Local Disease Outbreaks Research Articles

Characterization of size, structure and purity of serogroup X Neisseria meningitidis polysaccharide, and development of an assay for quantification of human antibodies

Serogroup X Neisseria meningitidis (MenX) has recently emerged as a cause of localized disease outbreaks in sub-Saharan Africa. In order to prepare for vaccine development, MenX polysaccharide (MenX PS) was purified by standard methods and analyzed for identity and structure by NMR spectroscopy. This study presents the first full assignment of the structure of the MenX PS using 13C, 1H and 31P NMR spectroscopy and total correlation spectroscopy (TOCSY) and 1H–13C heteronuclear single quantum coherence (HSQC). Molecular size distribution analysis using HPLC–SEC with multi-angle laser light scattering (MALLS) found the single peak of MenX PS to have a weight-average molar mass of 247,000g/mol, slightly higher than a reference preparation of purified serogroup C meningococcal polysaccharide. MenX PS tended to be more thermostable than serogroup A PS. A method for the quantification of MenX PS was developed by use of high performance anion exchange chromatography with pulsed amperometric detection (HPAEC–PAD). A novel and specific ELISA assay for quantification of human anti-MenX PS IgG based on covalent linkage of the MenX PS to functionally modified microtitre plates was developed and found valid for the assessment of the specific antibody concentrations produced in response to MenX vaccination or natural infection. The current work thus provides the necessary background for the development of a MenX PS-based vaccine to prevent meningococcal infection caused by bacteria bearing this capsule.

Risk for Emergence of Dengue and Chikungunya Virus in Israel

Risk for Emergence of Dengue and Chikungunya Virus in Israel

Using electronic health record alerts to provide public health situational awareness to clinicians

Alerting providers to public health situations requires timeliness and context-relevance, both lacking in current systems. Incorporating decision support tools into electronic health records may provide a way to deploy public health alerts to clinicians at the point of care. A timely process for responding to Health Alert Network messages sent by the New York City Department of Health and Mental Hygiene was developed by a network of community health centers. Alerts with order sets and recommended actions were created to notify primary care providers of local disease outbreaks. The process, effect, and lessons learned from alerts for Legionella, toxogenic E coli, and measles outbreaks are described. Electronic alerts have the potential to improve management of diseases during an outbreak, including appropriate laboratory testing, management guidance, and diagnostic assistance as well as to enhance bi-directional data exchange between clinical and public health organizations.

Genetic typing of equine influenza virus isolated in Poland in 2005 and 2006

Two equine influenza virus strains were isolated from horses during the local respiratory disease outbreaks in Poland in 2005 and 2006. The H3 equine influenza viral RNA was amplified directly from the clinical specimens with RT-PCR and HA1 fragments were sequenced. The highest homology of HA1 nucleotide sequences of A/eq/Pulawy/05 with A/eq/Aboyne/1/05 and A/eq/Pulawy/06 with A/eq/Essex/2/05 was found. The phylogenetic analysis based on amino acid sequences of HA1 fragments of 84 equine influenza virus strains isolated in Europe during the period of 1976–2007 was conducted to determine the evolutionary relationship of the two Polish and the other European isolates. The resulting phylogenetic tree clearly clustered A/eq/Pulawy/05 with the strains belonging to the European lineage of the equine influenza virus. On the other hand A/eq/Pulawy/06 was placed in the Florida sub-lineage of the American type strains. The presence of the same amino acids: methionine, asparagine and threonine at the positions 48, 159 and 163 respectively, in both Polish isolates, despite the fact that the strains are grouped in two different lineages may indicate the existence of the common ancestor. It is possible that A/eq/Pulawy/06 evolved locally rather than was introduced.

