13 research outputs found
Low-Cost Safe Water for the World: A Practical Interim Solution
A very large segment of the world's population is without a microbiologically safe water supply. It is estimated that in Latin America more than 40% of the population is utilizing water of dubious quality for human consumption. This figure is probably even higher in Africa and areas of southeast Asia. Water used for drinking and food preparation can be an important route of transmission for many of the most widespread and debilitating of the diseases that afflict humans. The cholera pandemic which struck Latin America in January 1991, and has become endemic in many of the countries, continues to exemplify the public health significance of contaminated drinking water. Ideally, this neglected segment of the world's population should be served with piped water systems that provide a continuous supply of microbiologically safe water, but this would require such enormous investments of financial and human resources that it is not reasonable to expect that it will be accomplished. Interim practical measures to assure microbio-logically safe water are necessary. The public health intervention to accomplish this is described in this paper and has an annual per family cost of which ranges between 4. It consists of providing individual households with one or preferably two suitable water containers in which to disinfect and store the essential quantities of water that need to be free of pathogens, with the containers of a design that will preclude recontamination of the contents and enable the production and distribution of the water disinfectants to be managed at the local level. It includes the necessary component of public education, promotion and involvement to establish the sustainability of the measures as a community-based endeavor. Investigation and demonstration projects are being carried out in 11 countries to determine and perfect and appropriate intervention, and it has been proven that it is economically, technically and socially feasible to assure microbiologically safe water for the world's population that is threatened by waterborne diseases. Carefully controlled microbiological analysis of the untreated and treated water shows that waterborne pathogens can be destroyed or inactivated, and carefully controlled epidemiological studies being carried out by the Centers for Disease Control and Prevention show that this intervention achieves considerable reduction in the incidence of waterborne disease. It is recommended that all developing countries initiate programs to replicate the health measure described in this paper in order to test its validity and to adapt it to their local conditions
Epidemiologic Studies of Cyclospora cayetanensis in Guatemala
In 1996 and 1997, cyclosporiasis outbreaks in North America were linked to eating Guatemalan raspberries. We conducted a study in health-care facilities and among raspberry farm workers, as well as a case-control study, to assess risk factors for the disease in Guatemala. From April 6, 1997, to March 19, 1998, 126 (2.3%) of 5, 552 surveillance specimens tested positive for Cyclospora; prevalence peaked in June (6.7%). Infection was most common among children 1.5 to 9 years old and among persons with gastroenteritis. Among 182 raspberry farm workers and family members monitored from April 6 to May 29, six had Cyclospora infection. In the case-control analysis, 62 (91%) of 68 persons with Cyclospora infection reported drinking untreated water in the 2 weeks before illness, compared with 88 (73%) of 120 controls (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.4, 10.8 by univariate analysis). Other risk factors included water source, type of sewage drainage, ownership of chickens or other fowl, and contact with soil (among children younger than 2 years)
Community Resilience, Centralized Leadership & Multi-Sectoral Collaboration
Since the end of the 1918 pandemic the world has faced three more influenza pandemics, the most recent being the 2009 H1N1 pandemic which infected 2 billion people in 6 months. Additionally, we face an ever increasing frequency of emerging infectious diseases with pandemic potential. These diseases could kill millions, cost billions, and have other significant economic, social, national security, and political consequences. If the United States and international system do not make progress towards closing the gaps addressed in this and previous Scowcroft white papers, countries will remain vulnerable to a devastating outbreak.One hundred years ago the 1918 influenza pandemic swept the globe, killing between 50-90 million people. The loss of life was so great that cities throughout the United States struggled to keep up with burials; it is estimated that 195,000 Americans died in October 1918 alone (CDC, 2018). During the height of the outbreak, Chicago reported 1,200 people dying per day and Philadelphia had so many dead bodies they weren’t able to bury them in a timely manner, with some awaiting burial for over a week (CDC, 2018). In 2006, the last remaining survivor of the 1918 outbreak was asked about his memories of the pandemic and he recalled that people would become ill in the morning and be dead by nighttime stating, “That’s how quickly it happened. They disappeared from the face of the earth” (Associated Press, 2006).
