Identifying future zoonotic disease threats: Where are the gaps in our understanding of primate infectious diseases?

Background and objectives: Emerging infectious diseases often originate in wildlife, making it important to identify infectious agents in wild populations. It is widely acknowledged that wild animals are incompletely sampled for infectious agents, especially in developing countries, but it is unclear how much more sampling is needed, and where that effort should focus in terms of host species and geographic locations. Here, we identify these gaps in primate parasites, many of which have already emerged as threats to human health. Methodology: We obtained primate host–parasite records and other variables from existing databases. We then investigated sampling effort within primates relative to their geographic range size, and within countries relative to their primate species richness. We used generalized linear models, controlling for phylogenetic or spatial autocorrelation, to model variation in sampling effort across primates and countries. Finally, we used species richness estimators to extrapolate parasite species richness. Results: We found uneven sampling effort within all primate groups and continents. Sampling effort among primates was influenced by their geographic range size and substrate use, with terrestrial species receiving more sampling. Our parasite species richness estimates suggested that, among the best sampled primates and countries, almost half of primate parasites remain to be sampled; for most primate hosts, the situation is much worse. Conclusions and implications: Sampling effort for primate parasites is uneven and low. The sobering message is that we know little about even the best studied primates, and even less regarding the spatial and temporal distribution of parasitism within species

Host Longevity and Parasite Species Richness in Mammals

Hosts and parasites co-evolve, with each lineage exerting selective pressures on the other. Thus, parasites may influence host life-history characteristics, such as longevity, and simultaneously host life-history may influence parasite diversity. If parasite burden causes increased mortality, we expect a negative association between host longevity and parasite species richness. Alternatively, if long-lived species represent a more stable environment for parasite establishment, host longevity and parasite species richness may show a positive association. We tested these two opposing predictions in carnivores, primates and terrestrial ungulates using phylogenetic comparative methods and controlling for the potentially confounding effects of sampling effort and body mass. We also tested whether increased host longevity is associated with increased immunity, using white blood cell counts as a proxy for immune investment. Our analyses revealed weak relationships between parasite species richness and longevity. We found a significant negative relationship between longevity and parasite species richness for ungulates, but no significant associations in carnivores or primates. We also found no evidence for a relationship between immune investment and host longevity in any of our three groups. Our results suggest that greater parasite burden is linked to higher host mortality in ungulates. Thus, shorter-lived ungulates may be more vulnerable to disease outbreaks, which has implications for ungulate conservation, and may be applicable to other short-lived mammals

Effective Network Size Predicted From Simulations of Pathogen Outbreaks Through Social Networks Provides a Novel Measure of Structure-Standardized Group Size

The transmission of infectious disease through a population is often modeled assuming that interactions occur randomly in groups, with all individuals potentially interacting with all other individuals at an equal rate. However, it is well known that pairs of individuals vary in their degree of contact. Here, we propose a measure to account for such heterogeneity: effective network size (ENS), which refers to the size of a maximally complete network (i.e., unstructured, where all individuals interact with all others equally) that corresponds to the outbreak characteristics of a given heterogeneous, structured network. We simulated susceptible-infected (SI) and susceptible-infected-recovered (SIR) models on maximally complete networks to produce idealized outbreak duration distributions for a disease on a network of a given size. We also simulated the transmission of these same diseases on random structured networks and then used the resulting outbreak duration distributions to predict the ENS for the group or population. We provide the methods to reproduce these analyses in a public R package, “enss.” Outbreak durations of simulations on randomly structured networks were more variable than those on complete networks, but tended to have similar mean durations of disease spread. We then applied our novel metric to empirical primate networks taken from the literature and compared the information represented by our ENSs to that by other established social network metrics. In AICc model comparison frameworks, group size and mean distance proved to be the metrics most consistently associated with ENS for SI simulations, while group size, centralization, and modularity were most consistently associated with ENS for SIR simulations. In all cases, ENS was shown to be associated with at least two other independent metrics, supporting its use as a novel metric. Overall, our study provides a proof of concept for simulation-based approaches toward constructing metrics of ENS, while also revealing the conditions under which this approach is most promising

Propuesta de mejoras en el proceso de tejido para disminuir el porcentaje de defectos en el área de producción de la empresa Cofaco Industries S.A.C en el año 2017