A REVIEW OF FOODBORNE DISEASE OUTBREAKS FROM 1996 TO 2005 IN HONG KONG AND ITS IMPLICATIONS ON FOOD SAFETY PROMOTION

ABSTRACT Foodborne diseases are an important cause of morbidity and mortality and are a growing global concern. A series of recent food safety problems has raised much public concern in the Hong Kong Special Administrative Region * . Despite the fact that many resources have been spent on food safety promotion, there has been no noticeable impact on the rising trend of local foodborne disease outbreaks. This quantitative research study aimed to identify what should be targeted in the current local food safety promotion. It presented a descriptive analysis of local official statistics from 1996 to 2005, followed by a comparison of foodborne disease outbreaks and food safety measures in some Asian places. Results found that about 72% of total local confirmed outbreaks were caused by Vibrio parahaemolyticus and Salmonella spp., while around 46% of the total outbreaks were due to inadequate cooking and contamination by raw food. It suggests that food safety promotion targeted on these factors may greatly reduce local foodborne disease outbreaks. Further elaboration could have been given if detailed breakdown in each outbreak had been provided.PRACTICAL APPLICATIONSBased on the official figures, the annual incidence of local foodborne disease outbreaks and the number of victims affected are generally increasing despite the fact that many resources and much manpower have been spent on food safety promotion and on investigating each foodborne disease outbreak in the Hong Kong Special Administrative Region. Official statistics for the past decade indicate that the majority of foodborne disease outbreaks has been dominated by some causative agents and contributing factors. Under limited resources, instead of providing some general food safety promotion programs, it suggests that the local food safety promotion should be targeted on these dominant factors. This may greatly reduce the number of outbreaks and victims affected. If this were carried out, not only could the economic burden in this health sector be reduced, but the public health campaigns could also be conducted more efficiently, and more resources could be released to prepare for combating other newly emerging diseases.

The Doctor as Weatherman: Medical Topography in Nineteenth-Century New Jersey

Intellectually active nineteenth-century New Jersey physicians participated in a national (and international) research endeavor known as medical meteorology, medical topography, or medical climatology. Close personal observation of weather and topography was a scientific endeavor that made New Jersey practitioners, often isolated in rural or town practice, feel part of a new scientific spirit in medicine. Investigations of climate and soil conditions helped organize and explain, however imperfectly, the confusing array of fevers and epidemics that constituted much of daily practice. Physicians communicated their local weather and soil conditions to colleagues in county and state medical societies in an attempt to correlate their observations with prevailing local disease patterns. Many were disappointed to find that medical topography often failed to explain or predict local disease outbreaks. For several decades after the Civil War, medical topography resonated in complex ways with mid- and late-nineteenth-century advances in sanitation and germ theory. By the 1880s, routine meteorological observations disappeared from medical journals, eclipsed by the rising hegemony of the laboratory in explaining health and disease.

Genetic characterization of equine influenza viruses isolated in Italy between 1999 and 2005

During local respiratory disease outbreaks, occurring in 2003 and 2004 in horse training stables within race-tracks in Rome, and on a stud horse farm in Bari in 2005, four strains of equine influenza (EI) virus were isolated. All outbreaks occurred in flu-vaccinated horses. Here, we are reporting the results of the genetic characterization of these isolates, together with that of another EI virus strain isolated in 1999 from a dead foal presenting pulmonary lesions. Alignment and phylogenetic analyses were carried out using the haemagglutinin amino acid sequences. The Rome and Bari isolates were identified as members of the American lineage, closely related to other recent strains isolated in America as well as in Europe, including the latest recommended American lineage vaccine prototype A/eq/SouthAfrica/4/2003. In contrast, the Italian 1999 isolate was clustered within the European lineage. In Italy, the most recent outbreaks of EI have been caused by the currently circulating American-like strains, even in vaccinated populations, confirming that vaccines should contain an updated representative strain of this lineage. Presently, companies are still in the process of registering updated vaccines but no product is yet available on the market.

An analysis of the pediatric vaccine supply shortage problem

In 2002, several factors resulted in pediatric vaccine manufacturers not being able to produce a sufficient number of vaccines to vaccinate all the children in the United States according to the Recommended Childhood Immunization Schedule. The resulting vaccine supply shortage resulted in thousands of children not being fully immunized according to this schedule, and hence, created an unnecessary risk for epidemic outbreaks of several childhood diseases. The Centers for Disease Control and Prevention responded to this crisis by using pediatric vaccine stockpiles to mitigate the impact of future shortages. This paper presents a stochastic model that captures the vaccine supply during production interruptions. This model is used to assess the impact of pediatric vaccine stockpile levels on vaccination coverage rates, by considering the probability that all children can be immunized according to the Recommended Childhood Immunization Schedule over a given time period and the expected minimum vaccine supply. The model is also used to assess the proposed pediatric vaccine stockpile levels recommended by the United States Department of Health and Human Services. The results of this analysis suggest that the proposed vaccine stockpile levels are adequate to meet future vaccine production interruptions, provided that such production interruptions do not last more than six months (which is not surprising, given that is the time period for which they were designed). However, given that recent vaccine production interruptions have lasted (on average) for over one year, the proposed vaccine stockpile levels are insufficient to meet the nation's pediatric immunization needs during such time periods, which in turn could lead to localized and/or widespread disease outbreaks. Moreover, a moderate investment in higher vaccine stockpile levels would lead to a significantly reduced risk of such events.