Since the end of the 1918 pandemic the world has faced three more influenza pandemics, the most recent being the 2009 H1N1 pandemic which infected 2 billion people in 6 months. Additionally, we face an ever increasing frequency of emerging infectious diseases with pandemic potential. These diseases could kill millions, cost billions, and have other significant economic, social, national security, and political consequences. Technological developments of the last hundred years have brought incredible international advancements and have created a more dependent and interconnected global economy, but these same advances that promote economic prosperity, also create new and unique challenges for pandemic preparedness and response.
In an increasingly interconnected world the threat of pandemics continues to grow. It is not a matter of if there will be a major pandemic, but when. The Scowcroft Institute of International Affairs is committed to elevating the importance of pandemic preparedness and biosecurity as a national security priority, and to bringing attention to the challenges and gaps, as well as
the opportunities to improve our response systems so that when the next pandemic strikes, the catastrophic impacts can be mitigated or reduced.
In this white paper, we address four gaps and provide accompanying recommendations that we believe must be addressed in order to increase our pandemic preparedness and biosecurity. These gaps and topic areas include: 1) Establishing greater community resilience; 2) Strengthening coordination and leadership at the federal level in the United States; 3) Changing the university and funding reward systems to encourage greater interdisciplinary research, education, and service; and 4) Elevating the importance and incentives for private sector involvement in pandemic preparedness and response, as well as their involvement in overall biosecurity. In addition to the topic areas, which are present in each annual policy white paper, we have included short inserts by experts in the fields of pandemic preparedness and biosecurity. Lastly, for the first time we have included a pandemic report card. This examines progress made, if any, on the recommendations presented in the 2018 Scowcroft Institute White Paper. The purpose of this new addition is to provide an added element of accountability for those at the national and international level tasked with pandemic preparedness and response. If the United States and international system do not make progress towards closing the gaps addressed in this and previous Scowcroft white papers, countries will remain vulnerable to a devastating outbreak
Diversity of picornaviruses in rural Bolivia
Fil: Nix, W Allan. Centers for Disease Control and Prevention; Estados Unidos.Fil: Khetsuriani, Nino. Centers for Disease Control and Prevention; Estados Unidos.Fil: Peñaranda, Silvia. Centers for Disease Control and Prevention; Estados Unidos.Fil: Maher, Kaija. Centers for Disease Control and Prevention; Estados Unidos.Fil: Venczel, Linda. Centers for Disease Control and Prevention; Estados Unidos.Fil: Cselkó, Zsuzsa. Centers for Disease Control and Prevention; Estados Unidos.Fil: Freire, Maria Cecilia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Cisterna, Daniel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Lema, Cristina L. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Rosales, Patricia. Ministry of Health and Sports; Bolivia.Fil: Rodríguez, Jacqueline R. Pediatric Hospital San Antonio de Los Sauces; Bolivia.Fil: Rodríguez, Wilma. Ministry of Health and Sports; Bolivia.Fil: Halkyer, Percy. Pan-American Health Organization; Bolivia.Fil: Ronveaux, Olivier. Pan-American Health Organization; Bolivia.Fil: Pallansch, Mark A. Centers for Disease Control and Prevention; Estados Unidos.Fil: Oberste, M Steven. Centers for Disease Control and Prevention; Estados Unidos.The family Picornaviridae is a large and diverse group of viruses that infect humans and animals. Picornaviruses are among the most common infections of humans and cause a wide spectrum of acute human disease. This study began as an investigation of acute flaccid paralysis (AFP) in a small area of eastern Bolivia, where surveillance had identified a persistently high AFP rate in children. Stools were collected and diagnostic studies ruled out poliovirus. We tested stool specimens from 51 AFP cases and 34 healthy household or community contacts collected during 2002-2003 using real-time and semi-nested reverse transcription polymerase chain reaction assays for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus and cosavirus. Anecdotal reports suggested a temporal association with neurological disease in domestic pigs, so six porcine stools were also collected and tested with the same set of assays, with the addition of an assay for porcine teschovirus. A total of 126 picornaviruses were detected in 73 of 85 human individuals, consisting of 53 different picornavirus types encompassing five genera (all except Kobuvirus). All six porcine stools contained porcine and/or human picornaviruses. No single virus, or combination of viruses, specifically correlated with AFP; however, the study revealed a surprising complexity of enteric picornaviruses in a single community