RESUMEN La presente investigación tiene por objetivo mejorar el proceso de tejido para disminuir el porcentaje de defectos en el área de producción de la empresa Cofaco Industries S.A.C. dedicada a la fabricación de tejidos y exportación de prendas. En la primera etapa de la investigación se realizo un diagnóstico de la situación inicial con el objetivo de identificar las causas raíces de la problemática. Para ello se elaboró un diagrama de Ishikawa y luego se priorizaron las causas más relevantes. El diagnóstico identifico que las causas principales son los factores mano de obra y maquina que afectan la productividad, en la utilización de máquinas de tejido de segunda procedencia alemana, falta de procedimiento en el proceso de tejido y capacitación al personal. En la segunda etapa de la investigación se investigó sobre máquinas de tejido de última generación que actualmente se emplean en otras industrias para procesos similares. Para la elección de la máquina de tejido, se utilizó la técnica de proceso de jerarquía analítica con la finalidad de identificar la mejor alternativa en función a criterios preestablecidos. La mejor alternativa identificada fue la máquina de tejido de procedencia italiana, la cual reemplazará a la máquina de tejido de segunda que actualmente se usa en el proceso. La ejecución de la propuesta de mejoras en el proceso de tejido para disminuir el porcentaje de defectos en el área de producción, se propone dos máquinas de tejido con sensores de procedencia italiana con procedimientos establecidos en el proceso y un plan de capacitación al personal. Como resultado se obtendría un disminución de defectos de 9.00 % a 0.25% PALABRAS CLAVE: proceso de tejido, producción, defectos, procedimiento, capacitacionesABSTRACT The present research aims to improve the weaving process to reduce the percentage of defects in the production area of the company Cofaco Industries S.A.C. dedicated to the manufacture of fabrics and export of garments. In the first stage of the investigation, a diagnosis of the initial situation was made with the objective of identifying the root causes of the problem. For this, a diagram of Ishikawa was drawn up and then the most relevant causes were prioritized. The diagnosis identifies that the main causes are the labor and machine factors that affect productivity, in the use of machines of second German fabric, lack of procedure in the weaving process and training of personnel. In the second stage of the investigation we investigated the last generation of fabric machines that are currently used in other industries for similar processes. For the choice of the tissue machine, the analytical hierarchy process technique was used in order to identify the best alternative according to pre-established criteria. The best alternative identified was the machine of tissue of Italian origin, which will replace the machine of second fabric that is currently used in the process. The execution of the proposal of improvements in the weaving process to reduce the percentage defects in the area of production, we propose two machines of tissue with sensors of Italian origin with procedures established in the process and a training plan for the personnel. As a result, a defect decrease would be obtained from 9.00% to 0.25% KEYWORDS: Weaving process, production, defects, procedure, trainin

Identifying wildlife reservoirs of neglected taeniid tapeworms : non-invasive diagnosis of endemic Taenia serialis infection in a wild primate population

Despite the global distribution and public health consequences of Taenia tapeworms, the life cycles of taeniids infecting wildlife hosts remain largely undescribed. The larval stage of Taenia serialis commonly parasitizes rodents and lagomorphs, but has been reported in a wide range of hosts that includes geladas (Theropithecus gelada), primates endemic to Ethiopia. Geladas exhibit protuberant larval cysts indicative of advanced T. serialis infection that are associated with high mortality. However, non-protuberant larvae can develop in deep tissue or the abdominal cavity, leading to underestimates of prevalence based solely on observable cysts. We adapted a non-invasive monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) to detect circulating Taenia spp. antigen in dried gelada urine. Analysis revealed that this assay was highly accurate in detecting Taenia antigen, with 98.4% specificity, 98.5% sensitivity, and an area under the curve of 0.99. We used this assay to investigate the prevalence of T. serialis infection in a wild gelada population, finding that infection is substantially more widespread than the occurrence of visible T. serialis cysts (16.4% tested positive at least once, while only 6% of the same population exhibited cysts). We examined whether age or sex predicted T. serialis infection as indicated by external cysts and antigen presence. Contrary to the female-bias observed in many Taenia-host systems, we found no significant sex bias in either cyst presence or antigen presence. Age, on the other hand, predicted cyst presence (older individuals were more likely to show cysts) but not antigen presence. We interpret this finding to indicate that T. serialis may infect individuals early in life but only result in visible disease later in life. This is the first application of an antigen ELISA to the study of larval Taenia infection in wildlife, opening the doors to the identification and description of infection dynamics in reservoir populations

