido para sífilis se utilizan en los laboratorios de la ciudad, pero se detectaron fallas en su uso adecuado, especialmente en el control de calidad. La capacitación en temas de prevención de la transmisión materno-infantil de la sífilis y el HIV había sido escasa en los dos años anteriores. El personal de salud expresó su interés por diagnosticar y tratar la sífilis gestacional en una sola consulta, usar las pruebas de diagnóstico rápido y asistir a actividades de capacitación.Conclusiones. Se requiere la capacitación intensiva del personal de salud, de quienes toman las decisiones y de los grupos académicos, para lograr una adecuada implementación de las nuevas estrategias de prevención de la transmisión materno-infantil de la sífilis y el HIV.

Objectives Cutaneous leishmaniasis is a vector-borne parasitic disease whose lasting scars can cause stigmatization and depressive symptoms. It is endemic in remote rural areas and its incidence is under-reported, while the effectiveness, as opposed to efficacy, of its treatments is largely unknown. Here we present the data management plan (DMP) of a project which includes mHealth tools to address these knowledge gaps in Colombia. The objectives of the DMP are to specify the tools and procedures for data collection, data transfer, data entry, creation of analysis dataset, monitoring and archiving. Results The DMP includes data from two mobile apps: one implements a clinical prediction rule, and the other is for follow-up and treatment of confirmed cases. A desktop interface integrates these data and facilitates their linkage with other sources which include routine surveillance as well as paper and electronic case report forms. Multiple user and programming interfaces are used, as well as multiple relational and non-relational database engines. This DMP describes the successful integration of heterogeneous data sources and technologies. However the complexity of the project meant that the DMP took longer to develop than expected. We describe lessons learned which could be useful for future mHealth projects.

IntroductionMost women in Colombia receive antenatal care (ANC), but goals for the reduction of congenital syphilis (CS) have not been met. In 2015 Cali had an incidence of 3.0 cases of CS per 1000 births.Point of care testing (POC) has proven cost-effective, and since 2015 it is now recommended by the Colombian Ministry of Health Guidelines. Nevertheless, POC for gestational syphilis (GS) has not been implemented in ANC. We sought to test the feasibility of POC and identify barriers to its implementation in Floralia, a public, primary healthcare centre in Cali.MethodsDuring a three-month period, we observed routine ANC in Floralia and offered women on-site rapid tests (RT) for syphilis. Process measures were compared with data from the clinical charts (CC) of women seen in 2015. Patients and administrators were interviewed and asked to describe ANC, syphilis screening procedures, and to identify opportunities for improvement.Results55 women were offered POC testing, 42 agreed to participate and were screened. 55 CC from 2016, and 123 CC from 2015, were reviewed. The median gestational age at which women sought health care was eight weeks. The first trimester of pregnancy had the highest percentage of women screened for GS: 97% were screened in 2015, and 100% were screened in 2016. Changes to screening procedures were hindered by existing contracts with insurance companies (IC); they determine what tests can be ordered and who can order them. Administrative procedures lead to missed opportunities for screening and treatment.Two women (1.6%) from the 2015 group were diagnosed with GS, and three (5.4%) were diagnosed during the intervention. POC testing allowed us to treat GS on the same day of the positive result, while using routine testing methods took 6 to 24 days.ConclusionDiffusion of the national guidelines for GS has been insufficient to control GS and CS: There is still confusion among health care workers, and contracts with IC do not include RT. POC for syphilis can be a part of ANC, but barriers need to be addressed before implementation.

Aedes aegypti is the primary vector of dengue, Zika, and chikungunya viruses. Studies have shown that insecticide resistance affects vector competence (VC) of some mosquito species. This study evaluates the effect of resistance to lambda-cyhalothrin and kdr V1016I mutation genotypes on the VC of Ae. aegypti strains for DENV-2, ZIKV, and CHIKV. Three Ae. aegypti strains with gradual lambda-cyhalothrin resistance (susceptible, resistant, and highly resistant) were infected with DENV-2, ZIKV, and CHIKV. Individual mosquitoes were tested to detect virus infection in the abdomen and head-salivary glands, using RT-PCR, and genotypes for V1016I mutations using allele-specific PCR. Recorded VC variables were midgut infection rate (MIR), dissemination rate (DIR), and dissemination efficiency (DIE). Lambda-cyhalothrin resistance affects differentially VC variables for ZIKV, DENV-2, and CHIKV. For ZIKV, an apparent gradual increase in DIR and DIE with the increase in insecticide resistance was observed. For DENV-2 the MIR and DIE were higher in insecticide resistant strains. For CHIKV, only MIR could be evaluated, this variable was higher in insecticide resistance strains. The presence of kdr V1016I mutation on mosquito resistant strains did not affect VC variables for three study viruses.

The Pareto Principle (PP) - that 80% of an attribute are found in 20% of individuals - is one way to characterize heterogeneity in infectious diseases. An alternative is the dispersion parameter (k) of the negative binomial distribution (NBD). The NBD has two parameters, while the PP is a single property which may hold for any distribution family. The objectives of the current work are: a) to obtain a relation between the PP and NBD, i.e. to specify which combinations of NBD parameters comply with the PP; b) for hookworm, a soil-transmitted intestinal parasite of humans, to identify whether the PP or the NBD is a more parsimonious description of heterogeneity of infection load. For objective a), an empirical relation is found in the form of a saw-toothed line on a plot of k against the mean, reaching an asymptote of approximately 0.24. For objective b), we estimate k and the mean from nine studies from a systematic review of hookworm in pregnant women. Seven studies had higher heterogeneity than the PP, ranging from 83:20 to 100:20: we call these super-Pareto. One study was sub-Pareto (74:20), and one was Pareto (80:20). This suggests that at least two parameters, as supplied by the NBD, are necessary to describe the heterogeneity of hookworm. The probability of reaching a target reduction in prevalence is less when there is greater aggregation, which suggests that estimating aggregation via a subsample could be worthwhile, in order to set a target coverage threshold before starting mass drug administration.