scholarly journals Clinically Unreported Salmonellosis Outbreak Detected via Comparative Genomic Analysis of Municipal Wastewater Salmonella Isolates

2019 ◽  
Vol 85 (10) ◽  
Author(s):  
Sabrina Diemert ◽  
Tao Yan

ABSTRACT Municipal wastewater includes human waste that contains both commensal and pathogenic enteric microorganisms, and this collective community microbiome can be monitored for community diseases. In a previous study, we assessed the salmonellosis disease burden using municipal wastewater from Honolulu, Hawaii, which was monitored over a 54-week period. During that time, a strain of Salmonella enterica serovar Paratyphi B variant L(+) tartrate(+) (also known as Salmonella enterica serovar Paratyphi B variant Java) was identified; this strain was detected simultaneously with a clinically reported outbreak, and pulsed-field gel electrophoresis patterns were identical for clinical and municipal wastewater isolates. Months after the outbreak subsided, the same pulsotype was detected as the dominant pulsotype in municipal wastewater samples, with no corresponding clinical cases reported. Using genomic characterization (including core single-nucleotide polymorphism alignment, core genome multilocus sequence typing, and screening for virulence and antibiotic resistance genes), all S. Java municipal wastewater isolates were determined to be clonal, indicating a resurgence of the original outbreak strain. This demonstrates the feasibility and utility of municipal wastewater surveillance for determining enteric disease outbreaks that may be missed by traditional clinical surveillance methods. IMPORTANCE Underdetection of microbial infectious disease outbreaks in human communities carries enormous health costs and is an ongoing problem in public health monitoring (which relies almost exclusively on data from health clinics). Surveillance of municipal wastewater for community-level monitoring of infectious disease burdens has the potential to fill this information gap, due to its easy access to the mixed community microbiome. In the present study, the genomes of 21 S. Java isolates (collected from municipal wastewater in Honolulu) were analyzed; results showed that the same Salmonella strain that caused a known salmonellosis clinical outbreak in spring 2010 remerged as the most dominant strain in municipal wastewater in spring 2011, indicating a new outbreak that was not detected by health clinics. Our results show that wastewater monitoring holds great promise to inform the field of public health regarding outbreak status within communities.

2017 ◽  
Vol 30 (8) ◽  
pp. 680-692 ◽  
Author(s):  
Domingos Fernandes Campos ◽  
Rinaldo Bezerra Negromonte Filho ◽  
Felipe Nalon Castro

Purpose The purpose of this paper is to investigate the expectations and quality gaps in services provided at city public health clinics in the city of Natal, Brazil, from the perspective of patients and healthcare service providers. Design/methodology/approach The research sample consisted of 1,200 patients who used public health services and 265 providers – doctors, nutritionists, physiotherapists, psychologists, pharmacists and managers at three health clinics in the city of Natal, Brazil. A scale with 25 health service attributes was used in data collection. Summary statistics and t-test were used to analyze the data. Findings The results show that the providers think that users have lower levels of expectations than those indicated by the users in all attributes. Providers and users have the most approximate insights into what attributes are considered most important: explanations, level of knowledge and attention dispensed by health professionals. Users and providers perceived similar quality gaps for most of the attributes. The gaps were statistically the same, when comparing the mean quality shortcomings by means of a Student’s test, considering a significance level of 5 percent, obtained independently by the manifestation of users and providers. Research limitations/implications The results reveal only a photograph of the moment. The study did not consider the differences that may exist between groups with different income levels, genders or age groups. A qualitative study could improve the understanding of the differences and coincidences of the diverse points of views. A more advanced research could even study possibilities so that health managers could promote changes in the service, some of them low cost, as the health professionals training for contact with patients. Practical implications The evaluation of the service quality complemented by the matrix of opportunities, importance × quality gaps generates information to help make decisions in the rational allocation of available resources and improvement of the quality of the service delivered to patients. Besides, it offers a focus to prioritize specific actions. Originality/value It is important to compare the perceptions of service quality between patients and the healthcare service providers who work in direct contact with them. The managers can smooth out these differences and ensure, over time, customer satisfaction. In this study, providers were asked to express what they think about the expectations of patients and about their own service performance delivered. Thus, not only the traditional gap 5 was measured, but it was also possible to evaluate the distance between what providers think that patients need and their actual needs.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jennifer B. Nuzzo ◽  
Diane Meyer ◽  
Michael Snyder ◽  
Sanjana J. Ravi ◽  
Ana Lapascu ◽  
...  

