Epidemiological transmission patterns of Taenia solium cysticercosis in endemic areas : the case of Ecuador

Taenia solium taeniasis/cysticercosis is a neglected zoonotic parasitic disease complex that causes public health and socio-economic problems in many developing countries. Despite the increasing knowledge about the parasite and the risk factors for infection, control of T. solium has received little attention from governments of endemic countries. To date, no national control program has been implemented in Ecuador although the country is endemic for neurocysticercosis (NCC). The objective of this thesis was to study the transmission patterns of T. solium taeniasis/cysticercosis in order to design appropriate and effective control strategies for this Neglected Zoonotic Disease in endemic areas, with special reference to Ecuador. Chapter 1 presents an overview of the current knowledge of T. solium including the life cycle of the parasite, the implications on public health and the economic impact of the disease, its diagnosis, epidemiology with an emphasis on Latin America, with particular attention to the situation in Ecuador. In addition, the current control measures available for T. solium taeniasis/cysticercosis are described. In Chapter 2, serological data on apparent prevalence of T. solium circulating antigens and/or seroprevalence of T. solium antibodies, apparent prevalence of human taeniasis and risk factors for HCC from endemic communities were gathered in order to understand the differences in patterns of exposure to the parasite and active infections with T. solium metacestodes in endemic areas around the world. A total of 39,271 participants from 19 countries, described in 37 articles were studied. A significant variation in the sero-epidemiological data was observed within each continent. Intrinsic factors in the human host such as age and immunity were the main determinants for the occurrence of infections while exposure was mostly related to environmental factors, which varied between communities. In Chapter 3, spatial and temporal variations in the incidence of hospitalized cases of epilepsy and NCC in Ecuadorian municipalities were analyzed in order to locate and characterize important clusters in space and time. Additionally, potential socio-economic and landscape indicators were evaluated to understand in part the macro-epidemiology of the T. solium taeniasis/cysticercosis complex. This study identified traditional endemic clusters in the highlands for both conditions as well as new clusters appearing in recent years in other zones considered non-endemic. Chapter 4 describes the dynamic nature of human T. solium larval infections in an Ecuadorian endemic community. In this study incidence rate and cumulative incidence figures of human T. solium larval infections are reported for the first time in Latin America. A sero-epidemiological cohort study was conducted in a south-Ecuadorian community to estimate the incidence rate of active cysticercosis and the incidence rate of exposure to T. solium. The proportion of infected individuals remained low and stable during the whole study year while more than 25% of the population showed at least one antibody seroconversion/seroreversion during the same time period. These estimates are of high importance to understand the epidemiology of T. solium in order to develop ad hoc cost-effective prevention and control programs. They are also essential to assess the burden of T. solium cysticercosis. The estimates generated here may now be incorporated in epidemiological models to simulate the temporal transmission of the parasite and the effects of control interventions on transmission. In Chapter 5, the findings of this research are discussed in the context of their contribution to the design of control strategies for T. solium, with special attention to the case of Ecuador. This research showed the implications of the variability of epidemiological patterns of T. solium in different endemic areas on the design of control strategies. Also, some tools were provided that could be used to help in the identification of priority areas of intervention within a country. The transmission dynamics of human cysticercosis were considered in order to give further recommendations when applying control measures in endemic rural and in urban areas of Ecuador. The approach presented in this research could be used to fine-tune the current control strategies of T. solium. However, further studies are needed to fill the gaps in the epidemiology of T. solium such as understanding the role of the environment in the transmission of taeniasis/cysticercosis

National innovation system, competitiveness and economic growth

Differences in income-elasticities of imports and exports among countries bring about distinct degrees of external constraints to growth. This argument has been pointed out by Prebisch and by authors in the Kaldorian tradition. Prebisch’s explanations for this phenomenon relate to the differences in international insertion between agrarian / peripheral and industrial / central economies. Kaldorian authors, in turn, refer to Prebisch only to explain why such elasticities differ between products and between countries. However, even after undergoing industrialization processes, several economies still face external constraints to growth. The aim of this paper is to explain differences in trade elasticities among industrial economies. Therefore, it intends to demonstrate, by using the Neo-Schumpeterian literature, the causal relations between the development of a National Innovation System, the differences in income-elasticities of imports and exports, the degree of competitiveness and the degree of external vulnerability of an economy.national innovation system, competitiveness, external vulnerability

Treatment of the Prominent Mandibular Angle by Using a Custom Made Surgical Splint

In this case report, we would like to present an alternative surgical technique for the treatment of the bilateral prominent mandibular angles by using a custom-made resin splint (template). The prefabricated template provided a precise outline for the osteotomy, which alleviated the uncertainty of the osseous cut. Furthermore, masseter muscle myomectomy was not necessary in this case which decreased morbidity, and procedure and recovery time, while assuring a more symmetric outcome

Hardy's paradox and violation of a state-independent Bell inequality in time

Tests such as Bell's inequality and Hardy's paradox show that joint probabilities and correlations between distant particles in quantum mechanics are inconsistent with local realistic theories. Here we experimentally demonstrate these concepts in the time domain, using a photonic entangling gate to perform nondestructive measurements on a single photon at different times. We show that Hardy's paradox is much stronger in time and demonstrate the violation of a temporal Bell inequality independent of the quantum state, including for fully mixed states.Comment: Published Version, 4 pages, 3 figures. New, more boring titl

Taenia solium human cysticercosis : a systematic review of sero-epidemiological data from endemic zones around the world

Background: Taenia solium cysticercosis is a zoonotic neglected disease responsible for severe health disorders such as seizures and death. Understanding the epidemiology of human cysticercosis (HCC) in endemic regions will help to expose critical information about the transmission of the disease, which could be used to design efficient control programs. This review gathered serological data on apparent prevalence of T. solium circulating antigens and/or seroprevalence of T. solium antibodies, apparent prevalence of human taeniasis and risk factors for HCC from endemic communities in order to understand the differences in exposure to the parasite and active infections with T. solium metacestodes in endemic areas around the world. Methods: Three databases were used to search sero-epidemiological data from community-based studies conducted between 1989 and 2014 in cysticercosis endemic communities worldwide. The search focused on data obtained from T. solium circulating antigen detection by monoclonal antibody-based sandwich ELISA and/or T. solium antibody seroprevalence determined by Enzyme-linked Immunoelectrotransfer Blot (EITB). A meta-analysis was performed per continent. Principal Findings: A total of 39,271 participants from 19 countries, described in 37 articles were studied. The estimates for the prevalence of circulating T. solium antigens for Africa, Latin America and Asia were: 7.30% (95% CI [4.23–12.31]), 4.08% (95% CI [2.77–5.95]) and 3.98% (95% CI [2.81–5.61]), respectively. Seroprevalence estimates of T. solium antibodies were 17.37% (95% CI [3.33–56.20]), 13.03% (95% CI [9.95–16.88]) and 15.68% (95% CI [10.25–23.24]) respectively. Taeniasis reported prevalences ranged from 0 (95% CI [0.00–1.62]) to 17.25% (95% CI [14.55–20.23]). Significance: A significant variation in the sero-epidemiological data was observed within each continent, with African countries reporting the highest apparent prevalences of active infections. Intrinsic factors in the human host such as age and immunity were main determinants for the occurrence of infections, while exposure was mostly related to environmental factors which varied from community to community