The Inactivation Kinetics of Monochloramine and Chlorine Dioxide on Monodispersed Hepatitis A Virus and MS2
In order to ensure virologically acceptable drinking water, the US EPA promulgated the Surface Water Treatment Rule and is preparing the groundwater disinfection rule (as well as amendments to the SWTR) to define requirements for disinfection to achieve specified degrees of virus inactivation. While free chlorine disinfection has been widely used since the early 20th century, the recent evidence that THMs and other chlorine by-products are carcinogens and cause other adverse health effects has focused attention on alternate disinfectants, including monochloramine and chlorine dioxide. Although previous studies have examined both disinfectants at high doses on inactivation of some important waterborne viruses, little information is available at realistic concentrations used in water treatment plants and at a range of pH levels. Therefore, in order to further characterize NH2C1 and C102 disinfection, inactivation kinetics were examined for two viruses: (1) HAV, a major waterborne pathogen, and (2) MS2, an indicator virus. Experiments were conducted using purified, monodispersed virus stocks in 0.01 M phosphate buffers at pH 6, 8, and 10. Disinfectant concentrations were at the realistic levels of 2.0 and 0.5 mg/l, respectively, for NH2C1 and C102. Inactivation kinetics were determined by computing the proportions of surviving viruses at carefully measured time intervals. Viruses were assayed by plaque techniques and both disinfectants were measured using the DPD colorimetric method. In order to compare inactivation data for the two viruses and the different test conditions, times to achieve a specified percent of virus inactivation as well as values for disinfectant concentration (C) x time for specified percent inactivation (T), or CT values were computed. In In previous studies inactivation data were treated as first-order in extrapolating to the times for 99.99% (4 log[10]) virus reduction. From examination of the experimental data from our experiments, it was evident that HAV and MS2 inactivation kinetics did not conform to the first-order model and were instead of the retardant die-off type. Subsequently, five alternative mathematical models were constricted and used to predict the kinetics of HAV and MS2 inactivation based in the experimental data. These models included: (a) a one-population model which assumes a decreasing disinfectant concentration over time, (b) a one hit, two-populations model assuming two subpopulations with different rate constants of inactivation, (c) a third model similar to (b) with the exception that the concentration of the disinfectant decreases over time, (d) a multistate model in which various stages of sublethal injury are assumed prior to inactivation, and finally (e) the distributive rate constant model, which is based upon a spectrum of inactivation rate constants for the viruses. The measure of fit was determined for each model using the least-squares method and the results for 2, 3, and 4 log[10] inactivation times were compared to the standard first-order regression model. The results indicate that a large discrepancy in the predicted times is found both between the various models and within the models when experiments of different sampling time points are used. Consequently, these data suggest that the assumption of first-order disinfection kinetics underestimate the time necessary for adequate reduction of viruses in drinking water.Master of Science in Public Healt
Brote de poliomielitis en Haití y la República Dominicana debido a un virus derivado de la vacuna antipoliomielítica oral
In October 2000, the Ministries of Health of the Dominican Republic and Haiti notified two cases of acute flaccid paralysis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occurred in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the Centers for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3% genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5% genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0%. Thus, the 3% genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas
Brote de poliomielitis en Haití y la República Dominicana debido a un virus derivado de la vacuna antipoliomielítica oral
Evaluation of an Inexpensive Handwashing and Water Treatment Program in Rural Health Care Facilities in Three Districts in Tanzania, 2017
Unsafe water, sanitation, and hygiene (WASH) conditions in healthcare facilities (HCFs) can increase the risk of disease transmission, yet WASH coverage is inadequate in HCFs in most low- and middle-income countries. In September 2017, we conducted a baseline survey of WASH coverage in 100 HCFs in three rural Tanzanian districts. Based on needs calculated from the baseline, we distributed handwashing and drinking water stations, soap, and chlorine solution; we repeated the survey 10 months later. The intervention improved coverage with handwashing stations (82% vs. 100%, p < 0.0001), handwashing stations with water (59% vs. 96%, p < 0.0001), handwashing stations with soap and water (19% vs. 46%, p < 0.0001), and handwashing stations with soap and water within 5 m of latrines (26% vs. 53%, p < 0.0001). Coverage of drinking water stations increased from 34% to 100% (p < 0.0001) HCFs with at least one drinking water station with free chlorine residual (FCR) > 0.2mg/ml increased from 6% to 36% (p < 0.0001), and in a sample of HCFs, detectable E. coli in stored drinking water samples decreased from 46% to 5% (p < 0.001). Although the program increased access to handwashing stations, drinking water stations, and safe drinking water in HCFs in rural Tanzania, modest increases in soap availability and water treatment highlighted persistent challenges