Abstract Background The 2014–2016 Ebola outbreak was a wake-up call regarding the critical importance of resilient health systems. Fragile health systems can become overwhelmed during public health crises, further exacerbating the human, economic, and political toll. Important work has been done to describe the general attributes of a health system resilient to these crises, and the next step will be to identify the specific capacities that health systems need to develop and maintain to achieve resiliency. Methods We conducted a scoping review of the literature to identify recurring themes and capacities needed for health system resiliency to infectious disease outbreaks and natural hazards and any existing implementation frameworks that highlight these capacities. We also sought to identify the overlap of the identified themes and capacities with those highlighted in the World Health Organization’s Joint External Evaluation. Sources of evidence included PubMed, Web of Science, OAIster, and the websites of relevant major public health organizations. Results We identified 16 themes of health system resilience, including: the need to develop plans for altered standards of care during emergencies, the need to develop plans for post-event recovery, and a commitment to quality improvement. Most of the literature described the general attributes of a resilient health system; no implementation frameworks were identified that could translate these elements into specific capacities that health system actors can employ to improve resilience to outbreaks and natural hazards in a variety of settings. Conclusions An implementation-oriented health system resilience framework could help translate the important components of a health system identified in this review into specific capacities that actors in the health system could work to develop to improve resilience to public health crises. However, there remains a need to further refine the concept of resilience so that health systems can simultaneously achieve sustainable transformations in healthcare practice and health service delivery as well as improve their preparedness for emergencies.


2019 ◽  
Vol 47 (3) ◽  
pp. 412-426 ◽  
Author(s):  
Tsion Berhane Ghedamu ◽  
Benjamin Mason Meier

Immunization plays a crucial role in global health security, preventing public health emergencies of international concern and protecting individuals from infectious disease outbreaks, yet these critical public health benefits are dependent on immunization law. Where public health law has become central to preventing, detecting, and responding to infectious disease, public health law reform is seen as necessary to implement the Global Health Security Agenda (GHSA). This article examines national immunization laws as a basis to implement the GHSA and promote the public's health, analyzing the scope and content of these laws to prevent infectious disease across Sub-Saharan Africa. Undertaking policy surveillance of national immunization laws in 20 Sub-Saharan African countries, this study: (1) developed a legal framework to map the legal attributes relevant to immunization; (2) created an assessment tool to determine the presence of these attributes under national immunization law; and (3) applied this assessment tool to code national legal landscapes. An analysis of these coded laws highlights legal attributes that govern vaccine requirements, supply chains, vaccine administration standards, and medicines quality and manufacturer liability. Based upon this international policy surveillance, it will be crucial to undertake legal epidemiology research across countries, examining the influence of immunization law on vaccination rates and disease outbreaks.


2020 ◽  
Vol 46 (7) ◽  
pp. 427-431 ◽  
Author(s):  
Michael J Parker ◽  
Christophe Fraser ◽  
Lucie Abeler-Dörner ◽  
David Bonsall

In this paper we discuss ethical implications of the use of mobile phone apps in the control of the COVID-19 pandemic. Contact tracing is a well-established feature of public health practice during infectious disease outbreaks and epidemics. However, the high proportion of pre-symptomatic transmission in COVID-19 means that standard contact tracing methods are too slow to stop the progression of infection through the population. To address this problem, many countries around the world have deployed or are developing mobile phone apps capable of supporting instantaneous contact tracing. Informed by the on-going mapping of ‘proximity events’ these apps are intended both to inform public health policy and to provide alerts to individuals who have been in contact with a person with the infection. The proposed use of mobile phone data for ‘intelligent physical distancing’ in such contexts raises a number of important ethical questions. In our paper, we outline some ethical considerations that need to be addressed in any deployment of this kind of approach as part of a multidimensional public health response. We also, briefly, explore the implications for its use in future infectious disease outbreaks.


mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Ellen E. Higginson ◽  
Girish Ramachandran ◽  
Tracy H. Hazen ◽  
Dane A. Kania ◽  
David A. Rasko ◽  
...  