Properties of a federated epidemiology query system

Purpose The purpose of the study was to establish knowledge about how online access to epidemiological data from general practitioners (GPs) electronic health record (EHR) system should be provided. Before such systems are developed and deployed a decision about the appropriate system architecture must be made. Such a decision should ideally be based on knowledge about the properties of different system architectures. This choice is important because the system architecture may affect the willingness of GPs to participate in providing epidemiological data from their EHR system. Method Verifying the performance and properties of an architectural approach by implementing and deploying a system on a trans-institutional level and performing evaluations studies is a very resource demanding method to establish a foundation for the decision of appropriate system architecture. Instead, we have tried to create this foundation by constructing a prototype system, establish knowledge about the properties of the system using experiments, and finally compare the properties of the federated approach to the properties of the centralised approach. By using this methodological approach we provide the best available knowledge, on this stage, for the appropriate system architecture to use for providing access to epidemiological data from the local population. Results Our experimental results show that it is possible to improve the timeliness and the temporal and spatial resolution of epidemiological data, compared to traditional centralised disease surveillance systems. Up-to-date epidemiological data from the local population may be provided directly from the source EHR system within 4 s. The responsiveness of the system is minimally affected (0.1 s) as the number of participating data providers grows from 1 to 49 data providers. The comparison of the federated approach to the centralised approach indicates that federated approaches avoid the privacy issues involved, as intended; it offers better scalability when computing speed is compared, and it provides better specificity because more data about the patient may be used. Conclusion The conclusion from our study is that the federated approach to providing epidemiological data about the local population has many benefits over the traditional centralised approach. A federated approach to an epidemiology system may raise the GPs awareness of local disease outbreak because it is possible to share information about incidence rates of communicable diseases and use of laboratory requests in a geographical area that predates laboratory-based disease surveillance. The effects of the federated approach could be improved data quality in the EHR systems and improved representativeness of the epidemiological data for the areas covered by such systems.

Re: "Can syndromic surveillance data detect local outbreaks of communicable disease?".

To the Editor: We read with interest the paper by Cooper and colleagues [1]. We concur with the conclusions of the paper. As public health professionals covering a city of 5·3 million persons and involved in infectious disease surveillance and outbreak investigation, we also face the challenge of syndromic surveillance [2]. Despite an emergency information system that records emergency admissions from all emergency departments in our region [3], and despite a law stating that it is a crime not to report an infectious disease to the health authorities, and despite the increase in our profile due to TV serials about field epidemiologists, even we frequently hear about important outbreaks from the radio or newspapers. How can the media detect small clusters of disease? What sources do they use for their information? How is it possible that journalists without any experience of infectious disease, epidemiology or surveillance are so good at identifying outbreaks? A partial answer to these questions is that the media listen more attentively and respond more quickly to local rumours, and although they have no knowledge of the disease, they do know a lot about people. In other words people identify an outbreak based on the anamnesis (history of the exposure) and not on the clinical factors (symptoms, signs and laboratory findings). A brief analysis of the literature regarding syndromic surveillance [4–8] did not reveal many papers that propose including anamnestic criteria to increase sensitivity and specificity of the surveillance – even though identifying the history of an exposure is as fundamental to syndromic surveillance as it is to foodborne disease surveillance. These criteria were vital in detecting the few cases of SARS in Italy [9], and their application is also vital when dealing with more common illnesses such as foodborne gastroenteritis. The main problem in introducing anamnestic criteria to case definitions is that potential exposures of interest can change rapidly and sometimes unpredictably: travel exposure, the easiest to monitor, changes according to the epidemics and to the disease under surveillance; other types of exposure, such as anthrax spores in letters, cannot be predicted. It is exactly this second type of exposure that the media and the vox populi are so responsive to. The information systems on which our surveillance systems are based do not have such intuitive power. In our opinion, the future challenge in syndromic surveillance is to include the anamnesis of the exposure in the case definition, despite its unpredictable nature, which could increase both the sensitivity and specificity simultaneously; in other words, we need an intuitive system of surveillance.

Can syndromic surveillance data detect local outbreaks of communicable disease? A model using a historical cryptosporidiosis outbreak.