Interactions between Micro- and Macroparasites Predict Microparasite Species Richness across Primates

Most wild animals face concurrent challenges by multiple infectious organisms, and immunological responses triggered by some parasites may increase susceptibility to other infectious agents. Immune-mediated interactions among parasites have been investigated among individuals in a population, but less is known about broader comparative patterns. We investigated the “macro-micro facilitation hypothesis” that higher helminth prevalence in a host species provides greater opportunities for intracellular parasites to invade, resulting in higher richness of intracellular microparasites. We obtained data on average helminth prevalence for 70 primate hosts, along with data on richness of intra- and extracellular infectious organisms. Using Bayesian phylogenetic methods, we found that primate species with higher overall helminth prevalence harbored more species of intracellular microparasites, while the positive association between helminth prevalence and extracellular microparasite species richness was weaker. The relationships held after controlling for potentially confounding variables, but associations were not found in focused tests of prevalence for six genera of well-studied helminths. The magnitude of support and effect sizes for overall helminth prevalence on intracellular microparasite species richness was similar to support for other well recognized ecological and life-history drivers of parasite species richness. Our findings therefore suggest that intrahost parasite interactions are as important as some ecological characteristics of hosts in accounting for parasite richness across host species.This is the publisher’s final pdf. The published article is copyrighted by the University of Chicago Press for the American Society of Naturalists and can be found at: http://www.jstor.org/page/journal/amernatu/earticles.html.Keywords: coinfection, immune response, comparative study, immune trade-off, parasitis

The Spread of Fecally Transmitted Parasites in Socially-Structured Populations

Mammals are infected by a wide array of gastrointestinal parasites, including parasites that also infect humans and domesticated animals. Many of these parasites are acquired through contact with infectious stages present in soil, feces or vegetation, suggesting that ranging behavior will have a major impact on their spread. We developed an individual-based spatial simulation model to investigate how range use intensity, home range overlap, and defecation rate impact the spread of fecally transmitted parasites in a population composed of social groups (i.e., a socially structured population). We also investigated the effects of epidemiological parameters involving host and parasite mortality rates, transmissibility, disease–related mortality, and group size. The model was spatially explicit and involved the spillover of a gastrointestinal parasite from a reservoir population along the edge of a simulated reserve, which was designed to mimic the introduction pathogens into protected areas. Animals ranged randomly within a “core” area, with biased movement toward the range center when outside the core. We systematically varied model parameters using a Latin hypercube sampling design. Analyses of simulation output revealed a strong positive association between range use intensity and the prevalence of infection. Moreover, the effects of range use intensity were similar in magnitude to effects of group size, mortality rates, and the per-contact probability of transmission. Defecation rate covaried positively with gastrointestinal parasite prevalence. Greater home range overlap had no positive effects on prevalence, with a smaller core resulting in less range overlap yet more intensive use of the home range and higher prevalence. Collectively, our results reveal that parasites with fecal-oral transmission spread effectively in socially structured populations. Future application should focus on parameterizing the model with empirically derived ranging behavior for different species or populations and data on transmission characteristics of different infectious organisms

Lost in reviews:Looking for the involvement of stakeholders, patients, public and other non-researcher contributors in realist reviews

The involvement of non‐researcher contributors (eg, stakeholders, patients and the public, decision and policy makers, experts, lay contributors) has taken a variety of forms within evidence syntheses. Realist reviews are a form of evidence synthesis that involves non‐researcher contributors yet this practice has received little attention. In particular, the role of patient and public involvement (PPI) has not been clearly documented. This review of reviews describes the ways in which contributor involvement, including PPI, is documented within healthcare realist reviews published over the last five years. A total of 448 papers published between 2014 and 2019 were screened, yielding 71 full‐text papers included in this review. Statements about contributor involvement were synthesized across each review using framework analysis. Three themes are described in this article including nomenclature, nature of involvement, and reporting impact.Papers indicate that contributor involvement in realist reviews refers to stakeholders, experts, or advisory groups (ie, professionals, clinicians, or academics). Patients and the public are occasionally subsumed into these groups and in doing so, the nature and impact of their involvement become challenging to identify and at times, is lost completely. Our review findings indicate a need for the realist review community to develop guidance to support researchers in their future collaboration with contributors, including patients and the public

Multidrug-resistant Tuberculosis Management in Resource-limited Settings

Managing MDRTB through national programs can yield results similar to those seen in wealthier settings