ABSTRACT Enteric fever is caused by three Salmonella enterica serovars: Typhi, Paratyphi A, and Paratyphi B sensu stricto. Although vaccines against two of these serovars are licensed (Typhi) or in clinical development (Paratyphi A), as yet there are no candidates for S. Paratyphi B. To gain genomic insight into these serovars, we sequenced 38 enteric fever-associated strains from Chile and compared these with reference genomes. Each of the serovars was separated genomically based on the core genome. Genomic comparisons identified loci that were aberrant between serovars Paratyphi B sensu stricto and Paratyphi B Java, which is typically associated with gastroenteritis; however, the majority of these were annotated as hypothetical or phage related and thus were not ideal vaccine candidates. With the genomic information in hand, we engineered a live attenuated S. Paratyphi B sensu stricto vaccine strain, CVD 2005, which was capable of protecting mice from both homologous challenge and heterologous challenge with S. Paratyphi B Java. These findings extend our understanding of S. Paratyphi B and provide a viable vaccine option for inclusion in a trivalent live attenuated enteric fever vaccine formulation. IMPORTANCE We developed a live attenuated Salmonella enterica serovar Paratyphi B vaccine that conferred protection in mice against challenge with S. Paratyphi B sensu stricto and S. Paratyphi B Java, which are the causes of enteric fever and gastroenteritis, respectively. Currently, the incidence of invasive S. Paratyphi B sensu stricto infections is low; however, the development of new conjugate vaccines against other enteric fever serovars could lead to the emergence of S. Paratyphi B to fill the niche left by these other pathogens. As such, an effective S. Paratyphi B vaccine would be a useful tool in the armamentarium against Salmonella infections. Comparative genomics confirmed the serovar-specific groupings of these isolates and revealed that there are a limited number of genetic differences between the sensu stricto and Java strains, which are mostly hypothetical and phage-encoded proteins. The observed level of genomic similarity likely explains why we observe some cross-protection.


2018 ◽  
Vol 13 (02) ◽  
pp. 372-374 ◽  
Author(s):  
Emma Quinn ◽  
Kai Hsiao ◽  
George Truman ◽  
Nectarios Rose ◽  
Richard Broome

AbstractGeographic information systems (GIS) have emerged in the past few decades as a technology capable of assisting in the control of infectious disease outbreaks. A Legionnaires’ disease cluster investigation in May 2016 in Sydney, New South Wales (NSW), Australia, demonstrated the importance of using GIS to identify at-risk water sources in real-time for field investigation to help control any immediate environmental health risk, as well as the need for more staff trained in the use of this technology. Sydney Local Health District Public Health Unit (PHU) subsequently ran an exercise (based on this investigation) with 11 staff members from 4 PHUs across Sydney to further test staff capability to use GIS across NSW. At least 80% of exercise participants reported that the scenario progression was realistic, assigned tasks were clear, and sufficient data were provided to complete tasks. The exercise highlighted the multitude of geocoding applications and need for inter-operability of systems, as well as the need for trained staff with specific expertise in spatial analysis to help assist in outbreak control activity across NSW. Evaluation data demonstrated the need for a common GIS, regular education and training, and guidelines to support the collaborative use of GIS for infectious disease epidemiology in NSW. (Disaster Med Public Health Preparedness. 2019;13:372–374)


2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Sabrina Diemert ◽  
Tao Yan