Assessing and monitoring vaccination coverage levels: lessons from the Americas Estimación y monitoreo de los niveles de cobertura de la vacunación: lecciones aprendidas en las Américas
Según lo establecido por la Organización Panamericana de la Salud (OPS), conseguir una alta cobertura de vacunación es una meta esencial para la Región de las Américas. Es indispensable lograr niveles de cobertura de 95% o mayores para poder alcanzar los objetivos de la OPS de eliminar el sarampión y la rubéola, controlar las enfermedades prevenibles mediante la vacunación, y hacer perdurar la eliminación de la poliomielitis en territorio americano. Para poder alcanzar esos niveles, es imprescindible que las estadísticas de vacunación sean fiables y que las autoridades sanita- rias midan y monitoreen los niveles de cobertura a lo largo del tiempo. Los métodos elegidos por los directores de los programas de vacunación para calcular la cobertura dependerán de la información que haga falta. En general, los directores del Programa Ampliado de Inmunización (PAI) necesitarán información acerca de la cobertura para poder: 1) determinar la verdadera cobertura en los niveles nacional y local, 2) determinar cuán adecuada es la cobertura en una zona determinada, 3) monitorear las tendencias a lo largo del tiempo, y 4) monitorear las actividades de vacunación mientras se están llevando a cabo. Para lograr lo primero -determinar cuáles son los niveles verdaderos de cobertura-, los administradores tienen dos opciones: a) valerse de los datos acerca de las dosis administradas (es decir, el número de dosis de la vacuna que se ha administrado, dividido por la población que debió recibir una dosis) o b) llevar a cabo una encuesta para determinar la cobertura. Para lograr lo segundo -saber si la cobertura en una zona determinada es adecuada (por ej., mayor de 90%)-, se puede realizar un muestreo por lotes para garantizar la calidad (MLGC). El MLGC es una metodología de encuesta basada en el uso de muestras pequeñas que permite determinar si la cobertura en una zona determinada es adecuada o no, pero no sirve para estimar el nivel de cobertura. Para el tercer propósito -monitorear las tendencias a lo largo del tiempo-, se pueden usar los datos correspondientes al número de dosis administradas. Para lograr el cuarto propósito -determinar si procede vacunar o llevar a cabo una campaña de vacunación u otra actividad afín-, la "herramienta de monitoreo rápido" creada por la OPS es una magnífica solución. Cada uno de estos métodos posee ventajas y desventajas. Los datos sobre el número de dosis administradas, más la herramienta de monitoreo rápido, deben usarse para lograr las metas de vacunación en las Américas. Ambos métodos son los preferidos actualmente por la OPS para estimar la cobertura de vacunación
Methods for evaluating the impact of vertical programs on health systems: protocol for a study on the impact of the global polio eradication initiative on strengthening routine immunization and primary health care
BACKGROUND: The impact of vertical programs on health systems is a much-debated topic, and more evidence on this complex relationship is needed. This article describes a research protocol developed to assess the relationship between the Global Polio Eradication Initiative, routine immunization, and primary health care in multiple settings. METHODS/DESIGN: This protocol was designed as a combination of quantitative and qualitative research methods, making use of comparative ethnographies. The study evaluates the impact of the Global Polio Eradication Initiative on routine immunization and primary health care by: (a) combining quantitative and qualitative work into one coherent study design; (b) using purposively selected qualitative case studies to systematically evaluate the impact of key contextual variables; and (c) making extensive use of the method of participant observation to create comparative ethnographies of the impact of a single vertical program administered in varied contexts. DISCUSSION: The study design has four major benefits: (1) the careful selection of a range of qualitative case studies allowed for systematic comparison; (2) the use of participant observation yielded important insights on how policy is put into practice; (3) results from our quantitative analysis could be explained by results from qualitative work; and (4) this research protocol can inform the creation of actionable recommendations. Here, recommendations for how to overcome potential challenges in carrying out such research are presented. This study illustrates the utility of mixed-methods research designs in which qualitative data are not just used to embellish quantitative results, but are an integral component of the analysis