A national UK surveillance system currently uses data from a health helpline (NHS Direct) in an attempt to provide early warning of a bio-terrorist attack, or an outbreak caused by a more common infection. To test this syndromic surveillance system we superimposed data from a historical outbreak of cryptosporidiosis onto a statistical model of NHS Direct call data. We modelled whether calls about diarrhoea (a proxy for cryptosporidiosis) exceeded a statistical threshold, thus alerting the surveillance team to the outbreak. On the date that the public health team were first notified of the outbreak our model predicted a 4% chance of detection when we assumed that one-twentieth of cryptosporidiosis cases telephoned the helpline. This rose to a 72% chance when we assumed nine-tenths of cases telephoned. The NHS Direct surveillance system is currently unlikely to detect an event similar to the cryptosporidiosis outbreak used here and may be most suited to detecting more widespread rises in syndromes in the community, as previously demonstrated. However, the expected rise in NHS Direct call rates, should improve early warning of outbreaks using call data.

ENVIRONMENTAL PREDICTORS OF ROSS RIVER VIRUS DISEASE OUTBREAKS IN QUEENSLAND, AUSTRALIA

Ross River virus (RRV) disease is the most common mosquito-borne disease in Australia, with the majority of cases reported from Queensland. In this study we investigate the relationship between local RRV disease outbreaks and standardized rainfall and temperature data in Queensland. No one set of variables could be found to accurately predict RRV disease outbreaks across all of Queensland, although good predictive models could be developed for smaller regions. The variables identified as important in predicting RRV disease outbreaks differed between regions, and also between summer and autumn. This work highlights the sensitive relationship between virus prevalence, mosquito bionomics, and climate, illustrating that critical climatic factors differ depending on underlying environmental conditions. Identification of factors leading to RRV disease outbreaks will help local authorities identify periods of high risk, optimizing the provision of additional mosquito control measures.

Distribution and Characterization of Rice yellow mottle virus: A Threat to African Farmers.

Africa produces only 2.7% of the world’s rice and is the second-largest riceimporting region in the world (6.5 Mt in 2003). This amount represents about 25% of the world rice importation (40). With an average of 2 t/ha, excluding Egypt, rice production in Africa remains significantly below the world average (Asia 3.8 t/ha, Latin America 3.0 t/ha, United States 7.0 t/ha; Food and Agriculture Organization of the United Nations [FAO], published online). Insects and diseases are the two major constraints limiting rice production in Africa and Asia. Of all the rice diseases, the one caused by the Rice yellow mottle virus (RYMV), discovered in Kenya in 1970, is one of the most damaging in Africa. RYMV has been reported in many countries in East and West Africa, where in some cases whole fields have been devastated. RYMV has only been reported from the African continent and is endemic in every country where it has been reported. RYMV is a member of the genus Sobemovirus and possesses all the characteristic biophysical and biological properties of the members of the genus. The major insect vectors are chrysomelids, which play an essential role in primary infection, while secondary infection is due mainly to plant-to-plant contact. The virus particles are stable in infected dried leaves. Limitations to the spread of the virus include restricted mobility of the insect vectors, a limited host range, and absence of seed transmission. Partially resistant and highly resistant varieties have been identified, but currently the disease is not controlled adequately, and its incidence is increasing significantly in Africa. Due to the importance of rice as a staple food, the scientific community is active in studying the virus and the resistant mechanisms in rice. At the Institut de Recherche pour le Developpement (IRD) and the International Laboratory for Tropical Agricultural Biotechnology (ILTAB), different tools, such as RYMV polyclonal and monoclonal antibodies, have been produced for RYMV detection; and a series of studies has been initiated for a better understanding of the virus–host interactions. The synthesis of an infectious clone, the sequencing of many isolates of the virus, and structural studies of virus particles permitted a study of the function of the different viral proteins and an increased understanding of the virus cycle. African virologists also have initiated studies on the epidemiology of the RYMV, mainly the virulence and variability of virus strains collected throughout Africa (36,45). The relationships between genetic variability of the virus and geographical distances have been studied (19). Currently, phytopathologists are working in the field to better assess the agronomic impact of the virus (36,61,62). Breeders and geneticists at IRD and West African Rice Development Association (WARDA) in Cote d’Ivoire are working together to identify and isolate natural resistance genes (6,41). The International Institute for Tropical Agriculture (IITA) in Nigeria undertook breeding programs in Africa. Molecular biologists are offering new ways of controlling the disease through production of transgenic rice plants (37,52). This article is intended to provide a review of the disease and give an update on recent research results. The disease’s impact on rice production in Africa, its distribution, symptomatology, and epidemiology, the physical and genetic characteristics of the virus, and resistance mechanisms and breeding efforts for resistance will be discussed.