ABSTRACT Clinical surveillance of enteric pathogens like Salmonella is integral to track outbreaks and endemic disease trends. However, clinic-centered disease monitoring biases toward detection of severe cases and underestimates the incidence of self-limiting gastroenteritis and asymptomatic strains. Monitoring pathogen loads and diversity in municipal wastewater (MW) can provide insight into asymptomatic or subclinical infections which are not reflected in clinical cases. Subclinical infection patterns may explain the unusual observation from a year-long sampling campaign in Hawaii: Salmonella enterica serovar Derby was the most abundant pulsotype in MW but was detected infrequently in clinics over the sampling period. Using whole-genome sequencing data of Salmonella isolates from MW and public databases, we demonstrate that the Derby serovar has lower virulence potential than other clinical serovars, particularly based on its reduced profile of genes linked with immune evasion and symptom production, suggesting its potential as a subclinical salmonellosis agent. Furthermore, MW had high abundance of a rare Derby sequence type (ST), ST-72 (rather than the more common ST-40). ST-72 isolates had higher frequencies of fimbrial adherence genes than ST-40 isolates; these are key virulence factors involved in colonization and persistence of infections. However, ST-72 isolates lack the Derby-specific Salmonella pathogenicity island 23 (SPI-23), which invokes host immune responses. In combination, ST-72’s genetic features may lead to appreciable infection rates without obvious symptom production, allowing for subclinical persistence in the community. This study demonstrated wastewater’s capability to provide community infectious disease information—such as background infection rates of subclinical enteric illness—which is otherwise inaccessible through clinical approaches. IMPORTANCE Wastewater-based epidemiology (WBE) has been conventionally used to analyze community health via the detection of chemicals, such as legal and illicit drugs; however, municipal wastewater contains microbiological determinants of health and disease as well, including enteric pathogens. Here, we demonstrate that WBE can be used to examine subclinical community salmonellosis patterns. Derby was the most abundant Salmonella serovar detected in Hawaii wastewater over a year-long sampling study, with few corresponding clinical cases. Comparative genomics analyses indicate that the normally rare strain of S. Derby found in wastewater has a unique combination of genes which allow it to persist as a subclinical infection without producing symptoms of severe gastroenteritis. This study shows that WBE can be used to explore trends in community infectious disease patterns which may not be reflected in clinical monitoring, shedding light on overall enteric disease burden and rates of asymptomatic cases.


2020 ◽  
Vol 135 (3) ◽  
pp. 343-353
Author(s):  
Tara Kirk Sell ◽  
Sanjana J. Ravi ◽  
Crystal Watson ◽  
Diane Meyer ◽  
Laura E. Pechta ◽  
...  

Objectives The spread of Zika virus throughout Latin America and parts of the United States in 2016 and 2017 presented a challenge to public health communicators. The objective of our study was to describe emergency risk communication practices during the 2016-2017 Zika outbreak to inform future infectious disease communication efforts. Methods We conducted semi-structured telephone interviews with 13 public health policy makers and practitioners, 10 public information officers, and 5 vector-control officials from May through August 2017. Results Within the public health macro-environment, extended outbreak timeframe, government trust, US residence status, and economic insecurity set the backdrop for Zika communication efforts. Limited resources, staffing, and partnerships negatively affected public health structural capacity for communication efforts. Public health communicators and practitioners used a range of processes and practices to engage in education and outreach, including fieldwork, community meetings, and contact with health care providers. Overall, public health agencies’ primary goals were to prevent Zika infection, reduce transmission, and prevent adverse birth outcomes. Conclusions Lessons learned from this disease response included understanding the macro-environment, developing partnerships across agencies and the community, and valuing diverse message platforms. These lessons can be used to improve communication approaches for health officials at the local, state, and federal levels during future infectious disease outbreaks.


2012 ◽  
Vol 19 (6) ◽  
pp. 825-834 ◽  
Author(s):  
Rezwanul Wahid ◽  
Raphael Simon ◽  
Shah J. Zafar ◽  
Myron M. Levine ◽  
Marcelo B. Sztein