Zanamivir: a rational approach to influenza B.

Influenza B viruses have co-circulated with the HIN1 and H3N2 subtypes of influenza A since 1977. Influenza A viruses are found in various animals, whereas influenza B viruses are probably restricted to humans. The lack of an animal reservoir means that the virus has no potential for genetic reassortment across species. In addition, influenza B viruses are more serologically homogeneous than influenza A viruses. Thus, the chance of influenza B causing a pandemic is much lower than that of influenza A. However, influenza B viruses are still a frequent cause of local disease outbreaks and epidemics as a result of antigenic drift. Any prophylactic or therapeutic measure must, therefore, be effective against both influenza A and B viruses. Zanamivir is the first widely approved neuraminidase inhibitor for the treatment of influenza. It is delivered directly to the primary site of viral replication, the respiratory tract, and is well tolerated and effective in the treatment of both influenza A and B. Data in prophylaxis are also encouraging. Zanamivir is the only drug proven to be clinically effective against both influenza A and B virus infections.

News Briefs: Dramatic increases in logging in remote tropical regions of Africa have made it possible for local disease outbreaks to spread worldwide,

News Briefs: Dramatic increases in logging in remote tropical regions of Africa have made it possible for local disease outbreaks to spread worldwide,

Pneumococcal disease in Sweden: experiences and current situation

During the last decade, the incidence of invasive pneumococcal disease in Sweden has risen, seemingly due chiefly to an increasing incidence of pneumococcal bacteremia among the elderly. On the other hand, mortality due to invasive disease in Sweden is low, approximately 10% for bacteremic pneumococcal pneumonia. Beta-lactam resistance in Streptococcus pneumoniae is still a relatively minor problem in Sweden, with only 3%–4% of strains demonstrating decreased susceptibility to penicillin. However, local outbreaks of pneumococcal disease with up to 10% resistance have occurred among children, especially in southern Sweden.

Status of electronic reporting of notifiable conditions in the United States and Europe.

To improve the computer connectivity and network strategies to connect U.S. county health departments (CHDs), state health departments (SHDs), and the Centers for Disease Control (CDC) for reporting notifiable conditions. HSPNET-L mailing list discussions and individual Internet communications were used to compare selected features of notifiable conditions networking in the United States, France, and the United Kingdom. In the US, the CHD is the agency that first responds to an infectious disease outbreak on receiving notifications from physicians. Prompt recognition by the SHD that a widespread outbreak has occurred depends on the way in which county data are received, the "age" of the data, and the time taken to analyze them. Similarly, the recognition of the national scale of the outbreak depends on the promptness with which SHDs report to the CDC and the age of the data. An analysis of the French Communicable Disease Network suggests that an expansion of electronic links between US CHDs and SHDs will improve timeliness. Electronic data exchange allows CHDs to set up a local database and reduces transcription errors, mailing costs, and telephone costs. A fuller use of e-mail or other electronic communication by US CHDs will allow them to use a local database as a tool for managing local disease outbreaks more effectively and independently. Federal and state agency access to the CHD databases will enable early reporting of epidemic outbreaks. Periodic posting of public health information on Internet servers is recommended for immediate access to the public health data by Internet users worldwide.

Polymorphism of the migration of double-stranded RNA genome segments of avian reoviruses

A number of field isolates of avian reovirus were characterized by analysis of the migration pattern of their genomic double-stranded RNA (dsRNA) segments upon polyacrylamide gel electrophoresis. Comparison of the various isolates has demonstrated (i) no relationship between serotype and migration of any individual dsRNA segment, (ii) marked polymorphism of migration patterns of all dsRNA segments among isolates of the same serotype as well as among different serotypes, (iii) no correlation between genotype and disease state, (iv) less marked variability in migration pattern from isolates within a restricted geographic locale compared to isolates from distant locales, (v) the presence of a single genotype in local outbreaks of disease, and (vi) the relative invariant migration of several dsRNA segments among the avian reoviruses, one of which (S1) may serve to distinguish the avian from the mammalian reoviruses.