ABSTRACTEnteric fever caused bySalmonella entericaserovar Paratyphi A infection has emerged as an important public health problem. Recognizing that in randomized controlled field trials oral immunization with attenuatedS. entericaserovar Typhi live vaccine Ty21a conferred significant cross-protection againstS. Paratyphi B but notS. Paratyphi A disease, we undertook a clinical study to ascertain whether humoral immune responses could explain the field trial results. Ty21a immunization of adult residents of Maryland elicited predominantly IgA antibody-secreting cells (ASC) that recognizeS. Typhi lipopolysaccharide (LPS). Cross-reactivity toS. Paratyphi A LPS was significantly lower than that toS. Paratyphi B LPS. ASC producing IgG and IgA that bind LPS from each of theseSalmonellaserovars expressed CD27 and integrin α4β7 (gut homing), with a significant proportion coexpressing CD62L (secondary lymphoid tissue homing). No significant differences were observed in serum antibody against LPS of the different serovars. Levels of IgA B memory (BM) cells toS. Typhi LPS were significantly higher than those againstS. Paratyphi A or B LPS, with no differences observed betweenS. Paratyphi A and B. The response of IgA BMto outer membrane proteins (OMP) fromS. Typhi was significantly stronger than that to OMP ofS. Paratyphi A but similar to that to OMP ofS. Paratyphi B. The percentages of IgG or IgA BMresponders to LPS or OMP from theseSalmonellastrains were similar. Whereas cross-reactive humoral immune responses toS. Paratyphi A or B antigens are demonstrable following Ty21a immunization, they cannot explain the efficacy data gleaned from controlled field trials.


Author(s):  
Huailiang Wu ◽  
Jian Huang ◽  
Casper J. P. Zhang ◽  
Zonglin He ◽  
Wai-Kit Ming

AbstractBackgroundA novel coronavirus disease (COVID-19) outbreak due to SARS-CoV-2 infection occurred in China in late-December 2019. Facemask wearing is considered as one of the most cost-effective and important measures to prevent the transmission of SARS-CoV-2, but it became a social concern due to the recent global facemask shortage. China is the major facemask producer in the world, contributing to 50% of global production. However, even full productivity (20 million facemasks per day) does not seem to meet the need of a population of 1.4 billion in China.MethodsPolicy review using government websites and shortage analysis using mathematical modelling based on data obtained from the National Health Commission (NHC), the Ministry of Industry and Information Technology (MIIT), the Center for Disease Control and Prevention (CDC) of the People’s Republic of China, and Wuhan Bureau of Statistics.FindingsSupplies of facemasks in the whole of China would have been sufficient for both healthcare workers and the general population if the COVID-19 outbreak only occurred in Wuhan city or Hubei province. However, if the outbreak occurred in the whole of China, facemask supplies in China could last for 5 days if under the existing public health measures and a shortage of 853 million facemasks is expected by 30 Apr 2020. Assuming a gradually decreased import volume, we estimated that dramatic increase in productivity (42.7 times of the usual level) is needed to mitigate the facemask crisis by the end of April.InterpretationIn light of the COVID-19 outbreak in China, a shortage of facemasks and other medical resources can considerably compromise the efficacy of public health measures. Effective public health measures should also consider the adequacy and affordability of medical resources. Global collaboration should be strengthened to prevent the development of a global pandemic from a regional epidemic via easing the medical resources crisis in the affected countries.Research in contextEvidence before this studyWe searched PubMed and Web of Science for articles in English, between 1 Jan 1980, and 1 Jan 2020, using the search terms 1) (infection OR infectious disease* OR outbreaks) AND (modelling); and 2) (mask* OR facemask* OR medical resource*) AND (infection OR infectious disease* OR outbreaks). Most relevant studies identified were performed to predict diseases spread and to determine the original infection source of previous epidemics like SARS and H7N9. However, few studies focused on the medical resources crisis during the outbreaks.Added value of this studyTo the best of our knowledge, this is the first study to investigate the facemask shortage during the novel coronavirus pneumonia (COVID-19) outbreak in China. We have summarized in detail the management strategies implemented by the Chinese governments during the outbreaks. By considering three scenarios for the outbreak development, we simulated the facemasks availability from late-December 2019 to late-April 2020 and estimated the duration of sufficient facemask supplies. Our findings showed that if the COVID-19 outbreak occurred only in Wuhan city or Hubei province, facemask shortage would not appear with the existing public health measures. However, if the outbreak occurred in the whole of China, a shortage of facemask could be substantial assuming no alternative public health measures.Implications of all the available evidenceOur findings provide insight into the public health measures to confront medical resources crisis during infectious disease outbreaks. Effective public health measures should consider the adequacy and affordability of existing medical resources. Governments across the world should revisit their emergency plans for controlling infectious disease outbreaks by taking into account the supply of and demand for the medical resource. Global collaboration should be strengthened to prevent the development of a global pandemic from a regional epidemic via easing the medical resources crisis in the affected countries.


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